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Automatic trans shifting questions...

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Old 03-11-2003, 09:18 AM
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Captain_Kaboom
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Default Automatic trans shifting questions...

I replaced my old L48 with a higher HP crate engine, and now I don't think I'm shifting at the right RPMS/MPH. Can you adjust the stock shifting points on this old 3-speed? What are the stock settings supposed to be? Any idea of what I should set them to for ~60 HP increase over stock?

Thanks,
Kaboom


Old 03-11-2003, 09:30 AM
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mrvette
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Default Re: Automatic trans shifting questions... (Captain_Kaboom)

You have a kickdown cable and a vacuum modulator on that tranny, which shuld be a turbo 350.....make sure both are hooked up....the engine should not affect the tranny performance all that much...

if fiddling with them does not do it...I wonder if the fluids are clean?? and if not, if the tranny is being forced over the edge into slipping....
if it's a stock built unit....well time for rebuild and a good Trans Go shift kit...

OR get a 200 -4r tranny for highway cruising....

GENE
Old 03-11-2003, 10:25 AM
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Captain_Kaboom
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Default Re: Automatic trans shifting questions... (mrvette)

Fluids are clean; replaced when I had the engine dropped in. I don't think it is slipping- it just doesn't downshift from 3rd to 2nd unless I'm ~40 mph or so. So when I'm crusin at 50 and when I step on it, I want it to downshift so I can hit my peak RPM range. Otherwise I don't hit the peak range till around 70+ or so in 3rd... a bit to fast for some of these back roads...

Am I way off base here, or do you think that something is wrong with my tranny?
Old 03-11-2003, 02:49 PM
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Default Re: Automatic trans shifting questions... (Captain_Kaboom)

Off hand without actually driving the car, I think the tranny is normal....you will have to shift with the lever....
of course a shift kit is recomended....

GENE
Old 03-11-2003, 03:18 PM
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Corz
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Default Re: Automatic trans shifting questions... (mrvette)

just drop it down manually :thumbs:
Old 03-11-2003, 03:19 PM
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Default Re: Automatic trans shifting questions... (mrvette)

Trans Go here I come....!

Old 03-11-2003, 03:41 PM
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Jvette73
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Default Re: Automatic trans shifting questions... (Captain_Kaboom)

Part throttle upshifts can be adjusted by the modulator. If you want to change full throttle automatic upshift points then you need to modify the govenor. If its shifting too early an easy solution is to manually shift up when you want as has already been stated. Whats the rpm range of the cam in your motor? For best performance, to start with its a good idea to shift up just before the high end of the cams rpm range.


[Modified by Jvette73, 2:41 PM 3/11/2003]

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