VP converter- Trans visual ID guide

Discussion in 'The "Juice Box"' started by Jim Weise, Dec 19, 2007.

  1. Larry J

    Larry J Stuck on Buick

    I hear ya Devon, I told people it felt like a shift but most didn't believe it until they experienced it. But a lock up is like a shift even at light throttle, only it lowers your RPM so much you shouldn't use it until at least 35MPH. Still the SP400 is a great unit, and strong, I still use a 400 with a trans brake and no SP for racing, but I haven't given any thought to a transbrake/SP.
  2. DaWildcat

    DaWildcat Platinum Level Contributor

    Hi Larry,

    With a lot of power I don't think I'd transbrake a SP unit...it wouldn't have any of the usual anti-ballooning add-ons to keep it happy, unless some of the rebuilders like Trishield are doing more than I was aware of.

    The general consensus is that a fixed pitch converter is more consistent than a SP at the track, even running the SP on a timer.

    Interesting note...I believe one of that F.A.S.T. heavy hitters, Greg Gessler, runs the TH350C lockup trans in his 10 sec, stock appearing bias ply-tired GS!

  3. I had no trouble running consistent times within a couple hundreths with my S.P 400 but then again a 12 second car is a whole lot different than a real race car. now my reaction time is a whole different story but thats not the trannies fault:puzzled:
  4. GSX1

    GSX1 GSX1

    So What is the best way to Control the converter for the street ?

    Hooking up to the brake switch ? This applies 12v to the converter to get it in to High stall At stops And when you take your foot off the brake you will lose the High stall for any kind of launch / take off right away? this actualy would put you in low stall for take off the second you release the brake.

    Or Using the timer control box?
    then it will be delayed 0-11 sec. depending on What you want to do.

    While writing this post I Think i Awnsered my own question. I think the box is a better choice to be able to take advantage of the high stall working with the cam for launching both on the street and at the track . or is ther a disatvantage to doing this ??
  5. Kiwi-Riv

    Kiwi-Riv Member

    Hi guys, I just discovered I have a SP tranny in my 67 Riv, I'm very excited about this! Now I've begun leaning all about what I can do with it. I've just got a couple of questions about it.
    What's the best way of running a kick down switch? The car is missing all evidence of ever having and switches or brackets for the kickdown, where should I mount the switch?
    Secondly, for the high / low stall, if I apply 12V to the right terminal on the SP plug, will it give me a high stall when I'm at a stop light so I can smoke the bags easier? Then if I leave the 12V switched on will it give me amazing gas milage? Or do I turn the switch off to get better gas milage? I'm just trying to get my head around how it works.

    cheers, Paul
  6. DaWildcat

    DaWildcat Platinum Level Contributor

    Paul, by far the stock setup is the way to go, see http://home.comcast.net/~shinzan/ST400_linkage.jpg . The stock setup gives you high stall any time the throttle is closed, and any time the throttle is 2/3 open or more. The plunger switch next to the carburetor also gives you detent (passing gear) at 3/4 throttle or so.

    If you want to control the converter with a momentary switch, you'll get high stall whenever +12V is applied to the top spade terminal on the left side of the transmission case. For better fuel economy while cruising, keep your finger off the switch for low stall.

    I still make use of the idle stator switch shown in View B, so the converter is in high stall at idle to help prevent the converter from lugging the idle down. I no longer use the plunger switch next to the carb in View C, as my transmission doesn't require passing gear and I control high stall while driving with a microswitch on my column shifter as described above.

  7. collector

    collector collector

    Another very quick way to ID a s/p converter is that the splines are very deep on the s/p and you cannot feel them. You can ID a s/p blindfolded!

    BRUCE ROE Well-Known Member

    Check that your trans still has the switch pitch function. With the engine off, applying 12V to either of the electrical tabs should cause a "click" inside.

    You could use the original type switches on the throttle linkage; there are no timers or torque sensing. Aftermarket kickdown switches can be mounted. I prefer the slide switch the General put just above the gas pedal in most cars & trucks using a THM400 trans.

    With a simple kickdown, you still neeed a stator control. Many use a manual switch to select the performance mode (high stall, 12V applied to stator lug) or the economy mode (low stall). A diode to the brake light circuit can put you in high stall at a stop. Some timers are available to better match your needs. A combination of manual & automatic stator control can be done. For street driving, I use a slide kickdown and a stator control with timers + torque sensing to cover idle, mid range, and WOT. Bruce Roe

  9. DavidC77

    DavidC77 "Matilda" 1970 Buick GSX

    I bought my car and was told it had a Switch Pitch Turbo 400 in it.

    1970 Buick GSX (tribute car), 455 Stage 2, TB 400, 3.42 posi.

    I have a on / off toggle switch hooked up to it.

    When I have it off it seems like an easyer shift, when I turn it on I get a snapper shift.

    It doesn't seem to change my idle RPM though when I turn it on or off, should it ???

    I also don't see any change in the RPM when I'm going at speed ether. Should I be seeing a difference in RPM at speed ???

    I would have to check as far as to how it's powered, I had to replace the switch but I only replaced the switch, I didn't chase the wires to see were they went. But I would say it's only a on / off switch as there is nothing hooked up by the carb or anywere else that I can see that would control the tranny.

    It was wrote up like this in the add:

    Backing up the big block is a unique Turbo 400 outfitted with a "switch pitch" transmission and converter. With the simple flick of a switch located on the side of the console, this transmission will give you a high stall speed for performance driving, and a low stall speed for economy cruising. This equates to having the stall of a 10" converter for strip use and the stall of a 12" or 13" converter for street and highway driving, resulting in a half-second quicker ET on the strip and 2-3 more mpg on the street.

    You folks have any thoughts ???


  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    With the transmission in gear, you should notice a difference in RPM when you flip the switch. It isn't complicated. The electrical connection on the side of the transmission has 2 spades. The vertical one is the kick down, the horizontal one is the SP. Applying 12 volts to the connection gets you high stall. Taking it away, gets you low stall. Verify that you have 12 volts at the switch, and down near the transmission. Use a multi meter, or test light. You can use a jumper wire from the + battery terminal to test the solenoid inside the transmission. Remove the connection plug at the transmission. Touch the wire to each spade. You should hear the solenoid click each time you touch the spade with the wire, and remove it. The kick down solenoid and stator solenoid will each click with the application of 12 volts.
  11. DavidC77

    DavidC77 "Matilda" 1970 Buick GSX

    AH OK, I'll try that, I don't remember if I really looked at it that way or not.

    I have one of those new Power Probe testers http://www.powerprobe.com/powerprobe/Home.html
    so I will be able to do it easyer with that.

    I let ya know what I find.
  12. DavidC77

    DavidC77 "Matilda" 1970 Buick GSX

    Well I was doing some other work to her tonight and I thought about what you said as far as the RPM should drop, I had it jacked up on all 4 corners so the tires were off the ground. I got in and tryed throwing the switch while it was idleing, I didn't notice much change in the RPM when it was in park (if any), but when I put it into drive and I pushed the switch up there was a big change in the RPM.

    Seeing that it did that I didn't take the Power Probe and test out the conections, I was sure it was working by the big RPM drop I saw.

    Thanks for the help :TU:

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