HessViper

Please do not assume that my silence indicates that what you just asked me caused me to think about anything our team is not already well aware of.

We will provide real, proven, answers, soon.

Thank you for the first polite post towards any member on our team.

Hopefully you understand why we are in no hurry to divulge details to you at this time.

3 Z06ZR1

Plus the dealer would never know and also a free unicorn ride coupon is included

3 Z06ZR1

More obvious is people here are really stupid about how the mod world works but continue to post BS! If you add enough mods to make anywhere near 800 hp you would have to have the car professionally tuned to make it work you talk all day but you are totally clueless! You cannot add any good mods without a tune past the intake and expect results. Tuning includes required changes to the tune.
You go from one line of BS to the NEXT Where is the two pump intercooler you were crowing about? Just more BS!

The T-man

update-

So after 150 miles or so the car runs even stronger, so the theory of it tuning out the gains seems incorrect.
And anyone chiming in w/ some strong opinions re: not using one better have at least run one to make your comments worth reading...

dar02081961

Your observation is inline with how the PCM should work and respond to additional air.

Those claiming the results will be learned away over time never ever offer a technical explanation as to how the PCM learns away power (reduces power) while adding fuel and adjusting the AFR back to commanded to compensate for more air. (worst case,still more fuel + more air=more power). Or how the CAI not seeing and accounting for more air by design which results in a slightly leaner AFR AND more air than stock can produce less power. (best case, still more air @ better afr for power= more power).

The PCM is not programmed to reduce power when it encounters more air. It simply adds fuel to keep the AFR in the intended area during closed loop. If the power is there due to increased airflow it will remain there as long as the additional airflow is there. This is all during closed loop at best.
During open loop there is very little learning. So the majority of any power gains observed on day one will remain.
There is very limited feedback from the O2 sensors to the PCM to learn from in open loop (WOT) therefore its called open loop. Very little information that is learned during closed loop is carried over to open loop and therefore during open loop (WOT) there is very little that could possibly be learned away.

Warp Factor

The way it's been explained is that the stock tune is too rich for maximum power (for detonation resistance and cooling reasons), and the aftermarket air intake leans it to a better power-producing mixture.
But after a while, the long-term fuel trims (which are carried over to open loop) compensate to take it back near stock values, so some of the initial increase goes away. I think it was Terry@BMS who actually showed this with dyno graphs.

This would apply to stock tunes, and not necessarily to cars which have been tuned.

C7/Z06 Man

Terry @ BMS has pointed this out.

He has said something along this line; if the engine can 'only' consume 1,000 CFM's than building a 1,400 CFM system (CAI) will not add additional horsepower. He also said that they modified (cut the front air filter supports off, etc.) the OEM air box to accept a longer/larger 'test' filter which flowed a lot more CFM's (capable of more HP) than the one they sell but the engine picked up 'ZERO' HP on their dyno because the engine could not use the extra flow capability. According to him the "rwhp" would have to be in excess of 700 HP before a larger filter may make 'any' difference.

If the engine can only consume X amount of air regardless and the 'stock' intake tubing size can support a lot more HP according to the people who know and without a tune how does the engine make more HP?

1) The stock air filter used on the LT4 may be a little more restrictive so additional air and fuel with a less restrictive filter that is being metered correctly in the OEM setup will produce more (safe) HP. I found that out when I first went to the higher flow 'Green' OEM replacement filter that Lingenfelter uses in their 720 HP package.

2) Due to the aftermarket units overall design and/or placement of the MAF sensor, etc. the ECM may not be reading all the air that is going in the motor causing the AFR to be leaner which would produce more HP with the 'same' amount of air. However the computer now sees a leaner condition from other sensors like the exhaust 02 sensors and starts to modify to bring the tune back in line. Well now we have an engine that is being metered (per all the sensors) within acceptable limits and due to some additional air being ingested from less restriction the car still is making more hp than stock BUT not as much as that very first pull or so on the dyno, If you check my AFE/BMS real world track test out (link in my post above) I think it may point in that direction.

3) Being I have both setups that I paid for and can use I don't believe I have a dog in this fight. My interest is increasing the car performance using what really works; that is why I try stuff and also remove stuff if it does not work. And I appreciate others like Terry of BMS that will report the 'real' results.

PS: Now if its a really cold day and/or the barometric pressure is up the 02 molecules are closer together which means more oxygen in a giver space and as long as knock (reduced timing) does not step in you are going to go quicker/faster. That is why the stock record was set in the Northeast (MD) in December!

3 Z06ZR1

That would be assuming everyone installs the Aftermarket intake on then dyno'd the car. What I saw was results 599-604 rwhp first pull on the dyno but this was after the intake had been installed for at least 3 months and driven 5,000 miles or more. Indicating a 40 rwhp over stock.
I also read the data driving around when I installed my first Halltech and it only was reading plus 3 on the long term fuel trims.
Then on the second observation a 35-30 rwhp from a second Halltech install on an A8 car. . The stock filter and intake combo restrict power vs using a Halltech intake
I no longer care about this old argument since I have one car tuned for the mods and the other is getting the mods soon the 2300 is already sitting here.
But just saying what I saw. the gains are retained and do not go away from an intake install.

trevor90

for those of you with HT, or AFE, post your dyno graph. I'm not buying "butt dyno"

3 Z06ZR1

I had the same result with the Halltech intake. 40 rwhp on M7. This post is right on! You add the 2300 and headers and you really have a *** kicker!

The T-man

anyone know good tuner in Norcal?

MP&RPZ06

AFE CAI, Borla- X-pipe (with no cats on x-pipe), and Katech Ported TB. Three run average was 609 RWHP and 615 RWTQ.
2000 miles on mods prior to dyno run.

http://www.youtube.com/watch?time_continue=2&v=ZLpx3EWVwB0

First run was the best 610 and 625 RWTQ.

thelastday

Trying to decide whether to do a PTB or CAI first on my Z06. What would you guys recommend?

saleen556

dar02081961

I see.
This theory is correct to a degree. And yes some of the gains could be learned away.
But the reduction of the original gains is relatively small.

Let’s agree;
1. Some of the gains from the filter/CAI change simply come from more available air flow (less restriction).

AND

2. Some of the gains come from the CAI leaning out the AFR.

Can we agree that any gain from #1 above should remain relatively constant regardless? This is based on the fact that if the PCM sees more air we know it adds the proper amount of fuel to keep the commanded AFR. Thus as long as the additional airflow provided by the filter/CAI is available and more fuel is added to maintain the AFR the result is more air and more fuel at the correct ratio and this must result in more power. Thus the power gained from the additional air is always available.

So that brings us to #2 above but we are forced to revisit the theory in order to keep things straight.

The theory says the gains will be learned away based on the percentage of positive LTFTs. It says that after a period the LTFTs that are learned in closed loop will compensate for the intentional lean condition the CAI manufacture tricked the PCM into at WOT. This lean condition occurs because the CAI maker doesn’t allow the MAF sensor to “read/see” all of the airflow and thus it under calculates (misses) some air and underestimates the correct amount of fuel to maintain the commanded AFR. Thus the resulting leaner AFR produces more power on top of what we gained in #1 above.

Very sound logic. But let’s look a little deeper.

The theory says the PCM adds the positive LTFT’s it has learned from closed loop into the WOT fuel calculation. This brings the AFR back to commanded and this is how open loop can “learn” without having a feedback loop. This open loop “learning” (applying the LTFT’s to WOT) should correct fueling and get rid of the “lean AFR” the CAI tricked the PCM into. Thus causing some folks to claim the gains from the extra airflow are “learned” away.

The key here is SOME of the gains may be learned away.

How much of the gain can be learned away? Let’s apply some logic.

Most folks that have added CAI’s have seen the LTFT’s go positive about 2-5% (more fuel).

Many of the dyno runs done immediately following CAI installations see the AFR go .2 or.3 leaner which is in line with the LTFT’s folks are seeing after putting some miles on the car.

For the sake of discussion let’s say the initial gain from the CAI is 40 horsepower.

Let’s worst case the positive LTFT’s at 5% and say the PCM added 5% fuel to WOT.
By default this means at most 5% of the WOT fuel calculation is affected by LTFT’s.
So at WOT, 5% fuel is all that can possibly be “learned away” or corrected for by “learned” LTFT’s.

This means that of the 40 horsepower gained from installing the CAI, at most 5% of that 40hp gain came from tricking the PCM into a lean condition.
5% of 40 horsepower is a staggering 2 horsepower. Therefore at most 2 horsepower is learned away over time.

To add another blow to this theory is the fact that not all of the LTFT percentage is brought over into the WOT calculation. There are many discussions about what amount of the LTFT is added to the WOT calculation. But many say only a percentage of the entire LTFT correction is added to WOT.

dar02081961

I vote CAI first, but you cant go wrong either way.

KillerC7zo6

dar02081961

If GM's intake had been available 3 years ago I probably would have purchased it.
It has several positives going for it even though it doesn't claim to add as much power as some of the others.
I have not seen a head to head comparison of the GM with another CAI.

So this is strictly my opinion without any data to back it up.
I think any of these CAI's made by reputable companies to include the GM CAI will all dyno within 5 hp of each other.
If this were ever proven to be true the GM would be the no brainer choice for obvious reasons. JMHO.

saleen556

The T-man

Use aFe = no code worries