Help with torque converter?

[440fish]

First of all Merry Christmas to all..


Im going through the "debug" process on the 69 Bee i purchased recently. Bare with me as i don't know specifics on any of the engine internals as it was purchased from a dealer who didn't have any specifications.

When at idle (in drive) ~1050 rpms she really wants to "take off" and i need excessive brake pressure to sit at a light. I cant lower the rpms any more due to the big cam (no idea what the specs are) or it will stall out due to poor vacuum. This lends me to believe that the stall speed on the converter is too low for the engine?

Also, shes very soft coming off the line until the engine gets up in the 3500 rpm range where the cam comes into play. Am i correct to assume a higher stall speed converter will allow it to get up in the rpms some on launch? Sorry, im a 4 spd guy so this is my first 727.

Im not looking to have some sort of a drag car but i feel this thing is dragging an anchor until it gets up in the rpms... I chatted with B&M and they felt a Holeshot 2400 would be good for my needs?

Here's what i DO know about the power-train setup.

440 with Performer RPM, 780 Quickfuel carb, Comp 2" Headers, much bigger cam than stock. mopar electronic ignition. 3:23 gears with 17" / 255 tires.

I had a local speed shop fine tune the carb with an a/f diagnostic tool when i bought the carb so the carburation is pretty spot on. She starts, idles etc very nicely.

Thank You

 

[dvw]

How big is the cam? A stock 10 3/4" converter should stall at close to 2400 with your combo. Depending on the cam you may not like a loose converter with the 3.23 gear. Can you get it to idle lower than 1000 in gear? How much vacuum does it hold in gear?
Doug

 

[wedge5]

I would have to say first off that the gears are not doing you any favors with a large cam. Second off a 10" converter with a 3500 stall would be bare minimum, that 2400 stall is a waste of time

My last 440 used a .509 cam, 10.5 CR, 4:10, 29.5" tires with a Dynamic 10" 3500 converter. It cruised great on the street and highway, it also launched like a SOB.

My old drag car(sbc, it was cheap) Anyway, used a low 500 lift cam and I had a B&M 2400 stall. The car fell on its face until 3500 or so. Ditched that stall and installed a 3500(off brand). The car woke right up with that change.

Call Rick at A&A transmission, explain your combo and he will head you in the right direction. He is a true Mopar guy also.

 

[440fish]

I would have to say first off that the gears are not doing you any favors with a large cam. Second off a 10" converter with a 3500 stall would be bare minimum, that 2400 stall is a waste of time

My last 440 used a .509 cam, 10.5 CR, 4:10, 29.5" tires with a Dynamic 10" 3500 converter. It cruised great on the street and highway, it also launched like a SOB.

My old drag car(sbc, it was cheap) Anyway, used a low 500 lift cam and I had a B&M 2400 stall. The car fell on its face until 3500 or so. Ditched that stall and installed a 3500(off brand). The car woke right up with that change.

Call Rick at A&A transmission, explain your combo and he will head you in the right direction. He is a true Mopar guy also.

Thanks for the advise. From what im finding the 2400 seems a little low. Is Rick a member here?

Ultimately the car is a street machine that willl see some highway driving but it needs some more launch. I plan on gears too so id like to talk to a knowledgeable tranny shop.

 

[HT413]

There is a guy selling a COAN 3200 stall converter here. From what I know of his combo, if it idles well in his, I'd bet it would be a kitten in yours. Talk to him.

 

[Greg Ducato]

If your idle in gear is over 1000 rpm and pushing against the brakes I would suggest at least a 3000 stall and maybe higher. This will not only let the engine get into it's power easier but will also produce a more comfortable idle. You will be walking a fine line with 3.23 gears as the stall speed will be very close or greater than cruise RPM. If you plan to keep those gears invest in a huge trans cooler.