I know I read an article recently (last 6 months) explaining all about the wiring of the variable pitch (switch pitch) turbo 400 transmissions that Buick did in the mid-late 60's. The problem is I can't figure out where I read it. I've searched the internet without much luck. It may have been in Rod-n-Custom another magazine. The article was really cool because it even had diagrams of different ways to wire the "switch"....one of which was in conjunction with the brake light switch. Anyone else know what I'm talking about? Thanks.
http://www.buickperformance.com/switchpitch.htm http://www.webrodder.com/article.php?AID=85&SID=6 and searching buick switch pitch on here will find a few...
On the drivers side of the ****** is a plug with two clips in it, this you know. I believe the top clip(I'll check when I get to the shop) is for the switch pitch and the other is for the Kick down. Each clip works when powered...........any brake light type switch will work, I just hooked up a push ****on on a center console to work the switch pitch. I have seen them attached to the shift lever, like a line lock. But I like the brake pedal switch best. Good luck.
Thanks guys. That webrodder article was the one I saw....it gives 3 wiring options. I ***ume that if I hook power to the top spade and it doesn't allow the engine to rev higher at takeoff than I've got the wrong terminal and I can just try the other one, right? I won't screw anything up if I hook power to the wrong one......right?
The Buick Super Turbine was used in mid 60's. Totally different from Powerglide and used to replace the old Roto-hydramatic. It had a switch on the throttle linkage that used to set high pitch at idle, back to low at takeoff, and back to high as you mashed the pedal. I can remember sitting in my friends 67 Buick Le Sabre and seeing that switch down there as his mom drove us to school. I wondered what the switch was for .....later on as I got older I found out what it was for. The switch pitch TH 400 was used in the big GM cars like Caddy's, Buick Electra and Riviera, Pontiac Catalina, and so forth. Variable pitch worked the same way - made for a real smooth idle. Use the carburetor mounted switch and bracket. Switch was found on BBC Chevelles and Corvettes in those years. Have one on my 1967 El Camino. Bring 12 v to the switch and send 12v from switch to terminal on trans. Don't get the transmission controlled spark switch found on later transmissions confused with variable pitch trannies. Check out the difference in input splines in variable vs. non-variable trannies.
Experienced word of warning: Put a HUGE cooler on that thing if you're going to be doing any hi-perf driving. Those converters put a LARGE amount of heat into the fluid. Go ahead, ask me how I know... Want a size to get - at least double what is recommended for your application with a normal TH400 Cosmo
Whoa, didn't even think about the cooler. I'm pushing a 2000 lb. model T and have way more hp than needed. I don't plan on runnin' any races, but anticipate teaching the import tuner guys a few lessons at the stop lights. I currently have one of those 14" cylindrical coolers with the fins.....is that enough? Should I put a transmission temp gauge in? What temp. should that transmission run at?
hey i have the same set up and need to know as well. i have a 425 nailhead in a 32 chevy . i have the same cooler. the guy that rebuilt my trans said it would run hot if you showed off so put a big cooler on it. but another guy said the 14"cylindrical would work just find .... let me know
I believe I had an 8 p*** on a Suburban running a 472 Cadillac. Not enough. On the other hand, I had an Iveco truck, 12,000 GVW with a 727. It had a 14" square radiator for the trans, with it's own fan. That was enough for that application. IIRC, trans temps should be under 250º at all times. Over 275º and you seriously shorten lifespan, over 300º and it's cooked. Cosmo
Pontiac and Chevy never used the switch pitch ST300 and SP400 transmissions. Oldsmobile, Buick, and Cadillac used the switch pitch transmissions from 64-67 (ST300) and 65-67(SP400).
Hey, don't forget Rolls-Royce used them also. There were two different converters that I know of: 800-2,400 and 800-2,800 stall speed. I believe the the 800-2,800 was used on the Super Turbine (2 speed) but they are interchangeable. The converter will not fit a 200 trans, besides how would you activate it. Your best bet is to get the firewall mounted control for the converter and go from there. You have to be careful when scouring the yards for one because the '71-74 models also had a plug with 2 prongs like the VP model, but the second plug in it was for spark control (no advance until high gear), you have to look at the stator support splines to differentiate between a regular 400 and VP, the VP splines are only half as long as the normal ones. Good luck.
So back to the question of cooling........where can I find an equation or chart to calculate how big of a ****** cooler I should run with this (or any other engine/****** combo)?
Just get a cooler for 10,000 GVW and put a fan on it with a switch you control and watch the temps, turn the fan on at 180 deg and you will be good to go. Damage occurs above 240 deg.
I bought a B&M remote ****** cooler with a fan already attached to it. Mounted it beside the ****** and installed a 180 deg. switch in the outlet line and wired it to a relay to turn the fan on and off. Also installed a B&M trans temp guage. Ive never seen it go over 200 deg.
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