Looking at beefing up my c6 Z06 to run at the Texas Mile, which is a top speed event. I understand that the rear spoilers help hold the car down at speed. Does anyone know if the GM full length spoiler will adversely affect drag (slow the car down,etc)
Thanks!!!

 

The more down force generated the more drag. They talk about down force adjustments and implications during a Formula 1 race. I have never seen any figures on the area of the different spoilers and resulting forces generated. When these values are known the effect on the top end speed can be calculated.

 

Which spoiler are you looking at. Ive seen a few different ones:

ZR1
GM Full lenghty
Some Carbon Fiber more pronounces one but can't remember where?

 

Here's a thread for you to review:

http://forums.corvetteforum.com/c6-z...e-spoiler.html


Unfortunately, the OP did 2 mods at once, so the result from just adding the spoiler alone isn't known.

And.....he never reported the final results to us after he said he was going to remove the Beehive.

Jim Hall's stuff is really good, and I'm quite sure that his intake didn't cause any reduction in speed. I don't have his Beehive, but I do have his Killer Bee, and it adds a very nice power increase - I've had a couple other C6 Z06 guys ride with me on the track, and they say SOTP tells them my car pulls a lot harder than theirs.

I'm certain that the spoiler is what accounts for his loss of 4 mph.

Actually, I bet with the increase he probably got from the Beehive, the loss would probably be more like 6 or 8 mph if he just added the spoiler without the increase in power from the Beehive.

So....if you're looking for a little more downforce for cornering better at high speed - go with the spoiler. If you're looking for best top speed - the spoiler will just add more drag and lower your top speed.

JMHO, YMMV!!!

Bob

 

Sounds like, for the street and high speed straight runs, going to the low rise base C6 rear spoiler would be the answer.

 

I have the low rise base spoiler on my z06 now, but am concerned that, at speed, it wont be enough to hold the rear of the car down??
I know the z06 spoiler is higher. Would think the higher spoiler is needed?
Opinions?

 

Not an expert, but anything added or taken away will have an affect. Kind of like A = B + C. Now it becomes a "balancing act". As has all ready been mentioned, temperature, altitude, fuel, drag, etc. will DEFINITELY affect the results, a jugling act and every day will be different UNLESS you are in a CONTROLLED ENVIROMENT. GM has done a pretty good job on averaging it out as many have stated. You really have a "Corvette Tax" when you pay a lot of dollars for a few tenths of a second.

 

Your car does not need any kind of spoiler to hold its back end down at speed. In its bone stock configuration the C6 Z06 was designed, developed, and tested to have a manufacturer advertized top speed of 196 miles an hour. During the development of the car it is driven flat out for a full tank of gas at that speed. The notion that cars need downforce to "keep the back end down" comes from trying to make crappy old cars go speeds they were never designed for; any modern sportscar will reach top speed without generating much lift.

I've had my bone stock C6 at 203mph before; it was rock solid. No issues whatsoever at that speed.

And, yes, obviously, anything you add to your car will also add drag. You can increase downforce if you need it in order to negotiate high speed corners, but it will cost you in top speed. For a straight line top speed event keeping it stock is the way to go.

 

i think they look cool.

 

Never been to 203 in a C6 (), but mine's dead stable at 170, even diving into turns.

This shot of my car at 160 or so leads me to believe there's plenty of downforce. There's less rear fender gap than standing still, indicating that the rear spring is a bit compressed, i.e. downforce happening. A spoiler will add drag, and put additional heat in your tires- not a huge deal for a mile event, but if you're running fast for longer the heat is a real (and scary) issue.

The Camaro we used to run in the Unlimited class for open road racing had a small rear spoiler. With it removed, we had much more top end, around 5mph or so. This was at speeds around 212-216 or so. The car would make nearly 220 with the spoiler off.



Edit- here's a shot of us crossing the finish at Silver State Classic. We were trapped officially at 217 crossing the line. Front air dam basically on the ground, diffuser, just the small spoiler on. W/O the spoiler the rear was light at speed.




Aww man.......just posting these pics gets my blood going. We're leaving for the Bonneville 100 ORR on Thursday in Wendover. Taking the new (to me) C6 there to run it. Can't wait to see the needle pushing 170..........now look what you've done- gotta go get in the car and drive for a while. Thurs can't come fast enough.

 

with scottycards - I've only been up in the 17x's, but the car was rock solid and very planted with the OE Z06 spoiler.

If you're set up to view signatures, you can see mine doing 175 across the start finish line. Click on that picture to see a video, and you can see that it's very stable down the front stretch - even while putting in slight steering inputs at high speed.

I looked at your profile to see what mods you have, but nothing about your car was there.

What performance mods do you have, or is it stock???

I believe at the Miami Mile events the stock Z06 is getting around 170 something, but it was quite hot at those events earlier this year in April and last October.

So....you won't be turning, and unless you have mods that will be pushing you well up over 200, I think the stock spoiler will be fine.

Bob

 

If you were road racing the car I'd recommend it but since you are only doing a straightline event, you'll be fine.

 

for a top speed type of event you could even take the factory spoiler off if you are hunting that last couple of mph and exhausted other options. as long as you are only going in a straight line, you should be fine. combination of full throttle and the car's shape is sufficient to maintain traction.

make sure you apply brakes gently though, weight transfer to the front due to braking at high speed is when you will probably have the least stability in the back due to low(er) aero downforce there. i am assuming these types of events provide a long stretch for braking so you wouldn't have to stomp on the pedal like you would at the roadcourse at the end of a long straight...

I have a C5 and the only situation where the rear become unstable at speed (in a straight line) is when I have to brake hard from speeds over 140. I believe C6 shape is considered to be more advantageous for drag/downforce balance so I would be very suprised if aftermarket aero modifications were important for straight line/top speed runs.

 

Sounds like you know what you are talking about!!
just thought the spoilers were there for a reason!!
I put the base c6 spoiler on my c6 Z06. Are there any disadvantages vs the stock c6 z06 spoiler?

 

Just bought the z06, no mods.
i will be adding headers, exhaust,intake, ported tb, cam, and tune.
Thinking of milling the heads as well. I think i will be at 570 rwhp or so.
Maybe not enough for 200 in the mile. Think I will need 650 - 700 rwhp on my car for that?

 

Slightly less drag, MAYBE. I run a Z06 spoiler on my C6 because I think it looks cooler (yes, I know, major ricer argument ). Honestly when you consider how small either spoiler is, and how below the roof line it sits, that thing is just riding in the aerodynamic wake (turbulence) or your rear window; neither one is doing a whole lot.

 

I think you need close to 800 to the tires to break 200 in a standing mile. That's based on what I've seen from people who attended the event.

 

I can't drive the car fast enough to know, but it does look good!

 

570 rwhp is probably around 670 engine hp, so I think you'll be able to do maybe 190 mph.

Here's a video of a 705 engine hp Hennessy modded ZR1 doing almost 197 at the Texas Mile:

http://www.youtube.com/watch?v=DuU-yNQv7IY&feature=fvw


And - John Heinricy was driving and he's got a liiiitle bit of seat time in the ZR1 and CTS-V!!!

A bone stock ZR1 with the stock 638 hp did about 184 mph at the Miami mile in April, so you'll probably be somewhere between the bone stock ZR1 and the Hennessy modded one.

Have fun!!!!

Bob

 

Blev- this is going to sound crazy, but removing your outside rear view mirrors will get you 1-2, maybe 3 mph in a mile, I bet.

At those speeds, it's all about frontal area. Don't know if it's practical on a C6 (never considered removing mine), but if you really need an extra mph or two, it should help.

Good luck on your quest. It takes huge power, a good run, and the right conditions to pull a deuce in a mile. Last fall, at the Mojave Mile, only one car did it. RJ Gottleib's Big Red Camaro. That thing is a BEAST.