Depends on what you want to do with the car. The 4l60's can be build strong, but they will need a refresh. How much it bothers you to pull them every so often. Avoid the 700r4 if you are already running the 4l60 since you will just be giving up the main advantage of the 60, tunability. The 4l80e does not eat the amount of power people claim unless you are running the huge stock torque converter. Want to pay once and never worry about it again? Go 4l80e, but it takes some work to set it up.

 

I agree wholeheartedly. You also have to realize that circuit racing will probably be a lot harder on the tranny than drag, too. When you think about it, drag is relatively easy on a trans. All it is is upshifting. With circuit racing, you're going to be downshifting (which is a lot harder on a trans than upshifting) and you're going to be dealing with a lot more heat issues. Drag racing doesn't get the tranny nice and hot like a circuit race does. Basically, a trans will probably last longer drag racing as compared to circuits IMO, all things considered equal, and a 4L60E that may last several seasons drag racing may get destroyed in no time circuit racing due to all the heat buildup and downshifting.

Honestly, a T-56 would be your best bet out of them all, but if you must stay auto, 4L80E is the way to go IMO.

 

Actually, I've hit 250* in one pass between the burnout and the actual run. Granted, it cools down quicker because you stop and let it sit for awhile, but just about every run I've ever done registered over 200*. You're right, it's not for prolonged periods of time, but drag racing produces more heat than I like to see.

 

See that's what I though. I was thinking a T-56 would be best for circuit? I don't have to stay auto. I know people here that have done it and are willing to help me. Granted the T-56 swap would be the most expensive, I think? Although I never though of a 4L80E till now and how much do those swaps generally cost? I fell like a big asking tho put in a none electric version of my same tranny the 700R4. Goes to show you not to always listen to your friends I mean I really like the car either way and they both have their advantages to me...but I would think the T-56 would be better for the circuit courses? Am I right or can they both work fine auto or manual?

 

You can do it with either , But honestly a t56 might be the better choice

 

circuit racing an m6 would be more fun

 

In your original post, you stated street, drag and circuit. That's a tough one. Neither tranny is ideally suited for all those uses. What's your primary use gonna be? More drag or more street/circuit?

 

U just might need another cooler....i know my tranny doesnt see 200 even at the track.

 

Track and semi-pro circuit will be the primary focus for the car. Street drag just for kicking *** on the weekends and a little test and tune days at the NHRA drag strip just for fun will be second. The car is being built for what I like to call "Forza ****"

 

With drag being the secondary focus, sounds like the 6-speed is better suited to your needs. It might be a little more money-wise, but it isn't supposed to be that bad of a swap.

 

You could always take the middle ground and get a 4L80E with a manual valve body

 

If there was a way, and maybe there is to lessen or eliminate auto transmission lag then I would stay auto. My fear is the tranny taking to long on down shifts in or out of the corners. Is there a way to reduce lag? I know my stock 4L60E took a cool minute to engage from like 3rd to 2nd.

 

FLT builds badass 6 speeds too FWIW.

 

Shift speeds are mostly in the tune. A good shift kit can help as well. If you have a good tuner, you're set. My tranny has zero lag when shifting......it's always in the right gear!

 

That was going to be my suggestion... a Full Manual 4L60E. I believe it is the better choice. A 6 speed will keep the driver very busy, constantly. With only 3 gears to choose from for most of the run I just don't see how it could be a bad choice.

Everyone we have built one for has loved it!

There are plenty of solutions for keeping the unit cool.

g

 

manual 4l60e now thats something to consider! choices choices & more choices! lol

 

4L60's can be built.. I have one in my 4800lb truck with 700+ rwhp.. Holds up just fine on the street and at the track even with 12.5 wide tires and 150 shot off the line.. Temps never get over 200 even at the track...

 

So a manual like "stage4" 4L60E tell me more about it. Sounds like what I'm looking for

 

The reason for that suggestion was that in a Road Racing situation you need a very positive upshift and downshift on demand. You would need a very good shifter for this... a nice Ratchet style shifter would be ideal.

A Manual 4L60E would give you just that, instant up and down shifts when you need them without any lag time at all. Lock-up could be deleted in 3rd and overridden in 4th if necessary by using a Manual Switch that would cut the PCM signal. But I don't foresee lock-Up being an issue as I would trust that if you're in 4th gear you are at WOT which would inhibit Lock-Up. But you could retain Lock_up for cruising.

Because the converter would be relatively tight you would not be generating obsecene temps like a high stalled unit would. Either way the temps could be controlled by a well designed cooling system.

The best thing I could tell you is to talk to the guys who are running similar powertrains sucessfully and see what they are doing. From there get with the right Professionals to make it happen!

g

 

I Feel The Pain... I Have Broke 5... I Say Build The 4l60e Yourself