Switch Pitch Tranny Controls

In the tuning thread I asked Doc if leaving the car in high stall was the optimal way to run the quarter, he replied-

"Yep,,,, just set and think about it, there are several ways to do that ... there is a guy that markets a electronic controller for about $115 that is supposed to do the best job.... but you can wire to the brake light , you can install and use a dimmer switch,,, toggle switch,,, the factory set up, use mercury switches... there is a number of ways to do that, I even heard of using vacume switches..."

GSGTX also replied that he uses a toggle to go to low pitch about 4K, which I guess almost turns a ST-300 into a 4 speed!

The controller that Doc mentions is probably one developed and sold by Bruce Roe, a Toronado guy - I talked to Bruce and while the unit is a little spendy (165.00 now) , it has some interesting features, including vacuum actuation and programable delays for high to low stall transition for vaccum, throttle position and brake application. He hasnt heard of anyone using it on a ST-300, but figures it would work. Has anyone here used on - either on a 300 or a 400?

Anyway, before I consider that I need to confirm what I've got is working correctly..Carmen provided me with a pretty cool diagram (much like Ed's, thanks) that not only employs a on/off toggle, but a momentary switch that bumps the tranny to high stall for as long as you hold it. If I understood him correctly, hitting the switch just before launching would put the converter in high stall, and the lag in going back to low stall would take most of the way through first gear (4000 RPM?). I'll probably just run a momentary switch to test the pitch control first, then figure out what the best long term solution.. I really dont want to be trying to find toggle switches or buttons at 90 mph.

All this confused me because with the factory set up going to high stall at 60% throttle, shouldnt I already have it all the way through the 1/4? Carmen explained if I brake torque the car at launch, I wont have it initially because I'm off idle, but not at the trigger point. I've already got traction issues, wouldnt additional stall make them worse at launch?

My questions:

• Has anyone used The Bruce Roe controller?
• Will the use of the brake switch/momentary switch give me pitch off the line until the throttle position sensor kicks in?
• Is there an ET advantage to kicking it over to low stall for the last 1000 RPM of first gear?
• Will high stall at launch just make it tougher to find traction?

Sorry to pepper you all with questions -
Rhett

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I'll try and take a stab at your questions.

I can only recall one or two people running Bruce's controller. They had nothing but good things to say about it, however it is spendy, and I personally opted to go with a simplier approach.

I'm not sure what your referring to when you say throttle position sensor. Are you talking about the factory SP carb switches? In any case, wiring high stall to the brake lights and or momentary switch will allow you to launch in high stall. It will go back into low stall when you get off the brakes, or release the momentary switch.

There might be a slight advantage, however it's probably negligible.

Yes, by launching at a higher RPM you are in the peak, or closer to peak torque. More power/torque means harder to get traction.

In terms of what I did, I just wired high stall to a toggle switch. Although Bruce's controller or the factory setup would be easier, a toggle switch is the simpliest approach. Usually I'll just leave in high stall, except when I'm out crusing on the highway. Hope I was able to help some! I'm sure you'll get some more responses soon.

 

Appreciate the quick resonse, Andy. And yes, I meant the carb switch, I didnt know what the true term for it was...

When you set yours up, you overrode the carb switch entirely, right? Or does it still do it's thing when you've got the toggle switch in low stall?

 

I use the factory throttle switch as well as a push button mounted on my shifter T handel. I use a toggle switch with 3 positions 1 set for full auto mode same as stock middle position to turn it off and the oTher position to run my push button on my shifter

here is how i use it

for reguar street play i leave it in auto mode BUT my push button still controls it as well

at the track I have it on the button on my shifter only so when i launch it is in high stall 1/2 to 3/4 way through 1st gear then switch it to low stall, and it just pulls hard all the way down the 1/4 gives better MPH and once you are in the power you want more hold and less slip

for long highway drives i turn it off

just my .02

 

Ok, so if your talking about the carb switch, that kicks on high stall at about 60% throttle I believe. So, yes, below the throttle position where the carb switch kicks on, use of a momentary switch would give you high stall.

My car didn't originally come with a ST400, I transplanted that over the winter, so I don't have any of the original SP switches or wiring. So I either flip the toggle up for high stall, or leave it down for low stall. The majority of the time I just set it in high stall and forget about it, unless I'm crusing on the highway for an extended period of time, then I will switch it to low stall.

Personally, from reading threads on this board and others, I think people make this (setting up low/high stall) WAY too complicated. It's totally fine to ask questions and understand what's going on, but people seem to think setting up when and how you go from low to stall to high stall and vice versa is rocket science. It isn't :laugh: .

 

Thanks for everyone's feedback.

Andy, I agree - it's a pretty simple on/off type thing, or at least it should be..the piece I was missing is how to work increased stall into my 1/4 mile runs, and how to automate it the best possible way.

I like the way Mr. Buick has got it set up, it seems to preserve the ability to leave it functioning as the factory intended, but also override manually.

And of course, there's the spendy controller, which if set up correctly should do it all without any intervention.

Mr Buick - It also seems your momentary switch is bringing 12v into the stock system from another source, (fuse block, etc..the same way it's shown in the schematic Ed put up in the other thread, only simpler). Is it just teed into the power lead at the trans? No problems with backfeeding the stock wiring?

Rhett

 

I just tapped into switched power I did this in 1995 and have made run over 500 1/4 passes and put on aprox 25,000 miles in the 15 yrs and not a problem yet maybe i did it wrong ou: hahahahahahaha

it still runs high 12's to low 13's on street tires, and pump gas, no headers, std bore SF455 block, ported 71 heads, big crane cam 13" convertor, 3.42 posi, 3" duals off the stock manifolds, I am pretty please with her so far

ken

 

I've got a simple electronic timer that is wired
the instant you hit the brakes it goes to high stall.
you let off the brake and whatever time you set (mine's 3 seconds) and it goes to low stall.
http://www.electronickits.com/kit/complete/elec/ck1614.htm
they have a kit version and a pre-assembled version.
I also have a bypass switch added to the box i put it in that keeps it in high stall.