Tuning a 4l60e

[B A Barakus]

Even though it will be tuned by a pro... Anyone have a high HP tune file for a 4l60e they can share. Twin Turbo pushin about 750. Built Tranny.
Thanks
shockawe@nycap.rr.com

[B A Barakus]

Sorry.. wrong section.
Just looking to compare notes with what I have so far.

[Redline Motorsports]

J,

No receipe to plug and go. Needs some massaging especially with a built trans. Most aftermarket trannies have the line pressure raised internally and playing with some of the calibrations can reak major havic. If you can, e-mail me the current tune file.

Howard

[joecar]

Moved to trans. subforum.

Measure line pressure at pressure tap on LHS of trans as you drive (do a few WOT pulls)... be sure it's always above 90 psi, and at WOT be sure its at around 230-250 psi; any higher than 250 psi can cause internal problems (pop the retaining ring out of clutch packs, damage accumulators, crack case, ...); but check with your trans builder.

[B A Barakus]

Thanks H,
just wanted to see what a well operating tranny tune looked like.. didnt plan on using.. but sometimes when you look at them, you can begin to see patterns and learn to ask the right questions.

[joecar]

Mostly, the shift pressures will be up a little, the shift times will be down a little (or zero sometimes), torque reduction may be lowered or zeroed, TCC kickdown TP set at 100%, shift curves and TCC apply curves upped a little from mid-range and up...

There's not that much to tune: firmness (via pressures, times, TR), PT shift curves, TCC apply curves, WOT shift MPH/RPM.

Shift kits and/or built trans may or may not require stock shift pressures and/or zero shift times.

When you drive it, 50% TP should produce a firm positive downshift, and reducing the TP just a little should then produce a firm definite positive upshift (firm not harsh, not spongey, may even chirp tires (in your case it should)).

Firmness may also depend on traction of tires and ATF fluid used.

At all times, engine must be functioning well and in tune (since PCM uses calculated engine torque to lookup various tables).

[B A Barakus]

Joe for Prez. Thanks man. Im sure I'll be back with questions as I continue to research this stuff. The tranny is shift from 1 to 3, then 4.. never touching 2nd... all by 22 mph (on a lift, no resistance). When driving , im in 4th inside 30-40 feet at low tps. Under constant , say 25% tps, car will up and downshift (or Im feeling tcc engage or disengage). Seemed great at WOT, except would bounce off 1st gear limited due to turbos spooling and rpm raising too fast..seemed liek tranny ws unable to shift before rev limit was hit.