bobmoore2

I installed this on the car just because I like how it looks. It is the GM part that is used on the ZHZ Hertz rental Corvettes. That was before the car's first track day, so I have no 'before spoiler' data.

It is about the same size as the Z06 spoiler, but doesn't have the notch-out in the middle.

Do you think this spoiler generates any significant downforce? I'm thinking it doesn't, because it is just too small. It may improve the aerodynamic drag slightly by re-attaching the air flow coming off the rear window. Or it may just add drag.

Does anyone have any before-and-after experience with this spoiler?
Or does anyone have (or know where I could find) any actual scientific data on this spoiler? I google searched for about an hour, but found nothing.
I would also appreciate educated opinions about this spoiler from some folks who have used other spoilers.

Here are some photos:

wallyman424

probably minutely, but nothing you'll be able to measure or feel while driving

bobmoore2

Thanks. That's what I thought.


More opinions from other folks, please.

davidfarmer

I have a homemade spoiler of similar dimensions, probably a bit taller, and I feel it did help some. My test corner was coming out of turn 2 at VIR. I feel I'm able to be on full throttle a bit sooner with the spoiler, and in a Vette that's my top priority.

It wont let you go flat out through the uphill S's, but it will add some grip in the back!

VGLNTE1

Similar to katechs...wish this was made for the c5 instead of useless glue on crap to mimic a c6

gkmccready

http://www.acproducts.us/corvetteracebod.htm

ACP makes a spoiler that looks pretty similar and deems it "wind tunnel tested!"

John Shiels

not much in my opinion as the shape is not even molded into the car it has a thick lip / edge laying on the body which will make huge drag for what it is.

Webz

Looks similar to what is on GT C6R. Probably not there for the looks.

Joe_Knesek

I agree with you John. The leading edge looks like it would produce a lot of drag diminishing any benefit of downforce.

Short-Throw

I thought you drove 'flat out?'

AU N EGL

the small 1" spoiler at 45* works well enough. put a 4" rear spoiler and it will kill straight line speed, but lots of corner down force

John Shiels

When companies tweak windshield trim and door handles for mileage I can only imagine what that bid lip does.

Joe_Knesek

Whoever built this spoiler compromised function for a simpler mold. The areas highlighted below cause airflow detachment resulting in lift.

throwit

I always wondered why the C6R ran both the spoiler AND the wing??? I think the C5R did it as well, except the spoiler was built into the rear fascia.

Seems like the spoiler would slow the air beneath the wing...which is a BAD thing right?

Anyone know???

Joe_Knesek

Bernoulli's principle suggests that an increase in compressible flow decreases pressure (downforce) and a decrease in compressible flow increases pressure.

http://www.reference.com/browse/bernoulli's%20principle

throwit

Honestly, thats a bit much for me to fully comprehend.

Ultimately does that mean adding a spoiler in addition to a wing is a good thing??

Joe_Knesek

In this case, yes.

SIK02SS

a good body shop can mold the leading edge to be flush and make it look like 1 piece molded on the car (like it came that way)

for reference:

factory Camaro SS with center mount exhaust:



Mine, same valance only molded:

John Shiels

They can mold it in and it still isn't going to do very much at all. It would look better but cost a ton! To small and wrong angle for anything except looking nice.

bobmoore2

Like I said in my OP, I bought it for the way it looks, not because it will "really plant the rear end" like an expensive racing spoiler. So I don't expect much downforce from it.

I'm wondering though, whether it might generate some downforce (say, 25 to 75 pounds at 60 or 80 mph.) That's not enough to greatly improve lap times, but it might be enough to have a small effect on the handling feel.

Part of the reason I'm asking is that I have noticed that my C6 Z51 handles differently than my C5 Z51 did. Not just much better, but the understeer/oversteer balance is very different also. My C6 Z51 on similar size tires (285 front & 305 rear) wants to understeer A LOT MORE, than my C5 did. Since I had put on the spoiler before my first C6 track day, I'm wondering if that added variable is having a significant effect after all. (Next time I won't make two changes at once.)

My C5 seemed almost perfectly balanced with smaller tires in front. My C6 with this spoiler seems to need equal width tires front to back to get a good front rear balanced feel. I'm wondering whether other people have experienced the same balance feel difference when moving from a C5 Z51 to a C6 Z51, or whether my spoiler might be giving me a unique difference in my case. I haven't seen anyone else on the CF talking about this handling feel difference being as pronounced as it was in my case.