Originally Posted by RJay

Actually I have and honestly I preferred the 901. Both are truly vague, though better than the 60s bug I had as a kid, but at least the 901 is in a race pattern that makes it a little harder to seriously screw up. In fact if I had the $$$ required to make it strong enough, I'd build up a race 901 for my car as I much prefer the shift pattern.

The thing I've noticed anecdotally is that not all of these gearboxes are created equal and I've no clue as to why. I've driven 915s that shift great and others that shift like crap. Same for 901s. And its not just couplers or even the adjustments. I dunno if mounts make a difference or whats inside the case, but whatever it is, it seems there is a wide range as to how good or bad these boxes can be. I recently pulled my 915 for a second rebuild and installed another one in the interim for this season. The new one shifts fantastic despite having suffered 100K+ street miles without a refresh. The old one was a piece of poop even right after its first rebuild. I'm wondering if I shouldnt stop right where I am, move over my LSD from the old box and refresh the one thats in there now this winter.

Originally Posted by DogInBlack

http://www.youtube.com/watch?v=U1EBGDE_e90

Money shifted on the back straight at Road Atlanta. I'm usually very particular about gear changes for exactly this reason. For some reason the rockers, exhaust valves, and a couple of intake valves didn't like the environment of 9-10,000 rpms. Thankfully, we didn't jump time.

To borrow a quote, "I feel dirty" having messed up this car because it is so pristine. Besides crying in public about my bonehead move, I want to share my experience as one that you can learn from.

There was a thread here a week or two ago about shedding some extra time each lap, and it was mentioned that you can speed up your shifting. I disagree. Unless you are on an unlimited budget, because all you are doing is adding unnecessary wear to your drivetrain and run the risk of the money shift.

Also, may I suggest, if you have a mechanical overrev, safely get out off line and traffic and shut the car off immediately. At 10a, you see that I wanted to try and limp it over the hill to get to the pits. DON'T do that. It could have been worse for me, and I was going to be getting a tow anyway.

Thanks to all for the help at the track, thanks to those of you checking on the status of the car, and especially thanks the folks at Orton Performance for the help and speed of getting me back up and running for Barber next week.

Originally Posted by Chris M.

In the 915 world where the money shift seems most common (not a coincidence) they almost always occur on the upshift trying to get from 4th to 5th but instead hitting 3rd. I've talked to several people who learned how to rebuild an engine because of it. The lockout spring that allows access to the 5th/Reverse plane isn't that obvious so I always try to be careful. I hope I never have to hear the sound in either one of those videos. Ouch.

Originally Posted by Chris M.

In the 915 world where the money shift seems most common (not a coincidence) they almost always occur on the upshift trying to get from 4th to 5th but instead hitting 3rd. I've talked to several people who learned how to rebuild an engine because of it. The lockout spring that allows access to the 5th/Reverse plane isn't that obvious so I always try to be careful. I hope I never have to hear the sound in either one of those videos. Ouch.

Originally Posted by PedroNole

I did this exact money shift on the front straight at Sebring and fortunately only blew the pressure plate. I'll find the video and post it for those that like that WEEEEEEEEEE sound of an overrev. I've also done the money shift TWICE in the same exact spot at Homestead (coming out of turn seven) going from 3rd to 4th and hiting 2nd instead. Blew the pressure plate both times. Interesting that some guys have blown the engine and I seem to blow pressure plates (standard SACHS PowerClutch).

Yes, I have the WEVO gate, and every other possible 915 "better to shift with" part out there. I think between gear box linkage issues, flex of the body vs. the tranny in the corners and other various items, I've put 6-7 pressure plates in my car in the last 24 months. The upside is that the engine and tranny come out and go back in REALLY quick now.

I will say this....when it's right, it shifts like a hot knife through butter. When it's even the teensy bit wrong though.....

Originally Posted by Steve Weiner-Rennsport Systems

Hey Peter,

Given your experiences and expenditures with blown PP's, you'd be a prime candidate for a Tilton twin-disc setup.

Originally Posted by Larry Herman

I don't think that would be a good idea. It seems like the pressure plate is the "fusible link" in Peter's setup. Money shift with the Tilton and he is sure to grenade the motor.