I didn't want to make this a multiple choice poll as I'm more interested in leaving this question open-ended.

So my question is, at what point does everybody feel that a 4L60, no matter how built, is just not enough? 300hp? 400hp? 600hp? Any FI or nirous car? Sub 12, 11, or 10 seconds?

I know there will be many answers, as with everything some have had better luck than others. But there has to be a level where there is just no point in trying it.

 

I ran my 4L60-E down to a 10.06 with about 500 RWHP. I now know how to have one built alot better. So, I'll say 600 RWHP is currently about the limit. Just a guess.

 

theres a lot of factors you need to consider. a stock auto trans will go out on a stock car eventually, its just a matter of time. my first trans went out at about 11K miles. i had road raced it and had many times down the strip with it. my current setup lasted about 3-4K miles before it went south. i put another stock trans in with 10K miles from a supposad stock SS and since i have put about 5-6K miles on with my current combo. the differences are now i have a deep trans pan, and a trans temp guage. i dont let it get hot...and i dont do a lot of wot downshifting anything. it still shifts as crisp as i put it in. the key to making a tranny last is keeping it cool and not doing a lot of downshifting.

 

Depends upon how hard you drive it and how long you expect it to go without freshening. If you're over 500 RWHP and drive the car hard, the 4L60 probably isn't for you.

 

My history with my '94's 4L60E:

After I did the cam etc. the stock trans did not live long. I had a complete race/HD rebuild done by Mike Kurtz in 1998 and that lived until about 10 days ago. That was in a car with 350 RWHP/365 RWTQ and for 25K miles and 300 passes at the track and ~100 on the street.

Now I have "the best" available rebuild using some parts that were not even available back in '98, so the tranny is stronger than it ever has been. I will be spraying a 100 shot on it and it "should" hold. However, my builder said that if I want to go any higher, a turbo 400 should be in my future.

I can let you know later how it holds ~450-475 RWHP street racing. I will be running motor only at the track as I don't have a cage.

 

Just the kind of replies I was looking for

I knew this would be very subjective to what everyone feels is an "acceptable" lifespan. 10k miles, 20k miles, etc. Personally if I can get 20-25k from a trans before a rebuild I'm happy. But there comes a limit where no amount of aftermarket can get a 4L60 to that level, and I'm interested in finding where that level is.

 

My stock 4L60 lasted about 10k miles behind a heads/cam combination @ 400rwhp. Ross House rebuilt my 4L60, and now I am running the same heads, larger cam and nitrous. The transmission is holding up great after 8 months at a little over 500rwhp. If you can find someone that really knows how to complete a rebuild, you would be amazed what it can hold up to. I am actually building another set up at this moment that I plan on making alot more power with. I will find out how much the built 4L60 can hold... but I am sure it is going to give! I have been told the breaking point is 600rhwp but I might be able to push it further

 

I agree w/the how hard you drive it!

Pete, you know how much I've raced my car. I now have 12,000 miles on my car. I would say about 6,000 of that was every day/drag racing miles the rest of it is pretty much all drag racing driving. My tranny started to feel mushy before the big vert when in. Then after the Vig 4400 went in and 17 hard launches at 2,000 my stock tranny gave way. All that before it hit the 12,000 mark... very high up in the 11,000 range for miles.

 

my stock tranny went about 13K miles behind a H/C,Vig3200 stall set up and about 100 1/8th mile passes before it went south. I just had it rebuilt to a stage III set up which they tell me should be able to handle up to 600 RWHP as long as you freshen it up once a year. My car should be making about 425 RWHP on motor and 525 on the bottle. We'll see how long it lasts. I really would have liked to go with a built 200-R4 but the cost was almost twice as much as the 4L60E stage III.

 

Thanks Miriah

That's about how long my last stock rebuild lasted, well actually 16k with MANY bottles of juice, plus the fact that I beat the ever living snot out of my car every day I am in it. What I'm really after here is what can be expected from a seriously built up 4L60 in the long term

Since I have my trans sitting in peices on my workbench right now, it's time for me to start doing some planning. As of right now I'm sidelining my car till spring.....


..... and that's all I'm going to say

 

Cool cool... good luck with your planning on the car. I know you'll have it spitting out nice #s

Just let me know what day your racing so we can both get new best ETs. You know how our luck runs. You get a new best I get a new best

 

Yes, we've definately shared a few good days! I'm hoping ot have the car "done" by spring. It's not coming out of the garage until I'm confidant it can run (a whole lot faster than it runs now). If it's not ready to my liking by then, well it will just sit there another year I guess

 

I killed my Trans a few weeks ago and after pulling it apart I found that I broke the sun shell. From what I hear that’s a common problem with the 4l60e.

For the rebuild I’m putting in blues and steels, a larger sun shell… deep pan, super servo’s “billet” But really the Trans was in good shape after 61k. My over drive steels had some diss color from heat. I mean they can’t last forever but I think with regular fluid changes it will have a longer life. Keep the thing from slipping

I know this might not be the best way to find out the weak points but when you tear a part up replace it with stronger after market. That’s if you don’t mind pulling the Trans all the time…

 

Well I feel lucky cam only car 2800vig 26,000 miles over 400passes and still feels tight probly jinxing myself now.

 

another vote for about 600rwhp.

i killed my built tranny with a stock 6.0.



oh yea, 9psi and a 100shot too with 4wd launches in a heavy truck. had to be close to 600rwhp before it let go.

i had alot of 8psi and 75shot passes, probably 50 or more. no dyno numbers but i am prety sure that is over 500rwhp.

 

Well I really want an Auto too but don't want to have to deal with the 400 1 to 1 ratio. This link here says they are rated to 700 hp with a 1 year 12000 mile warranty.....hmmmmmm has to be flywheel hp

http://www.fbodytrans.com/index.html#transmissions

 

I just got one of there stage 2 trans, My stock trans is still holding up after over 300 passes and 23000 miles.

I let you know when I get it in, just wait for a fresh convert.

 

Did they tell you that te rating was for flywheel HP or RWHP for the warranty? I'm just curious about that even though they said they had a 4500lb, 1000hp, 1000tq Impala running their level 3 tranny