Torque Converters

[VermontTy]

This has been discussed in several areas (I've searched ) but haven't really found the specific cut & dry answer I'm looking for.

Can someone tell me...how to select the correct stall RPM based on modifications made (stock engine, fuel-internal-turbo upgrades, then an all out drag strip engine) What is "the norm" for each level of modification, if there is such a thing. What is the pro and con of going with a 2800 versus a 3200rpm stall? What is the performance gain of going with one or the other? Going with a lockup or non-lockup? What kind of driving style would best fit what style / rpm converter?

In my case, Waller is building me a engine with kind of the usual goodies; eagles, SRP, ported intake & Vortecs, Comp cam, 20g. The truck has a 3" system, Walbro, RPM AFPR, 50# injectors, ATR I/C pump, aux. I/C and will be running an Ultimate. I'll end up having Walller build my tranny once all is running again this spring.

I'm not looking to build a world class 11 second truck, but want to be able to do the occasional boosted launch and 1/4 mile run. It'll mostly be a daily driver. Reliability and driveability is above all out performance for me. Any thoughts or suggestions would be appreciated. I apologize of there is a thread somewhere I missed with this exact info, feel free to add a link to it. Thanks all.

-adam
::brews::

 

[tbauer03]

waller would be the man to talk to about stall converters but if you are just using a 20g turbo you shouldn't need a high stall at all. The stock converter would work fine but you may want to upgrade to a nicer converter since everything else is getting upgraded.

 

[Captain Morgan]

Re: Torque Converters

What is the pro and con of going with a 2800 versus a 3200rpm stall?

Stall speed for a stock or mild motor will usually be based purly on the size turbo you are running. For a 20G, TE-44, ect, a 2800 stall converter is probably the most popular choice. Larger turbos will benefit from a higher stall, 3000-3200. Ballbearing turbos however run just fine with lower stall converter due to there easy spool up.
Of course, all that balances on how you drive the truck, either lots of street or lots of track.

From the sounds of it, you'll be just fine with anything in the 2800 range.

What is the performance gain of going with one or the other?

The performance gain will come in the form of less turbo lag.

Going with a lockup or non-lockup?

Unless you plan on driving it like 80% on the track and 20% on the street, stick with a lockup converter.

What kind of driving style would best fit what style / rpm converter?

everything above.

 

[tnsyty]

What is the stock convertor stall again? I thought it was already around 2600-2800. When i installed my 20G, I could not luanch at anything above 2psi. It just couldn't spool enough. I was told to use a 3000 with thet 20G turbo. On the old turbo, I could Luanch at 8-10 psi. Hmmm.

 

[93ty475]

What is the stock convertor stall again? I thought it was already around 2600-2800. When i installed my 20G, I could not luanch at anything above 2psi. It just couldn't spool enough. I was told to use a 3000 with thet 20G turbo. On the old turbo, I could Luanch at 8-10 psi. Hmmm.

my stock stall was about 2100 to 2150....my syclone came with a 20g with the larger exhaust housing...i think it was called the "big dog turbo" or something like that...it sure was a "dog" with the stock converter...i could hold zero to 1 lb of boost at the line and ran consistent 2.35 short times...i imagine you would need at least 2800 stall for that turbo...