Home » Public Forums » GMCnet » Switch Pitch Torque Converter??? (How to use it)
| Switch Pitch Torque Converter??? [message #251332] |
Mon, 02 June 2014 19:25  |
lotsofspareparts
Messages: 726
Registered: May 2014
Location: Arlington, WA
Karma: -9
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So the 77 Eleganza II I recently purchased has a switch pitch torque converter with controller.
I am hoping someone recognizes the controller and can provide some information about how to properly use it.
I did fiddle with it a little while driving my purchase home.
Consists of a toggle switch, and a momentary push button.
Holding the button down while cruising @ 55mph caused the engine rpms to rise over 3200.
Flipping the toggle switch from one position made the rpms while cruising go up and down about 4-500 rpms I think.
Jared & Tina Lazaron + 14yr old Daughter.....
77 Eleganza II "Recherché".....
73 Canyon Lands 230 "Elephant"
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| Re: [GMCnet] Switch Pitch Torque Converter??? [message #251334 is a reply to message #251332] |
Mon, 02 June 2014 19:43  |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Jared, where the switch pitch really makes a difference is at low speed
like leaving a stop sign or stop light. Think in terms of torque
multiplication. The part of the converter that is bolted to the flex plate
turns at engine speed. The output shaft of the driven torus requires a
finite amount of force (torque) to make it rotate. The more oil that is
directed onto the vanes or the steeper the angle of the vanes, the greater
the force that will be applied. You will experience a difference in rpm as
well. Once the lock up speed of the converter is achieved, the less
multiplication of forces. Clear as mud, right!
Jim Hupy
With the route 66 rolling rally, currently at Ken Burton's hangar at
Valparaiso, IN. On to Ypsilanti, Mi. Tomorrow. Really missing Dwayne and
Sharon Jacobson.
On Jun 2, 2014 7:25 PM, "Jared" wrote:
> So the 77 Eleganza II I recently purchased has a switch pitch torque
> converter with controller.
>
> I am hoping someone recognizes the controller and can provide some
> information about how to properly use it.
>
> I did fiddle with it a little while driving my purchase home.
>
> Consists of a toggle switch, and a momentary push button.
>
> Holding the button down while cruising @ 55mph caused the engine rpms to
> rise over 3200.
>
> Flipping the toggle switch from one position made the rpms while cruising
> go up and down about 4-500 rpms I think.
>
>
> http://s287.photobucket.com/user/lotsofspareparts/media/1977%20GMC%20Eleganza/IMG_20140602_171151_4781.jpg.html
> --
> 77 Eleganza II "Recherché"
> Arlington, WA
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: [GMCnet] Switch Pitch Torque Converter??? [message #251336 is a reply to message #251334] |
Mon, 02 June 2014 20:03 |
lotsofspareparts
Messages: 726
Registered: May 2014
Location: Arlington, WA
Karma: -9
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Senior Member |
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Clear as mud is right.
So it is to be used when building speed from a dead stop.
I guess I will wait till I get the brakes up to snuff and experiment with it up and down our low traffic road.
Thanks for the info, Jared
Jared & Tina Lazaron + 14yr old Daughter.....
77 Eleganza II "Recherché".....
73 Canyon Lands 230 "Elephant"
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| Re: Switch Pitch Torque Converter??? [message #251337 is a reply to message #251332] |
Mon, 02 June 2014 20:03 |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma: 11
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Senior Member |
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lotsofspareparts wrote on Mon, 02 June 2014 17:25So the 77 Eleganza II I recently purchased has a switch pitch torque converter with controller.
I am hoping someone recognizes the controller and can provide some information about how to properly use it.
I did fiddle with it a little while driving my purchase home.
Consists of a toggle switch, and a momentary push button.
Holding the button down while cruising @ 55mph caused the engine rpms to rise over 3200.
Flipping the toggle switch from one position made the rpms while cruising go up and down about 4-500 rpms I think.
]
Love the switch pitch and the set of controls is nice.
The switch pitch has two stall speeds. One is lower RPM than the stock converter and I love that guy. That is the "normal" driving setting. When you flip the switch or press the button the stall RPM raises cinsiderably and is a higher stall than the stock. The reason for the button, I would think, is that when ever a torque converter slips... And unless you have a lockup converter they always slip... Heat is created. Slipping in actually inefficient and automatics have cooling lines to to dump the heat.
So, when driving normally, no switch or button, everything is tighter and less heat is built. Makes my coach acts more like a modern car... No big rev up, it just goes from a stop. But if there is a hill or you need to get up a freeway on ramp, the higher "switched" stall can get you moving. Just remember heat is rising in the transmission.
I think about 30 seconds at a hard pull is fine. Some say a minite. I dont see much on the temp gauge but have a feeling things are a lot hotter inside the torque converter. Using switch to maneuver in a hilly camp ground is fine. But to "switch down" on a long hill can spell disaster. The heat just can't be carried off fast enough.
So, getting on the freeway, hit the button. I have only a switch and tend to keep one hand on it so I don't forget.
About RPM... It varies depending on the current RPM of the engine. At 2800 both normal and switch are above their stall and the difference is slight. At 2700 running up the onramp it is sort of fun to have it drop back to 2400 with a bit of boost from engine inertia.
A simple definition of stall is lock the brakes, stomp the gas and look at the tach. (i dont do this to my coach...leave it to the race guys) Stock GMC is somewhere around 2200. Switch pitch normal, must be around 1700. Switch is something like 2600 or a bit more.
Love the switch pitch but you have to pay attention.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
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| Re: [GMCnet] Switch Pitch Torque Converter??? [message #251338 is a reply to message #251336] |
Mon, 02 June 2014 20:14 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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Jared,
Chances are your switch pitch controller came from Bruce C Roe. He's a
regular at our GMC EFI Google group. His email is his initials & last name
(no spaces) at juno.com. Check with him to find out whether that is indeed
what you have.
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI & EBL,
Manny Brakes & 1-Ton, etc., etc.
www.gmcwipersetc.com
On Mon, Jun 2, 2014 at 9:03 PM, Jared wrote:
> Clear as mud is right.
>
> So it is to be used when building speed from a dead stop.
>
> I guess I will wait till I get the brakes up to snuff and experiment with
> it up and down our low traffic road.
>
> Thanks for the info, Jared
> --
> Jared & Tina Lazaron
> Daughter: Alina Lazaron 7yrs old
> 77 Eleganza II "Recherché"
> Arlington, WA
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
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Unsubscribe or Change List Options:
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: Switch Pitch Torque Converter??? [message #251339 is a reply to message #251337] |
Mon, 02 June 2014 20:23 |
lotsofspareparts
Messages: 726
Registered: May 2014
Location: Arlington, WA
Karma: -9
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Senior Member |
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Awesome, thanks for the info.
I will put it to the test this weekend, after I finish the brakes.
Gonna let the wife take it for a spin this weekend as well.
She has never been comfortable enough to drive the truck pulling our 24' travel trailer but has driven the "Ginourmous" (her description) Uhaul from Sedro- Woolley WA to Meridian ID, which was over 400 miles. She drove it for a friend who flew her back to Sea-Tac afterwards. This coach will be nice for me as I can take a break from driving.
Jared
Jared & Tina Lazaron + 14yr old Daughter.....
77 Eleganza II "Recherché".....
73 Canyon Lands 230 "Elephant"
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| Re: [GMCnet] Switch Pitch Torque Converter??? [message #251343 is a reply to message #251338] |
Mon, 02 June 2014 20:32 |
lotsofspareparts
Messages: 726
Registered: May 2014
Location: Arlington, WA
Karma: -9
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Senior Member |
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Ken Henderson wrote on Mon, 02 June 2014 18:14Jared,
Chances are your switch pitch controller came from Bruce C Roe. He's a
regular at our GMC EFI Google group. His email is his initials & last name
(no spaces) at juno.com. Check with him to find out whether that is indeed
what you have.
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI & EBL,
Manny Brakes & 1-Ton, etc., etc.
www.gmcwipersetc.com
On Mon, Jun 2, 2014 at 9:03 PM, Jared wrote:
> Clear as mud is right.
>
> So it is to be used when building speed from a dead stop.
>
> I guess I will wait till I get the brakes up to snuff and experiment with
> it up and down our low traffic road.
>
> Thanks for the info, Jared
> --
> Jared & Tina Lazaron
> Daughter: Alina Lazaron 7yrs old
> 77 Eleganza II "Recherché"
> Arlington, WA
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Sent him an email with the picture I posted.
Would be great to have some more info about this.
Thanks for the info.
Jared
Jared & Tina Lazaron + 14yr old Daughter.....
77 Eleganza II "Recherché".....
73 Canyon Lands 230 "Elephant"
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| Re: [GMCnet] Switch Pitch Torque Converter??? [message #251354 is a reply to message #251338] |
Mon, 02 June 2014 21:30 |
lotsofspareparts
Messages: 726
Registered: May 2014
Location: Arlington, WA
Karma: -9
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Senior Member |
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Ken Henderson wrote on Mon, 02 June 2014 18:14Jared,
Chances are your switch pitch controller came from Bruce C Roe. He's a
regular at our GMC EFI Google group. His email is his initials & last name
(no spaces) at juno.com. Check with him to find out whether that is indeed
what you have.
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI & EBL,
Manny Brakes & 1-Ton, etc., etc.
www.gmcwipersetc.com
On Mon, Jun 2, 2014 at 9:03 PM, Jared wrote:
> Clear as mud is right.
>
> So it is to be used when building speed from a dead stop.
>
> I guess I will wait till I get the brakes up to snuff and experiment with
> it up and down our low traffic road.
>
> Thanks for the info, Jared
> --
> Jared & Tina Lazaron
> Daughter: Alina Lazaron 7yrs old
> 77 Eleganza II "Recherché"
> Arlington, WA
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Made email contact with Bruce, it is not his controller but he gave me good insight on how it is probably set up.
Jared
Jared & Tina Lazaron + 14yr old Daughter.....
77 Eleganza II "Recherché".....
73 Canyon Lands 230 "Elephant"
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| Re: [GMCnet] Switch Pitch Torque Converter??? [message #251355 is a reply to message #251336] |
Mon, 02 June 2014 21:45 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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lotsofspareparts wrote on Mon, 02 June 2014 19:03Clear as mud is right.
So it is to be used when building speed from a dead stop.
I guess I will wait till I get the brakes up to snuff and experiment with it up and down our low traffic road.
Thanks for the info, Jared
A torque convertor tends to lock up hydraulically as the speed goes up so the switch pitch becomes less effective the higher the RPM. It works best off the line.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: Switch Pitch Torque Converter??? [message #251358 is a reply to message #251339] |
Mon, 02 June 2014 21:49 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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lotsofspareparts wrote on Mon, 02 June 2014 19:23Awesome, thanks for the info.
I will put it to the test this weekend, after I finish the brakes.
Gonna let the wife take it for a spin this weekend as well.
She has never been comfortable enough to drive the truck pulling our 24' travel trailer but has driven the "Ginourmous" (her description) Uhaul from Sedro- Woolley WA to Meridian ID, which was over 400 miles. She drove it for a friend who flew her back to Sea-Tac afterwards. This coach will be nice for me as I can take a break from driving.
Jared
The switch pitch changes both the stall speed and the stall ratio--they are two different things but work together by not only increasing the torque multiplication but also getting the engine speed up where the torque is higher.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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