Trans is loosen it

[farmtruc]

I went to the track yesterday to see if I could launch this thing any better than last week. I think I have it down so I don't really spin off the line. About 3psi seems to do the trick and 12psi in the slicks.
But something started to happen, I knew it was going to , it was just a matter of time.
After I launched, the trans will slip at the top of first and at the top of second, it still ran a 12.1 letting off twice, so I know it has enough power to go well into the 11's.

SO now the decision, do I go with a TH400/350 or do the 4L80E??

We all know how proven the TH is, hell it's been around forever, but I loose my overdrive. And cruisen on the highway now with these 3.07's and the 60, it's very nice. Plus I'm going to install about a 3000 converter, so the TH may be too much. BUT, I have considered the Gear Venders Overdrive unit, that would even things out a bit.
I know the 80E is just as stout, I'm just having a hard time deciding.

What you guys think?

thanks,

[kinjo1977]

I would go with the 80E. Sure it will eat some power, but that thing will take a hell of a beating. And with these troubling times in the petro industry, who knows how expensive gas will get. So that OD will come in handy on the 80E.

[RedHeartbeat]

Tough choice. I like the turbo 400 with the gear vendors over drive. What is sweet about that setup is you actually end up with a 6 speed transmission instead of a 4 speed. What purpose the 6 speed would serve is beyond me but I have been known to go to excess just because I could. You could even load the turbo up more by have the o/d unit engaged at the starting line. That's a scary thought, overdriven 2nd gear finishes with 3.07s and tall slicks.

[chrisj6]

Yeah it'll eat some power but if anyone has it Allen has a few ponies he can spare maybe? 80e is my vote.

Chris

[RedHeartbeat]

Rather than to have it slip at high rpm have you thought about maybe shifting at 4500-5000? With the turbo spooling you should have plenty of grab short shifting.

[bud8fan]

check and see if you can get the 80e somwhere for dirt cheap...if not then go for the turbo 400
ps: i'll check down here for a cheap 80e myself and keep you posted...

[farmtruc]

It'll probably end up being an 80E, but like you said Red, the gv and 400 would be cool.
I shift at 5600 and the rev limiter is at 6500, so i did raise it, but it still hits. The shifts just aren't holding anymore.

thanks for the input,

[storm5.3]

80E is just a TH400 w/ an OD...Just look at the gear ratios to see that...Zed

[ONE04FX4]

C3C5 on tech had an ext denali with a stroker motor and a th350 and was running tens in it. they say that the th350's will hold more than the 60's. that is a hell of a decision.

[GMCwantsLS1]

I read somewhere that there is a heavy duty 4L70E coming out. I think I would go with the 4L80E and keep the electronic shifting and the overdrive.