4L60E Trans and Converters

[Dan Fahey]

Originally Posted by Dean Feiock

A 4L60E will never be competitive in K/SA. Besides the mass of the transmission, and mass of the converter, they simply have to much of an RPM drop between 1st and 2nd. Sure the 2.84 will help, but it's still a band aid.

The same problem occurs when you swap out the rear planet in a TH350 to make it a 2.75 first gear. When you do this, you lower first gear and second gear stays the same. So again, you are increasing the RPM drop between the 1-2 shift.

And then there is the converter issue. You will never get one built that will be competitive. NEVER! I've played with some of the best lockups made in my 200's. And the weight of the converter always negated the lock up advantage.

A TH200 is the only way to go. A 2.91 first gear upgrade would be perfect. Sure, a well built unit with a steel stator tube, billet drums and pistons, updated rear sprag, and roller bearing conversion can be pricey. But you don't need all that to start out.

Even a stock planet 2.75 ratio TH200 would be worth an easy 2 tenths over that 4L60E.

And when you are done, the TH200 will have resale value, the 4L60E will not.

Have you run your car in the 1/4 mile or just 1/8 mile? I can send you a time slip so you'll know where you need to be. While my stuff isn't stupid fast, I can hold my own.

Thanks for the feedback;
Beg to differ...
The Yank Locking Converter works fine.
It is heavy dampening the hit going into second without a hitch.

Best run of 12.68/105, 1/8th-8.02 ET., 60ft 1.61
A few more changes, Roll Bar, Fuel Cell enough to run the K/SA index.
This is good enough for now.

Going to a 200 means a complete expensive Engine and Drive Train upgrade to be competitive.
Winter project if there is time.

D