Today, our GM trainer told us that even though the GTO is limited at 155mph, without the electronics stopping it, it's top speed is 176mph. Reason given for the limiting was the rating for the tires.

I disagreed. The Vette coupe weighs in around 500-600lbs less and has a top speed of around 175. He said that the GTO had a slightly lower Cd than the Vette's 0.29, aiding the top speed figure.

The GTO is said to have the Z06's tranny and gears too, correct? This would also back my arguement since that box has lower/closer gearing, thus less top end.

Anybody have facts/expirience to back either case?

If this is true, I am very impressed.

 

Thats crazy...With your points and there is no way the GTO has less drag than a C5 If it does, it has a bigger frontal area anyway which nulls it.

 

There is no way the GTO has a lower drag coefficient then a C5.
The GTO weighs more.
And you right with the close gearing there is no way.

I bet it could possibly get into the 160’s but not 176.

 

Road and Track lists drag Co as 0.31 for GTO (pretty freaking good IMO)

Don't think that top speed is possible though, i say 160ish.

 

with open headers it could hit 170 if the cars a freak

 

Weight doesn't really impact top speed. Its effects are mainly on acceleration. So, the fact that the GTO weighs more doesn't mean much.... but I think pigs will fly when a "blocky" GTO in stock form will run 175+ MPH.

 

weight doesnt affect top speed?so youre saying vehcles with identical drivetrains but one weighs 500 lbs more will acheive the same top speed?

 

Top speed has virtually nothing to do with top speed...if a car is heavier it may take it longer to get to it, but thats about it...

What matters is rolling resistance, drag coefficient, horsepower and gearing...thats about it...

 

i know what you meant but still...

 

Yes, this is correct.

I am very surprised that the GTO has a drag coefficient of .31 because that is pretty damn good for a car like that. I think that is better than the Camaro and way better than the Mustang but still behind the Vette.

 

I've read serveral articles that quote the C6 @ .28 drag co. , but even with a low d/c if the airflow isn't controlled, it'll be next to impossible to control the car at those speeds...
Hp and gearing do play the bigger part in top speed, assuming you're not driving a P/U truck...(ie; flying brick..)

 

As others have already stated, weight has nothing to do with a vehicle's top speed other then the time it takes to reach it. If top speed is your only concern it's actually advantageous to use a heavy vehicle, inertia adds stability

I think many of you would be surprised how aerodynamic you can make a "block". Huge gains can be made to a brick just by rounding off the corners. What matters most is actually what happens at the rear of the car, not the front. Clean seperation is key (take note of the sharp edge and big *** of the C5's tail.... almost a Kamm effect). Aerodynamics are much more involved than what "looks" sleek.

Even so, with the gearing and frontal area I can't see a stock GTO hitting 176 mph without a nice tail wind

 

I know they've got a CSV Veloce (modded version of the Monaro) up to about 174mph, but it's got a 440hp motor ...

 

A devout GTO fan here.

GTO's top speed without the electronics stepping in is in the 165 to 170 mph range, not 176.

I think the trainer probally meant 166, but I can easily see it doing more since it has a superior exhaust to the 163 mph Camaro Z28 and (yes it's true) GTO has a slightly better drag coefficient as well.

 

The top speed on an LS1 Z28 is 163 MPH?