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View Full Version : Torque converter tune. Is it requiered?



yoheer
07-24-2023, 10:00 AM
I've swapped a rebuild v6 S10 converter to my LT1 Trans Am. 2.73 gears
Original TC is rated at 1,397 RPM
S10 converter is rated at 2,075 RPM. I've made a Brake test and actual stall is about 2,900-3,000
Do I need a tune for it and if yes what is it?

NomakeWan
07-24-2023, 11:14 AM
http://www.ltxtech.com/forums/showthread.php?29633-Stall-Wall-Help

Found this while looking around. I've never tuned anything more than shift points on the 4L60E as I've still got my stock converter, but what's written in that thread is sound from a theoretical standpoint and should work for you.

yoheer
07-24-2023, 11:31 AM
Thanx for the info.
Is it strong enough? I mean V6 converter.
I have a good healthy transmission.
Im afraid it can be damaged if the converter is destoyed.
It seems weird that 2,075 rated converter stalls at 3,000. I've made a brake test.

WASyL
07-24-2023, 11:01 PM
If You won't hit stall wall then nothing to be changed with torque converter swap.

yoheer
07-24-2023, 11:24 PM
What is stall wall?

NomakeWan
07-25-2023, 12:41 AM
Stall Wall is when your shift parameters for 1st Gear don't match the new higher stall, either causing the PCM to freak out and go into limp mode, or just causing it to fail to shift into 1st Gear at full throttle. Usually happens when a much higher stall speed torque converter is installed.

To see if you have that problem, just sit at a dead stop, put your foot on the brake, mash the gas pedal to the floor, then let go of the brake. If you just sit there with the RPMs bouncing off the limiter, you have a stall wall and need to change your tune to account for it. If you take off as expected, then you don't have a stall wall and are probably fine.

1project2many
07-26-2023, 08:03 PM
I have used a similar converter behind a 302 chevrolet in a K1500 Suburban for years. The engine and transmission have outlasted two Suburbans. I have added additional cooling capacity as well.

yoheer
07-27-2023, 12:56 PM
I have a big cooler alreagy.
Did you like your setup and driveability
I have a low end torque stock cam .
And now it is sluggish untill hammering the pedal.
I dont like it.

1project2many
07-27-2023, 07:40 PM
I like my setup. The combination of cam and small displacement engine is really good about making power to 5k+ rpm. It would be nice to have a little more low end when taking off with a trailer but it's very acceptable the way it is. If I were to make a change I would replace the 3.42 gearing with 3.73 gearing.

I would probably work on understanding the engine's powerband before changing the converter. I would probably not use a higher stall converter with a cam that produces peak torque at low rpm unless the vehicle configuration really demands it. I would definitely look at the tuning to see if there's any power to be found.