SpenceSpeed

Right now my car is putting down about 380hp. Want to get to ~600 over the next few years. First things I'm changing are the tranny and rearend. I have a 4L60e in it but it's toast from drag racing. Car goes to the track about twice a month and gets driven to work and back maybe once or twice a week. ~100mile round trip highway running. My questions are how well the 4L80e holds up to high torque/horsepower in street/drag cars. If I go with the TH400, what gears for the rearend so i'm not screaming at 3800rpm when highway driving but still get a good launch at the track. I know the 4L80e is a 4 speed VS the 3 speed TH400. The rearend is going to be a 12bolt Moser.

I want to beef up the drivetrain first with components that can handle ~600rwhp in the future.

I know there is a signifigant cost difference between the two trannies (if both are built for performance)

any feedback from either type tranny owners is appreciated

FastKat

iTrader: (10)

Good question, I would like to hear some input as well.

I think 1st gear in the 4L80E is 2.48 and 1st gear in the 4L60E is about 3.06.... so the 4L60E is going to give you a deeper first gear... probably giving you a harder launch. Also, I think 4th gear in the 4L80E is .75 compared to .70 is the 4L60E... giving the 4L60E lower RPMs at cruise on the highway. So basically the 4L60E is going to give you a deeper first and a shallower 4th while the 4L80E is going to give you a tighter set of gears... probably not optimal for highway cruising.

One idea is to keep your rear on the shallow side and getting a converter with a higher stall speed.

-Dave

SLowETz

iTrader: (12)

80E will hold the power, and be commute friendy.... cost and weight are the factors. A built TH400 is going to hold big power, be lighter, lower initial cost, and won't require surgical removal of your left nut when it does become time for a rebuild/freshen up.

I just did a M6 to TH400 swap...... a rmvb/TB'd/LU and there's absolutely nothing I don't love about this trans. I control shift points/ how hard it shifts, and when it locks up. Feels good tooling around... feels better when on it, and is a phuckin' blast to drive.

The lock up will give you a few/four hundred more rpm's on the street, help a bit w/gas mileage, and net you a few more mph through the lights.

Always been a 4-5-6 speed guy and can't believe it took me this long to step over to the right side of the tracks.

Car isn't a DD, but does see street time. Runing a 4.56 on a 28" ET Street and will prolly do yet another gear swap, but oh well.....

For a DD, a LU 400 w/a 3600-3800 verter, and a 3.42-3.73 gear would be perfectly liveable on the street and do nicely at the track IMHO. Matter of preference and what you're willing to tolorate.

Good luck!

98_Formula

iTrader: (15)

my next setup would prolly be a TH400, high(er) stall and maybe 3.08 gears in the back... i've been considering the same options as you, because teh next time my tranny goes i'm done with the 4l60e\

I haven't had any experience with either tranny (4l80e and th400) but i've been looking and reading up, and the setup i just wrote woudl be my first choice right now

TrakDay

iTrader: (7)

I had a th400 swapped into my 04 GTO and couldn't be happier! What a difference! Although I came from an M6.

Its a blast to drive on the street.

SpenceSpeed

The TH400 and 3.08's are what I was thinkin about also...

Thanks for everyones feedback...looks like TH400 and Moser12 this winter.

sleeperstyle

iTrader: (4)

do you have a link (if non-sponsor pm me) to who you used for purchase of your setup? lockup in a th400 sounds about like what im looking for, but i've read that to have the lockup is alot of extra coin..

SLowETz

iTrader: (12)

Call Mike Senia @ YANK >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

He'll hook you up!

sleeperstyle

iTrader: (4)

yank has an awesome rep but too much $ (gearstar) for the transmissions.

i was mostly interested in the lockup option. ALOT of guys can build a bulletproof th400

Out1aw

iTrader: (1)

To give you an idea, I know of two Silverados running around with 80E's and one Trans Am...

1. Parish8's Turbo + n2o Silverado (www.turbotruck.net). Running 10's with nothing but a shift kit.

2. Quicksilverado is running a STS system on an LS1 silverado running low 11's with nothing but a shift kit and decent (3000 i believe) stall on a 80E.

3. Cablebandit is running a twin-turbo Inconn system in the high 9's with a very modestly built 80E.

From what I've read those things barely flinch at 600+ horsepower stock.

dhdenney

iTrader: (53)

I thought I read somewhere he was running an FLT 80? Maybe I'm wrong, I don't feel like looking for it right now.