Plan for devleopment of high-performance, high-strength differential
01-03-2004, 05:03 PM
#54
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might be a stupid question- but can it be reinforcd with welding and fabrication. ive seen the v8 guys weld plate steel from the pumpkin to the snout and use girdles. has anyone used a different rear end in an s2000 and how much work would it be to do so?? might be interested but i need to know if the stock reare end internals will also need to be changed out. 
01-04-2004, 08:26 PM
#57
(copyied from another thread)
S2Kophiles,
I'm putting an S2K driveline into a race car and have some observations about the rear halfshafts which may be contributing to the differential failures.
Most drivelines are designed with some wind up somewhere to that shock loads such as clutch drops, or tyres touching down after wheelspins are cushioned. In most modern cars the halfshafts are made relatively thin so they wind up under load. In the S2K the rear halfshafts are huge, almost 2 inches diameter compared to many other cars with more horsepower that have 1 to 1.25 inch halfshafts. Apaft from the sprung clutch centre there is very little spring available in the S2K driveline. The standard S2K halfshafts are so thick I doubt there would be any real wind up in them.
Has anyone tried using thinner custom halfshafts in the S2K? I believe that using them would help reduce the shock loads in the differential and gearbox. I'm using custom halfshafts in my race car of 1" diameter which is the same as we have used previously with a Miata differential and rear hubs. We have run these at over 330hp without any problems with lots of race starts and slicks. ( with a solid clutch centre)
I remember an article on the turbo era F1 cars. They had so much torque that the Williams cars used to wind up the halfshafts a full 360 degrees under power. Amazing.
Speedracer.
S2Kophiles,
I'm putting an S2K driveline into a race car and have some observations about the rear halfshafts which may be contributing to the differential failures.
Most drivelines are designed with some wind up somewhere to that shock loads such as clutch drops, or tyres touching down after wheelspins are cushioned. In most modern cars the halfshafts are made relatively thin so they wind up under load. In the S2K the rear halfshafts are huge, almost 2 inches diameter compared to many other cars with more horsepower that have 1 to 1.25 inch halfshafts. Apaft from the sprung clutch centre there is very little spring available in the S2K driveline. The standard S2K halfshafts are so thick I doubt there would be any real wind up in them.
Has anyone tried using thinner custom halfshafts in the S2K? I believe that using them would help reduce the shock loads in the differential and gearbox. I'm using custom halfshafts in my race car of 1" diameter which is the same as we have used previously with a Miata differential and rear hubs. We have run these at over 330hp without any problems with lots of race starts and slicks. ( with a solid clutch centre)
I remember an article on the turbo era F1 cars. They had so much torque that the Williams cars used to wind up the halfshafts a full 360 degrees under power. Amazing.
Speedracer.
01-04-2004, 08:34 PM
#58
Oh,
Before people ask. Thinner driveshafts are not necessarily weaker. Driveshafts tend to break at their thinnest point. In the S2K The thinnest parts of the halfshafts are at either end where they are splined for the CV joints. It would be an interesting exercise to turn down a pair of stock shafts to the same diameter as the splined ends, and shotpeen them before reinstalling. You would be able to use Miata CV joint boots over the thinner shafts ( have looked at this already). This would provide significantly more cushioning and wind up in the driveline.
Speedracer.
Before people ask. Thinner driveshafts are not necessarily weaker. Driveshafts tend to break at their thinnest point. In the S2K The thinnest parts of the halfshafts are at either end where they are splined for the CV joints. It would be an interesting exercise to turn down a pair of stock shafts to the same diameter as the splined ends, and shotpeen them before reinstalling. You would be able to use Miata CV joint boots over the thinner shafts ( have looked at this already). This would provide significantly more cushioning and wind up in the driveline.
Speedracer.
01-04-2004, 09:41 PM
#59
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If the diff is available by this summer, I'm definately in for $500. I would however, need concrete evidence it can hold the power you're speaking of. Also, setting a goal of about 75% stronger than stock to be certain that it will safely hold 50% more power. 50% more power and slicks will be ideal.
01-05-2004, 12:47 PM
#60
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Originally posted by chris_barry
Oh,
Before people ask. Thinner driveshafts are not necessarily weaker. Driveshafts tend to break at their thinnest point. In the S2K The thinnest parts of the halfshafts are at either end where they are splined for the CV joints. It would be an interesting exercise to turn down a pair of stock shafts to the same diameter as the splined ends, and shotpeen them before reinstalling. You would be able to use Miata CV joint boots over the thinner shafts ( have looked at this already). This would provide significantly more cushioning and wind up in the driveline.
Speedracer.
Oh,
Before people ask. Thinner driveshafts are not necessarily weaker. Driveshafts tend to break at their thinnest point. In the S2K The thinnest parts of the halfshafts are at either end where they are splined for the CV joints. It would be an interesting exercise to turn down a pair of stock shafts to the same diameter as the splined ends, and shotpeen them before reinstalling. You would be able to use Miata CV joint boots over the thinner shafts ( have looked at this already). This would provide significantly more cushioning and wind up in the driveline.
Speedracer.