TH350 Shift Point Revisited
04-20-2004, 04:45 PM
#1
Melting Slicks
Thread Starter
TH350 Shift Point Revisited
Had the lightly modified '77 dyno'ed last weekend, and came up with 212 at the rear wheel at about 4700 rpm. And the peak torque figure was 277, pretty much flat from 2500 through about 3500 rpm. It very slowly tapers off after that to about 250 at 4500 rpm on its way to 200 at 5250 rpm.
My car was previous to today shifting from 1 to 2 at about 3500 rpm under WOT, and from 2 to 3 at about 4000 rpm. When in cruise mode, and the throttle was dropped, it wouldn't downshift from 2 to 1 at anything above 1500 rpm, and I really don't know about the 3 to 2 downshift, although it was better than the 2 to 1 shift point.
So after reading some archived threads, I decided to play with the detent cable, and it made a huge difference. All I did was raise the clip that holds the cable in place and let the spring push the cable out as far as it could (and then push the lock clip back down, of course). Now it'll downshift at any reasonable throttle drop as long as the RPM's not way up there to begin with. And the best part is that it's 1 to 2 and 2 to 3 upshifts are consistently at 4300 rpm. The car screams compared to what it did before, and I really like it. In cruise mode, it's just like always and will hit 3rd gear by the time I hit 25 mph or so under soft throttle input. Hammer it, and I'm outta here right now!
But I'm still wondering if I can get a few hundred more rpm out of it before it upshifts. I guess the B&M kit is in order for this?? Or do you have some other trick in mind??
Thanks,
W
PS. I guess a shift kit and higher stall speed torque converter should be next on the agenda?
My car was previous to today shifting from 1 to 2 at about 3500 rpm under WOT, and from 2 to 3 at about 4000 rpm. When in cruise mode, and the throttle was dropped, it wouldn't downshift from 2 to 1 at anything above 1500 rpm, and I really don't know about the 3 to 2 downshift, although it was better than the 2 to 1 shift point.
So after reading some archived threads, I decided to play with the detent cable, and it made a huge difference. All I did was raise the clip that holds the cable in place and let the spring push the cable out as far as it could (and then push the lock clip back down, of course). Now it'll downshift at any reasonable throttle drop as long as the RPM's not way up there to begin with. And the best part is that it's 1 to 2 and 2 to 3 upshifts are consistently at 4300 rpm. The car screams compared to what it did before, and I really like it. In cruise mode, it's just like always and will hit 3rd gear by the time I hit 25 mph or so under soft throttle input. Hammer it, and I'm outta here right now!
But I'm still wondering if I can get a few hundred more rpm out of it before it upshifts. I guess the B&M kit is in order for this?? Or do you have some other trick in mind??
Thanks,
W
PS. I guess a shift kit and higher stall speed torque converter should be next on the agenda?
04-20-2004, 05:36 PM
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Re: TH350 Shift Point Revisited (Wendell Allen)
Hi,
The transmission shift point depends on two things, detent cable (or kickdown cable) and the governor spring. The governor is a device with centrifugal weight that spin on the input shaft. It give the speed input to the transmission. You could find a transmission shop that would sell or install the proper spring to shift at higher RPM.
Stephan
The transmission shift point depends on two things, detent cable (or kickdown cable) and the governor spring. The governor is a device with centrifugal weight that spin on the input shaft. It give the speed input to the transmission. You could find a transmission shop that would sell or install the proper spring to shift at higher RPM.
Stephan
04-20-2004, 07:56 PM
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Re: TH350 Shift Point Revisited (Wendell Allen)
Governor reprogramming kits by B&M can be had from Summit Racing for about $28.
http://store.summitracing.com/partde...rt=BMM%2D20248
http://store.summitracing.com/partde...rt=BMM%2D20248
