951 racing transmission
01-27-2003, 01:19 AM
#1
Advanced
Thread Starter
Join Date: Dec 2001
Location: colorado
Posts: 62
Likes: 0
Received 0 Likes
on
0 Posts
951 racing transmission
I was talking to a fellow racer about setting up my 951 and he thought a 90 944s2 trans would have shorter gearing and ring&pinion making it a perfect set up for a race car...is that info true and is it a direct bolt on?thanks
01-27-2003, 09:56 AM
#2
Rennlist Member
<a href="http://members.rennlist.org/951_racerx/gearing.html" target="_blank">http://members.rennlist.org/951_racerx/gearing.html</a>
01-30-2003, 07:48 PM
#4
Rennlist Member
Do you mean PCA Club Racing, Stock Classes, Prepared?
If so - the rules are pretty tight. I have been researching it myself and it seems that you should have the same tranny and gearing as stock, or you go to GT classes. In Prepared, you can add non-Porsche LSD and different ring&pinion. I don't think you could put an S2 tranny in your car and run in prepared, but I am not really an expert - that's just my interpretation of the rules.
If so - the rules are pretty tight. I have been researching it myself and it seems that you should have the same tranny and gearing as stock, or you go to GT classes. In Prepared, you can add non-Porsche LSD and different ring&pinion. I don't think you could put an S2 tranny in your car and run in prepared, but I am not really an expert - that's just my interpretation of the rules.
02-15-2003, 12:56 AM
#5
1st Gear
Join Date: Jul 2001
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
I expect that wholesale transaxle replacement will result in a shift to GT class. Relative to the S2 transaxles durability, I've heard that they will hold up, and that they won't. I do understand that the gears are more durable from about 88 onward, but the R&P appear to be problematic. They are signficantly lower final drive ratios, however, which makes them attractive on some applications.
02-15-2003, 05:14 PM
#6
Instructor
Join Date: Feb 2003
Location: Tallinn, Estonia
Posts: 107
Likes: 0
Received 0 Likes
on
0 Posts
GTracer,
I do not know how this tranny change affects to the racing classes, but for sure I can recommend this simple procedure if you can get a S2 box somewhere. After my 951 original box broke up for third time and I was offered a 944S2 LSD brand new gearbox, I went to this. S2 box is not stronger, but it was new and with LSD. With shorter gears the car feels much better and indeed quicker. My slightly modified 951 (chips and boost) went 0-100km/62mph in 5.5 secs compared to factory 6.3 secs. Best 1/4-mile time I got was 13.97 (incl. reaction, so the ET ~13.3)
.
With the S2 box there's only one minor downside - on top speed event you run out of gears. It's quite funny to run on 5th, constantly hitting rev limitter on 7000rpm and having only 270kmh/168mph on speedometer (actual speed ~250kmh/155mph I guess).
Last but not least: S2 gearbox is 100% bolt-on in 1 hour for a specialist.
I do not know how this tranny change affects to the racing classes, but for sure I can recommend this simple procedure if you can get a S2 box somewhere. After my 951 original box broke up for third time and I was offered a 944S2 LSD brand new gearbox, I went to this. S2 box is not stronger, but it was new and with LSD. With shorter gears the car feels much better and indeed quicker. My slightly modified 951 (chips and boost) went 0-100km/62mph in 5.5 secs compared to factory 6.3 secs. Best 1/4-mile time I got was 13.97 (incl. reaction, so the ET ~13.3)
.
With the S2 box there's only one minor downside - on top speed event you run out of gears. It's quite funny to run on 5th, constantly hitting rev limitter on 7000rpm and having only 270kmh/168mph on speedometer (actual speed ~250kmh/155mph I guess).
Last but not least: S2 gearbox is 100% bolt-on in 1 hour for a specialist.
