Originally Posted by Katech_Jason

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

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

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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.


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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
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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.
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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.
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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...

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.


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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.



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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)


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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.

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

ANSWER: NO IT WON"T.

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

ANSWER: Yes somewhere around 300 mph

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Originally Posted by petermj

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

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

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

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

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

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

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

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

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

Originally Posted by LG Motorsports

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.



LG

Originally Posted by petermj

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...