I have used a few online top speed calculators. One using gear ratios, rpm, and tire sizes, and the other using CdA and horsepower. It looks like it could do 200 pretty easily. The car supposedly doesn't have a limiter so why won't it go 200?

Theoretical gearing top speed is about 217
Theoretical aerodynamic top speed is about 214

 

 

Aerodynamics. When they were testing the LS2 base coupe for the 2005 C6s, 186 MPH was all they could get until they folded in the mirrors and put duct tape over the fog lights. Then they hit 190.

 

So an extra 36 HP for the LS3 and a 5th gear OD should help a bit. I've seen 180 before running out of road going uphill in Mexico. I do have a mod or two.

 

Stock c6 is not going to hit 200 unless you drive it off a huge cliff.

Even the z06 has a top speed of 198...worse aerodynamics but a lot more power.

Zr1 can do it with 638 flywheel hp and a special short 6th gear.

It takes a long time to get there too. To get 200 mph in a standing mile you need around 800-900 rwhp.

Here I am taking it to my 6800 redline with 4.10 gears and 345 rear tires, about 185 at the Miami mile (I kept in it past the finish line).

While a stock c6 has the gears for it with the 3.42's, it doesn't have the power.

 

Purely and simply because a base c6 just doesnt have the power to hit 200mph.Its not that easy and not that many cars get to 200 mph.

 

I tried one time in my 08 auto and I quit at 175. I really don't know if it could have gone much faster. At the time the only thing I had was CAI.

 

Watch how fast I get to 130 mph, top of my 4th gear - it takes 11 seconds more or less...then look how long it pulls in 5th gear. When you are doing a top speed run it feels like forever as the air really starts pushing you back.

But note how smooth the car is on the runway...the windows didn't pop out of the top like my Mustang GT Vert did at 130+..the car was nearly rock steady at speed.

What a great car.

 

All kinds of wrong information and speculation in here.

1) All Corvettes have a speed limiter and a basic tune will not change it. Base C6= 186mph, Z06= 205mph and ZR1= not 100% positive but heard it's 205mph as well

2) Folding in the mirrors wont do anything except pop out as speeds increase. Joe and I witnessed this first hand in Miami a couple of years back.

3) As Joe suggested, aero is much better on base model but I would prefer the aero (i.e. downforce, etc) of the Z/ZR1 when shooting for 200mph. My car at 500rwhp and stock gear was knocking on 190mph in the standing mile. My new setup/power would easily run mid/high 190's but I don't think I'd go for it without some additional downforce to keep it stable. All was stable up to the limiter BUT thats what the car was designed around hence the limiter. Anything past that is uncharted territory and would be best not tested with assumptions.

 

^^^ My car was rock steady...perhaps because I have the Grand Sport aero.

That said, you know you are going that fast, believe me.

I think the limiter is due to tire speed ratings.

 

Mine was solid as a rock as well up to 186mph. After that is what I'm questioning.

Good point on tire ratings; that could be the reason but who knows.

 

I am pretty well 100% certain tire ratings drive speed limiters. Speed limiters seem to follow tire ratings...I've seen trucks with 112 limits, for their "S" rated tires.

Our cars have a second speed limiter if you run run flats, it's 80, not 55 as the DIC says.

Per the stock tune,
ZR1 limiter is 210
Z06 is 205

 

If you have a tire pressure error of any kind (real flat or system failure) the car will limit you to 55 mph in turns. Know this well since I have been victim of it several times and almost got booted in the rear by a BMW I had just passed in T4 at the Glen. Tire pressure sensor died and car immediately applied the front brakes, quickly slowing it from about 120 to 55. Luckily, the guy was an alert driver and side stepped me although it was close. We had a discussion in the garage at the end of the session. I know the speed limiter under these conditions is 55 because it drops to 55 on the HUD display and the speedo. When traveling in a straight line it allows you to go faster but I haven't determined if that is limited to 80 or not.

Bill

 

For sure, in my 05, it has only 2 speed limiters, 186 and 80.

The ZRI has a lot more speed limiters, check it out.

 

i had a V rating tire on my old truck

 

So you can only hit 22 MPH in your ZR1 when your four wheel drive is in low?

 

I've run as high as 80 (didn't attempt more) with a 0 pressure runflat tire in a straight line. The only other speed limiter I've encountered was 158, which is bypassed by turning off the traction control. According to the DIC messages I've seen, that also happens when the battery level falls below something around 10 volts. I've never attempted to test that warning for accuracy during an electrical failure.
'08 A6 F55 coupe for reference/comparison.

My '04 Silverado is speed limited to 97 mph.

 

My C6 makes 550 at the wheels, and I feel sure it would exceed 200 mph, except for one small thing.


the size of my *********!

 

The base c6 has a significantly lower coefficient of drag (.289 vs .34) than the Z but 70 to 100 less hp. In the end you have to keep adding more and more power the faster you want to go so IMO minimal power mods and maximum aero is the most logical approach. 460 to 470 hp and some drag reduction should get you to 200, but youre still going to have issues finding a place to do it. Makes germany that much more enticing to move to...

Aero mods:

for some free drag reduction you can start by removing the rear valence (it acts like a big parachute). You can also remove the engine vent covers on each of the front fenders to get better air flow out of the engine bay and get reduced lift (at 180mph the car feels like its floating so anything to reduce lift will be extremely beneficial if youre interested in driving at higher speeds).

If you have the base brake ducts you can swap to z06 which provide better cooling but should also cause less lift (GM started with the ducts the base cars currently come with, found they caused lift, then went to smaller 1" ducts but those didnt cool the brakes enough so they went back to the larger bore ones. Later the z06 ones were developed, which had a bore in between those two sizes and directed the air closer to the brakes).

If you close off the underside of the car with flat panels you can reduce lift and reduce the drag.

 

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