176mph for an unrestricted 2004 GTO?

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 :no: 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?:confused:

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...

Originally posted by Jason E
Top speed has virtually nothing to do with top speed...

:lol:

i know what you meant but still...

Originally posted by Jason E
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...

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 ass 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? :(

Originally posted by Meccadeth
The top speed on an LS1 Z28 is 163 MPH? :(

That's actually the speed the limiter kicks in at for the SS/WS6.
I remember car and driver testing the convertible models and the SS pulled to 160, but the WS6 pulled right to the limiter (so the top speed was most likely higher).

I could see the GTO being 170. The lower gearing would actually help the engine pull a little harder and closer to redline (the f-bodies could not pull to redline in 6th gear stock). Plus it doesn't have any tack on scoops ;) to slow it down.

Chris

Gto can go 176.....
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If you drop it off a cliff. =) but seriously, who drives that fast anyway

Originally posted by Aeromaks
Gto can go 176.....
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If you drop it off a cliff. =) but seriously, who drives that fast anyway

Exceptional point.

After seeing what it actually takes to bury the speedometer on a public highway, I'd say noone!

It takes a couple of miles of clear, straight, smooth road. At that speed, a radar detector is completly useless (at 160 mph you are going a quarter mile every 5.5 seconds!), and having any cars on the road when you do this is completely assinine (some drivers can't pay attention to you passing at 50 mph, let alone 150+ mph)!!

I've only had my 97 Z over 140 twice since I've owned it, and both was done on a desserted Arizona interstate in broad daylight. I simply can't see trying anything like this on any public road under any other conditions.

I was in my friends 2000 WS6 and we hit the speed limiter...I think that his HyperTech said 166 was the limiter, but it could have been 163.

Honestly, who cares what the car's speed limit is, I said dropping ot off a cliff in a joke, guinm put it into perspective, I bet most people here would crap their pants at those speeds, at a track, sure, but where are you going to SAFELY take the car up to upwards of 150mph?!?!?!?!?! at night it is out of question, and better hope there is no one else on the road,

where do you take a car to go that fast? Why the salt flats!!

Wow, I didnt know the cD on the GTO? Wow, thats low. With scoops, its .4! (just guessing) but it will have ram air so that will add like 60-90hp......

I have seen many an fbody video, and I have seen many cars reach that speed on roads. And did anyone see that busa that hit over 220mph? He was pulling a wheelie till about 160... I would figure with balls that big, it would be hard to ride a bike?

that haybussa had messed up gears.

hell, then if we go by speedo, my speedo says that everyone on nj turnpike drives 100.

3.73 gears without recalibration box on 3.23 =)

Originally posted by blckbrd84
That's actually the speed the limiter kicks in at for the SS/WS6.
I remember car and driver testing the convertible models and the SS pulled to 160, but the WS6 pulled right to the limiter (so the top speed was most likely higher).

I could see the GTO being 170. The lower gearing would actually help the engine pull a little harder and closer to redline (the f-bodies could not pull to redline in 6th gear stock). Plus it doesn't have any tack on scoops ;) to slow it down.

Chris

I believe that top speed in F-bodies can only be achieved in 5th gear. When you upshift into 6th from redline at 5th, the car actually slows down.

Originally posted by Jason E
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...

Now, isn't rolling resistance affected by the weight? The greater the pressure exerted by the wheels, the greater the rolling resistance?

Originally posted by muckz
I believe that top speed in F-bodies can only be achieved in 5th gear. When you upshift into 6th from redline at 5th, the car actually slows down.

Yes, you're right. But same idea that the engine can't pull 6th gear enough b/c it's so low :).

Chris

isn't top speed for 04 gto unmodified 155mph.

i didnt know you posted on here too al.:cool:

Originally posted by muckz
Now, isn't rolling resistance affected by the weight? The greater the pressure exerted by the wheels, the greater the rolling resistance?



Thats one variable acting on another.

Keeping all else constant, weight doesnt factor in the equation.

Top speed is simply a cancellation of forces. Aerodynamic drag vs torque at the wheels. When they match, acceleration reaches zero. Same theory as terminal velocity, only gravitational force is the accelerating force.

Originally posted by ULTIMTEORANGESS
i didnt know you posted on here too al.:cool:

signed up for this board. I heard this is the most active 5th gen site anywhere outside of GMI and C&G. And everyone here (for the most part) is fbody minded. Its a different perspective then LS2's comments.

different........uh yea i guess.;)