jorj7

I switched my 2.54 to a 2.20 so I'd be able to hit 200 mph at ~5,750 rpm instead of 6,430 rpm
(also with a tire change). But I wouldn't do it with just 400 rwhp, I waited until I got over 500...

Andre Hedrick

If you really want a 2.2 and you have a GT w/ LSD and NO PSD, we could work out a deal!

John Veninger

On what track?!

Vlocity

The only reason I would consider changing my 2.72 LSD to a 2.2 would be if I was out of gear on the road courses I go to... and with the 3-4 tracks that I run on a regular basis the 2.72 is well suited. I have only one corner that I can think of at Putnam Park where I have to just feather the throttle (no time to shift up and shift back down) so for me the answer is no.....I am right in the meat of the power band and it helps to have the little shorter gearing to throttle steer the car.

If this was a daily driver then the answer might be different.

Regards,

Ken

Jim R.

Unless I was trying to break 200 mph, no way would I switch. 2.7x or 2.20, either way the wheels are going to spin above a certain power level. A more relaxed highway cruise would be nice, but I've done 1000+ miles in a day without difficulty. At the 400 rwhp level, it may make 1st gear more of a stomp on it WOT gear, but as you get the power levels up a bit higher, I don't think it will matter which gears you have. Your right foot will get a feel for how much throttle to feed in, or how much smoke to let out of the tires.

Anyway, wheelspin is not such a bad thing, it is kind of like the fuse that protects the halfshafts, torque tube, clutch..........

Jim

AO

I agree that keeping the tires as the weakest link is a good thing.

Vilhuer

Yes, input shaft bearing is 8mm larger in '87-95 gearbox. Also 1st and 2nd gear syncros are different IIRR. Really minor stuff but at 400+ hp they might make a difference on gearbox longevity. If this is most important point then GTS box is only stock option.

hacker-pschorr

85 was the switch to the better syncros.

Vilhuer

Thats right but all Borg Warner syncros are not equal. '85-86 boxes used one syncro design for all gears. Later boxes received different metal parts for most critical gears.

dprantl

Thanks guys, all this is great info. I guess I'll just wait a while and see if I get used to it. Right now I just can't seem to shake the feeling that when I'm in 5th, it's like I'm actually in 3rd, especially since the exhaust note of the '91 makes it seem like I'm in higher RPM than I actually am (not to mention the power). Damn I wish this GT box had an overdrive 6th speed geared to ~230mph.

Dan
'91 928GT S/C
'86 928S 5-spd w/LSD *sale pending*

hacker-pschorr

Dan,
If / when you dump the GT box for a 2.20.....I call dibs

Vilhuer

Maybe one day there is.

John Veninger

ok, what are you working on?!!

Vilhuer

mark kibort

on the street and all tracks if you have a top speed of no more than 155mph


mk