stall convertor?

My boy Jason drives an 99 with an LS1. He's runnin about mid-12 maybe a little faster. I've got a Hurst Promatic 2 shifter with the Hurst shift kit, Jason tells me a 2800 stall will make my car shift harder. Is this true? I thought my TH350 was maxed.

As I understand it, a higher speed stall setting on the converter allows the engine to attain a higher stall RPM and is independent of the shift settings. If you hold the brakes, put the trans in drive and run the engine up to the maximum rpm it can go to, that is your stall speed. The purpose of a higher stall speed is to get the engine up into the higher HP range of RPM's to get a better launch. Engines with a lot of torque, like a Pontiac block, don't need a high stall speed, while the SBC can be helped with the higher stall speed.

stall is also needed when you have high than stock power if you don't change it it will cause the factory cheap one to "balloon" and then the thing won't launch at all

That's true, you always have to consider other upgrades when you pump up the power. I was not sure if he was talking about two cars or one car, but since a late model year probably does not have a TH350, and the trans was beefed up, I was assuming he was not upping the power any more.

I bought a rust free '56 two door Chieftain in the 60's (in Utah). It had a four speed hydramatic, and the stock 316 with a two barrel. I changed it to a 389 four barrel from a '60 Bonnneville, but kept the original hydro. I put the widest tires I could find (9.50X15) on the rear. With the large tires and high gearing (3.23) I did not have enough power from a stop to spin the wheels (that was good, since the launches were super fast for what I was running), but when it shifted to second gear it would chirp the tires. I had lots of fun with this sleeper, and then drove it all the way to NY towing a boat!

to high a stall and not enough power will actually slow you down

What Volkerc says is true. A stall converter can hurt you.
In answer to the original question, no, the trans will NOT shift harder. Actually, the opposite is true. Due to the higher stall speed (defines as where fluid "lockup" occurs), the converter will soften the shifts. Of course, if at a very high RPM, and the converter solidly locked up, it will hit as hard as it's capable of, but no harder just because of the converter.
To choose the correct converter, get one about 400 RPM below "cruising" speed. That is, see what RPM the engine is turning at the desired highway cruising speed (not max). Usually in the 55-65 range. The converter must be beyond "lockup" or "stall" before that. If not, excessive heat will be generated by the slippage inside the converter, as well as all the fuel going out the tail pipe. This guideline is for street vehicles, NOT race cars.

What Volkerc says is true. A stall converter can hurt you.
In answer to the original question, no, the trans will NOT shift harder. Actually, the opposite is true. Due to the higher stall speed (defines as where fluid "lockup" occurs), the converter will soften the shifts. Of course, if at a very high RPM, and the converter solidly locked up, it will hit as hard as it's capable of, but no harder just because of the converter.
To choose the correct converter, get one about 400 RPM below "cruising" speed. That is, see what RPM the engine is turning at the desired highway cruising speed (not max). Usually in the 55-65 range. The converter must be beyond "lockup" or "stall" before that. If not, excessive heat will be generated by the slippage inside the converter, as well as all the fuel going out the tail pipe. This guideline is for street vehicles, NOT race cars.


glad we agree on something, lol

Appreciate it guys. I'll work on the hp a little longer then worry about the stall.