DANZGLASS

yea they were not ready for the vettes over there.

PBA

Chris was having problems with the RPM transmission not holding up to the horsepower & torque. He removed the transbrake and put in my modified valve body with modified accumulators & separator plate, Borg Warner Hi-Energy 10 clutch 3-4 setup, Sonnax 2nd apply servo, and some other changes. Now it is holding up fine. The RPM transmission was not a "bad build" just mismatched to what his motor is putting out. Before the 1-2 shift with sticky tires was violent, these modifications smoothed that out. I like to see some low nines to high eights with these changes in the near future.

Chris Stewart

Thanks Dana, I appreciate all the help from you at Pro Built Automatics. It should have no trouble running those numbers. We will also be contacting you soon for some 4l60 rebuild parts on my sons LS1 Firebird.

Next up race, Northwest Nights Street Car Challenge. Going 1600ft on unprepped airstrip!

http://www.kstuned.com/pages/northwe...-car-challenge

ajrothm

You gonna let it shift to OD wot for the 1600' deal?

Chris Stewart

I think I can get done by locking the converter. I talked with Dana about it and he said the OD should work tho. I've just never done it, have you?

ajrothm

No... RPM told me not to let it shift to OD at wot so... I'd be scared to try it.. I need this tranny to live a while.

PBA

If you have some horsepower (using a small diameter torque converter) and are looking to make WOT 3-4 shifts and have the transmission live, then add the Sonnax 4th apply servo and open the feed hole in the separator plate to .135" - .155" and install the 4th accumulator spring in the case first then the accumulator piston. This somewhat eliminates the accumulator effect. The 3-4 WOT shift will now be very quick.

Chris Stewart

Yep with Dana's new tricks it has the setup if needed. Maybe at worst, it doesn't hold and I burnup the OD band. They are like $25-40 and not too hard to replace. I figure there's gotta be guys with 4l60's that have run the 1/2 mile or more?

ajrothm

I'm sure there has been but I don't know of any that had any decent power..(800+).. I know quite a few C6s with 6l80s that have done top end runs and let it shift to 5th even at wot...most of them were built and not sure how long they lasted tho..

I'd love to be able to do some top end pulls in 4th but... I can't lock my converter at wot so it would probably negate benefit from using 4th.

danieloneil01

That's badass but man would I hate to have hit one of those barriers. **** would hurt.