Z28GEN3

My engine is not stock, head work, chip work and cammed with some induction improvements along w/ an O.E. I am currently rebuilding my 1985, 27-splines, 700r4 tranny, i purchased a transgo shiftkit and have almost everything installed for automatic shifts including the 3-4 springs i have not completed the rebuild as of yet but it is 90% put together. just lacking a cooler and converter. my idle speed is about 1000-1200. everyone i've talked too says get a stall speed of 2000 to 2800 now i've checked out prices of those converters anywhere from $300-800, i think its over kill its just a 305 tbi. I did not get a stock converter with the trans as i got it for $90 with every intention of rebuilding it, and replacing the converter

Can anyone offer me a cure for this or suggestion on where to pick up a converter, would a remannedwith just a little higher than stock stall speed be okay or would a stocker work? I dont know anything about converters.

Berlinetta00

First, Ill explain the function of the converter, then you might better be able to decide which one is right for you.

The torque converter works as the "clutch" in an auto tranny, allowing for slip between engine speed and vehicle speed. It does this through a fluid coupling, which is to say that it is a hydrolic process. The converter has three basic parts: The impeller, the turbine, and the stator. The impeller is attached to the crank of the engine via the flywheel, and is the "pump" or the driving member. The turbine is the "driven" member, and is attached to the input shaft on the tranny. Imagine two fans facing each other. When one fan spins at a certain speed, the other fan will start to move as well from the air pressure. That is basically the inside of a converter.

Now the stall is the speed at which the turbine starts to spin in turn with the impeller. A lower stall will give you better streetability as the car will move more or less as soon as you let off the brake. A higher stall will make starts a bit worse, as the engine would have to rev to 2500 or whatever before the turbine would spin at a similar speed as the impeller. The positive side of the higher stall is by the time the car starts moving, you are well into the power band of the engine.

Floor guy

If I owned your car I would shoot for 2000-2200 stall. You are very limited in choices if you stick with the 27 spline.

Z28GEN3

Okay so maybe i miscounted the number of splines on the input shaft, i used some play-doh and pressed it on the splines i cut between one of the splines w/ a razor and i count 30 splines, not 27 like i previously thought.

Floor guy

How much money do you want to spend on a converter? If low budget, give Brian at Oregon performance transmissions. I bought a 2100-2600 stal factory type converter for $152 delivered. If you are looking for a quality converter check out pro-built. He is a sponsor on this forum.

Z28GEN3

I really dont have a high budget $230 is the most, i about flipped out when i saw the one i wanted for $800.