Originally Posted by Geared (Post 1576427668)

Just wondering the differences between the 2.

They look similar, but whats the actual difference, is one sleeker, one more beneficial, etc

I recently read that the LG requires no additional drilling or reinforcement....what about the APR product in this regard.

Difference in weigh? Carbon finish quality?

I have the opportunity to buy an APR locally at a good price....but need to know how it compares to the LG....as LG makes some interesting.

Thanks

jb

Originally Posted by petermj (Post 1576439114)

From looking at these two, if you do not have to drill, you lose four mounting points, two on each side where the ducts are;) If you get one that requires additional holes to be drilled, you will be lacking the metal mounting tabs that factory uses. In addition, the tray being integrated permanently, must make mounting lots of fun.:D

No additional reinforcement needed means that splitter does very little with regards to increasing downforce, the center tray does not provide enough structural reinforcement to the splitter to prevent flexing, should some real awesome downforce be generated (I am pretty sure it is not thanks to those invaluable and very useful brake ducts:rolleyes::D The fact the spoiler (as I saw being claimed somewhere here) can hold up to 200 mph is not necessarily a positive testimony to the actual effectiveness of a splitter.

Originally Posted by Geared (Post 1576427668)

Just wondering the differences between the 2.

They look similar, but whats the actual difference, is one sleeker, one more beneficial, etc

I recently read that the LG requires no additional drilling or reinforcement....what about the APR product in this regard.

Difference in weigh? Carbon finish quality?

I have the opportunity to buy an APR locally at a good price....but need to know how it compares to the LG....as LG makes some interesting.

Thanks

jb

Originally Posted by gotjuice? (Post 1576439739)

I agree with the first paragraph and strongly dissagree with the second paragraph. The LG is very strong/sturdy as the undertray is built into the front lip. The ZR1 unit will bend at speed because it does not have the undertray. I am sure Lou will chime in on the quality of his splitter. As for mounting, It is harder to mount with the undertray. I modified mine so as I can remove and install in about 5 minutes.

Originally Posted by Corvee (Post 1576439755)

I owned an APR unit and the LG piece seem to be very close in terms of manufacturing materials and design. Both do not appear to be full carbon fiber pieces. The brake duct of the LG unit is open at the top of the spilliter and a closed loop with the APR -this restricts the air flow to your front brakes.

It really depends on your application. Both will work well for street duty. If you are looking for a track dedicated piece, then consider the Katech unit with the full undertray (for downforce) and integrated brake ducts. Being a full carbon fiber piece it is also significantly lighter, but more expensive as well.

Originally Posted by petermj (Post 1576440902)

I see no harm in disagreements;)

From the structural integrity POV, APR is a better design, due to those extra mounting points that are missing from LG. If you increase the number of mounting points, the piece itself does not have to be very sturdy, as long as the bumper itself has some stability to it. From looking at APR spoiler, the way those screws over the duct mount, it is still just as much PIA as the LG design-neither one shows a lot of thought being put into service aspect of the part. Ironically enough, those ducts do very little to help brake cooling. They are there to decrease the downforce as a matter of fact-at expense of increased drag and decreased structural integrity. I am pretty sure the Z06 relies considerably more on relatively smooth area undrer the bumper than on that front splitter or the original lip. I would say what is available is 99% visual bling than actual function. This includes the side skirts. BTW, if you design the splitter correctly, you do not need an undertray, usually these two are mutually exclusive. And Z06 is already pretty smooth in this area. Katech is on to something because they do not use the original ZR1 frontal shape but between the price and the final product, I'd pass as well. Their undertray, uhm no, I gotta be polite here:crazy: Then again, I am sure they all have some true crushing explanations regarding what these things do.

Clarification about Katech splitter: the one I am referring to does not cost 2 grand, it costs 40 grand because it can be had only with their club sport 535hp monster package:rolleyes: The one available to the masses is not any different than the other two, except for those uber cooling ducts of course

Originally Posted by petermj (Post 1576441032)

if you are worried about the weave, just paint them both:crazy: Here is something you can do if you are worried about ducts being restricted: take some duct tape and tape them off completely and start waiting for your brakes to start glowing red or fading. You may be in for a long wait. Check out the Katech club sport splitter, it has no ducts and you can certainly make the ducting they offer for 400 bucks purely optional. The reason for holy design is there to do something else. This has more to do with the reason why the lip of the ZR1 splitter is so thin in the center area.

Originally Posted by Katech_Jason (Post 1576446318)

This needs some clarification. The splitter that you see on the silver ClubSport mule that was all over the internet and magazines was an MTI splitter because the Katech splitter had not been developed yet. You can purchase the MTI splitter if you wish. Future ClubSports will have Katech splitters. The MTI splitter does have brake ducts, they're just in the undertray and you can't see them. When we wind tunnel tested the Katech splitter we saw huge increases in downforce when we added the undertray.

http://www.google.com/url?source=img...9gbJjqAJi4T8YQ

Originally Posted by petermj (Post 1576446900)

Ah me bad, I forgot about MTI and their $2k take on vette splitter. When you say huge downforce increase, did you quantify this? Also, an increase is expected but... is it due to entire undertray or more like to the area close to the leading edge? I am also very curious about the shape of the lip and the raised area back of the leading edge of the splitter. I am still trying to understand how these brake ducts supposed to work due to the low pressure area under that tray... I am also curious about the way this thing mounts, the tray must come off somehow I am guessing? I am so curious because I am pretty much done with my take on the Z06 splitter and after mentioning my design idea that I implemented, I was told that at high speed, I would be facing a strong possibility of tearing the POS bumper off without mounting the splitter directly to the frame. If you have some numbers, I'd be willing to find out using a static load on the splitter mounted to the splitter (unless the number is close to the weight of the car itself)

Originally Posted by fperra (Post 1576449232)

Lou, I just installed your front splitter today. A couple of comments:

The holes on the bottom for screwing in the mounting bolts on the one I installed were only about 1/8" in diameter. Kind of hard to get a socket through there.:crazy:Obviously, I had to drill them out.

Also, I noticed from your picture that there are two screws on the backside of your under tray holding it down. On my splitter there are no holes for this. Can you give me some dimensions so that I can drill them in the right place?

Originally Posted by fperra (Post 1576449319)

No, no hardware came with it. Also, the CF side extensions came with no hardware. I think that only consists of 28 3/16th pop rivets, so that's no big deal.

Originally Posted by LG Motorsports (Post 1576449077)

Hi Guys,

Using general force numbers in % do not tell anything other than which end did what.

Originally Posted by Katech_Jason (Post 1576447099)

Yes, I can quantify that with our wind tunnel report.
http://www.katechengines.com/street_...a%20report.pdf


The splitter mounts to the front fascia using the production bolts. The front fascia reinforcement is recommended. With the reinforcement, the bolts go through the splitter, through the fascia, and into the reinforcement. The undertray bolts on to the splitter via the flange in the front, and two 90 degree brackets that mount to the radiator support.

Originally Posted by petermj (Post 1576451286)

agreed. I would like to see the actual NUMBERS that contributed to these percentages as well. Good for a sales brochure though.

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

Uhm, are you sure about this? Air dam/spoiler "spoils" the air flow and creates turbulence that results in slower air flow. Slower air flow is less pressure, thus, the opposite of lift me think?

ANSWER:

Totally sure about this one. Tested it. Consider that a C6 is a bottom breather. It uses the air dam to push air into the radiator opening from the HIGH PRESSURE in front of the air dam. ON a Z06, that opening is blocked off and the high pressure now pushes up on the block off, which causes lift. When I asked the chief GM aero guy about this and why they left the dam on the Z06, he said just to meed CAFE requirements by reducing drag under the car.

ALSO, you can see that the rear spoiler on the Z06 is just a minor change compared to the C6. that is because even with the better front fascia and lip the down force is mostly negated by the air dam pressure.


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

Are you sure about this one? Maybe the side skirts would be the ones creating lift reduction instead of that rear spoiler or at least a combo of both? The stock splitter will flex plus it was designed for very limited lift reduction. Thus, this is more of visual bling than actual improvement.

ANSWER:

the side skirts keep air from "rolling" off the side of the car and keep it from going under the car. But the lift from the air rolling under is very small but it is a part of the total equation. It is less effective as a front splitter because the air is attacking it on a huge angle and has less stack up of air.

The front splitter does exactly what the side skirts do but because the air piles up on top of the splitter even if it pushes the fascia down, is still a ledge that piles air on top and makes the most high pressure in a forward direction
---------------------------------------------


Uhm wait, doesn't the factory ZR1 set up use the reinforcement? Thus, when used as it was designed to be used on ZR1, this should not be an issue.

ANSWER:
The factory splitter, being weak from the design distorts the front fascia and pulls it down FROM the flex in the middle. The largest percentage of high pressure is on the sides that are strengthened by the turn toward the side of the car.
----------------------------------------------



This is a given since any opening in frontal area will increase drage. The question is, why do you retain the factory openings in the splitter then?;)

ANSWER:

Brakes. They matter.
--------------------------------------------

I seriously doubt this is the case because as a matter of fact, there is no downforce on top of the splitter or anything else;) And as a matter of fact, the factory air dam is way more effective in supplying the air flow to the brake ducts because physics says so...:D

ANSWER: You are kidding right? No high pressure which is down force on the front splitter????? And at the brake ducts, if 100% of the air could make it through the small brake openings then there would be no high pressure in front to cause high pressure. But all the air can NOT make it through the small opening and thus there IS high pressure even in front of the brake ducts.
Remember that it is called a "splitter" because it splits the air and keeps air on TOP of the splitter which creates down force.

The other way to add down force is to put venturi on the under tray in the area of the wheels and each side because it has an escape path as it expands and causes a LOW pressure. Venturi do not work in the center of the car unless there is a flat bottom with an escape path. ANd yes, we did try this in the GM wind tunnel.


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

This is not true because the dam will create lift reduction not increase, see the explanation above.

ANSWER: Wrong again but I don't want to keep offending you. As the air hits the air dam it makes PRESSURE. the vectors from that pressure push in all directions.
Up, down, and sideways. the Sideways direction reduces drag because it pushes the air off to the sides and keeps it from going under the car.
THe UP direction vectors push up and they push up against the block off panel on a Z06 which causes LIFT. The pressure in the down direction can not push against anything because it is open to the air and that produces no down force but does contribute to lift as the air flows under the car to a certain extent adding minor lift from the bottom of the car. The only direction that the pressure vectors can push on is UP against the block off panel on the Z06 or Zr1. So by removing the complete air dam from the bottom will add to the total down force minus the minor lift from the added air flow under the car.



--------------------------------------------
No, it will not offset anything. The only thing that will increase will be the drag but it will be put to good cause by reducing the lift. Removing that factory dam should be last thing that anyone should do on these cars.

ANSWER: I am apologizing in advance because you are totally wrong.
Keep in mind that the front ZR1 splitter also STOPS the air from flowing down from the high pressure that is plastered to the front of the Fascia. with out the splitter the air flows down and under the car causing more lift. with the front splitter installed, it reduces the air that can travel off the fascia that would normally flow under the car and SMASH into the under air dam. even on a stock Z06 just removing the air dam will add down force because of the reduction of the upward push from the air hitting it. Yes it produces less drag but it adds lift FOR SURE. (straight from the GM aero guy's mouth)


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


ZR1 comes with the reinforcement stock, thus no flexing ON A CAR. As a matter of fact, I was trying a few today and they do not flex, the side skirts flex though.

ANSWER:

See way above. They do flex at high speed. ANd yes, I have pushed down on a stock splitter vs our splitter and like I said, it is like pushing down on a flat piece of metal vs pushing down on a square tube.

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

Leave the whole thing, it will work better for sure.

ANSWER: NO IT WON"T.

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



chances are very good, depending on speed, you would bottom out the suspension first.

ANSWER: Yes somewhere around 300 mph

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

:D

Originally Posted by petermj (Post 1576451315)

this is a sales brochure with unitless comparative quantification. BTW, I did not see any place explaining how the baseline was established and under which set up the factory air dam was removed.;)

Originally Posted by Katech_Jason (Post 1576452781)

We won't post units for reasons made obvious in this thread. You seem to want to debate two ALMS/World Challenge/Grand-Am/Trans-Am teams for the sport of it. Both of which have over 30 years in the professional racing industry.

Originally Posted by SearayC5 (Post 1576453095)

Hey Lou,
Thanks for all the information you have supplied regarding your splitter. So your front splitter comes with all the neccesary hardware to install? Then the side splitters already have holes pre-drilled and we need to rivet them in or how do you recommend installing them? Do they come with instructions? Also will the front splitter fit with a front mounted intercooler for a supercharger? Finally with the skirts/front splitter/and the LG rear spoiler how much effect will these have on the vehicle around 190 MPH in a mile run? Will all of these be able to handle that force. I am just about to purchase the front and side splitter from you guys and want to be prepared for everything before install.

Again I truly appreciate the input from you guys.

Originally Posted by LG Motorsports (Post 1576451770)

ALSO, in grand AM Rolex series, the cars all have a 2 " splitter per the rules. The Corvettes were granted a 3 " splitter to add ONE inch to the front down force. That was the only thing we could change.

It needed a 2 degree increase in Rear wing to rebalance the car. I think that is pretty clear that extending the splitter adds down force.
We also had our first SUPER VEE race car from LOLA that was delivered with an adjustable front splitter to "ADD FRONT DOWN FORCE" in a bulletin from Lola. That would be Eric Broadly who designed the Lola and did the wind tunnel testing.

Yes, nothing wrong with a disagreement but I will compare credentials with anyone except Tom Froling the aero wind tunnel lead man on the Corvette Z06. He also was our engineer each time we went into the wind tunnel at GM. He is on the forum and maybe he will chime in. in fact, I will email him and have him critique this thread.

Thanks
Lou G

Texas mile video showing air dam at front of the car to NOT give it anywhere to PUSH up on the front end which is the opposite of the air dam under the car. The car was un drivable at 190 mph before the changes. It was all over the road.

also notice that we put the front air dam down to the ground and let it grind it self down to where it wanted to be at 210.3 our top speed. As we closed off the radiator opening it also went faster.
Think of Aero wind as you would if it was water. it is all fluid dynamics but easier to visualize what water would do.


http://www.streetfire.net/video/lg-m...mph_195518.htm <<<<<Video of Texas mile showing aero nose
Thanks again.

Originally Posted by SearayC5 (Post 1576453095)

Hey Lou,
Thanks for all the information you have supplied regarding your splitter. So your front splitter comes with all the neccesary hardware to install? Then the side splitters already have holes pre-drilled and we need to rivet them in or how do you recommend installing them? Do they come with instructions? Also will the front splitter fit with a front mounted intercooler for a supercharger? Finally with the skirts/front splitter/and the LG rear spoiler how much effect will these have on the vehicle around 190 MPH in a mile run? Will all of these be able to handle that force. I am just about to purchase the front and side splitter from you guys and want to be prepared for everything before install.

Again I truly appreciate the input from you guys.

Originally Posted by blkz (Post 1576453742)

Lou , this winter I want to take the next step in aero improvement . Presently have the MTI front splitter under tray brake ducts fans and rear spoiler . My plan was to go with your GT2 wing and an extractor hood but not do too much more with the front splitter because it is hard enough to load on a trailer as it is . What are your thoughts on car balance . What would you do differently . Thanks . Walt

Originally Posted by petermj (Post 1576453790)

I fully understand the importance of height of the splitter, the angle, profile and width issues;) This is exactly why the undertray bugs me, especially on the street or street/track cars. Seems to me that undertray fixes or at least tries to fix problems that it creates in the first place. What I find particularily puzzling is that the depth aspect of these undertrays. In other words, chances are very very good this undertray does not have to extend toward the rear of the car at all. Also, and again, from what I see and understand, the factory type design of the splitter may be intentionally limiting the "splitting" effect and unnecessarily increase the frontal drag. Assumming the splitter functions as a splitter should: separating the air flowing under and above the car and regulating the flow rates to affect the pressure diffferential. With the factory type ducting, the cure seems way worse than the disease itself. I am trying to learn and learning is never about just what you have but mainly about what you do not have and what does not work. Fluid dynamics allows the cat to be skinned in many way, some cheaper and simpler than others. Structural aspects of the design help as well.;)

Originally Posted by LG Motorsports (Post 1576453900)

If you use our ALMS adjustable wing with various gurney flaps you should be able to balance the car. if you want more front, just push the flat under tray forward and re mount it with an inch sticking out.

Or you can cut a venture in the tray and gain free down force with almost no extra drag.

if you need to do that, just give me a call

Thanks
Lou G

Originally Posted by LG Motorsports (Post 1576454006)

2" is not the height, it is how far forward the splitter sticks out in front of the original body work.

In ALMS we got a 100mm (4") front splitter. Going from 2" to 4 inches sticking out was worth 4 degrees that we had to add to the rear wing to match the down force.

What you don't understand is that by having a longer front splitter, the air that is split on top has a larger area for the force to push down on. That makes the down force.

on any Corvette that is mildly modified, you will always have enough power to overcome the drag except at terminal velocity.

ALSO, no race team worth their salt would post specific numbers from the wind tunnel on a "Forum" for the world to see. Sorry.

The ZR1 splitter was put on for an advantage in GT2 Lemans competition, not for the street. the street was for looks and the down force was just an added perk. they did not worry about the bottom for the street.

Extending the bottom back is essential to smooth out and reduce under body drag. there is a rule in every class Except ALMS, using under trays that limit the rearward flat bottom to the middle of the front axle center line. Alms has a complete flat bottom rule. EVERY surface on the car in a class with rules, has an effect. Every one.

if you want to learn, buy a book first. Please don't expect more info that we already gave you until LG Motorsports stops racing. Then I will post up anything I want.

flow speed is NOT the issue, it is the creation of low pressure areas which can be done by expanding the area for the same amount of air to enter, eg venturi in the under trays.

Aero is so complex that air usually does something other than predicted, That is why they have wind tunnels in every Formula one factory and every race team in the pro ranks has used them to find out what you are learning here for free. Wind tunnels cost about $15k-20k for an 8 hour shift. You better have your plan fully developed so you don't waste MONEY.

ANd thats my story and I am sticking to it!!

PS, still don't know what you do for a living

LG


See below and HAVE at it: We race with specific aero RULES, these cars do not



http://i762.photobucket.com/albums/x...icle_rado3.jpg


http://i762.photobucket.com/albums/x...icle_rado4.jpg

Originally Posted by LG Motorsports (Post 1576455402)

One more tidbit.

When the air dam on the Z06 is removed and you add rake to the chassis, and add the side skirts, you will add some down force by making the car into a slight venture. The air would expand at the rear as it exits which created a low pressure under the car because it flows into a larger space.

The problem is that the bottom of the car at the rear is very turbulent. SO in World challenge, we milled the rear of the rear aluminum crossmember and installed a flat plate and called it our "Fuel Cell Protection" and they let it stay.

:thumbs:

LG

Originally Posted by petermj (Post 1576455655)

Are you sure about it? Seems to me that the way the inner part of the fenders aka gravel machine guns are designed, the air would be directed from around that area, this is why the ZR1 side skirts are tapered at the front. I would think you want as little air flow as possible from front to the back of the car (that lift thing again;) ) and as slow as possible. If you remove that dam, you will increase the air flow and smoothe it out -totally counterproductive to what may benefit lift reduction. I do agree about messy rear but this is where correctly designed undertray below an upgraded rear diffuser should be considered. Seems to me you kinda go this way except your way does not integrate the rear design...

Originally Posted by lemans (Post 1576455978)

Hey Lou,

My car has the APR front splitter. If I remove the center section of the three piece lower air dam, will that decrease lift at all?

Thanks for your insight.:cheers:

Originally Posted by LG Motorsports (Post 1576456081)

Yes sir.

if you want to use the stock brake duct inlets, then leave the outer two side dams to help pressurize the brake cooling inlet.
Plus the side portion of the dam just lets air run into the suspension so it is not as important.

Plus just for your own joy, take it to the track and really try to feel what your car is doing. THEN remove the air dam from under the car and see of the car gets looser (or if the front sticks better)
Then report back. :)

Oh yeah, "I am sure about this" :yesnod:

LG

Originally Posted by LG Motorsports (Post 1576455674)

In summary: If you can keep all the air out of the underside of the car like a Nascar then the bottom is of no importance. but if you have any air flow at all, and by removing the air dam you gain down force, reduce lift and the air under the car will increase but not enough to negate the need to remove the under body air dam.
That said, as long as the air is traveling under the car, then MAKE GOOD USE OF IT!

I suggest that YOU go to a wind tunnel, test all your misconceptions and report back.


Bottom line:
Do what you want.
AND tell us what you do for a living.

LG

Originally Posted by petermj (Post 1576456752)

I suggest you may want to read the books you recommend to me yourself before making these statement about the OEM air dam removal. :thumbs: These are not misconceptions at all, these are expected results of law of physics and fluid dynamics specifically being valid. Back in the 1930, the old Autounion, currently Audi racing teams learned about this part the hard way;) Now, what difference does it make what I do for living to present my points here? I am not a dentist BTW and do have a bit of fluid dynamics awareness and structural engineering among other things.

I actually tried to be a good sheep and follow the rest, slapping the "ZR1 style" ground effects on the car, got this stuff and almost had a heart attack after realizing how clueless and structurally flawed these things were. So I started changing things myself since I honestly cannot buy into this sales pitch that really dominates the market, not to mention the counterproductivity of majority of stuff available out there. The old saying about doing stuff yourself to get it right, certainly applies here.:thumbs: Just to give you an idea and this is far from finished. I do not really want to show anything else since you and others seem to have a good thing going while I enjoy the resin fumes in my garage. But today is pretty frigging cold so I stopped by for a while here:D

http://i686.photobucket.com/albums/v...DSCI0029-1.jpg

Originally Posted by LG Motorsports (Post 1576456816)

Have at it, because of course we have it all wrong.

Tomorrow when I wake up, life will be the same for me regardless of what YOU do.

LG

Originally Posted by LG Motorsports (Post 1576456816)

Have at it, because of course we have it all wrong.

Now explain what you are going to do at the rear of the splitter in front of the tires. And also tell us why and I will critique your explanation and give you my opinion.

BUT, with all due respect, you are pretty arrogant for just having "thought" about front splitters and claiming expertise. You have never been in a wind tunnel but claim to know what aero changes actually do because of why??

I stopped posting on the forum for a while because I hate arguing with arm chair Experts who know everything but have experience nothing.

Tomorrow when I wake up, life will be the same for me regardless of what YOU do.

LG

Originally Posted by CorvetteZ51Racer (Post 1576457029)

The one thing you seem to be missing is that slowing down the airflow does NOT decrease pressure....at least that's not the whole story. Air has a certain Total Pressure. That pressure is made up of two components. Static pressure and velocity pressure. When the airflow hits the front of the car, whether the nose, the airdam, the splitter, the mosquitoes stuck to the nose of the car, whatever, it creates drag that is a function of the velocity pressure exerted on the normal area of the front of the obstruction. This is drag. When the air slows down due to the obstruction, it's velocity decreases, decreasing it's velocity pressure, but INCREASING it's static pressure. The static pressure that is generated due to the air stagnating over the top of the splitter is what creates the downforce. The length of the splitter doesn't materially impact the static pressure generated, but it DOES offer MORE AREA for the pressure to act upon, thereby increasing the downforce.

How does a wing work? Bernoulli effect which, when combined with the principles of total pressure, velocity pressure, and static pressure, mean that the air that flows under the wing moves slower (ie higher static pressure) than the air flowing over the top of the wing (ie lower static pressure). The Differential STATIC pressure creates lift on the wing surface. The greater the velocity differential top to bottom on the wing, the greater the static pressure differential, and therefore the greater the lift.

Ever looked at a car from the side and a wing from the side? They seem to have a similar silouette. Therefore, cars naturally have lift. This is exacerbated by the fact that the air that flows under the car hits suspension pieces, exhaust, firewalls, etc and slows down MORE, increasing the differential static pressure. This INCREASES lift. That's why NASCAR and EVERY race car out there wants to either eliminate airflow under the car, or make the bottom of the car as flat and smooth as possible (take a look at the underside of ANY prototype race car - I have, on the Daytona Prototypes I used to design and build engines for). That keeps the undercar velocity UP, reducing the differential velocity betwen under and above the car, and thereby reducing lift.

The reason splitters work, carefully designed bodywork angles work, etc to create downforce is that as the velocity of the airflow increases, the angle between the surface of incident and the airflow path must be smaller in order to eliminate laminar separation of the air flow. If the angle is small enough, the air stream stays "adhered" to the surface of the car and the velocity pressure exerts a force on the surface of the car to produce downforce without substantial reduction in velocity which creates drag. Once the airstream becomes separated from the surfaces of the car, it's not coming back, it's creating drag, and any aero components behind it are useless.

Oh, and what I do for a living? I have two degrees in engineering, hold a professional engineering license in mechanical engineering, and worked as an R&D engineer and track support engineer for Roush and Yates Racing Engines in the Daytona Prototype program. And if I hadn't had to buy new track wheels, I would've bought Lou's complete aero package for my Z. Because it works. Period. I've ridden in cars at the track at 160 MPH back to back with my own, and the difference is OBVIOUS. Oh, I also do computational fluid dynamics modeling for work, and did a master's thesis on CFD of two phase compressible fluid flow in the intake tract of a NASCAR restrictor plate motor.

Originally Posted by CorvetteZ51Racer (Post 1576457029)

The one thing you seem to be missing is that slowing down the airflow does NOT decrease pressure....at least that's not the whole story. Air has a certain Total Pressure. That pressure is made up of two components. Static pressure and velocity pressure. When the airflow hits the front of the car, whether the nose, the airdam, the splitter, the mosquitoes stuck to the nose of the car, whatever, it creates drag that is a function of the velocity pressure exerted on the normal area of the front of the obstruction. This is drag. When the air slows down due to the obstruction, it's velocity decreases, decreasing it's velocity pressure, but INCREASING it's static pressure. The static pressure that is generated due to the air stagnating over the top of the splitter is what creates the downforce. The length of the splitter doesn't materially impact the static pressure generated, but it DOES offer MORE AREA for the pressure to act upon, thereby increasing the downforce.

How does a wing work? Bernoulli effect which, when combined with the principles of total pressure, velocity pressure, and static pressure, mean that the air that flows under the wing moves slower (ie higher static pressure) than the air flowing over the top of the wing (ie lower static pressure). The Differential STATIC pressure creates lift on the wing surface. The greater the velocity differential top to bottom on the wing, the greater the static pressure differential, and therefore the greater the lift.

Ever looked at a car from the side and a wing from the side? They seem to have a similar silouette. Therefore, cars naturally have lift. This is exacerbated by the fact that the air that flows under the car hits suspension pieces, exhaust, firewalls, etc and slows down MORE, increasing the differential static pressure. This INCREASES lift. That's why NASCAR and EVERY race car out there wants to either eliminate airflow under the car, or make the bottom of the car as flat and smooth as possible (take a look at the underside of ANY prototype race car - I have, on the Daytona Prototypes I used to design and build engines for). That keeps the undercar velocity UP, reducing the differential velocity betwen under and above the car, and thereby reducing lift.

The reason splitters work, carefully designed bodywork angles work, etc to create downforce is that as the velocity of the airflow increases, the angle between the surface of incident and the airflow path must be smaller in order to eliminate laminar separation of the air flow. If the angle is small enough, the air stream stays "adhered" to the surface of the car and the velocity pressure exerts a force on the surface of the car to produce downforce without substantial reduction in velocity which creates drag. Once the airstream becomes separated from the surfaces of the car, it's not coming back, it's creating drag, and any aero components behind it are useless.

Oh, and what I do for a living? I have two degrees in engineering, hold a professional engineering license in mechanical engineering, and worked as an R&D engineer and track support engineer for Roush and Yates Racing Engines in the Daytona Prototype program. And if I hadn't had to buy new track wheels, I would've bought Lou's complete aero package for my Z. Because it works. Period. I've ridden in cars at the track at 160 MPH back to back with my own, and the difference is OBVIOUS. Oh, I also do computational fluid dynamics modeling for work, and did a master's thesis on CFD of two phase compressible fluid flow in the intake tract of a NASCAR restrictor plate motor.

Originally Posted by petermj (Post 1576457071)

Uhm, why do you call me arrogant? And where did I claim any expertise? It does not take an expert to observe and point out some basic flaws. Seems to me like you had me penned wrong, not an airmchair expert of any kind, just trying to apply some basic stuff and questioning what goes directly against it (and I am covered most of the time in FG and filler dust). Also, I am not stuck on the splitter, this is about the entire car as a matter of fact. You should give me at least some credit for not just moaning but doing something about it. I wish I could discuss certain design aspects and solutions but these are things that are more or less proprietary, especially considering I do not sell anything nor I ever plan to do so. The guy from Katech refused to disclose his actual test results and you expect me to present you with design solutions, LOL...

Originally Posted by petermj (Post 1576457071)

Uhm, why do you call me arrogant?

Originally Posted by LG Motorsports (Post 1576457174)

Wow, Proprietary? then you must be an expert :lol:

It appears that you are a good body man with very little knowledge of how air really works. I am sure that everything that you come up with has NEVER been thought of on this planet. Your magic front splitter is about as common as they come.

Most real Corvette race cars deal with a set of rules. Ride height, splitter length, Flatness of the splitter and under tray, How far back they can go etc. Trans am cars were allowed only a 3/4 inch rise at the back of the under tray. Why do you think that was a rule?

So it would be better to keep it to your innovations to yourself.

That way you won't confuse all the real racers and engineers who might read it. :crazy:

Favorite quote: "Some people know so much....That isn't so"


Here is your quote that you denied:

LG

Originally Posted by LG Motorsports (Post 1576457174)

Here is your quote that you denied:

LG

Originally Posted by LG Motorsports (Post 1576457174)

Wow, Proprietary? LG

Originally Posted by petermj (Post 1576457682)

the explanation above called it static, I called it AMBIENT. I suggest you read that explanation over and over until you really get it.

And there is a very reason why my splitter design actually incorporates and reinforces the effect of the OEM dam. Beats using that tray:thumbs:

You may want to read up here

http://en.wikipedia.org/wiki/Spoiler_(automotive)

Originally Posted by CorvetteZ51Racer (Post 1576457909)

The reason I called it static and not ambient is because they are different. If the wind is blowing, the ambient pressure is not the static pressure of the surrounding space, it is the total pressure.

Oh, and before you go arguing with racing engineers and experts who have one numerous championships, prestigious races, etc, and are used to using multimillion dollar labs to solve design problems instead of Wikipedia, you may want to reseach Wikipedia enough to know that the information submitted there is not vetted by any experts in the respective field, but is actually a compilation of responses from the general public. Just like the general public thinks that torque gets you off the line and horsepower gets you top speed (oh God, did I just open ANOTHER can of worms?????) the general public has no understanding of fluid dynamics.

Lou and Jason and their companies spend $20k for an 8 hour session in a wind tunnel to try to tell them things that they would otherwise have to get from either trial and error (and LOTs of it) or pay for a $20k workstation, a $100k piece of CFD software, and hire a $200k a year computational fluid dynamicist to do the work.

Originally Posted by petermj (Post 1576457779)

Here is the thing, most of my design is on the bottom part of the splitter, I designed it from the bottom up, after realizing that tray should be avoided at all costs. Please do not be so harsh, I spent a lot of time on this part alone. I like to think a lot before pouring resin. I had to deal with rigidity and ease of installation issues as well. Somehow I do not think there are too many people around knocking out splitters and aero kits in their garages...

Originally Posted by SlickBlackVette (Post 1576458160)

Man you like to beat dead horses.:willy::willy::willy: Make your toy, shut the hell up, and leave the real design work and racing to the experts.

As for what he does for a living....my vote goes to pissing people off arguing about things he only knows enough about to be dangerous. Around here we call those folks liberals or tools.

Originally Posted by petermj (Post 1576458045)

In colloquial terms, the wiki explanation seems pretty good to me, unless you feel an urge to point out any inaccurate info it may contain. The NASA study was not available at this time. T&E seems like a pretty good approach to me, assumming the baseline is reasonable. LOL at multimillion dollar labs coming up with these designs, sorry could not help a chuckle. Although makes you kinda wonder why they even bother considering that GM allegedly spent big bucks and yet they insist on improving on this perfection. I hope I am not getting busted soon for doing this stuff in my garage without a healthy R&D budget. I bet you could tell right away which design commanded a healthy budget too...

Originally Posted by CorvetteZ51Racer (Post 1576458222)

Ok, then let's get specific. The sheer comment that a spoiler (which has nothing to do with a splitter...) on the rear of the car delays air separation from the boundary layer on the rear of the car is pure bull. A spoiler put on the back of a car to increase rear end stability at speed is put there because separation has ALREADY OCCURRED and the spoiler height is set such that it is in the airstream that has separated and tries to redirect some of the energy back to the car through the struts connecting the spoiler to the car.

Originally Posted by petermj (Post 1576458485)

if you are shooting randomly in the dark, T&E sucks, however, starting from a valid point with sound approach, T&E becomes progressive improvement and verification. In the case of aerodynamics, you can establish a pretty decent starting point period, assumming you are using a sound concept to begin with instead of trying to improve a turd.

Originally Posted by petermj (Post 1576458485)

And BTW, if you use MODIFIED Bernoulli's Equation, you may be able to understand why even though the air slows down behind the air dam, the pressure drops as well. This is a counterintuitive thing but this is exactly what takes place... Yes there is a drop in STATIC pressure behind the dam. Long live the front undertray.

Originally Posted by petermj (Post 1576458045)

In colloquial terms, the wiki explanation seems pretty good to me, unless you feel an urge to point out any inaccurate info it may contain. The NASA study was not available at this time. T&E seems like a pretty good approach to me, assumming the baseline is reasonable. LOL at multimillion dollar labs coming up with these designs, sorry could not help a chuckle. Although makes you kinda wonder why they even bother considering that GM allegedly spent big bucks and yet they insist on improving on this perfection. I hope I am not getting busted soon for doing this stuff in my garage without a healthy R&D budget. I bet you could tell right away which design commanded a healthy budget too...

Originally Posted by CorvetteZ51Racer (Post 1576459097)

T&E is ALWAYS progressive improvement and verification, whether you start with a good foundation or not. The point is that by the time you reach the same end result, T&E has taken considerably more money and time to get there. T&E has it's place. Fluid dynamics is not one of them, and neither is engine development (which is merely complex FD).

Originally Posted by Z06Gates (Post 1576459549)

Dude give it up! The more you post, the dumber you sound!

Originally Posted by CorvetteZ51Racer (Post 1576459097)

BTW, I laugh at your comment about multiple vendors "knocking out the same stuff" being "uninspiring". Ever think that the reason they do is because it works? The reason, also, why they don't throw the OEM design away and start over rather than modify it to be the way you want it is because no one would pay for it. If the solution is effective, not perfect, and marketable, it's a better business decision for the vendor AND the consumer than something that is effective, perfect and NOT marketable due to excessive cost.

Originally Posted by songman3 (Post 1576461055)

I just wanted to say many thanks to Lou for his in depth contribution to this thread - I've learned a great deal from his posts.

I'm sure there will have been 101 other things he could have better been doing, rather than taking time out to post here - so big respect to a guy who has 'been there and done it' - and really knows what he is talking about!:thumbs:

I for my part have the highest regard for professionals like LG and Katech whom I know, leave no stone unturned in their pursuit of Corvette excellence, expending considerable resources as they do in the development of 'cutting edge' products that keep my favorite car right where it should be - out in front of the pack.:flag:

Thanks too, to Corvette Z51 Racer for his well informed contributions here too - all in all, a very interesting read.

I was interested in LG's set up for the Mile Run car - without wishing him to divulge any 'dark secrets', I wondered if Lou might have any general tips with regard to getting the best aero configuration and setup for the Z06 in a straight line maximum speed attempt.

Many thanks:)

Originally Posted by LG Motorsports (Post 1576462182)

Ok, Top speed, Mile runs. Start with a "domino's Pizza" sign on the roof!:lol:

JUST KIDDING, :yesnod:

Originally Posted by LG Motorsports (Post 1576471973)

We thought that part was a secret! :D

Originally Posted by CTYANK2 (Post 1576480653)

Hi Lou - I have a question, but first thanks for sharing your knowledge and experience here. What are your thoughts on just installing side skirts on my 06Z without the front splitter - what can I expect at high speeds? Pro & Con. Many guys seem to damage/replace splitters often (and I probably will too) I'm wondering what is to be gained with just the side skirts. Thanks! :thumbs:

Originally Posted by ZenOhSix (Post 1576481268)

Lou,

I appreciate your involvement in this thread. As much as I also read into petermj's percieved goating, it also shows that you have used various R&D to develop a product. To which, I believe I will be placing an order this week on an LG splitter and side skirts. I do have one thing that has me some-what on the fence:

http://www.aprperformance.com/images...MG_6109_cr.jpg

From the pictures of the LG components, I do not see this verticle piece as with the APR kit? In the gray Z06 you have on the website, it seems like you have something here - but the shadow makes it very hard to see.

Thoughts / Comments?

Thanks,
Mike

Originally Posted by the_teapot (Post 1576481457)

I've been following this thread and have found it to both be informative as well as entertaining. Despite being but a simpleton, I have an uncontrollable need to post my insight into fluid dynamics and front splitter designs. After considering the various manufacturers, materials, finishes, installation procedures, hottest spring fashion trends, whether time really bends due to the gravity of a black hole... I found the need to pursue the answer to my dilemma through the study of fluid dynamics. Inasmuch, I sought guidance in the requisite knowledge which resides safe inside my repository of greatness. I embraced the trek into my garage and opened the repository of greatness (the garage refrigerator) from which I retrieved a container of deliciousness (a beer) and through consumption achieved enlightenment.

Perhaps my decision process is flawed since I don't dabble in engineering academics or stand in front of a fan or fly airplanes. Regardless, I figure I'll go with the carbon fiber LG Splitter to replace my fiberglass splitter once I find a deal on a used one. From what I gather it's a solid design, doesn't require fascia reinforcement, unrestricted duct airflow, fairly simple installation, and is backed by years of race experience.

I'm gonna go study some more fluid dynamics stuff by drinking another beer. :cheers:

Originally Posted by LG Motorsports (Post 1576481569)

:yesnod::lol:
GOOD ONE ! :thumbs:

LG

Originally Posted by songman3 (Post 1576461055)

I just wanted to say many thanks to Lou for his in depth contribution to this thread - I've learned a great deal from his posts.

I'm sure there will have been 101 other things he could have better been doing, rather than taking time out to post here - so big respect to a guy who has 'been there and done it' - and really knows what he is talking about!:thumbs:

I for my part have the highest regard for professionals like LG and Katech whom I know, leave no stone unturned in their pursuit of Corvette excellence, expending considerable resources as they do in the development of 'cutting edge' products that keep my favorite car right where it should be - out in front of the pack.:flag:

Thanks too, to Corvette Z51 Racer for his well informed contributions here too - all in all, a very interesting read.

I was interested in LG's set up for the Mile Run car - without wishing him to divulge any 'dark secrets', I wondered if Lou might have any general tips with regard to getting the best aero configuration and setup for the Z06 in a straight line maximum speed attempt.

Many thanks:)