Hey Guys, I need some input to get me close on my 95 4l60E tune. I have always run a 6 speed and recently switched to a race built auto. I would like some ideas on where to set the trans using tuner cat.

I JUST switched from the M6 to a 4l60e and havent driven the car yet, but switched the ecm to an auto.

The car is a 95 with a 355 built for spray (200 shot). I am curently running 4:10's and a 3400 nitrous converter. 275-40-17 drag radials. My shift point is 6200 rpm. Motor tune was done by me and is spot on, i just have never tuned an auto.

What should I change in the trans tables to give me a good base line to go with. I do drive the car on the street , maybe 7,000 miles a year.

Currently, the ecm has the stock trans tune in it, so what should i start with?

Thanks

 

I've finished the main portion of adjusting my shift points and lockup speeds and am in the fine-tune tweaking phase right now. If you're using tunercats, there are a few different tables you need to familiarize yourself with in order to get the tranny operations you desire.

Normal Mode Up/Down Shift Points
TCC Normal Mode Engage MPH vs Gear vs TPS
TCC Normal Mode Disengage MPH vs Gear vs TPS

The Up/Down shift points table lets you modify at what MPH the transmission will shift up or down a gear, depending on the throttle. If you're tuning for shifting based around a sweet spot in your powerband and/or a higher stall torque converter, the direct MPH value isn't so useful and you'll instead want to convert MPH/gear into RPM/gear, make your tuning adjustments based on the RPM values, and then convert back into MPH. I can send you an excel file to do this if you tell me your gears ratio and email.

In updating my shift point patterns I had three objective: keep stock-like performance for low throttle operation (~33% TPS or less) to maintain good economy; more aggressive gearing and holding for >33% throttle for more performance, and more aggressive kickdown operation for higher throttle (>%50) for a better "kick in the pants" feel when jabbing the throttle for quick passing. While you probably have an idea of how you want your transmission to perform, it's good to have specific goals to work towards instead of just shooting for something that works better. Once you've met a tuning goal you can revise it if it's not satisfactory, but it will help keep you on target and make logical progressive adjustments to reach it.

Shift points will have the biggest effect on "feel", much like changing to higher rear end gears, but changing the torque converter lockup and unlock speeds can help with drive-ability and economy especially with higher stall converters. Stock tune has the torque converter lock up at a minimum speed of 44 MPH in 4th gear, which is fine for the highway but lots of backroads around here have speed limits of 35-40 MPH which means lots of time spent unlock, killing gas mileage for mundane conditions. Slight hills will just have the tranny slipping instead of doing anything useful, so I wanted to get rid of that and have the converter lock up at lower speeds for normal driving but unlock with a stab of the throttle for better part throttle acceleration.

With the tables you can adjust 4th gear, and 3rd gear lockup and unlock MPH based on any TPS%, but you can also adjust 2nd gear to lockup (which in stock tune will never happen). I've found in normal driving that lockup in 2nd is more annoying than useful, but it can have it's uses when you've put the gear shift in 2 and don't want to shift to 3rd. Thus it can be useful to set your 2nd lockup values at a higher value than the 2->3 shift, in order to keep it locked in certain traffic situations or whatever you want when you're holding 2nd gear.

I think there are a few guides around to read about this. It seems like a lot to learn at first but it's pretty easy once you understand what's going on in the PCM and how that relates to real-world. You might find your initial tune way off at first but with some datalogging and taking things slowly and one at a time, you'll find good trans tuning makes a big difference towards drive-ability.