Trying to figure out how to get a higher stall cheaply. If you had a 454/TH400 combo what could you do to get a higher stall. Would a factory SBC converter stall higher behind the 454? Say the 454 converter was designed for a very heavy vehicle. Would putting it in a much lighter vehicle make it stall higher, lower, or the same? Or should I just stop thinking about all these little details when I wake up in cold sweats at 2am?
There is definitely some science to this. I know some people get a cheap high-stall for a 4l60e behind an LT1 by installing a S10 V6 torque converter. I've also heard you can put something like a Vega converter in a TH350 for a cheap high-stall.
More torque for the same given RPM will increase stall speed (say you put a BBC in front of a SBC TC). More vehicle weight will increase stall speed. Higher gear ratio will lower stall speed. Basically anything that creates resistance for the wheels to turn will increase stall speed.
so on the SBC/400. I can't think of a SBC that had a 400 , It seems though we got Vega TC to raise the rpm?stall for a 350 tranny.I think the heavier truck actually lock up at a lower rpm. the 70's cadillac's stall at 2600 B Bodies(full size) most cams that are streetable are coming on by 3000.If they wern't so heavy I'd send you a couple. go to a tranny rebuilder they have a listing of TC's and their Stall Specs.
If I’m not mistaken the factory corvette l88 with the th400 got like a 2200 stall . My dad has 12 to 1 427 tripower engine in his 69 convertible with a th400 that went in for autocross in the early 80s. Not sure if he changed the stall but it’s a factory 390hp l36 which he still has and was a very successful autocross car here back in the day.
One thing I’ve learned is a engine that makes more torque will stall higher then one that makes less.
Basically the stall speed goes up with greater torque and down with less torque. By extension, if you have two converters designed for the same stall speed but one was designed for a small engine and one for a larger engine, bolting the small engine converter to the big engine will give a higher stall speed.
I have used a stock torque converter from a 2.0L Neon in a 3.0L Caravan for a cheap ($100-120 at that time) high stall converter and was very happy with it. Just keep in mind that with stall speed comes heat and inefficiency. The amount of power you lose across the converter is going to go up so if you are building some high power car and actually concerned about your 1/4 mile trap speed you will probably need to spend money having qualified people build or recommend a proper converter. If you just want your mild project hot rod or DD to 'feel better' or only need a few hundred more rpm to get rid of that dead spot in the powerband leaving a light, then yeah, just bolt in a converter for the same trans from a smaller engine. You may have to change or modify your flexplate if the attachment pattern is different.
Of course the "right" way to do this is to get the proper stall converter, but this is GRM.
Yes, many small block converters will give you a higher stall... provided your big block is actually making more torque than the SBC application it came from. Most likely it is, even in stock form... but then again, you wouldn't want a higher stall in stock form.
Most small blocks used the smaller bolt pattern on the flexplate, so you'll probably have to either redrill or find an SBC application with the bigger bolt pattern.... or find the right flexplate for the converter you use.
You may also find that you are playing a guessing game. You might find that you went too far or not far enough and have to play with multiple TCs to get the right stall.
And its wise to add a cooler. And do your best not to decrease TC diameter. You want to find the largest converter you can with vanes that support your torque curve, not just reduce the size of the TC for heat reasons.
Thanks hive. That confirms some ideas I had and clarifies others. Now let's hope I can do the actual build instead of a mental build.
Back in the early 80's the trick was to go find a 4cyl late 70's Monza in the junk yard and grab the converter to put behind built 350s for cheap high stall... Magazines made it so popular you couldn't find them. The converter companies all cry'ed they wouldn't last.
I chose a rebuilt unit for my 67 Dart drag car from a place called GER out of PA they would cut apart the unit change the angles on the fins re-heat treat and weld and balance for $99! Everyone said they sucked don't do it.... It worked great. at 1st i thought it was junk as i didn't feel even the slightest drag / engaugement when i put it in gear. then i floored the gas and at 3200rpm the front end just lanched in to the air and the tire spun. So much fun.
I've got no idea if GER is still around or not.
Converters are relatively cheap - talk to the manufacturers, telling them what you have and what you want.
I have a Hughes 2500 stall in my daily '77 C10. Idle drop going into gear is just like stock (it's fairly cam'd, idles at 8inHg in drive), and if you drive it nice and gentle, it drives just like stock. Put the hammer down, and the engine scoots up to 2500rpm and the rest of the drivetrain catches up. I also have deep enough gears that I'm cruising on the highway at 3000rpm, well above stall. Got a big cooler, too. On a good day, I get 12mpg.
I was warned by Hughes "absolutely no towing whatsoever," so I drive super gentle when hauling stuff in the truck or doing a dump run with my trailer. I DO NOT haul much more than 1000-1500lbs at a time.
I think for my next truck I want high-stall again for the cam, but lock-up like a 4L60 or something, so I can have a lot less slip.
Some tranny shops can restall converters, ive been told its pretty cheap but no personal experience.
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