Stock converter stall?
- Thread starter 87gninpa
- Start date
Harleyreb1
New Member
- Joined
- Feb 2, 2010
1600 i think, I'm sure Dusty B will know for sure.
Royal-T-Ltd
Well-Known Member
- Joined
- Jul 12, 2003
i think its around 2200-2400 rpm
mikestertwo
Well-Known Member
- Joined
- Sep 13, 2006
It's in the 2000-2200 stall range depending on how much power you are making.
In GM terms it is a 2025 stall and that would be coded as CA8F and they are mostly the CB8F which is listed as a 1996 stall. These are calculated without boost by GM but you can always get more stall out of them with more torque the turbo 6 makes. So Mikestertwo is right.
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Dusty Bradford
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- May 24, 2001
Turbo converters don't have the same stall ratings as an n/a motor. An n/a motor makes a certain amount of power at a given rpm. So when footbraking an n/a car, the engine will reach an rpm where it will no longer gain more rpm.......this is found with using a transbrake.
With a turbo car, the turbo will make boost with the load from the converter, the rpm will continue to climb, generating more boost which in turn makes more torque........and they just continue to climb.
A stock converter may stall 1800rpm at 0 boost but stall 3200 rpm at 15psi. I generally rate the stalls at 0 boost. A stock converter usually comes in around 1800, a restalled D5 will be around 2200.
With a turbo car, the turbo will make boost with the load from the converter, the rpm will continue to climb, generating more boost which in turn makes more torque........and they just continue to climb.
A stock converter may stall 1800rpm at 0 boost but stall 3200 rpm at 15psi. I generally rate the stalls at 0 boost. A stock converter usually comes in around 1800, a restalled D5 will be around 2200.
i'm pretty sure the correct convertor for the 86/87 GN is CBCF original part # 8653420----replacement part # 8656954-------i have never seen any code convertor come out of a positively "known to be original" car except for a CBCF---------i think the clutch denoted by the third letter C makes it a stronger clutch than the code "8" ???.............RC
I have 8 of these in my possesion. All are from turbo Regals. Some hotair and some intercooled. All are this exact tag and codes. I have personally only seen one with the CA8F code and I think it was a fluke and none with the CBCF. The "C" as the clutch would make it stronger with the "330 ft/lb 28 degree travel" compared to the "8" having "300 ft/lb 44 degree travel". I am just presenting what I have in storage and what I have seen and my GM literature. I am more inclined to believe you and Dusty since you guys deal with these more on a daily basis than I have. Not may TRs around this area, especially that are stock. 
GM has been known to missprint.
GM has been known to missprint.I have 8 of these in my possesion. All are from turbo Regals. Some hotair and some intercooled. All are this exact tag and codes. I have personally only seen one with the CA8F code and I think it was a fluke and none with the CBCF. The "C" as the clutch would make it stronger with the "330 ft/lb 28 degree travel" compared to the "8" having "300 ft/lb 44 degree travel". I am just presenting what I have in storage and what I have seen and my GM literature. I am more inclined to believe you and Dusty since you guys deal with these more on a daily basis than I have. Not may TRs around this area, especially that are stock.
i do have a lot of them on the shelf from a lot of cars--------i have about 2 dozen that i think have enough of a pedigree that i can be certain about their authenticity and the CBCF code-------i'm not at my shop right now but from memory i think the 84/85's are coded CBBF--------that would indicate a similar unit but with a slightly weaker clutch, right???--------from everything i can gather i don't see any difference in the clutch code "8" and "B".............RC
You are right about the clutch. "8" and "B" have the same specs. I believe someone who has more dealings with these than the printing of GM, or whoever did the publishing of their documents for them. I have been dealing with these cars since '97 so you have a lot more experience than I do. :biggrin: Knowledge is power.
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
A stock 12" converter from a GN is about 400 rpm looser than a Monte SS converter.
