NA transmission
#1
Racer
Thread Starter
NA transmission
Does anybody make an upgraded pinion shaft for the O16?
Don't need to change the gear ratio just keep it from stripping teeth
Don't need to change the gear ratio just keep it from stripping teeth
#2
Rennlist Member
#3
Rennlist Member
@Tempest: did you also have to go through the flaming hoops of changing out the rest of the rear suspension? Presume that you have the earlier VW suspension in your 924? Just wondering.. TIA.
#4
Rennlist Member
#5
Rennlist Member
There is an upgraded ring-and-pinion set available for the 944 eight-valve, normally-aspirated cars. Same ratio. What they did was take the pinion design used for the 944S, which has wider (at the tooth root) and longer (wrt. differential radius) teeth. It requires an upgraded differential carrier (large front aluminum case section) machined to accommodate the ring gear. I've been doing these upgrades for some of my customers.
Of course, it's also true that if you build the original transmission correctly, maintain it, and use a decent fluid, it will last just fine in a stock hp car. You should not be "stripping teeth" with it.
Of course, it's also true that if you build the original transmission correctly, maintain it, and use a decent fluid, it will last just fine in a stock hp car. You should not be "stripping teeth" with it.
#6
Drifting
There is an upgraded ring-and-pinion set available for the 944 eight-valve, normally-aspirated cars. Same ratio. What they did was take the pinion design used for the 944S, which has wider (at the tooth root) and longer (wrt. differential radius) teeth. It requires an upgraded differential carrier (large front aluminum case section) machined to accommodate the ring gear. I've been doing these upgrades for some of my customers.
Of course, it's also true that if you build the original transmission correctly, maintain it, and use a decent fluid, it will last just fine in a stock hp car. You should not be "stripping teeth" with it.
Of course, it's also true that if you build the original transmission correctly, maintain it, and use a decent fluid, it will last just fine in a stock hp car. You should not be "stripping teeth" with it.
I am upgrading a new engine build to a stroke 2.8L and using the the rebuilt 944 transmission that you did for me. I plan to run it in SVRA, Sprint races. What is your recommendation on preservation of this transmission?
#7
Rainman
Rennlist Member
Rennlist Member
My NA's transmission shredded the ring/pinion teeth 60 miles into an 80-mile highway trip. Just 75mph or so cruising the whole way - and never abused it before that.
The difference between gearing from an NA to an S2 is very minor so there's little reason, IMO, to not just upgrade to an S2 box with it's much larger(stronger) gear set.
That said, I have a 951 box in my car and my hot 2.9L NA engine I was running last year would spin the tires with alarming ease. The added displacement is a big help.
The difference between gearing from an NA to an S2 is very minor so there's little reason, IMO, to not just upgrade to an S2 box with it's much larger(stronger) gear set.
That said, I have a 951 box in my car and my hot 2.9L NA engine I was running last year would spin the tires with alarming ease. The added displacement is a big help.
Last edited by V2Rocket; 09-24-2021 at 11:46 AM.
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#8
Racer
Thread Starter
There is an upgraded ring-and-pinion set available for the 944 eight-valve, normally-aspirated cars. Same ratio. What they did was take the pinion design used for the 944S, which has wider (at the tooth root) and longer (wrt. differential radius) teeth. It requires an upgraded differential carrier (large front aluminum case section) machined to accommodate the ring gear. I've been doing these upgrades for some of my customers.
Of course, it's also true that if you build the original transmission correctly, maintain it, and use a decent fluid, it will last just fine in a stock hp car. You should not be "stripping teeth" with it.
Of course, it's also true that if you build the original transmission correctly, maintain it, and use a decent fluid, it will last just fine in a stock hp car. You should not be "stripping teeth" with it.
I like the acceleration of the Na trans mated to the turbo engine. The car was a different animal from it is now with a turbo trans
#10
Rennlist Member
#11
Racer
Thread Starter
Does anybody know the dimensions of the 944 NA pinion shaft maybe have Cad or line drawing to share?
Seeing what it would cost to have one or two made of newer stronger Metal?
Seeing what it would cost to have one or two made of newer stronger Metal?
#12
Rennlist Member
I bet it would cost significantly more than just swapping transmissions. Heck, just the labor to fit a new ring and pinion costs a lot, as it takes a fair amount of time and skill. Not to mention when you get it that far apart you'd be crazy to not proceed with a full rebuild.
#13
Rennlist Member
If you're going to be pushing a bunch more horsepower through the transmission, the upgrade or a swap to a later transmission make quite a bit of sense. I would approach the question looking at the top speed you expect, match it to the useful power band in 5th gear.
#14
Rennlist Member
#15
Drifting
Not sure on HP for 2.8L stroker NA. I was looking for 200hp
Tom
Last edited by T&T Racing; 09-29-2021 at 07:18 PM.