Tbi tuning for 4l60e shifting

Printable View

11-05-2019
5.7sierra

Tbi tuning for 4l60e shifting

I was reffered to Dave on this site for the question below.
My setup is a 95 k1500 5.7tbi. I have Dart iron eagle heads, flat top pistons, 202/208 lt1 roller cam. Long tube headers with true duals and Borla mufflers. Since modifing the engine the 4l60e now shifts a little early, especially into 4th. It locks the torque converter early also which lugs the engine. Do you think buying a stage 2 Jet chip will change the shift points enough? Other options would be to order custom chip or start learning to burn eprom.
11-05-2019
Fast355

Quote:

Originally Posted by 5.7sierra

I was reffered to Dave on this site for the question below.
My setup is a 95 k1500 5.7tbi. I have Dart iron eagle heads, flat top pistons, 202/208 lt1 roller cam. Long tube headers with true duals and Borla mufflers. Since modifing the engine the 4l60e now shifts a little early, especially into 4th. It locks the torque converter early also which lugs the engine. Do you think buying a stage 2 Jet chip will change the shift points enough? Other options would be to order custom chip or start learning to burn eprom.

Jet will not do anything to help you. Time to custom tune it. I refered you to Dave because he has done mail order tuning. I too have done it but have been so busy with work and projects I have not had time to mess with it in a couple of years. I am sure you are making more torque with less throttle which causes your upshifts and tcc lockup to happen at a lower road speed than stock. I have done nearly the same build before that you are running. I had Vortecs. With the 3.08 rear gear and 28" tall tire I did not shift into OD until almost 60 mph. Below 60 mph it was 3rd with lockup applied. Locked 3rd was ~2,200 rpm @ 60 mph and 4th locked was ~1,600. I much prefer driving around with the converter locked than unlocked for efficiency and heat reasons. You would also probably be surprised how much a well dialed in tune will also eliminate that "lugged" feeling. With the swirl ports gone you will need more timing advance overall.
11-05-2019
dave w

1 Attachment(s)

BlueCat Transmission Tuning: https://forum.hptuners.com/showthrea...Table-Software

BlueCat screen shot below:

I use Excel to Copy / Paste / Transpose the BlueCat tables into the TBI Chip.

dave w
11-05-2019
5.7sierra

Quote:

Originally Posted by dave w

BlueCat Transmission Tuning: https://forum.hptuners.com/showthrea...Table-Software

BlueCat screen shot below:

I use Excel to Copy / Paste / Transpose the BlueCat tables into the TBI Chip.

dave w

Thanks guys. I will buy the stuff and start tuning. Sounds like it's well worth the time and effort.