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11 inch converter

gtxrt

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how much difference in stall between a 1967 383 12 inch converter and a 1971 11 inch that came in a 383 super bee.
 
To the best of my knowledge the Torque converters were just like everything elese on these cars. They are not all the same.

383 -2 brl cars came with a different converter than a 383- 4brl . There was an optional high stall converter also offered.

THe answer to your question is not straight forward and needs a little more information. But I think its safe to say, the difference between lower rated and higher stall converters were generally around 300 - 500 rpm .

But I don't think anyone can answer your question, and say all 12 inch converter from 67 stalled at "x" and 11 inch from 71 stalled at "y'.
 
And engines of the day were sometimes different in their torque output....even if they were built to be the same, they usually weren't. An engine producing higher torque than rated can have a higher stall point using the same converter than an engine that produces lower torque than it was rated at. I had a 70 383 4 barrel Challenger that was a dog. It ran ok but not like many other Challengers that were built like it.
 
different in their torque output.
Agreed, This is why,say you want a 3000 stall converter,so you call and order a 3000 stall.They may ask many questions as far as engine build and type of car,weight,etc.Always give this info even if they don't ask.The first "Performance" converter I bought was for a 904 and I wanted a 3000 stall. That is exactly what they sold me. Put it in and it would stall at 2300 and no more.Called and asked why.Answer was how much Hp/Torque is in front of it? I said maybe 200 Hp.It was a Built Slant Six. Was told "Put 350 Hp in front of it and you will get your 3000 stall. This was 30+ years ago. Allot has been learned since then.
 
The difference between a 12" convertor and an 11" is very noticeable. A stock 11" will be much quicker than a stock 12".
As others have said actual stall speed varies a widely depending on the torque input and the internals of the convertor. That's why talking stall speed is nearly meaningless.
 
the reason i was asking in a 3800 lb car with 2.76 gears will be putting in 2.94 posi shortly with a mild built 440 and a hughes 24-20 11" street rod converter it has way to much slippage it flashes to 3500 rpms and just touch the gas at 60 mph it flashes 600 rpms. i have a choice between the stock 12' or the stock 11' of a 71 super bee. i was trying for maybe 200-300 rpms over stock 12" and no more. 11" might still be to much.
 
Factory stock 11'' of the late 60's and into the 70's had a stall speed of around 2200.That was cars with the HP Big Block engines.
I believe you will be fine with the converter from the 71 Bee.
 
the reason i was asking in a 3800 lb car with 2.76 gears will be putting in 2.94 posi shortly with a mild built 440 and a hughes 24-20 11" street rod converter it has way to much slippage it flashes to 3500 rpms and just touch the gas at 60 mph it flashes 600 rpms. i have a choice between the stock 12' or the stock 11' of a 71 super bee. i was trying for maybe 200-300 rpms over stock 12" and no more. 11" might still be to much.

Not sure why your 11" hughes convertor would flash 600 RPM at a cruising speed. But a good stock 11" convertor is just fine, not even close to too much.
 
Not sure why your 11" hughes convertor would flash 600 RPM at a cruising speed. But a good stock 11" convertor is just fine, not even close to too much.
hughes said because of the 2.76 gears plus weight of car, am cruising at only 2200-2300 rpms besides.
 
hughes said because of the 2.76 gears plus weight of car.

Ya, even so, at cruising speed the convertor shouldn't flash like that. At 60 MPH the weight of the car doesn't matter that much since it's already moving, but I guess that tall of a gear may trick the convertor some because it's resisting acceleration. A good working stock 11" is still a very mild piece that should perform well. A top quality aftermarket convertor can far exceed the OEM parts.
 
Ya, even so, at cruising speed the convertor shouldn't flash like that. At 60 MPH the weight of the car doesn't matter that much since it's already moving, but I guess that tall of a gear may trick the convertor some because it's resisting acceleration. A good working stock 11" is still a very mild piece that should perform well. A top quality aftermarket convertor can far exceed the OEM parts.
i will try the 11". i will post the results when i get it in at the end of the week.
 
I swapped my 12" for an 11" b&m holeshot 2400 on my 71 440, the 12" flashed to 2200 while the 11" went to 3200. I also added some alloy heads, cam etc at the same time so more power against the converter but same engine stroke. The 11" drives fine at light to medium loads but is a bit mushy at lower rpm's on moderate acceleration. I would be happier if it was a bit tighter for street use but it is OK. Some say the B&M converters are a bit spongy, I have around 8% slip at a 65mph cruise with 3.23 gears on flat ground. I would imagine a factory 11" would be tighter.
 
I ran a stock 340 11" convertor (similar to the RR/Super unit) behind a blown small block. Even with the torque of the blower motor it only flashed to around 2600. It will flash lower in your application.
Doug
 
got the 383 11" on, feels just right now. can tell it's a little more than the 12". i wouldn't want any more stall then this one.
 
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