Aftermarket Torque Converters

    I am in the process of swapping out my old stock C4 for a PA Super Streeter transmission. My old one bled to death on the garage floor. As part of the process I also want to upgrade from the stock converter to something a little beefier. I don't need anything too radical because I only use the car for street driving, no racing. I have been on the web looking at all of the suggestions, formulas, etc. I even called a few places. I can't figure how high of a stall speed to go with. According to the shop manual a Hipo came from the factory with a 1750-1950 rpm converter. According to the aftermarket manufacturers, I should be running a 3500-4000 rpm converter because of the 310 degree duration of the cam. But that's with 3.73 and above gears. I am also being told that if I go higher than 2400 stall, that I have to install an trans cooler. Does anyone have any suggestions? Has anyone else found a combination that works?

    Great topic as I've pretty much always been a stick guy but within the last 10 years have excepted the automatic thing.Anyway I've played with a bunch different combinations thru the years and for your application I would go with a 2800-3000 rpm stall.Don't go with no more then that as it's tough to drive on the street.A 2500-2800 with under a .300 duration camshaft is perfect but anything over that you should be in the 3000 rpm stall range.What ever convertor you buy check with manufacturer as weight of car(big factor)make a difference in flash point of convertor and they usually have all that data.From all the practice I've had a install of a tranny cooler on any automatic is a great thing and a requirement as far as I'm concerned even on stock trans as heat is what takes a automatic out.Most people spend a good dollar amount redoing automatics with good parts like shift kit(biggest bang for the buck),servo,extra clutches,convertor etc. so take from someone who knows as I've spent years track testing mods to tranny and motor combinations.With your gears etc. it should run real good so take it to the track and have some fun.

    I guess I'm just not understanding the whole theory behind the stall RPM. I think the best explanation I've read is it is the equivalent of dumping the clutch on a manual trans. So a 2400 rpm stall is like revving your engine up to 2400 RPM before you let out the clutch. On the other hand I've been told that it is the point where the engine will stall if you give it gas while holding the brake. That would make sense to me ("stall" speed). All I know is when I bought the car it only had 2nd & 3rd gear and the previous owner broke the tires loose pulling out in 2nd. With a stock 1950 rpm converter.

    I can tell you that I would stay around 2800, no more than that. Also, yes to the cooler question. A cooler and changing the fluid every 20,000 miles will go a long way towards keeping it in one piece.


    Also, the most important thing. Wanna sell the old tranny?

    With any automatic you don't want to foot brake it as you take the stall out of the equation.The whole idea of a convertor with stall is to use it in the manner for which it was designed.Yes it's like dumping a clutch at 3000 rpm and the flash I talked about is the time between idle to lock-up point at which the convertor reaches it highest point with lock and then motion.I personally change fluid about every 15000 as the factory requires change at 30000 but automatic trans fluid has cutting properties and should be changed on a regular basis.I've run 8500 rpm stalls before but only for drag use!

    RPM, you said I shouldn't go with higher than 3000 rpm because it would be tough to drive on the street. Why? I guess the only way I an going to truly understand this is a comparison. I have 2 equal cars one with a 2000 rpm converter and one with a 3000 rpm. What happens when they are at a dead stop and pull away? 66kcar, the transmission I'm taking out is a PEE-C code with a 1967 date code. Not a PEE-K.

    A stock convertor is around 1200-1400 and produces a moderate amount of heat with no take off because it's locked all the time.Duration kills bottom end as it's designed to work on the top end so you need something to wake it up down low.With a stall speed of 3000 the convertor is loose or not locked up all at once letting the rpm's come up to where it does lock fully so it will leave better.With that big a duration camshaft the motor will be sluggish at best with little performance until you get rolling.My thought is why go thru the extra bolt ons unless your looking for performance.Now with that being said the convertor at 3000 stall speed and tranny cooler you'll be ready to do some performance runs.

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