converter stall

[falcon cobra]

Patrick has I think a C-4 and larry had one and now has a T-5 but what stall speed do you have or did you have with your converter? I need to get one other than stock. thanks ..jh:shift:

[BadBird]

Mine was a 3200 I believe. It seemed a bit radical for my liking. Something a little less maybe? Larry

[pbrown]

Mine is a 3400 custom made unit from Edge Racing.

[falcon cobra]

I was lead to believe the stall is to be about 500 rpm below cruse rpm, so lets say if it turns 3000 @ 60 it should be around a 2500 stall or its slipping to much. :confused: I could be wrong...jh

[doghows]

Hmmmm, mine is a stock converter for a 91 mustang with the 5.0. H.O. And it's 1800 stall? I ran this same setup in an early bronco and used a 1200 stall unit?
Any transmission shop guys on the forum?

[Luva65wagon]

Having been out of the loop concerning automatics until recently (like... as of last night) I have never tried to even figure out what "stall converter" even means. I know... and I call myself mechanically inclined.

I was always led to believe (from somebody I once asked) that the stall speed was the speed you had to achieve for 100% engagement of the converter. This was to allow engines with radical cam engines no load in-gear engagement rather than in neutral, then into gear, then into neutral, then into gear - doing so manually to keep the engine from stalling at an idle. When they accelerate and hit that RPM, by then they should be fully engaged. Whether there was some intermediate level of engagement - AKA slip of the converter - I don't know. Cause I don't know anything about this. But would really like to know once and for all.

:D

[doghows]

I think you hit it right on the head Roger. That was my thinking but I am no transmission guy either. That was the reason for the lower stall on my off road truck. Full engagement ,no slipping. I think the slipping part is in the converter not the transmission though???

[Luva65wagon]

I think the slipping part is in the converter not the transmission though???

As I understand it, yeah. You don't want slip inside the transmission under load for sure. Idling, maybe.

The torque converter is like a fluid clutch - and in fact I've read, and it was presented again to me this last week (John or Gene), that some have actually put a clutch in front of an automatic transmission somehow. It's been a while since I read about that - and it may have only applied to some ancient transmission. IDK. The "front pump" is directly connected to the converter, but I'm not sure it all that is doing the pumping. The converter is pumping too, I think.

But again, what do I know? Someday I will have to look into this. Maybe when I grow up.

[SmithKid]

B&M made it. Had several names: Clutch-Flite, Clutch-Turbo, and I believe there was one based on the C-4 or C-6.

[falcon cobra]

The B&m was a hydra-matic. with a clutch. go to www.hughespreformance.com (http://www.hughespreformance.com) they explain stall speed. my stock conv. sometimes would kill the motor when shifted to drive...jh

[ew1usnr]

These are some notes I took on the subject:
A higher stall speed equals greater initial torque multiplication and quicker take-off speed. The penalty for a higher stall speed is increased slippage which means higher temperatures and decreased gas mileage. It's a trade-off.

Fordomatic Transmission gear ratios: 4.37*, 1.82, 1 (1963 Sixes)
Fordomatic Transmission gear ratios: 3.73*, 1.82, 1 (1963 V-8)
*1st and torque converter. 2.40 x 1.82 = 4.37 and 2.05 x 1.82 = 3.73

"The 1963 Fordomatic has a torque converter multiplication of 2.40 (for sixes) or 2.05 (with a V-8) when the turbine is stalled providing a maximum overall reduction of 4.37 or 3.73, respectively, when the throttle is hit hard. Stall is an operating condition where the turbine is stationary and the engine throttle is wide open, making the rotational speed of the impeller as high as possible. Stall can be approximated to when a vehicle moves from rest. Maximum torque multiplication occurs instantaneously as the vehicle begins to move.

Stall speed is measured in the car by applying the brakes and revving the engine in First gear against the brakes. Most street cars cannot keep the rear tires from spinning if you add too much throttle, and this tends to limit the stall speed."

Fordomatic and torque converter:
3377

[pbrown]

Match the torque converter with the properties of the cam. Most cams will state what they need. If not, call the cam company.

Earlier autos including the C4 never achieve a no slipping mode of operation. This was introduced in the C5 and very common AOD. These have locking torque converters with actual clutch mechanisms that engage at higher rpms and in third gear and higher to eliminate slippage.

You don't want to run a stock converter with an performance cam.

[SmithKid]

A little "googling" shows the clutch/automatic is still being manufactured for all 3 of the major brands. Looks like the only requirement is lotsa $$$. I found a do-it-yourself kit for under a grand.