Slow Z06

Got this on another board. Found it to be a good read although long winded:


Greetings All Forced Induction Enthusiasts:

I would like to compile a thread concerning the various questions about forced induction. I will be constanly adding new information based upon testing and expirience in hopes it can be beneficial to the Blower Bistro and it's visitors for both the expirienced and inexpirienced. The common basis I will be touching grounds will be the following. (Dyno Testing, Detonation, Intercooler/Aftercooler, Various Supercharger Tests, FMUs, and other accessories based on expirience.)

Dyno Tuning

The first thing I would like a customer would be a datalog. If you can get a copy of your short pull datalogged, I'd like to take a look at it. I can almost guess what the problem is currently, but without the datalog information I can't tell you for sure. If you are familiar with datalogging and what it can do for you as a expirienced tuner will know, let me educate you a little on exactly what it does. As I have learend through my expirience of tuning:


OPEN & CLOSED LOOP OPERATION

What are they and why are they important? Because in order to have a complete stock like ECU after having the vehicle modified, you need to work like the stock ECU. You need to at least understand how the ECU works with open and closed loop operation.

- CLOSED LOOP OPERATION
Closed loop is when the ECU is set to feed off the factory O2 sensor. Its target is to get a perfect stoichiometric ratio of 14.7:1. Isn’t that too lean? For tuning WOT runs, yes. But in the real world, not necessarily. Ever since emissions testing came along, all vehicles were required to both run cleaner and still have good gas mileage. Look at the chart below.






As you can see, stoich is where HC and CO are both at minimal levels. Of course there’s not much you can do here about NOx, but as long as it’s not at its peak either. That’s what counts.

So how does stoich fall into good gas mileage. Well, think about it. If you had more air vs. fuel, then you would be using less fuel. Take for example a 9:1 a/f ratio vs. a 14.7:1 a/f ratio. A 9:1 means you are using 9 parts air to 1 part fuel. That’s a lot of fuel being used for just 9 parts of air. So when you use 14.7:1, you get more fuel economy. As a matter of fact, the leaner you run, the more fuel efficient your vehicle is. Hence Honda Imports are calling it's VTEC-E engines “Lean Burn” engines. They burn learner to get more gas mileage for each part fuel.

The downfall to burning lean is that you will create more NOx as can be seen in the chart above. NOx is directly related to heat. So the leaner your combustion, the hotter your engine burns. As a result, you get a lot more NOx pollutants out your tailpipe which is not good for emissions. Another reason why stoich is the ideal target ratio for gasoline powered engines. Its currently the best spot for gas mileage and emissions.

Okay so how does the ECU and O2 sensor work? The ECU constantly takes feedback from the O2 sensor to keep in the stoich range. The graph below is what our stock O2 sensor’s range is.






The O2 will constantly fluctuate back and forth between rich and lean. That’s just how it works. If you pull a waveform of the O2 over time, you will see that it’s a sine wave. That’s why many people see their Autometer A/F meter gauge fluctuate back and forth. The meter isn’t totally worthless. If anything, it’ll tell you if the O2 is not functioning right. Better yet, start calling it the O2 sensor gauge instead of the A/F mixture gauge. At least now you know your money wasn’t totally wasted.

So what does this all mean really? It means it’s important to have good gas mileage in a modified car. It means you can’t just forget about this part of the ECU when dyno tuning. Once we cover the open loop operation, then we’ll tie everything together.

- OPEN LOOP OPERATION

Okay finally, we’re done with the emissions stuff and ready to handle the big power stuff everyone’s been waiting for. Open loop is when the ECU feeds off directly from preset fuel maps stored in the ECU. The ECU totally ignores the information sent to it from the stock O2 sensor. If you have the Autometer A/F gauge, this is where you will notice that it goes rich.

Okay so I lied, the Autometer does have a bit more use to it than just flashing bouncing lights. It reads your A/F in open loop operation, otherwise known as WOT (wide open throttle). Keep in mind though, its scale of accuracy is very little. And it can’t tell you how rich or how lean you are, just a direction of richer or leaner. When it comes to an engine, more precise info is needed.

This is as far as most people will go in terms of tuning. This is the tuning part we all talk about when you visit your local dyno tuner. Because all your dyno runs are done at WOT, this is the fuel map that your local tuner saves for you when you are satisfied with your results.

This method is preferred because you don’t want to be running the stock fuel maps when you are boosting or have cams that are beefier than stock. That stock fuel map just won’t do it for you. If you’ve gone this far, kudos for you because now you have made all those performance parts you put into your car worthwhile. It’s now actually doing some good than just taking up space.

So what about people who want dual setups? You know, that high boost drag strip map and then a street tune so it’s street able or drive able. You can, but that’s going to be quite hard. As a matter of fact, only a few setups can allow for that. Even then, it’s going to take some time to upload the new map for each time you switch from drag strip to street.


Quote:
Quote:
Originally Posted by RandomRacer@Track

This statement I see a lot :
"Is it ok for a daily driver at 7-10 psi and 13 at the track."


This is a NO NO someone tell me what's wrong with this statement ?

When you tune your tuning for what ? AFR ! Guess what....When you tune the car at 10psi and then head down to your local track and crank it up to 13psi !!! What do you think happens to your AFR ? You guessed it... It's not the same as 10psi !!! What does this mean ?
NOT SMART huh....DUH !

When you tune on a dyno and set your AFR and your at 10-psi, that's what your tuning is set at !!! PERIOD ! Crank that psi up and all the $$$ you just spent went down the drain because your NOT properly tuned anymore ! When you crank up the boost your pushing more air in the motor and this means your AFR = AIR FUEL RATIO has NOW CHANGED !!!= RISK ! HIGH RISK !! DANGER ! Not smart ! When you tune, your tuned ! LEAVE it alone or your NOT tuned anymore ! Now, now you stand alone guys read below...

Let me clarify a bit more on the tune for proper afr and set it and forget it...

What that means is you need to load another fuel map for that psi level if you were to crank up the boost from 10 to say 13-15psi.
If your running a stand alone system. But again keep this in mind.
You still need to tune proper!



I don’t think I can say it any better than that for multiple boost applications. Just pick what boost level you want and stay with it. Now your car runs like a champ… but sadly, only at WOT.

You soon realize that your gas mileage is poor. You worry about emissions because of all these performance parts on the car. What are you going to do when you have to take the sniffer test? Swap all those parts back out for stock? Heck no! Go one step further. Datalog that sucker!


- DATALOGGING

What datalogging is what others may refer to as street tune. What street tuning does is allows the ECU to learn what the car needs at certain throttle/RPM/load through each gear. A laptop is NOT a must on any of these systems, its just an added feature to help tuning to a next level.

The most important thing you will need here for datalogging is a WBO2 (wideband O2) sensor and controller. In most cases, you’d want to get a gauge also. Otherwise, it would defeat the purpose of getting a WB kit in the first place.

The WBO2 sensor is practically the same size as the stock unit, but uses 7 wires instead of 4. Its also a 5V sensor compared to the 1V sensor that’s used with the stock setup. Here are some pictures of the WBO2 sensor and the factory sensor for comparison purposes.




Since the stock system is calibrated to feed off a 1v signal, using the 5v sensor is a bad idea. JUST DON’T DO IT. That’s where the WB controller comes in. You will need the WBO2 controller to make any use of the WBO2 sensor.

As I said before, when I started out there weren’t too many options. As a matter of fact, there was only the FJO unit, which many dyno tuners themselves used for well over $1k, and the TechEdge unit. So I opt for the TechEdge unit for cost. Today there are many other choices to choose from. PLX, Innovate Motorsports, Zeitronix, FJO, AEM, & Wideband Commander are among the many other choices out there. So look over all of them and choose which one best suits your needs and fits your budget.

With the WBO2 kit, you are now able to do another pat of tuning that many people can not get at a regular dyno tune (which only does WOT tuning, especially roller dyno's). I will not go into the datalogging technique myself because it’s different for each unit and standalone that you are using. What I will say though is that once you have it hooked up, drive around town with it. Do whatever you want. Make sure you get as many different possible driving conditions as possible.

Once you are done, you have to set the WBO2 to target 14.7:1 when you are in closed loop. Have the ECU set to ignore the 14.7:1 a/f ratio when in open loop so that it reads off the WOT fuel maps.

In essence what you are trying to do is what the manufacturer has done to the stock ECU. Have it target a particular a/f when in closed loop and have a designated fuel map to run off when in open loop. This way you can have both fuel economy and power in only one map. Now you won’t have to worry about adjusting for different fuel maps or boost levels at the drag strip and worrying about possible damage to your engine. With the functions of open and closed loop at the flip of your foot, you will have a stock like ECU built to match your setup.

Your car is already set up to do all these wonderful things. You just got to know how to take advantage of it. It’s all about open and closed loop operation. Once you understand that, you will be able to have max power at WOT runs and good fuel economy while driving regularly. Talk about a Jekyll & Hyde setup.

Lastly, I said all the above to say this: If your tuner isn't expirienced in the world of "custom tuning" then he's not going to be able to look at your datalog map and know how to adjust to your cars behavior. Your car may have some small issues. (exhaust leak, vacuum leak, wiring etc etc) But you cant be able to pinpoint these issue if your tuner can't give you an idea from your datalog map. He could have loaded a different fuel map to see how you car reacts, but I'm almost convinced he is only used to tweaking out the box tunes. He hasn't have the slightest idea what "custom tuning" is all about.

--------------------------------------------------------------------------



Turbo vs Supercharger


It's one of the most common questions we are asked - the answer to which is almost impossible to find
"What is better - a supercharger or a turbo?"

We only wish the answer were that simple, but unfortunately it is not. The simple answer is:
"It depends."
But don't worry, we'll go into more depth than that here. Both superchargers and turbos have distinct advantages and disadvantages. Selecting the right kind of forced induction for your vehicle will depend upon your particular vehicle, your driving habits, your power preferences, and your needs.

Clearing Up Confusion



--------------------------------------------------------------------------

According to Merriam-Webster's dictionary, a supercharger is defined as:
"a device (as a blower or compressor) for pressurizing the cabin of an airplane or for increasing the volume air charge of an internal combustion engine over that which would normally be drawn in through the pumping action of the pistons".
A turbocharger is defined as:
"a centrifugal blower driven by exhaust gas turbines and used to supercharge an engine".


According to Webster's, a turbocharger is included in the definition for superchargers - it is in fact a very specific type of supercharger - one that is driven by exhaust gasses. Other superchargers that do not fall into this category - the kind that we are all used to hearing about - are normally driven directly from the engine's crankshaft via a crank pulley. So in reality, it is not fair to compare all superchargers to turbochargers, because all turbochargers are also superchargers. For the purpose of this discussion, however, a supercharger will be considered all superchargers that are are not driven directly by the engine, while turbochargers will be considered all superchargers that are driven by engine exhaust gasses.

Similarities



--------------------------------------------------------------------------

Both superchargers and turbochargers are forced induction systems and thus have the same objective - to compress air and force more air molecules into the engine's combustion chambers than would normally be allowed at atmospheric pressure here on Earth (14.7 psi at sea level). The benefit of forcing more air molecules into the combustion chambers is that it allows your engine to burn more fuel per power stroke. With an internal combustion engine, burning more fuel means that you convert more fuel into energy and power. For this reason, supercharged and turbocharged engines normally produce 40% to 100%+ more power (depending on the amount of boost - check out our horespower calculator) than normally aspirated engines.

How They Work


--------------------------------------------------------------------------------

A supercharger is mounted to the engine and is driven by a pulley that is inline with the crank (or accessory) belt. Air is drawn into the supercharger and compressed by either an impeller (centrifugal-style supercharger), twin rotating screws (screw-type supercharger), or counter-rotating rotors (roots-type supercharger). The air is then discharged into the engine's intake. Faster crank speed (more engine rpm) spins the supercharger faster and allows the supercharger to produce more boost (normally 6 to 9 psi for a street vehicle). Typical peak operating speeds for a supercharger are around 15,000 rpm (screw-type and roots style superchargers) and 40,000 rpm (centrifugal-style superchargers).

A turbocharger operates in much the same way as a centrifugal (internal impeller) supercharger, except it is not driven by pulleys and belts attached to the engine's crank. A turbo is instead driven by exhaust gasses that have been expelled by the engine and are travelling through the exhaust manifold. The exhaust gas flows through one half of the turbocharger's turbine, which drives the impeller that compresses the air. Typical operating speeds of a turbocharger are between 75,000 and 150,000 rpm.

Head to Head Comparison


--------------------------------------------------------------------------------

Now it's time to evaluate the turbocharger versus the supercharger according to several important factors.

Cost
The cost of supercharger and a turbocharger systems for the same engine are approximately the same, so cost is generally not a factor.

Lag
This is perhaps the biggest advantage that the supercharger enjoys over the tubo. Because a turbocharger is driven by exhaust gasses, the turbocharger's turbine must first spool up before it even begins to turn the compressor's impeller. This results in lag time which is the time needed for the turbine to reach its full throttle from an intermediate rotational speed state. During this lag time, the turbocharger is creating little to no boost, which means little to no power gains during this time. Smaller turbos spool up quicker, which eliminates some of this lag. Turbochargers thus utilize a wastegate, which allows the use of a smaller turbocharger to reduce lag while preventing it from spinning too quickly at high engine speeds. The wastegate is a valve that allows the exhaust to bypass the turbine blades. The wastegate senses boost pressure, and if it gets too high, it could be an indicator that the turbine is spinning too quickly, so the wastegate bypasses some of the exhaust around the turbine blades, allowing the blades to slow down..
A Supercharger, on the other hand, is connected directly to the crank, so there is no "lag". Superchargers are able to produce boost at a very low rpm, especially screw-type and roots type blowers.

Efficiency
This is the turbo's biggest advantage. The turbocharger is generally more economical to operate as it as it is driven primarily by potential energy in the exhaust gasses that would otherwise be lost out the exhaust, whereas a supercharger draws power from the crank, which can be used to turn the wheels. The turbocharger's impeller is also powered only under boost conditions, so there is less parasitic drag while the impeller is not spinning. The turbocharger, however, is not free of inefficiency as it does create additional exhaust backpressure and exhaust flow interruption.

Heat
Because the turbocharger is mounted to the exhaust manifold (which is very hot), turbocharger boost is subject to additional heating via the turbo's hot casing. Because hot air expands (the opposite goal of a turbo or supercharger), an intercooler becomes necessary on almost all turbocharged applications to cool the air charge before it is released into the engine. This increases the complexity of the installation. A centrifugal supercharger on the other hand creates a cooler air discharge, so an intercooler is often not necessary at boost levels below 10psi. That said, some superchargers (especially roots-type superchargers) create hotter discharge temperatures, which also make an intecooler necessary even on fairly low-boost applications.

Surge
Because a turbocharger first spools up before the boost is delivered to the engine, there is a surge of power that is delivered immediately when the wastegate opens (around 3000 rpm). This surge can be damaging to the engine and drivetrain, and can make the vehicle difficult to drive or lose traction.

Back Pressure
Because the supercharger eliminates the need to deal with the exhaust gas interruption created by inserting a turbocharger turbine into the exhaust flow, the supercharger creates no additional exhaust backpressure. The amount of power that is lost by a turbo's turbine reduces it's overall efficiency.

Noise
The turbocharger is generally quiter than the supercharger. Because the turbo's turbine is in the exhaust, the turbo can substantially reduce exhaust noise, making the engine run quieter. Some centrifugal superchargers are known to be noisy and whistley which, annoys some drivers (we, however, love it!)

Reliability
In general, superchargers enjoy a substantial reliability advantage over the turbocharger. When a a turbo is shut off (i.e. when the engine is turned off), residual oil inside the turbo's bearings can be baked by stored engine heat. This, combined with the turbo's extremely high rpms (up to 150,000rpm) can cause problems with the turbo's internal bearings and can shorten the life of the turbocharger. In addition, many turbos require aftermarket exhaust manifolds, which are often far less reliable than stock manifolds.

Ease of Installation
Superchargers are substantially easier to install than a turbos because they have far fewer components and simpler devices. Turbos are complex and require manifold and exhaust modifications, intercoolers, extra oil lines, etc. - most of which is not needed with most superchargers. A novice home mechanic can easily install most supercharger systems, while a turbo installation should be left to a turbo expert.

Maximum Power Output
Turbos are known for their unique ability to spin to incredibly high rpms and make outrages peak boost figures (25psi+). While operating a turbocharger at very high levels of boost requires major modifications to the rest of the engine, the turbo is capable of producing more peak power than superchargers.

Tunability
Turbochargers, because they are so complex and rely on exhaust pressure, are notoriously difficult to tune. Superchargers, on the other hand, require few fuel and ignition upgrades and normally require little or no engine tuning.

Conclusion


--------------------------------------------------------------------------------

While the supercharger is generally considered to be a better method of forced induction for most street and race vehicles, the turbo will always have its place in a more specialized market. Superchargers generally provide a much broader powerband that most drivers are looking for with no "turbo lag". In addition, they are much easier to install and tune, making them more practical for a home or novice mechanic.

I hope you have found this discussion informative and unbiased. Sometimes when I explain this to people, they say that we are biased towards superchargers because that is all most shops carry. I remind those customers that a turbo is a kind of supercharger and that I truly hope to see turbochargers conquer superchargers someday.

--------------------------------------------------------------------------

Types of Superchargers:


When you begin to search for the best supercharger for your vehicle, the choices can sometimes seem overwhelming. With so many manufacturers, it's sometimes difficult to know where to start. This guide is designed to give you an overview of each supercharger manufacturer and will hopefully help you decide which brand is the best choice for you.

Often we are asked which supercharger is the best. This question is impossible to answer as each make of supercharger has its own set of characteristics (price, low end power, high end power, ease of installation, reliability, etc.) that make it unique. The combination of these characteristics may make a particular supercharger the "best" or the "worst" choice for your application depending on your requirements. With the help of this guide you will get a feel for which brand will most likely best suit your needs.

The feature that most separates the different brands of superchargers is the type of compressor that is used. There are three different types of supercharger compressors - centrifugal, twin-screw, and roots (click to learn more on each type of supercharger). It will be helpful to familiarize yourself with these three types of superchargers before deciding which supercharger is best for your application. In many cases you will find that there is only one type of supercharger available for your vehicle. In general, this indicates that there is one type of supercharger compressor that is clearly the best choice for your vehicle by most standards.

Roots vs. Centrifugal vs. Screw Type Supercharging

The most effective performance enhancement that you will ever do to your car or truck is definitely a supercharger. That is why it is very important that you choose the right type of supercharger to get the right kind of power for the type of conditions that you will put your vehicle through. This is a guide to help understand it's not just about forcing more air down the throat of your motor. There are different ways to get the air to the motor and these different ways create different type of power curves.


--------------------------------------------------------------------------


Centrifugal Type Supercharging
Centrifugal Supercharging compresses the air inside the case of the supercharger using an impeller. Then, discharges the air out of a scroll to the motor. This design is similar to turbo-charging except for centrifugal superchargers don't use the exhaust to build pressure, they use a belt, driven by the crank pulley to spin the impeller. Centrifugal supercharging is definitely one of the more user-friendly ways to supercharge your motor. The ability to change the impeller sizes and to spin the impeller at different speeds creates a more inexpensive way to have flexibility in your power curve. Centrifugal superchargers have become the standard for street use and light-duty racing and far outsell all other types of superchargers.


Recommended Usage:
Street Use - Commercial Use - Road Racing - Drag Racing


Positive Points:
1) Lots of Flexibility for Power Adjustments
2) Lower Discharge Temperatures
3) Great Reliability
4) Easy to install

Negative Points:
1) Not as much power at low RPMs as Roots or Screw type superchargers

Manufacturer Availability:
Paxton - Powerdyne - ProCharger - Vortech

Vortech's Centrifugal Type Supercharger




Roots Type Supercharging
The Roots Type Supercharger is the first style supercharger that was ever used and can be dated back to the 1880s when the Roots brothers designed it as an air conveyor for mine shafts. Roots blowers act like air pumps (not compressors), and In general, Roots blowers have a two or three lobe rotor design, depending on the size of the case. Roots blowers will give you positive pressure to your motor from just a crack of the throttle, and will give all that they have to offer at full throttle no matter what the rpm of the motor. Roots Type Superchargers may look awesome hanging out of the hood and are great for those looking for drastic power increases at lower RPMs. Roots blowers are also extremely reliable and require very little maintenance, which is why Ford, GM, Mercedes, Jaguar, and Austin Martin have all featured Roots blowers as original equipment on select high performance vehicles.

Recommended Usage:
Street Use - Towing - Extreme Drag Racing - Show Vehicles


Positive Points:
1) Boost throughout the entire RPM range, right off of idle
2) Highest Potential for Gain (A must-have for all-out drag racing)
3) Excellent Reliability
4) Great Appearance & Stature (Most common supercharger type for show vehicles)

Negative Points:
1) Sometimes Violent Throttle Response
2) Lower boost ratings at higher RPMs
3) Higher Than Normal Discharge Temperatures
4) Lengthy installation times

Manufacturer Availability:
Allen Engine Development - BDS - Magna Charger - B&M- Holley - Littlefield - Mooneyham - Weiand

Holley's Roots Type Supercharger
[img]http://ckjuice.com/svt/holley_roots.gif





Screw Type Supercharging
Screw type superchargers are derived from the Roots type concept but with vast improvements for street use. Although from the out side, screw type superchargers may look a lot like Roots type superchargers, on the inside you will find a twin-screw design that compresses air unlike Roots type superchargers which pump the air into the motor. Screw type superchargers have an axial-flow design that compresses the air as it moves between the screws to create positive pressure without creating the heat that Roots type superchargers can create. The Screw type supercharger's ability to produce a dramatic increase of power from idle and through out the rest of the power curve make them a great choice for heavy vehicles, towing or commercial use.

Recommended Usage:
Street Use - Towing - Road Racing - Drag Racing


Positive Points:
1) Great Power at Low RPMs (Great for Towing)
3) Factory Fit & Appearance
4) Great Reliability

Negative Points:
1) The Power Doesn't Keep Climbing in the High RPMs (Power curve is very flat)
2) Challenging To Achieve High Boost Levels or CFMs
3) Lengthy installation times

Manufacturer Availability:
Kenne Belle - Whipple

Whipple's Screw Type Supercharger





Allen Engine Development
Supercharger Type: Roots (Eaton)

Overview: Allen Engine Development is a small manufacturer of a select few roots supercharger systems for the Ford 4.6L Mustang / Thunderbird engine.

Pros:
• OEM quality
• Excellent power at lower rpms
• Very complete system - no additional modifications required
• Integrated intercooler system included with every system
• Self contained - no need to tap the oil pan for lubrication


Cons:
• Kits available for few vehicles
• Kits are fairly expensive, but reasonably priced considering intercooler is included
• REV I kits have lengthy install times (new REV II kits are much easier)

Systems Available For:
• 4.6L GT Mustang
• 4.6L Thunderbird

Paxton Automotive
Supercharger Type: Centrifugal (Paxton)

Overview: Paxton Automotive is the first aftermarket automotive supercharger manufacturer. Paxton makes high-end centrifugal superchargers for a variety of Dodge, Ford, Lincoln, and GM vehicles.

Pros:
• High quality compressor and components
• Very complete system - no additional modifications required
• High peak boost capabilities - great for racing
• Excellent installation instructions
• 100% maintenance free - no oil to change

Cons:
• Not self contained - tapping the oil pan is required
• Little boost / small power gains below 3000 rpm

Systems Available For:
• Dodge Ram
• Plymouth Prowler
• Ford 4.6L Mustang and Cobra
• Ford 5.0L Mustang and Cobra
• Ford 6.8L Truck/SUV
• Ford F-Series Truck 4.6/5.4L
• Lincoln Navigator 5.4L
• GM Truck/SUV 4.8/5.3/6.0L
• GM Truck/SUV 7.4L



Powerdyne Automotive
Supercharger Type: Centrifugal (Powerdyne)

Overview: Powerdyne Automotive manufactures a complete line of centrifugal supercharger systems for many GM, Ford, and Dodge cars and trucks. Known for being one of the only self contained centrifugal superchargers and for being a low-cost leader, Powerdyne Automotive has proved itself to be a powerful player in this industry.

Pros:
• Excellent value - low cost and good performance
• Very complete systems - no/few additional modifications required
• Super quiet "SilentDrive" belt driven internals make almost no noise
• Self contained - no need to tap the oil pan (except for XB-1A systems)

Cons:
• Internal belt needs to be replaced every 50,000 miles (except for XB-1A systems) and must be sent to Powerdyne
• Installation instructions need improvement
• Not capable of high boost outputs above 12psi
• Little boost / small power gains below 3000 rpm

Systems Available For:
• Dodge Ram 5.2/5.9L
• Dodge Dakota 5.2/5.9L
• Dodge Durango 5.2/5.9L
• Ford 4.6L Mustang
• Ford 5.0L Mustang and Cobra
• Ford Explorer
• Ford F-Series Truck 4.6/5.4L
• Ford F-Series Truck 5.0/5.8L
• Ford Lightning
• GM Camaro / Firebird / TransAm
• GM 4.3L Truck / SUV
• GM 4.8/5.3/6.0L Truck / SUV
• GM 5.7L Truck / SUV


ATI ProCharger
Supercharger Type: Centrifugal (ATI)

Overview: ProCharger is known as a leading centrifugal supercharger brand and has established a reputation for its high quality intercooled supercharger systems that are capable of putting out incredibly high levels of boost. ProCharger is a strong believer in the benefits of intercooling and include an intercooler in almost every system they sell. Their P-1SC and D-1SC supercharger compressors are the only gear-driven centrifugal compressors available, and are very easy to install.

Pros:
• Very high performance - cool (intercooled) discharge
• Self contained - no need to tap the oil pan (P-1SC and D-1SC only)
• Very upgradable - compressors capable of high boost outputs

Cons:
• Lots of compressor noise (whine)
• Fairly expensive, but reasonable considering intercooler is included
• Little boost / small power gains below 3000 rpm


Systems Available For:
• Ford 4.6L Mustang
• Ford 4.6L Cobra
• Ford 5.0L Mustang
• Ford 5.0L Cobra
• Ford V6 Mustang
• Ford F-Series Truck 4.6/5.4L
• GM Corvette C5/ZO6
• GM LT1 Corvette
• GM TPI Corvette
• GM Camaro / Firebird / TransAm
• GM TPI Camaro / Firebird / TransAm
• GM Carbureted Big Block / Small Block
• GM 5.7L Truck / SUV EFI
• GM 5.7L Truck / SUV TBI
• GM 4.8/5.3/6.0L Truck / SUV
• GM 7.4L Truck / SUV


Vortech Engineering
Supercharger Type: Centrifugal (Vortech)

Overview: Vortech sets the industry standard with their huge line of automotive and truck superchargers. Vortech sells more superchargers than any other single manufacturer - and for good reason. Vortech quality is second-to-none and their impressive manufacturing plant is the best in the industry. Their high quality supercharger systems have enjoyed years of success on the race track and are capable of incredibly high boost output levels.

Pros:
• Very high performance - capable of high outputs - aftercoolers available on some models
• Reliable, high quality compressor and components
• Very upgradable - compressors capable of high boost outputs
• SQ line of compressors are "Super Quiet"

Cons:
• Tapping the oil pan is required
• Little boost / small power gains below 3000 rpm


Systems Available For:
• Ford 2.5L Contour
• Ford 4.6L Mustang
• Ford 4.6L Cobra
• Ford 5.0L Mustang
• Ford Lightning
• Ford 4.6/5.4L F-Series Truck / SUV
• Ford 5.0/5.8L F-Series Truck / SUV
• Ford 4.0L Truck / SUV
• Ford 6.8L Truck / SUV
• Ford 7.4L Truck / SUV
• Lincoln Navigator
• GM Camaro / Firebird / TransAm
• GM Corvette
• GM 4.3L Truck / SUV
• GM 4.8/5.3/6.0L Truck / SUV
• GM 5.7L Truck / SUV
• GM 7.4L Truck / SUV
• Dodge Durango
• Dodge Dakota
• Dodge Ram
• Honda Civic
• Honda S2000
• Acura Integra


Whipple Industries
Supercharger Type: Twin Screw (Lysholm)

Overview: Whipple Industries is rapidy emerging as a leading manufacturer of twin-screw supercharger systems for many truck and marine applications. Utilizing only the best quality Lysholm twin screw compressors, Whipple supercharger systems are completely self contained and provide amazing power gains even at very low engine rpms. Ideal for trucks and towing vehicles, these supercharger systems are truly a cut above.

Pros:
• Excellent power at lower rpms and great for towing
• Very complete system - no additional modifications required
• Easy to install
• Self contained - no need to tap the oil pan for lubrication
• Very high quality

Cons:
• Kits are fairly expensive
• Installation manuals need improvement


Systems Available For:
• GM 4.8/5.3/6.0L Truck / SUV
• GM 5.0/5.7L Truck / SUV
• GM 7.4L Truck / SUV
• GM 8.1L Truck / SUV
• Ford 6.8L Truck / SUV
• Chrysler 2.4L PT Cruiser
• Mercruiser Marine









--------------------------------------------------------------------------



How Your Drivetrain Handles Boost

The short answer to this question is both yes and no, so let's start with the basics. (See a comparison of supercharger types here!)

Drive train defined:
The system that transfers power from the engine to the wheels is known as the drive train or driveline. It includes the clutch or torque converter, the transmission, differential, ring and pinion gears, axles, and where applicable drive shaft(s) and transfer case, universal and/or CV-joints.

Power train defined:
The complete system of the engine and the drive train.

Understanding Factory Drive Train Limitations

The drive train in your car or truck is designed, by the manufacturer, to be strong enough to handle full engine power at the vehicle’s load and gross weight limits. Safety margins are factored into each component so that the entire powertrain will survive moments of particularly strenuous conditions. (ex: Shifting an automatic transmission into “Drive” and applying power while the vehicle is rolling in reverse). In some cases, the vehicle’s Powertrain Control Module (PCM) is programmed to identify stressful drive train conditions and take actions electronically to reduce them. One such example of this is where power is reduced during down or up shifting to extend the life of the transmission.

Many systems can also limit torque taking off from a stop. Abusive situations can also be identified by the PCM, such as a driver shifting back and forth between reverse and drive to create a rocking motion, or a high throttle position when putting the vehicle into gear - also known as “the drop shift.” The manufacturer knows exactly how much stress each component can handle under various conditions before it fails. The onboard computer (PCM) provides a way to extend the safety margins of the drive train without installing larger, heavier components. This contributes to higher fuel economy and lower cost.

Are Supercharger Kits Designed With Drive Train Limitations in Mind?

A Supercharger kit is the single best power upgrade you can make to your vehicle. Every supercharger manufacturer goes through extensive design, prototyping, testing, tuning, and qualification of each system before it can ever be brought to market. Most kits are tuned to be installed on otherwise factory-equipped engines. Power levels are specifically tuned not to exceed the critical thresholds of the OEM drive train components. An example of the Supercharger industry’s engineering confidence in their products' effect on powertrain lifespan is MagnaCharger’s 3-year/36,000 mile limited powertrain warranty.





What Affect Do Other Upgrades Have?

As explained, a supercharger kit installed to the manufacturers' specifications will not exceed the factory power train’s capacities. Problems will start to appear as other engine parts are upgraded to increase power even more. There are a few upgrades that will have an adverse affect on the drive train when combined with the supercharger. Here are some examples:

1. High-Stall torque converter. A torque converter multiplies torque from the engine to the transmission by a factor proportional to the rotational speed difference between them. Basically, a higher stall converter alone will cause the transmission to experience momentary input torque levels much higher than a stock converter would.

2. Boost Upgrade. Installing a smaller pulley on the supercharger is an easy way to get more power if detonation can be controlled. This extra power may be in excess of the drive train’s capabilities.

3. PCM Reprogramming. A popular performance modification to the PCM is to remove the Torque Management subroutines that reduce power in favor of drive train preservation.

4. Wider or larger diameter tires. From a drive train’s perspective, larger tires or wider high-traction tires have a similar effect when launching from a stop. Either tire upgrade will reduce wheel spin. Wheel spin actually reduces stress on the entire drive train once it begins. Increasing traction with a tire upgrade will increase driveline stress if the previous tires were able to break traction before.

These upgrades are so effective that together, with the supercharger, failure of a major drive train component is just about guaranteed to happen sooner or later if these components are not also upgraded to handle the additional torque.

Back to the Original Question:

In the never-ending quest for more power, it is this torque that ultimately dooms the weak link. Twin Screw and Roots superchargers make full boost right off idle when you jab the gas. At this instant, the engine may reach its torque peak just as the vehicle begins to move forward. The torque peak of a centrifugally supercharged engine would be seen in the higher end of the RPM range. Launching a centrifugal vs. twin-screw or roots with the same peak boost is therefore less stressful on the drive train and less likely to cause a failure for that reason.

It takes lots of torque to break parts, and twin-screws and roots superchargers make more of it. It is typical to see peak boost levels of centrifugal supercharger kits calibrated and tuned to one or two pounds greater than a roots or twin-screw kit for the same engine. The centrifugal supercharger kits do not have to be de-tuned to keep power levels manageable at low RPM.

Conclusion

Adding power, in excess of what the supercharger kit provides on a stock vehicle, is possible as long as attention is paid to the limitations of the transmission and the rest of the drive train components. If you’re building a torque-monster for towing and the best possible hole shots, driveline upgrades will be required.




--------------------------------------------------------------------------

Detonation

As you probably have already figured out, detonation (aka "knock") is a big issue in the world of forced induction. You probably know that detonation is a bad thing, and that by adding a supercharger (or any forced induction power adder), you must take additional measures to avoid detonation, especially if your engine has other modifications. Normally the simple solution to stop detonation is to run higher octane fuel... but before we get ahead of ourselves, let's start from the beginning.

What is detonation / knock?

Under normal conditions, the combusting air and fuel mixture inside the combustion chamber ignites in a controlled manner. The mixture is ignited by the spark, normally in the center of the cylinder, and a flame front moves from the spark towards the outside of the cylinder in a contolled burn. Detonation occurs when air and fuel that is ahead of the flame front ignites before the flame front arrives because it becomes overheated. Under these conditions, the combustion becomes uncontrolled and sporadic and often produces a pinging noise, or a "knock" noise when the conditions become worse.

So far, detonation sounds cool... why is it bad?

Detonation is definitely not cool. Detonation causes sudden pressure changes in the cylinder, and extreme temperature spikes that can be very damaging on engine pistons, rings, rods, gaskets, bearings, and even the cylinder heads. Even the best engine components cannot withstand severe detonation for more than a few seconds at a time. More severe detonation obviously leads to more severe forms of engine damage. If there is enough heat and pressure in the combustion chamber, detonation can begin to occur before the spark plug even fires, which would normally initiate the combustion. Under these circumstances, known as "pre-ignition", the piston may be travelling up towards a wave of compressed, exploding gas. These are the worst kinds of detonation conditions, and can bend con-rods and destroy pistons.

What causes detonation?

Detonation occurs when several conditions / factors inside the combustion chamber exist at the same time. Increased compression, high temperatures, lean fuel/air mixture, advanced ignition timing, and lower octane fuels are all factors that PROMOTE detonation conditions. The good news is that, because there are so many factors in play, you can always find a way to eliminate detonation if it exists.

So, where do superchargers fit in?

A supercharger increases the amount of air inside the combustion chamber (see "Bye Bye 14.7 psi"), which in turn increases the compression inside the combustion chamber. Along with increased compression comes higher temperatures and higher pressures, which as we know, tend to increase the chances that some form of detonation will occur. In order to compensate for the increased compression and heat, we must change one or more of the other factors / conditions to move us away from our detonation threshhold. Tuning the supercharger system to the engine in this way for maximum performance without detonation is something that supercharger manufactuers do so, chances are, you won't have to worry about it unless you do other modifications to your engine that place you closer to your detonation threshhold.

How do I get rid of it?

The two most common tricks used by supercharger manufactuers and engine tuners looking to obtain maximum performance without detonation is 1. use higher octane fuel, and 2. retard the ignition timing.

Higher octane fuel burns more controllably and is not as likely to combust before the flame front. This is why racing engines use 100+ octane gasoline. The ONLY benefit of racing gasoline is that it moves you away from the detonation threshhold, which allows you to be more aggressive with power producing factors - i.e. raise compression, advance timing, etc. This is why you'll be disappointed if you put racing gasoline in your mom's bone-stock '82 Toyota Cressida thinking you'll turn it into a race car. If you don't have detonation, the increased octane will do you no good. For cars designed for daily street driving, you obviously won't want to fill up with 100+ octane fuel every week at the tune of 5 bucks a gallon. This is why supercharger manufactuers tune their supercharger systems to run properly without detonation on 91 octane fuel - aka "premium" at your local gas station (in some states premium gasoline is around 93 octane).

Retarding the ignition timing will delay the timing of the spark, which also moves you away from your detonation threshhold. Most popular "power programmers" or "chips" increase engine power by advancing the ignition timing, and requiring you to run a higher octane fuel to avoid detonation. These work great, except the advanced ignition timing is NOT compatible with most superchargers, unless you're happy to run 100 octane fuel. In fact, many supercharger systems include an "ignition boost retard" that retards the ignition timing when it senses boost from the supercharger. This allows you to maintain stock performance while not under boost, yet still remain safe while the supercharger is making its boost (and power).

Another way to avoid detonation is to cool the incoming air charge to lower the temperature inside the combustion chamber. On a supercharged application, this task can be handled by an intercooler (see "Let's Talk Intercoolers") or by a water injection system (less common). The intercooler takes the incoming air charge and passes it over a series of air-cooled or water-cooled fins and ducts, thus cooling the air in the same way that a radiator cools your engine's coolant. Intercoolers are thus very popular in higher output supercharger systems, where detonation becomes more of a problem. Often times, the intercooler allows you to run more boost and also allows you to eliminate the ignition boost retard, meaning you'll notice increased performance, and still experience no detonation. Another way to lower the temperature of the combusting air and fuel is to run cooler heat range spark plugs. Many supercharger manufacturers will recommend cooler plugs for you supercharged engine.

Because lean condition (fuel starvation) also contributes to detonation, it is important to make sure that the fuel system (pump, injectors, etc.) is capable of delivering the increased fuel requirements of the supercharged engine. Often times, an otherwise perfectly tuned engine will experience detonation just because the fuel pump can't deliver enough fuel to the engine. Upgrading certain fuel components is almost always necessary when supercharging an engine. Most supercharger systems normally include the upgraded fuel components if they are necessary. If you are installing a supercharger on an engine with other modifications, make sure you consider the additional fuel requirements and compensate with larger injectors and / or a bigger fuel pump.

Some modern vehicles come with "knock sensors" that listen for detonation, and automatically retard the ignition timing to eliminate detonation. Although these devices are effective in preventing engine damage, they are not tuned for performance, so you should not rely on the knock sensors and expect your engine to run its best.

Conclusion

Altough detonation can be potentially damaging to an engine, a simple understanding of what it is, and what causes it, will help you stay away from your detonation threshhold. Pay attention to "knock" and pinging noises that come from your engine becuase they could indicate detonation inside the combustion chamber and should be dealt with immediately. If you're looking for a new supercharger system, don't worry too much about detonation - the manufacturers have designed the system for use on your stock engine, and if you follow the manufactuer's fuel recommendations, you will not have a detonation problem. If you ever do notice detonation, perhaps from bad (low octane) gasoline or extremely high air temperatures, just drive with a light foot until you are able to resolve the cause of the problem.

--------------------------------------------------------------------------

What is an FMU?

Horsepower is a result of two key components: air and fuel. The supercharger itself, whether a centrifugal, roots, or twin screw, really only provides one of the two major ingredients for making more power. Each supercharger kit is a complete system that increases both air and fuel flow into the engine. A supplemental fuel system upgrade must complete the package.
The FMU Explained

There are several methods used by various supercharger kit manufacturers to deliver supplemental fuel to the engine under boost. An FMU, or “Fuel Management Unit”, is the chief component used for one of these methods. An FMU is often referred to as a boost-dependant fuel pressure regulator. The FMU is essentially a variable fuel-pressure regulator that automatically raises fuel pressure as boost rises.

Depending on the capabilities of the stock fuel pump, a booster pump may be used in conjunction with the FMU. The FMU is downstream (after) of the stock regulator. As boost pressure begins to rise, the FMU starts restricting the flow of fuel returning to the gas tank. Like a garden hose, if the flow is restricted, the pressure increases. The increase in restriction results in an increase in the pressure of the fuel being delivered to the factory fuel injectors. Higher fuel rail pressure enables the fuel injectors to deliver more fuel in the same amount of time than they do at the static stock fuel pressure.





The FMU is calibrated precisely for each supercharger system - a rise in fuel pressure equals a directly proportional rise in boost. The ingenious simplicity of the system means that no computer recalibration is required. Without the FMU, the stock fuel system would not be able to maintain an air-to-fuel ratio low enough to prevent a lean condition. FMU-based systems are the most popular with supercharger kit manufactures.



Other Types of Supplemental Fuel Systems Used With Supercharger Kits

Some supercharger kits take a different approach to supplemental fuel supply. One of these alternate methods, to an FMU-based approach, uses an auxiliary EFI computer. This computer is connected to one or more separate fuel injector(s) installed just before the intake manifold. The auxiliary injector(s) work like a TBI to provide additional fuel to all cylinders. These systems do not require an increase in fuel pressure over stock and, therefore, the fuel flowing through the factory injectors is not increased.

On most supercharger systems, booster pumps are not needed unless the supercharger kit manufacture determines (through testing) that the stock fuel pump is not able to provide enough volume to supply both the factory and auxiliary injectors. These kits do not require recalibration of the factory computer.

The most effective way of compensating for the additional fuel required under boost is to replace all of the factory fuel injectors with higher-flowing ones. This method requires recalibration, or replacement, of the factory computer with a new fuel map appropriate for the new injectors. Replacing all of the fuel injectors is expensive and labor intensive, thus making this fuel system upgrade the least popular among supercharger kit manufacturers.



It should also be noted that some engines are designed with proprietary fuel injection that makes swapping out injectors impossible. Just like the others, supercharger kits getting this fuel system treatment may require a booster pump or replacement of the stock pump depending on the application.

For specific information about which fuel system upgrade is included with each kit, start with our Shop by Brand page and select an application.

Conclusion

So, that's the bare-bones of an FMU. In the next installment, we'll get into more the more detailed and technical aspect of this darling of the Fuel Management program - the FMU.

Getting Technical

The FMU, also know as a “boost dependant fuel pressure regulator,” only increases fuel rail pressure when boost is applied to the reference port on the FMU. This regulator is in the return fuel line and is downstream of the static fuel pressure regulator. The FMU is a simple mechanical device that can be calibrated by changing the internal ring and spacer. Inside an FMU is a piston. The boost pressure comes from the manifold to a fitting on the FMU and applies pressure to a washer sitting on the piston. The larger the washer, the more pressure it applies on the piston. The piston pressure blocks the flow of fuel down the return line. This backup creates a higher line pressure because the fuel cannot freely pass through.

As explained in the previous article, there are two key ingredients to making horsepower: fuel and air. We are going to discuss the most popular methods of increasing the quantity of fuel, to support the air entering the motor under boost, and its relationship to the amount of power you are trying to make.

3 Steps to Delivering More Fuel

Traditionally, there are three most common ways to deliver more fuel to your engine. They are:

Upgrade Your Injector Scenario
Utilize the Power of the FMU w/ Existing Injectors
Use a Computer Programmer to Regulate Fuel Management With Upgraded Injectors
Upgrade Your Injector Scenario

To get more fuel, you can run larger injectors, increase the pressure to the injectors you already have, or add an auxiliary set of injectors. The auxiliary set of injectors usually squirts fuel into the manifold and requires a secondary injector driver to tell the injectors when to fire and for how long. This method is effective for street cars because it lets the car run like normal with smaller injectors. It is also good for cruising because it prevents the motor from overloading with fuel and stumbling. It then allows the second set of larger injectors to give more fuel when you are trying to make power. The major downside is that this method is very expensive because of the additional components required. Furthermore, it can be very difficult to tune because of the wide adjustment range of a completely separate set of injectors. This common dilemma led to the eventual creation of the FMU.

Utilize the Power of the FMU

The FMU is great because it allows the car to run normally on a small injector, but can also increase the rail pressure under boost which, in turn, forces more fuel through the same size orifice. The fuel that the FMU adds has a direct relationship to the boost pressure. The proportionality is usually stated in a ratio, for example 12:1. This means that the FMU will add 12psi of fuel for every psi of boost. (For example, 10psi of boost will add 120psi of fuel pressure.) When all is said and done, this could net a total of about 140psi of fuel pressure which is often too much for a little injector to handle. It is also the reason most people opt for a combination of larger injector and lower ratio of FMU. This is an ideal setup because it allows the same quantity of fuel but at a lower pressure which is more constant for tuning and less fatiguing on the injectors.

Computer Programs and Fuel Management

The third most popular method of increasing fuel is to add larger injectors and use a computer chip to calibrate and control them. This often can cause the car to run great under boost. However, it is often harder to mange when the car is a daily driver or when cold started. Even this method only can supply enough fuel to support a given amount of pressure. Eventually it, too, requires an injector so large that it would not be suitable for any type of street driving - just racing.

Conclusion
This is why the FMU has become so popular. It offers great versatility for street and strip use. You get the ability to support horsepower and still have the street ability of a daily driver. It is also mechanical and not very complex, so there is little chance of having any reliability issues. The final attribute of an FMU, that has make it popular, is its ability to be easily recalibrated (for a relatively low cost) to match the injector choices you make.

--------------------------------------------------------------------------

The Mystery of Octane


What is octane? The concept of octane is peculiar to many people, including myself. I can't see it, I can't hold it, I can't buy it by itself, but I know I know I pay extra for it if I want more than 87 of it in my gas. Today we take an in-depth look at what octane is, and what significance a gasoline's octane rating has with regards to a supercharged engine.

The Simple Definition

An octane rating (87 vs. 89 vs 92, etc.) is a measure of a gasoline's ability to resist detonation, which manifests itself in a pinging or "knocking" noise. Higher numbers indicate that the fuel can be compressed to a higher level before detonation / knock occurs in an engine, which occurs when. As described in "Detonation, Knock, and Pre-Ignition 101", detonation / knock occurs when air and fuel that is ahead of the combustion flame front ignites before the flame front arrives.

The Complicated Definition

Octane is actually more than just a rating - it is a hydrocarbon just like methane (single carbon atom), propane (three carbon atoms), butane (five carbon atoms), and heptane (seven carbon atoms). Octane (C8H18) is a hydrocarbon with eight carbon atoms and eighteen hydrogen atoms. 100% octane fuel is remarkably resilient to compression (i.e. it does not combust when compressed) and is thus resilient to detonation / knock. This resilience is derived from the branching of octane's carbon chain (see figure). Because of the nature of octane as being resilient to detonation, all fuels are compared to 100% octane as a benchmark fuel, from which an "octane rating"can be obtained. Heptane, a hydrocarbon with seven carbon atoms, compresses very poorly and spontaneously combusts even under small amounts of compression. In other words, Heptane's behavior when compressed is diametrically opposed to Octane's behavior under the same conditions. For this reason, Heptane (which has an octane rating of zero) is the other benchmark fuel used in the octane rating system to determine a fuel's octane rating. A fuel that spontaneously combusts (knocks) under the same amount of compression as a fuel composed of 87% octane and 13% Heptane would have an octane rating of 87. This is not to say that 87 octane gasoline is made up of 87% octane and 13% heptane, rather that the 87 octane gasoline "knocks" in a laboratory knock engine at the same compression ratio as a fuel composed of 87% octane and 13% heptane.



The coomposition of an octane hydrocarbon.

Unfortunately, it gets even more complicated. Because various fuels respond differently under varying engine loads, a gasoline may get a different octane rating on a free running engine and one under load. For this reason, the octane rating label that we see at the pump (monitored by the U.S. Cost of Living Council) is actually an average of two octane ratings - the motor method rating (where the engine is run under a load) and a research method rating (where the engine is run freely). The formula used to get the CLC Octane number on gas pumps in the United States is thus: (Motor Octane Number + Research Octane Number) / 2.

What's the benefit of higher octane?

Higher octane fuel has only one beneficial feature - it allows an engine to run at higher temperatures with more advanced ignition timing under higher levels of compression witout detonating / knocking. Higher octane fuel does NOT have more potential energy and will not make an engine perform better unless that engine is knocking. On modern engines with knock sensors, higher octane fuel may make the engine run better if the knock sensors are retarding the ignition timing, which hinders performance. High octane fuel does not burn cleaner, it does not clean your engine, it does not increase horsepower or torque (unless you are experiencing knock), it does not smell better, it does not increase fuel economy (unless you are experiencing knock) and is not better for the environment. If you buy higher octane fuels for any of the above reasons, STOP!

When should I switch to a higher octane fuel?

First off, never run lower octane fuel than is recommended by the vehicle's manufacturer. If the vehicle manufacturer recommends 89 octane gasoline, this means that the engine has been tuned to perform optimally without detonation on 89 octane fuel. Once you've done some modifications to your engine, the manufacturer's recommended gasoline may no longer suffice. Obviously, if you can hear detonation inside your engine in the form of pinging or "knocking", try a higher octane fuel. You will also need to run a premium grade fuel (91+ octane) if you have a supercharger, turbocharger, or if you have an ignition programmer that advances your ignition timing.

Why is higher octane fuel more expensive?

Higher octane fuels are more expensive because they must go through more refining steps that increases the octane rating. These additional steps do not make the fuel better in any other way.

How is it possible to have 100+ octane gasoline?

There are some fuels that are even more resilient to compression than 100% octane. Some additives, like tetraethyl lead, increase the gasoline's ability to operate without knock. Some racing and airplane fuels have octane ratings of 110+!


That's all the time I have for now I will be adding more information as I have time to post in depth. Thanks for reading and I hope this was beneficial to your needs for understanding the complex world of forced induction.

Chip
____________________________________

1996Cobra SVT (Vert)
Chip@ckjuice.com
www.ckjuice.com
My Space

briann510

Very good read! Thanks...

I also just legally passed the California sniffer test last week! The guys couldnt believe how clean it blew on both runs making the hp it is. I knew as long as they didnt get into open loop which aint gonna happen on the rollers at 15 & 25 mph it would pass.