LG Motorsports

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"

LG

lemans

LG Motorsports

HEY,

WHat am I doing inside on a Saturday at 3:02 pm when I have a ZR1 sitting outside waiting for me.

See ya later.

I will check back later after they let me out of jail for doing 190 in a 60......Just kidding.

LG

petermj

I suggest you may want to read the books you recommend to me yourself before making these statement about the OEM air dam removal. 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. 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

LG Motorsports

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

petermj

hey, at least you cannot accuse me of just complaining and doing nothing about it. And I am fully aware of how voice of majority works...

CorvetteZ51Racer

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.

petermj

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...

LG Motorsports

good explanation John!!

petermj

not sure if you are referring to me but I never claimed that slowing down the air flow by creating turbulence results in decreasing of pressure. If this was referring to my input, I simply pointed out that this prevents pressure increase and thus not affecting the pressure differential between the air above and below the splitter. The thing to worry about is not to increase the pressure under the car but instead keeping it as close as possible to ambient air pressure. Very nice and informative response. I take it you must be a dentist?

LG Motorsports

Wow, Proprietary? then you must be an expert

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.

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


Here is your quote that you denied: LG

fperra

I've been following this thread since the beginning, and if you are not arrogant, you sure do come across as so. And everyone is eagerly awaiting your answer to LG's question as to what you do for a living.

petermj

Did you just call me arrogant a while ago? Did you read that explanation above? You may want to read it again... Again, I would not be cheering too much unless wing flaps stop working on all planes This explanation did not discredit anything I said. And of course there are restrictions on design in racing. Once in a while, someone has a great idea that nobody else can follow and the majority gets bitter Dumbing down is the way of life and this may include racing among other things.

petermj

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

You may want to read up here

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

petermj

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...

CorvetteZ51Racer

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.

petermj

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...

SlickBlackVette

Man you like to beat dead horses. 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.

petermj

brilliant

CorvetteZ51Racer

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.

And yes, go see if you can find on Wikipedia how much it costs to build a rolling road wind tunnel that's large enough for full size automobiles.

Keep in mind that OEM solutions are a HUGE compromise (except in the case of Bugatti, Ferrari, McLaren, etc where cubic dollars are paid for a set of keys) between functionality and COST. Automobile manufacturers that build on the "cost is no object" model are either bankrupt or sell very few cars. Racing teams, on the other hand, are on a "spend money to win" model (assuming the sponsors follow along). The goals and objectives are TOTALLY different.

And T&E is an AWFUL way to do R&D. My thesis work alone is proof of that. 90 different camshaft and intake profiles in a T&E methodology. best improvement over the original engine was 1.5 HP (test engine was a fully developed NASCAR plate motor). After running some serious statistical analysis and using some "cheap" $30k CFD modeling software, a single test showed a 5 HP improvement. THAT's why racing teams don't do T&E. They wouldn't have any time OR MONEY to build the car!

Have fun with your T&E.