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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: team39763 on September 07, 2008, 12:06:36 am
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Does it shift off vacuum readings using that vacuum modulator thing? I was just wondering because I haven't messed with the modulator or governor/weights. I usually just shift my truck myself with the ratchet shifter or just put it in 3rd to drive around in the pits. I was wondering what it would do if I left it in 3rd to race. It has as TransGo shift kit w/no kickdown and that's about it(was rebuilt with good clutches/steels). I didn't want to just go out and try it, because I don't like hitting my rev limit. I broke my tensioner twice by hitting the rev limit a bunch(several people warned me about that). Will it most likely just shift early or will it hold the gears a little longer than usual? I really don't care what it does, I just don't want really late shifts when I take off at WOT. I may go ahead and buy that B&M Gov. recalibration kit. I'm planning to use the 2step next time at the track, that way I can hit the converter with full force, it'd be nice to not have to shift it myself immediately off the line.
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I wonder that myself. My TH350 has lousy shift points. WOT is at best 4000 rpm and doesn't downshift anywhere above 2000 rpm.
What's your launch technique? Do you have a full manual valve body? If so, when you are puttering around in the pits, it's in 3rd gear only? Finally, what's a 2-step supposed to do?
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Na, mine is a regular auto valvebody. My launch technique is different everytime. I've been trying to find a technique that feels right, but nothing seems to feel that fast. Usually when I try to punch it from a stop, I have to shift before I even get the pedal to the floor. So I decided to hook up my 2step(basically a second rev limit). I have it wired to my brakes, so when they are pressed the motor can only be stalled up to what my brakes will hold(3000) even with the pedal floored. When I release the brakes, I'll already be WOT right off the line.
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Up shifts occur when governer pressure rises. Down shifts occur via your detent cable. The vacuum modulator delays an upshift or forces a downshift. You can get an adjustable modulator and you can set your detent cable to help fine tune your sift points.
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Good info Vile. I'll have to scope that out. (speaking of detents, do you have any advice about my column shifter issue?)
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Good info Vile. I'll have to scope that out. (speaking of detents, do you have any advice about my column shifter issue?)
What is your column shifter issue?
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