I thinks it's Wyoming that has no speed limit during the day time. I'm just saying. Go west young man.

I removed my hood seal a few months ago. When it rains you can actually tell alot of air is coming out of the gap. I couldn't tell you if it's a good thing or not. I drive over 100 with no adverse affects. The reason I removed the seal is to lower the underhood temps and had heard it also would help to release air trapped under the car.

 

I know the C5 Z factory body, just lowered is good for 190 with 550rwhp!!

 

I have hit the 180mph mark with my lowered on stock bolts, coupe, a handful of times. 428rwhp. The whole world just seems to be a blurr.

 

For what i's worth My C5 with around 400 RWHP saw 174 MPH and seemed to suck down to the road at about 130 (at the time it had no air dam)

Aerodynamics at high speed are a lot like approaching the speed of light, a 10 percent increase in speed requires a 40 percent increase in power as you approach the speed of sound, and the same 10 percent increase in speed only take 10 percent more power at say 20 MPH, those aren't exact number just spit balling to illustrate the point.

I don't think it would take 600RWHP to do it, I think with 500 RWHP it can be done but it would just take a LOOOONNGGG time. I would have 700HP+ at the wheels, with some aero mods to make 200HP possible without needing sixteen miles.

It is a goal within reach, just like everything else you just need the time, money, and intestinal fortitude.

 

I look forward to those msgs, thnx! I have 3.42 gears right now and im trapping the quarter at 120mph. I just adjusted some shift points today, trying to get as much mph and power out of every gear.

 

Well, stock I hit 160 mph no problem. Car was solid and so was steering. I know a stock C5 A4 can hit 170+ so now witha 450rwhp LS6 I wonder....

BTW, I hit 160mph on a road in Mexico... yeah, Mexicooo.

 

I saw a top gear where they wanted to go 200 for less than 15k or something like that, and some ricer hatchback with a big turbo went 200, so a C5 really isn't that far out of the ball bark, I think more money would be spent in safety equipment them performance mods.

 

I'll throw in my 2 cents as a reference. I've driven the Silver State Challenge twice now. My max tech speed was 165mph and last May I drove it exactly 165 for over 40 of the 90 miles. I could have shifted into 5th and accelerated but my tech speed would not allow it. Like others have mentioned earlier to legally go faster means roll cage, fuel cell, etc. Here's the details of the event:
- 1998 C5 vert
- NA 492 rwhp @ 6,600 rpm; 6 speed; 3.73 gears; 92 octane fuel, tuned for sea level, so performance suffered at 6,500' elevation.
- lowered, coilovers, Z06 bars, air dams, MCM heat extractor hood
- car weighs 3,388 lbs (full tank, no driver) + myself and my navigator added 440 lbs for a total of 3,828 lbs
- stock Z06 size wheels with Michelin PS tires.
- canvas top up; windows down
- 6500' elevation in Ely, Nevada
- 102 degrees OAT
- 165 mph; 6th gear; 4,000 rpm
- handling was solid with no float at any time
- did a stupid thing and raised the windows during the last 10 miles of the 90 mile run and popped my rear window seal. Not sure, but think I should either run with top down or top up with windows down.
- car could have gone faster, but not sure how much.
- one last reference point - car will do 160 mph in exactly 1 mile at 6,500' elevation.
- also just for reference, my cruise control actually worked at 165 mph and my speedo was about 3 mph slow as compared to my GPS.

Hope this is useful information for some of you.
John

 

 

best I've had the ***** to do was 168 with the top down. No aerodynamic problems at all.

 

I rented a C6 from hertz last year and did 150 on I-95, i did have the top down but i couldnt hold it for longer than a few minutes.

 

165 mph + , ran out of room too quick. The car that was a mile or so in front of me when I started, hit the brakes when he saw me in the rear view so I shut it down and did not zoom past him. Car was solid and would have done 175 mph. Stock 04 (at the time) with A4 and 273 gear.

 

I sure hope a C5 can go over 200mph, I have spent way too much money for it not too(see red car in sig). In fact I am looking for 210+ we will not be able to see until next year. Due to a crummy job by the roll cage builder I am limited to only a 155mph average with a 172 top speed this weekend in Battle Mountian, NV for the Pony Express 130 Open Road Race.
Jeffy'

 

Jeff,

See you at Battle Mtn.

I am thinking 200 (next car) and need to pick your brain.

Thanks,

J.R.
#240

 

Hit 165 in my 400RWHP 03/z06 very stable,felt like my 91 caviler @ 50mph.Why do fact. C5 racecars have big rear spoilers yet no spoilers on even high HP drag cars,in fact the only place I've ever seen spoilers are on the fact. cars.Is the C5 structure that good? When do you need one?Does anybody who races the silver state challenge or other high speed event use one? What makes the C5 stick so effectivly at high speedW/out a spoiler? Many things I expected from my C5 and was not disappointed however I was surprised at its extreme stability at speed.Not a fan of spoilers as 99% of cars that have them don't need/can't use them, c5 are in that speed catagory that maybe can use any comments anybody?

 

I remember reading in an old Car and Driver mag that when Lingenfelter was testing their twin turbo at the 200+ mph mark, their biggest concern was the hood. The air pressure at that speed puts tremendous stress on the hood from underneath. They recommended getting a heat extracting hood. It's got to be one that's won't disturb the lines of the car though.

BTW, I've hit 183 mph, my windows popped in at 180 mph, scared the hell out of me. Not sure how fast my vette can actually go, it was still pulling, most likely somewhere near or below 190 mph.









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i hit 165 and wasnt pushing it all the way with the windows down, rolled em up and got up to 185, c5 frc with intake, exhaust, drag radials and big brakes, and if i had more room on the texas highway it felt like i could of done more. gotta love texas

 

The Goodyear F1 Gs D3's are a 200 mile an hour rated tire. I wouldn't try it with any thing else

 

I don't know about 200 mph but I can say from first hand experience that you will need to cool the transmission and differential if you run any of the open road racing events averaging more than 140 mph.

Also, consider your front tire clearance. The down force on Jeffyvette's C4 caused some tire rubbing on the front fender. (not the event where he blew the tire)

On the other hand here is a picture of me doing 150+. Stock wheels, tires and ride height. The car looks like it is riding with a little extra ground clearance.



Lots of variables and lots of fun sorting things out. You and the car should start by entering the Open Road Racing events at 125 average and work your way up from there.


good Luck

 

I think you're referring to the C5.R and C6.R "factory" race cars ???



That is a "wing" not a "spoiler" ....

The difference ?????

A spoiler is designed to disturb (spoil) the airflow over the rear of the car. Many cars have an airflow that over the rear tends to LIFT the rear of the car which leads to high speed instability. A spoiler will reduce/eliminate that. The C5, because of the "chopped" rear end (that big flat back of the car) generates almost no lift .... the design of the rear end is the car's own "spoiler".

A wing is designed to create downforce .... it is basically an airplane wing that flies upside down. Look at a Formula 1 race car ... it has wings at the front and back of the car. A Formula 1 car's wings can create so much downforce that if you drove one inside a large pipe (like a large culvert) at speeds of about (depending on angle of the wing) 80 mph and higher, you can drive the car up the sides of the pipe and actually drive the car totally upside down .... the wings generate more downforce than the car weighs.

The C6.R and C5.R rear devices are wings that generate downforce to assist the car in cornering.