What stall for my new torque converter??

[77CVT]

OK, my '77 just ain't got enough poke off the line!  Let's see some expert opinions on what the stall speed my new torque converter should be based on:

350, 8.5:1, 3.36 diff, TH350 with shift kit, comp cams xe256 (212/218 @ 50), extractors and dual exhaust, perf intake (port matched), stock heads with valve work, 2.02/1.6 valves, recurved dist, rebuilt QJet.  226 rwhp.

At the moment it hits 2000 - 2200rpm and really starts to go.  The cam is supposed to be from 1500 - 5000 & Desktop Dyno est peak torque at 3500rpm (but only 17lb more than at 2000).

At 100kph it is at 2550rpm.

Got any suggestions?

[rebel]

Dude r u kiddin' .... that's a killer setup and I remember you recently got the exhausts done and boosted HP at the wheels ....

The best performance is obtained with a converter that has a stall speed slightly higher than the rpm of the engine when it starts to produce its strongest usable power. Too low of a stall speed will result in a bog, and launches will be slow, since the engine will not be in it's usable power range. Too high of a stall speed will result in the engine reaching its peak power range below the rpm.

You don't say what the type or range of your converter is so it's hard to say but .. for your diff ratio and since you say she rips at 2,200, set it to 2,400 - 2,800.

It is very important to match all of the engine components; cam, carburetor, torque converter, rear end gear ratio, etc, to work in the same rpm range for the best results.

So .... my personall recomendation, stick 3.55 in the butt and set the TC for 3000.

You may also want to consider a Holley double pumper (750 or 850). Not sure but I think your QJet will be primaries / secondaries setup so the Holley will get more juice into the belly.

At the end of the day, it comes down to your bucks for bang ratio (how much you are prepared to spend and what your expected output is).

That's my opinion, if you want experts, call Steve from SR Performance and see what he tells you ... even though you're unlikely to be his customer as you're in another state, he's a good bloke and won't mind giving you advice.

This is a great question and posting 77cvt, we need more of this techo stuff  ...

thnx ....

[77CVT]

I have the stock converter - 1800 stall (I think).

"So .... my personal recomendation, stick 3.55 in the butt and set the TC for 3000."..ha, ha if I could justify it to the missus I'd have done that already! :22

I was thinking a 2400 stall.  From what I understand, a 3000 would still be slipping at cruise (2550rpm).  I was considering a TH700 swap but the wallet dictates most things with this car. :(

As for the Holley, I think they are best for mostly flat out applications rather than cruisers.  The QJet is a very underrated carb - you just need to set them up right for your application (and parts are impossible to get here! - that in itself probably justifies getting a Holley).

All this torque converter tech stuff gets beyond me sometimes.  So....there's gotta be some more opinions out there?

[rebel]

OK, as suggested 2400 should do the trick as it's just above your peek power. If you really want response, check ut some after market performance converters rated at 2k and above.

TH700 sounds good but there's nothing wrong with the ol' TH350 you're currently running ....

Anybody else ......