alxdgr8

Well I just ran across a "what's the fastest you've gone" thread and I know I've topped out 4th gear at around 120mph (on a closed course of course, gps verified speedo). I was looking around some other threads and noticed most people with stock 951 trannies will do 130-140 in 4th gear. My tires are 265/35/18.

I don't have any numbers off the trans...I'll have to look when I'm back to the car in a week and a half.

This isn't the only case of me thinking my trans is not original. My option code sticker says it has LSD and a trans cooler (two seperate options), but when I looked under the car it does have LSD, but no cooler.

As far as the different trannies, I thought that it was usually only 5th gear that was different?...maybe I'm wrong though, but it sure seems like my 4th is off.

Darwantae951

Use clarks-garage.com when you find the number. It has all the info you could need for transmissions and you can check gear ratios.

alxdgr8

I could just be imagining things since I haven't driven the car in over a month...but for what I can remember 3rd gear doesn't go more than 100 (where most will do 115 or so) nor did it feel like 4th had another 15-20mph in case I wasn't all the way to redline.

Anyone know what the top speeds for 3rd and 4th are for an S2 trans?

931guru

+1e12

Darwantae951

FWIW in my car, 3rd won't go very far past 100 indicated. I know my car has the original transmission.

bigdeano

Same here, 3rd doesn't take me much past 100mph and 4th at redline... well im not sure cuz I'm not really concentrating on the speedo at that point in time.

Jfrahm

Your owners manual has acceleration curves and transmission diagrams. As per the diagram, the standard 944 trans should put you at about 38 mph at 4000 rpm in 2nd, the 944 turbo is at about 45 mph at 4000 rpm in 2nd. Maybe 72 vs 85 at 4k in 4th.

-Joel.

alxdgr8

I'll have to look at that when I get back to the car (sucks having it 6hrs away ) Anyone by chance the numbers for an S2?

Like I said, I'm probably just imagining things and I have a standard 951 tranny..but who knows.

badcoupe

don't forget to factor tire size in to the equation the turbo and s2 and NA have some different gear ratio's as well.

alxdgr8

According to http://www.catherineandken.co.uk/sti/tyres.html
A stock 951 with 265/35/18 tire and 6500rpm will do:

1st = 41mph
2nd = 70
3rd = 103
4th = 140
5th = 174

With an S2 tranny and the same redline/tires it would be
1st = 36mph
2nd = 61
3rd = 90
4th = 122
5th = 162

The S2 trans sounds a lot more like what I think mine is...I'll have to check the numbers.

dillon410021

I would like to know what tranny mine has. But I believe my speedo if off.

alxdgr8

Well I haven't confirmed the numbers yet but I'm pretty sure I have an S2 LSD tranny in the car. 3rd definitely tops out at 90mph and at 3000rpm I'm at 75mph.

S2:
5th, 3000rpm = 74mph

951:
5th, 3000rpm = 80mph

blown 944

My turbo trans runs ~115 in 3rd and 145 in 4th (proven on the dyno)

The S2 trans is much shorter in my red car IIRC my 4th topped at about 125

I remember wishing I had the turbo trans in when playing with Josh's bike on the highway ......hitting fifth gear under full power....... did not like

bearone

in mine, double the rpm for speed in 4th, 2k/40, 3k/60, 4k/80, 5k/100, 6k/120.

you're 145 in 4th is questionable as i really don't think you're running 7250rpm, unless you've got much taller than stock gearing.

driving from longbeach to phx, az, two months ago, 3k was about 80mph in 5th, confirmed with gps.

87951
95sl320 dd

MM951

FWIW, my 951 is ~2800rpm at 60mph, my old N/A was ~3000rpm at around 80