Thread: Stall converter

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Originally Posted by Stu Cool

Since your engine builder is familiar with your motor, the cam they put in it and your vehicle, I would ask them for a recommendation. You could get second and third opinions from a couple of the converter builders.

A literal explanation of what stall speed is: The RPM the engine will rise to when you apply the brake and throttle at the same time. A strong engine like yours will over power the brakes at some point and begin to spin the tires or slide the car forward. A transmission brake in a race application will enable you to give more throttle without this happening. A "high stall" converter will be looser as techinspector said, that will allow the converter to slip at lower RPM and not push the vehicle forward and will finally "Catch" at a higher RPM and give you a better launch. Compare it to a stick shift car, a stock converter is like dumping the clutch and flooring it at 1100 RPM. A 3000 stall converter is like dumping the clutch and flooring it at 3000 RPM. Of course there will be a little more slippage with the automatic, but that illustrates the point. Given your motor, I would think 4000 Stall would be too much for anything that you plan to drive very much on the street. Again, ask your engine builder what they recommend, and if you must error, I would suggest you do so on the low side.

Good luck with it, sounds like they built you a nice street fighter. Be careful!

Pat

Hi, I am looking for some information, and you seem to know your trade very well.
I changed an old 350 engine from a 1976 truck to a ZZ4 350 and installed a TCI SSF 700R4 tranny with a 2800 TC and changed the rear to a Posi 4.10, have not done anything else.

I am wondering though, people are telling me the truck should be spining rubber and the truck should be going like a bat outta hell, but all I can get is half ass performance. The Vacuum and Idle all seem normal, someone said maybe the timing might be off, but this is all brand new and installed by a Professional.

The Tires Chirp going from 1st to 2nd, however, can't seem to get the wheels to spin.
Should I be standing on the brakes while I give it gas? Is that not hard on the brakes? The Vehicle wants to creep forward as it is at stop lights when I have the brakes on. and the Rear seems to be making noise at this point just kinda creeking and squeeking, but once you drive the sound stops.

Any input is appreciated, thanks.

Wow, with that engine, the low first gear in the 700R4 with a 2800 stall and 4.10 gears it should snap your neck on take off and 1-2 shift should come pretty quick. I just read the previous posts so now I know more about your vehicle. 6200 lbs is a lot of beef to move even with the ZZ4, which is typically ideal for vehicles under 4000 pounds. With all that weight getting the tires to smoke may be a problem. A cam change to something set for more torque may help.

Pat