How to Choose Stall Speed of Torque Converter

[jdraker62]

I have a 2006 Mega cab 4x4 with a 5.9L Cummins. I don't have any modifications on the truck other than gauges, double deep Trans pan, Carli Leveling Kit and 35" tires. I am geared at 3.73. I have no idea what stall speed I should choose in a converter. I don't plan on racing the truck, I do plan on upgrading the transmission and adding a tuner and turbo upgrade. I will not be street racing although it would be nice to keep up better to our SRT Challenger. The truck has 130k+ miles on it and the transmission temps are starting to creep higher to around 160 to 170 going down the interstate in 80 degree weather. Thank you for your advice. I am purposely staying away from transmission builders in this thread.

 

[promisedland]

I put a Goerend 900-400 Triple disc TC in my truck,.. pulls much better! The stock TC is soooo loose. This one is 300-500 [i think] lower stall then stock. I dont have any check eng. codes at all. Was told i might.
Stock stall is about 2200rpms.

 

[cerberusiam]

The 900/400 would work fine with a tuner and few tweaks. It will be short on gear when trying to tow heavy but it works pretty well empty and light load. The 35's hurt the low end with 3.73 gears. The 06's are alot more sesceptible to DTC's from a tight TC than other years. More of an annoyance than anything. A tuner will help alleviate that problem.

I am thinking the 800/300 would be even better but it wil take a tuner and matching gears\tires a lot better to work effectively. The 900/400 seems to be a lot more forgiving in multiple combinations.

It will take a few more $$ to keep up better the SRT, even traction challenged as the SRT is.

 

[Tuesdak]

After the tuner and turbo upgrade do a video of the tach and boost from a 0-60 run. Then send the video to Yank and call them. Explain your setup and goals to Dave there and they can build you a converter to match your setup and goals. You may need DOT slicks...:-laf

Turbos are a trade off no matter what. (Not talking about the later year variable type turbo your truck doesn't have) Go larger and while you gain upper RPM power you trade the low end RPM. Simply put a large turbo will not spool up at low RPM like the small turbo you removed. This means you use a higher stall converter to allow the engine to come up to an RPM the turbo lights off at.

Give you an example of how the stall speed is part of a complete setup: Although the 5.9 has lots more low end I went through this with the GM 6.5 TD rat rod of mine. Put a large turbo on that pulls like a freight train past redline. Great for pulling a grade with a trailer that was my first goal. Sucks leaving the light as I wait for enough RPM for the turbo to light off, blow out the smoke, and get out of it's own way. Threw a 2400 RPM Yank triple disc at it. Now it revs the engine to 2000 RPM, turbo lights off, and if I am on the brakes will light up the rear wheels. It absolutely gets out of it's own way now and has the full benefit of the big turbo. When up to speed the TC clutch locks in and thus no heating or MPG concerns.

With a larger turbo stock stall may be a good setup as well as lower stall. Again it depends on your goals and specific to getting the engine to the power band ASAP to run a SRT down or MPG...