coupling and shift extension??? HUH
coupling and shift extension??? HUH Ok I'm finally getting this automatic transmission thing down but there's two things I can't wrap my head around yet nor can I get the answers. Well one I think I know the answer but not fully. So my questions are...
When someone says some stalls "couple faster" than others, what is that? Is that how fast they downshift and flash (aka get you going) from a roll? If so why not just say "flash faster"? If not, what the hell is it?
I've read that from a roll you want a stall with better shift extensions? Is that how much RPM they drop per shift?
Finally I haven't seen information on either of these on manufacture's sites. So how do you know what stalls are good and not?
When someone says some stalls "couple faster" than others, what is that? Is that how fast they downshift and flash (aka get you going) from a roll? If so why not just say "flash faster"? If not, what the hell is it?
I've read that from a roll you want a stall with better shift extensions? Is that how much RPM they drop per shift?
Finally I haven't seen information on either of these on manufacture's sites. So how do you know what stalls are good and not?
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From: Schiller Park, ILL Member: #317
After ~25 years of racing and modifying automatic transmission vehicles, I've never heard of the term "couple/coupling" before. Perhaps it's a more recent term for something that also has another, older name.
You are correct about shift extension though. This term relates to the rpm drop (or decrease of drop with the improved "shift extension" of a higher stall speed) after an upshift.
You are correct about shift extension though. This term relates to the rpm drop (or decrease of drop with the improved "shift extension" of a higher stall speed) after an upshift.
TECH Junkie
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From: White Bear, Mn
I think it is used in terms of when the impeller and turbine are spinning close to the same speed= most efficient point of the converter.
TECH Junkie
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From: White Bear, Mn
I shift at 7100 rpms and after a shift my rpms only drop to around 6200 rpms.
This is not a upshift comparison but this is my car going down the freeway at 80 mph in od with converter locked. I then go wot downshift into 3rd. Watch the rpms. Should give us a little idea on shift extensions especially if you're used to tight/ efficient low stall speed stock converters.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
http://www.hardtail.com/techtips/torqueconverters.html
TECH Junkie
Joined: Nov 2013
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From: White Bear, Mn
Interesting. I didn't realize there was a specific term for that, but it makes sense. Here's a tech article which references that term:
http://www.hardtail.com/techtips/torqueconverters.html
http://www.hardtail.com/techtips/torqueconverters.html
Good article also
Honestly with such a complex part I thought there would be more information ready when you go to buy one. Or am I wrong here and a 3600 from FTI is basically the same as a 3600 from Yank?
Assuming I'm right, how does one figure out the placement of shift extensions before buying a stall? Also how does one figure out the "coupling" of each converter without buying one?
Assuming I'm right, how does one figure out the placement of shift extensions before buying a stall? Also how does one figure out the "coupling" of each converter without buying one?
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After a shift it is where the rpms land after the shift. Like my car I run a pretty loose converter and it's a 4400.
I shift at 7100 rpms and after a shift my rpms only drop to around 6200 rpms.
This is not a upshift comparison but this is my car going down the freeway at 80 mph in od with converter locked. I then go wot downshift into 3rd. Watch the rpms. Should give us a little idea on shift extensions especially if you're used to tight/ efficient low stall speed stock converters.
https://youtu.be/hN6pPH8wfUA
I shift at 7100 rpms and after a shift my rpms only drop to around 6200 rpms.
This is not a upshift comparison but this is my car going down the freeway at 80 mph in od with converter locked. I then go wot downshift into 3rd. Watch the rpms. Should give us a little idea on shift extensions especially if you're used to tight/ efficient low stall speed stock converters.
https://youtu.be/hN6pPH8wfUA
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From: White Bear, Mn
TECH Junkie
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From: White Bear, Mn
Imo for most a off the shelf converter is fine but you can call and have one speced also.
There are just to many variables to put a simple guideline on a converter website on which to buy.
Different diameter, n/a, boost, nitrous, vehicle weight, shift rpm ect.
All converters are not all the same.
You could have something like I have pt4400 rated for 650 whp n/a and it's amazing.
Then you could have a different diameter 4400 nitrous converter rated for say 1500 whp and if I put that converter in my car I would probably be lucky if I could do a burnout power braking it.
What ya looking to put it in?
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After ~25 years of racing and modifying automatic transmission vehicles, I've never heard of the term "couple/coupling" before. Perhaps it's a more recent term for something that also has another, older name.
You are correct about shift extension though. This term relates to the rpm drop (or decrease of drop with the improved "shift extension" of a higher stall speed) after an upshift.
You are correct about shift extension though. This term relates to the rpm drop (or decrease of drop with the improved "shift extension" of a higher stall speed) after an upshift.
They may be similar but probably not the same.
Imo for most a off the shelf converter is fine but you can call and have one speced also.
There are just to many variables to put a simple guideline on a converter website on which to buy.
Different diameter, n/a, boost, nitrous, vehicle weight, shift rpm ect.
All converters are not all the same.
You could have something like I have pt4400 rated for 650 whp n/a and it's amazing.
Then you could have a different diameter 4400 nitrous converter rated for say 1500 whp and if I put that converter in my car I would probably be lucky if I could do a burnout power braking it.
What ya looking to put it in?
Imo for most a off the shelf converter is fine but you can call and have one speced also.
There are just to many variables to put a simple guideline on a converter website on which to buy.
Different diameter, n/a, boost, nitrous, vehicle weight, shift rpm ect.
All converters are not all the same.
You could have something like I have pt4400 rated for 650 whp n/a and it's amazing.
Then you could have a different diameter 4400 nitrous converter rated for say 1500 whp and if I put that converter in my car I would probably be lucky if I could do a burnout power braking it.
What ya looking to put it in?
I probably would go with something like the PT4000 but I don't want to drive around town like a CVT transmission at 3,000rpms all the time before lockup and have to go half throttle to get the car going. Plus I've heard that heavier cars make the looseness of the converter even more apparent while driving.
But I do want that hard hitting N/A stall and a GOOD roll racing stall.
TECH Junkie
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From: White Bear, Mn
A heavy *** G8 but it will have a 6l80 and not the usual 4l80 (I think) most fbody guys are used to here.
I probably would go with something like the PT4000 but I don't want to drive around town like a CVT transmission at 3,000rpms all the time before lockup and have to go half throttle to get the car going. Plus I've heard that heavier cars make the looseness of the converter even more apparent while driving.
But I do want that hard hitting N/A stall and a GOOD roll racing stall.
I probably would go with something like the PT4000 but I don't want to drive around town like a CVT transmission at 3,000rpms all the time before lockup and have to go half throttle to get the car going. Plus I've heard that heavier cars make the looseness of the converter even more apparent while driving.
But I do want that hard hitting N/A stall and a GOOD roll racing stall.
I will take a video today of my car driving and post it later today.
It does not take 3000 rpms to get moving and drives very nice.
You will see what I'm talking about in the video
Please do send a video but keep in mind I will be pushing around about 500lbs more than you
TECH Junkie
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From: White Bear, Mn
Couple videos here. Rpms on excel are a bit higher than I thought but it does not bother me. When I point the camera out the window that is to show that it's moving under its own power with just releasing the break pedal, no throttle.
Second video is a wot 2-3 shift to show shift extension. (Rpm drop after a shift)
Second video is a wot 2-3 shift to show shift extension. (Rpm drop after a shift)
TECH Junkie
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From: Iowa
you'll also have a 6l80e trans.
with a 4+ ratio 1st gear, you could put a soup can filled with vegetable oil in there and it would get off a stoplight.
If you don't understand how the converter works, then go with the recommendation from those who do like FTI, Yank, Circle D, etc etc
with a 4+ ratio 1st gear, you could put a soup can filled with vegetable oil in there and it would get off a stoplight.
If you don't understand how the converter works, then go with the recommendation from those who do like FTI, Yank, Circle D, etc etc
you'll also have a 6l80e trans.
with a 4+ ratio 1st gear, you could put a soup can filled with vegetable oil in there and it would get off a stoplight.
If you don't understand how the converter works, then go with the recommendation from those who do like FTI, Yank, Circle D, etc etc
with a 4+ ratio 1st gear, you could put a soup can filled with vegetable oil in there and it would get off a stoplight.
If you don't understand how the converter works, then go with the recommendation from those who do like FTI, Yank, Circle D, etc etc
-Dalton
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FTI COMPETITION CONVERTERS AND TRANSMISSIONS
"IT'S NOT CHEATING, IT'S THE COMPETITIVE EDGE."
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info@ftiperformance.com
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From: Wichita KS / Rancho San Diego
Well, i think your questions are impossible to answer without knowing the specifics of your car, for example the valvetrain, final drive ratio, and how high you plan to rev it. I suggest you consult with one of the converter manufacturers on here (Yank, Circle D, FTI) and spec something out with that will fit your car and what you intend to do with it.
Just for reference, all the posts here are about 4000+, but most guys with stock GT gears and valvetrain tend to run lower than f-bodies, like 2800.
Just for reference, all the posts here are about 4000+, but most guys with stock GT gears and valvetrain tend to run lower than f-bodies, like 2800.
On The Tree
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My new CircleD triple-disc 258mm has about 300-400 rpm drop between shifts.
It's a 3800. It's a little loose and I like it!!!
My old CircleD 278mm had about 1300-1500 drop. It was good but nothing like the 258mm.
It's a 3800. It's a little loose and I like it!!!
My old CircleD 278mm had about 1300-1500 drop. It was good but nothing like the 258mm.