rbt .to chevy sb 700 H.P.Problems

[Jeff Leaver]

I am new at this site and not sure where to post things ? hope I get some help or advice .I have a gt-40 style hand built race car 700 HP and about 600 Torque. I have an rbt transaxel That lasted about two years on the track and has been rebuilt many times. I know it was a mistake thinking a zf could handel this much torque but went for it any way. I am now in the proscess of rebuilding the car and am trying to keep the trans.I am turning it into a street rod and am going to try not to beat it on the race track , but I would like to do a couple of open track event a year with the car. I have just had the motor rebuilt and installed a kinsler EFI system and raised the torque so it is more streetable. It will still be about 675 HP and over 560 torque at 5000 rpm. Is it worth having it rebuilt again ? Need third gear sincros, shaft is taking out the pilot bushing, needs a new front case. One more thing ; the biggest problem is that the input shaft takes out the pilot bushing in two track events.I am in the process of having a new pilot bearing made insted of a bronze bushing.I have dial indicated at least 10 time and am within .004. Trani has had four years of abuse and I think the case is worn out ? 410 ci. small block chevy to ford zf

[J. Salmon]

I am impressed that you were able to get the transmission rebuilt many times in two years. I thought wait times were much longer for RBT, but maybe that is just if you are buying a box? It'll actually be thrilled if getting a ZF rebuilt is not that much of a problem.

[Gregg]

Originally Posted by leavergt

I have just had the motor rebuilt and installed a kinsler EFI system and raised the torque so it is more streetable.

Yikes!!

I would go for Porsche 930 box at this stage.

[Big-Foot]

If your pilot bushing is being taken out in only two events - I would suggest that you inspect the bellhousing for concentricity / run-out first.
Also - rather than a bushing, I would look into a roller-bearing for the pilot.

Now in regard to your anticipated use on the street - have you given any consideration toward a more docile package by dramatically de-tuning it to run on pump gas, perhaps be a little more low-rpm friendly etc. ??
I've a real hard time understanding the need for 500-600+ HP on a street driven vehicle with this low of a weight..
This coming from someone who recently built (and sold) a street driven 1000+ HP Chevy Nova.

-edit-

Runout in the bellhousing could also cause clutch drag which would speed up the wear and tear on the gearbox itself...