Explain this stall converter stuff, please!?!?

1989_351W · 08-27-2001, 06:15 AM

I'm only familuar with a 5 speed.
I don't understand stall converters. What does it mean a 2500 stall?
What is the stall for a stock AOD?
Is a stock AOD going to be able to handle a mildly modified 351W?

------------------
Michael Wigton
1989 351 Windsor
1964 1/2 Convertible

silver_pilate · 08-28-2001, 04:04 PM

The torque converter in an AOD is analogous to the clutch in a T-5...it links the engine to the tranny. Also, the same way you can "slip the clutch" while launching, the torque converter "slips" to allow rpms to rise. In other words, at the track, you would launch anywhere from off idle to 5000 rpms with a five speed to get the best launch. Similarly, whey you go WOT on an AOD from a standstill, the engine will be able to quickly rise to the stall speed of the converter and give you a better launch.

In most basic terms, the torque converter uses fluid dynamics and some big impellers to multiply torque from the engine to the tranny. The converter is designed so that there is a given amount of slip in it, or in other words, the engine is allowed to rev faster than it is turning the tranny. This allows the engine to reach its power band more quickly and thus make maximum power more quickly. The stall speed is basically the point where the converter will no longer slip and the engine is linked directly to the tranny.

On a stock AOD, the stall speed is somewhere around 1500 rpm. This is too low for the torquey 302 which makes it power somewhere around 2000-2500 rpm. A converter stalling around 2800 rpm is ideal for a midly to moderately modified mustang, however the stall speed of a given converter is not an absolute. It all depends on the amount of power and torque your engine is making.

Boy this is really getting rambly, so I'll cut it off now. If you have any more questions, let me know.

--nathan

------------------
--silver_pilate

'91 GT, Built 306, Wolverine 1087 cam, ported Windsor Jr. Irons, and all the goodies...click the link to the left to see a full list of my mods...

Tried and True 302 Being Built to Outrun You! heh heh heh...
--Texas Panhandle--
Check out my site

[This message has been edited by silver_pilate (edited 08-28-2001).]

08-27-2001, 06:15 AM	#1
1989_351W Registered Member Join Date: Jul 2001 Location: Spring Lake NC 28390 Posts: 44	Explain this stall converter stuff, please!?!? I'm only familuar with a 5 speed. I don't understand stall converters. What does it mean a 2500 stall? What is the stall for a stock AOD? Is a stock AOD going to be able to handle a mildly modified 351W? ------------------ Michael Wigton 1989 351 Windsor 1964 1/2 Convertible

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08-28-2001, 04:04 PM	#2
silver_pilate DURKA DURKA!! Join Date: Sep 1997 Location: Lubbock, TX...(TX panhandle) Posts: 1,418	The torque converter in an AOD is analogous to the clutch in a T-5...it links the engine to the tranny. Also, the same way you can "slip the clutch" while launching, the torque converter "slips" to allow rpms to rise. In other words, at the track, you would launch anywhere from off idle to 5000 rpms with a five speed to get the best launch. Similarly, whey you go WOT on an AOD from a standstill, the engine will be able to quickly rise to the stall speed of the converter and give you a better launch. In most basic terms, the torque converter uses fluid dynamics and some big impellers to multiply torque from the engine to the tranny. The converter is designed so that there is a given amount of slip in it, or in other words, the engine is allowed to rev faster than it is turning the tranny. This allows the engine to reach its power band more quickly and thus make maximum power more quickly. The stall speed is basically the point where the converter will no longer slip and the engine is linked directly to the tranny. On a stock AOD, the stall speed is somewhere around 1500 rpm. This is too low for the torquey 302 which makes it power somewhere around 2000-2500 rpm. A converter stalling around 2800 rpm is ideal for a midly to moderately modified mustang, however the stall speed of a given converter is not an absolute. It all depends on the amount of power and torque your engine is making. Boy this is really getting rambly, so I'll cut it off now. If you have any more questions, let me know. --nathan ------------------ --silver_pilate '91 GT, Built 306, Wolverine 1087 cam, ported Windsor Jr. Irons, and all the goodies...click the link to the left to see a full list of my mods... Tried and True 302 Being Built to Outrun You! heh heh heh... --Texas Panhandle-- Check out my site [This message has been edited by silver_pilate (edited 08-28-2001).]