moran75

Switch pitch torque converter - manually selected?

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Hi All

 

im running a stock 1965 riv 401ci.

 

interested in learning a bit about real world operation/benefits of the switch/variable pitch torque converter.

 

When working properly is the high setting automatically switched on when at a stop - in other words you have no choice- or is there some way of manually selecting it as and when you want to pull away a bit quicker from a stop? Off and on when desired?

 

all the best

 

kev

 

 

 

 

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1 hour ago, moran75 said:

When working properly is the high setting automatically switched on when at a stop - in other words you have no choice- or is there some way of manually selecting it as and when you want to pull away a bit quicker from a stop? Off and on when desired?

 

Stock set-up is automatic via switches on your throttle lever and throttle .

 

Here is a link with good info:

 

http://www.buickperformanceclub.com/SPTrans.htm

 

 

 

 

Edited by PWB (see edit history)

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As PWB said, the stock switches set the converter to high stall at idle (as at a stop sign) and will also engage high stall at about 2/3 ~ 3/4 throttle, just before the electrically triggered downshift to 2nd gear ('passing gear').  I can't really see where a manual switch to the high stall state buys anything performance-wise beyond what the stock control setup already provides.  ;)

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When a transmission is built only for high performance use, a high stall converter of 3,000 to 4,000 rpm stall speed is used. This allows the engine to operate on a higher rpm range at all times.  

 

I have an illustration of how to wire a direct wire to the switch pitch solenoid, but I'm on the upper level of the house with my leg in a cast* and the illustration is on the lower level of the house in my computer.  I've only got 6 weeks to go ?.  So if you can wait a while, I'll get to it.  Remind me some time before Turkey day.

 

One thing that you can do to get better performance from your ST400 switch pitch transmission is to use the smaller converter from the ST300 transmission.  It's smaller in diameter and combined with the torque of a 401/425, it will operate at a higher stall speed.  It will bolt directly to your flex plate and the splines are the same as the ST400.  The ST300 was the transmission used in 65 and 66 when the 401 was used in the Skylark series Gran Sport.

 

Ed

 

*Elective surgery - osteochondritus of the talus. 

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I sped on over to Kansas from Cali in my bucket of bolts Riv & snuck into Ed’s house to steal these pix while he was napping off the effects of his pain pills.

 

F3505D35-7AA4-4019-A90F-014009A8AD4F.thumb.png.fe32f4d2a80fdf77b963a24cc9907230.png

 

E05B6AB7-FDFC-4DFA-A0FF-B0AF61E498A0.thumb.png.26dd50857ac5367935d8f174a0454da7.png

 

just kidding. Collected one from Russ Martin’s site & Chris Nolan gave me the other. My kickdown & SP never worked. A buddy suggested we get it all back to stock & working right before we add this aux switch. So I’ve been enjoying the stock setup for now. Aux switch coming soon haha

 

Ed: hope the leg is ok & u don’t need pain pills.

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In reality in 1964 "Nail"flexplates DID NOT have 2 sets of holes & NOT ALL 1965's had 2sets of holes. By 1966 they ALL had 2 sets of holes. I have drilled the nec. holes in flexplates that didn't have them with good results.

 

Tom T.

 

 

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Thanks chaps...all very informative. I’ll be leaving ‘as is’ - if it’s not broke dont fix it , as they say.

 

Get well soon Ed..sure you’ll be back out on the football field soon.

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7 hours ago, moran75 said:

Get well soon Ed..sure you’ll be back out on the football field soon.

Thanks,

 

My football days are long over.  They lasted less than one day.  My freshman year in college, a friend of mine convinced me that I should tryout for wide receiver.  I talked to the football coach and checked out some equipment.  On the field that first day, the track coach saw me.  "Ed, you hurt that knee again and you'll lose your track scholarship." Back to the locker room and turned in my equipment. ?

  • Haha 1

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