JayP

I found the S and turbo have the same rear ratio, so would there be a significant difference between the two?

I've heard the turbo has strengthened gears but why build 3 units for the 944, the S model and the turbo?

User 41221

Yes, there is a big difference. The S tranny will break if you put it in the turbo.

Regards,

JayP

So... the turbo tranny is an upgrade to the S?

I'm looking to replace mine and I found a turbo unit locally.

TT

What car are you putting it into? If you are replacing an 'S' tranny with a turbo tranny in an 'S' car, you will probably regret it.

josephsc

Even though the gears are the same, the differential ratios are completely different. The S is 3.889 where as the Turbo is 3.375.

The Turbo tranny is taller than the 944S tranny -- I wouldn't want it.

sharky47

R&P is stronger in the turbo tranny.

Robby

Yeah, turbo gearing is much taller- I mean overall ratio, since the gears are the same, but the R&P of the turbo is much taller, as Joe said, etc... I think some turbo guys get the "S" R&P to run in their 951's for faster accel- might be from the S2- a 3.889 (OR 3.875 if S2) in a turbo makes it whip through the gears pretty fast, but I wouldn't really want it for a street car- especially w/some mods b/c it's just a bit too short- especially for a higher-boost turbo. But to put the taller 3.38 into a stock HP 944 S might hamper your acceleration a little more than you'd like...

What's the redline in a 944S- I'm guessing closer to 7000....? The Turbo redlines at 6400 & w/3.38, the speeds in each gear are: 40, 67, 99, 134, 167. At 6400 rpms, the S should be hitting: 35, 59, 87, 118, 147. I don't know the first thing about the size, shape, or other specs, or even if it would interchange, etc...

zoxx2004

944S gears w/3.889 final drive was put there because the 16 valves (S and S2) create hp on top of the rpm range.W/out the right final drive and taller gears the 944S would be real flat driving until hitting way outside illegal driving.It's actually flat until you hit over 4300 in most cases,and that @ 70+mph. Turbo in S -5th gear would be pointless.Won't have enough torque to pull hills.Going down hills would be ok thou.

Robby

regardless of vavles &/or where the HP is, shorter gears are faster to accelerate- however, higher boosted turbos like taller gears to some extent- get in a gear, build boost & accelerate- still, shorter gears are higher numerically & it's a multiplication thing- gearing multiplies TQ.... As for 5th being pointless- well, it's a crusing gear- even w/the shorter overall gearing, you're able to redline at 118 in 4th, assuming redline is >6400- for the street, that's pretty fast, so if even if you had a .72 5th combined w/3.38FD, you'd still have a useable 5th for the street- you wouldn't be able to accelerate for sh** but you'd get good gas mileage & the car would run quiet, since you'd be doing ~97mph @ 3200rpms...

What is the redline in 944S?

JayP

I'm looking for a replacement for my S. There is a turbo transmission available here locally and will probably use it as a replacement.

The car is used pretty much as a track car, and $ is an issue. The taller gear for 5th would only really be used on the tollway. I used 5th at Texas Motor and that was a WALL of BRICKS for the S.

Off the top of my head- redline for the S came at 120mph in 4th... 7000k?

Robby

Well, in this case, you'd be making all of your gears taller- not just 5th- if you're running tracks & you're actually using 5th a bit, then you probably would not want to do this unless you plan to get some serious power from the engine later on- like maybe dropping a turbo engine in & then I guess $ wouldn't be the issue for you, so this whole question would be pointless... if 6400 = 118, then 7000 = 129. Either you have a 6500rpm redline or we're off by 2mph- I mean, 118 is almost 120, so that would make sense... Of course, redline could be 6500....? 100rpm is probably worth 2mph... Either way, it's going to slow you down a bit to go to the turbo tranny, as others have mentioned...

Oddjob

I would strongly recommend against putting a turbo trans in an S - it will absolutely kill the acceleration, the S does not have the power/torque to pull the taller final gearing (R/P ratio) of the turbo trans. It would be a terrible downgrade for a track car, making it significantly slower than a 8v n/a coming out of corners. May be able to keep up with an old 924 with the 2.0 Audi motor.

Redline in the S is 6800.

tifosiman

I agree, the turbo trans wouldn't really be a good idea, regardless of the price. If the cost/availability of the S trans is prohibitive, a regular 944 N/A trans would probably last awhile and not be cost-prohibitive to get. If you could find a later one like an 88 or 89 that would be your best bet (of course the lower the miles on it the better).

M758

I agree Turbo tranny in 944S = DOG

While the trubo tranny is stronger the F/D is so far off it will just suck. Better to put an 8v tranny in the car. In fact the 8v tranny maybe the best for the car even from the start. The 16v has more hp than the 8v car, but this is in the upper rpms so I'd bet the 8v NA tranny is plenty strong for 16v valve car. I would not put and 8v NA box in to a 3.0L 16v car however.

Oddjob

Yep, good idea. Much better to put an n/a trans in the S, than a turbo trans.

And as mentioned, look for one with the short .829 5th (924S or 88 and later 944). But if you dont use 5th on the track, then it doesnt really matter that much.

I had put some thought into putting an n/a trans in my old S to get slightly shorter gearing. Never did it for various reasons (illegal for PCA, never stumbled across a short 5th 944 n/a trans with LSD, and slightly shorter gearing would not have made enough difference to justify the cost). But since you need a trans, that is probably the way to go.