GeritGoul

hey whats your top speed? ? or everyones for that matter

shoeys08dkcandygt

both of the s197 gt's ive owned have seen 130mph and the 07 saw the needle at 140mph a few times. both have had 3.55 gears in them.

Nuke

I've never been there but have heard that, stock, we top out around 145-147. Best I've done before chickening out was 125. Darned car is so smooth and solid that I really considered going higher but I decided against it. And I'm not sure what the factory default is on the speed limiter but if you have a tune it most likely has been turned off.

Thanks for the PM. I'll get the spreadsheets out later tonight.

shoeys08dkcandygt

+1 on being very smooth at speeds over 120mph and i dont think the factory puts a default on the gt's. i know the v6 is 108mph. i've never found a speed that the gt's cut the fuel off to the motor.

Riptide

I've had mine (3.55) up to 140. Once. It was smoother than I expected. But I don't intend to repeat that little escapade. Extremely dangerous. I had to shift up to 5th gear at about 135mph. Was at 6 grand on the tach. I'm sure top speed driving like that is actually probably harder on the engine than drag racing or street rodding around town from a stop. You're consistently holding the engine at or near top output for an extended period of time.

The general consensus around here, after having read these forums for a year or so now, is that if you have 3.55 it isn't worth it to go to 3.73. The change just won't be very noticeable vs. the cost of the install and parts. 4.10 on the other hand is a different story.

Nuke PM inbound. I'd like a copy of those spreadsheets please.

07musclemustang

yes there is really no gear other then geting into the mid or even high 4s that could affect your top speed. although with a higher gear you would actually see better top end performance aswell

Lifter583

Remember tire height plays a big part in ratios. Be sure to chose size wisely. I have the stock 17"(27" high)tires with 3.55s, blows out of the hole very well. Need to calculate your true ratio, with the tire height (Rev's) taken into account.

07musclemustang

very true tire high affects just as much as gear ratio all though going shorter tires could also loose unsprung rotational mass and dont forget loosing sidewall losses sidewall flex

mygt500

Im blown and have the stock 3.55 and love it but the mod bug will eventually get me to buy the 4.10's

jdmcbride

I was originally looking for a GT with the 3.31s so that I could switch out to 3.73s. But the only car that came optioned out the way I wanted it had the 3.55s.

I am happy with them overall. I can get 26 - 29 mpg on the highway if I keep it under 70 mph on the highway (using the cruise control) and the car pulls nicely in all gears at WOT!

Please note: I have done some performance mods that also increase efficiency over stock (UDPs, aluminum driveshaft, custom tune).