pros and cons of S2 tranny in 951?
11-28-2003, 01:57 AM
#16
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S2 ring and pinion
A little info first;
I have a 1987 951 with a S2 ring and pinion. I also do not have an oil cooler. I put my S2 ring and pinion in with an LSD.
A friend of mine has an identical 951 - we both have about 77,000 miles - both with APE stage 2.5 chips - everything else the same. (although mine is different now)
When we lined up on a lonely highway when our cars were identical (rolling start) 2nd gear on up, we can both hit the throttle, and I walk away from him with ease by about 2 car lenghts immediately and continue to widen the gap as we go up thru the gears.
I believe not only do the shorter gears make the car quicker, but you are also higher up in the power band to start with - thats why you get such a tremedous jump!
My top speed with a 6780 rpm redline with stock tires is about 154mph?
This is also my 3rd ring and pinion - 1st one had the lash set incorrectly and failed - 2nd one failed because of a factory defect - my 3rd one is holding up fine.
But I DO NOT DO drag strip starts, and I do not power shift - I was a former drag racer when I was young and held all the records in a 5 state area was was running inside a 10th of second to the national record - and built my own cars - I only state this fact to let you know that I don't believe the 951 transmission, halfshafts, and CV joints can take a lot of abuse like American mucsle cars. Just my opinion.
Although I have had 2 ring and pinions prior, I would do the mod again, because for the street, it makes things snappier and at the my local track here, I can only hit 150 to 152 mph at the end of the straight before the 1st turn - so the gearing is right for me - it might not be right for others.
Hope this info helps. I only know one other guy that did the same thing - but he only went thru 2 ring and pinions - now with some extra hp in my car, I hope I don't break it - it never ends - make more HP and now something else is weak link!
BTW, when I do a 2nd gear roll against my friends car now, I'm like 3/4 of a mile ahead of him or better when I shift into 4th - talk about leaving him in the dust!
I must admit it is not a fair match - but very helpful to run against a stock car with stock gears to see what difference there is as you mod your car
I have a 1987 951 with a S2 ring and pinion. I also do not have an oil cooler. I put my S2 ring and pinion in with an LSD.
A friend of mine has an identical 951 - we both have about 77,000 miles - both with APE stage 2.5 chips - everything else the same. (although mine is different now)
When we lined up on a lonely highway when our cars were identical (rolling start) 2nd gear on up, we can both hit the throttle, and I walk away from him with ease by about 2 car lenghts immediately and continue to widen the gap as we go up thru the gears.
I believe not only do the shorter gears make the car quicker, but you are also higher up in the power band to start with - thats why you get such a tremedous jump!
My top speed with a 6780 rpm redline with stock tires is about 154mph?
This is also my 3rd ring and pinion - 1st one had the lash set incorrectly and failed - 2nd one failed because of a factory defect - my 3rd one is holding up fine.
But I DO NOT DO drag strip starts, and I do not power shift - I was a former drag racer when I was young and held all the records in a 5 state area was was running inside a 10th of second to the national record - and built my own cars - I only state this fact to let you know that I don't believe the 951 transmission, halfshafts, and CV joints can take a lot of abuse like American mucsle cars. Just my opinion.
Although I have had 2 ring and pinions prior, I would do the mod again, because for the street, it makes things snappier and at the my local track here, I can only hit 150 to 152 mph at the end of the straight before the 1st turn - so the gearing is right for me - it might not be right for others.
Hope this info helps. I only know one other guy that did the same thing - but he only went thru 2 ring and pinions - now with some extra hp in my car, I hope I don't break it - it never ends - make more HP and now something else is weak link!
BTW, when I do a 2nd gear roll against my friends car now, I'm like 3/4 of a mile ahead of him or better when I shift into 4th - talk about leaving him in the dust!
I must admit it is not a fair match - but very helpful to run against a stock car with stock gears to see what difference there is as you mod your car
11-28-2003, 06:19 PM
#21
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3 turbos,
how much power are you making? if it is a good amount, is your first gear useless? i'm not really worried about that problem because my car is stock and soon to get chips, but thats it for awhile, i was just curious.
how much power are you making? if it is a good amount, is your first gear useless? i'm not really worried about that problem because my car is stock and soon to get chips, but thats it for awhile, i was just curious.
11-29-2003, 02:06 AM
#23
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stoked944,
"how much power are you making? if it is a good amount, is your first gear useless? i'm not really worried about that problem because my car is stock and soon to get chips, but thats it for awhile, i was just curious."
It is not tuned correctly yet - but on a Mustang dyno, it puts out 278hp at 10.5lbs. I have to have my chips reburned, as it is really rich in the upper rpm range
But short gears makes it feel like it has another 30hp.
I hope to have about 325hp at the wheels at 18lbs or there abouts.
1st gear although very short, is not too bad with LSD and R-compound tires. It does get squirrely(sp) in 1st and 2nd.
It probably would not be very good with street tires and no LSD, but I always run R-compund tires - ran regular street tires once, and it is not safe when you get on it - downright dangerous if you hit the throttle hard coming out of a corner.
R-compound tires and LSD makes it liveable.
"how much power are you making? if it is a good amount, is your first gear useless? i'm not really worried about that problem because my car is stock and soon to get chips, but thats it for awhile, i was just curious."
It is not tuned correctly yet - but on a Mustang dyno, it puts out 278hp at 10.5lbs. I have to have my chips reburned, as it is really rich in the upper rpm range
But short gears makes it feel like it has another 30hp.
I hope to have about 325hp at the wheels at 18lbs or there abouts.
1st gear although very short, is not too bad with LSD and R-compound tires. It does get squirrely(sp) in 1st and 2nd.
It probably would not be very good with street tires and no LSD, but I always run R-compund tires - ran regular street tires once, and it is not safe when you get on it - downright dangerous if you hit the throttle hard coming out of a corner.
R-compound tires and LSD makes it liveable.
