New crates auto shift points to quick?
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Melting Slicks
Joined: Jan 2005
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From: Madison Ms
New crates auto shift points to quick?
Well, the new crate is broken in!! After slammin' the accel. down a few time all the way, I noticed that the auto. is shifting really quick. Not getting the maxximmum rpms/torque out of each gear like I think it should. Can this be adjusted with the timing curve? Or is this strictly a rear end gearing/tranny situation?
Anything I can do to extend the time between shifts without messing with the tranny or rear end? I guess I could manually shift through the gears of the auto when so required! What do you automatic guys do?
I knew this was going to take me to a new part of the car I know nothing about...........
Anything I can do to extend the time between shifts without messing with the tranny or rear end? I guess I could manually shift through the gears of the auto when so required! What do you automatic guys do?
I knew this was going to take me to a new part of the car I know nothing about...........
Last edited by MsVetteMan; Jun 6, 2006 at 10:50 AM.
Melting Slicks
Joined: Mar 2006
Posts: 3,456
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From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
Shift manually when you want max rpm from each gear. At least that is what I do. My experience is that if you simply leave it in drive, (TH 400 at least) the shift will occur at approx 80% of peak.
Melting Slicks
Joined: Aug 2003
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From: Dayton Oh
When I had my Th350 in my 79, under mild acceleration the shifts came quick also thanks to the 355 rear. However, launching from stop using a hi-RPM stall and then WOT, the shift point was at 5,500RPM.
Thread Starter
Melting Slicks
Joined: Jan 2005
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From: Madison Ms
Originally Posted by gyopp
Did you hook your throttle kick-down cable back up? It may need to be adjusted. Check and see if it will shift to passing gear when you call on it at highway speeds.
Gene
Gene
It seems to do pretty well through first gear (though will still shift quicker than I like on open throttle) , but 2 to 3rd is the one that occurs pretty quick.
On typical driving, it seems fine.
If you are going to manually shift the 3 spd. auto, what rpm's should you shift at for each gear for full throttle?
Last edited by MsVetteMan; Jun 6, 2006 at 12:39 PM.
Thread Starter
Melting Slicks
Joined: Jan 2005
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From: Madison Ms
Originally Posted by Brettmc
Doesn't the vacuum modulator control shift points on the TH350??
Brett
Brett
Anyone clear this up?
Melting Slicks
Joined: Mar 2006
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From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
The upshifts are controlled by the vacuum modulator. Therefore, the shift point will change with engine specs.
I have never seen a stock AT that will get you to the top of the curve while in drive.
Shift manually at the rpm stated on the build sheet where you have just exceeded max HP. You may need to experiment and get to know your best shift point by the seat of your pants, literally.
You could also have the tranny tricked out.
I have never seen a stock AT that will get you to the top of the curve while in drive.
Shift manually at the rpm stated on the build sheet where you have just exceeded max HP. You may need to experiment and get to know your best shift point by the seat of your pants, literally.
You could also have the tranny tricked out.
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Race Director
Joined: Jul 2004
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From: Scottsdale Arizona
Originally Posted by dosoctaves
The upshifts are controlled by the vacuum modulator. Therefore, the shift point will change with engine specs.
I have never seen a stock AT that will get you to the top of the curve while in drive.
Shift manually at the rpm stated on the build sheet where you have just exceeded max HP. You may need to experiment and get to know your best shift point by the seat of your pants, literally.
You could also have the tranny tricked out.
I have never seen a stock AT that will get you to the top of the curve while in drive.
Shift manually at the rpm stated on the build sheet where you have just exceeded max HP. You may need to experiment and get to know your best shift point by the seat of your pants, literally.
You could also have the tranny tricked out.
I had to replace my modulator valve and wasn't able to get a direct replacement. The two that I tried shifted too low, just as you described. I was able to solve the problem by getting an adjustable modulator (Kragen, Pep Boys...) and adjusting it all the way. You could also get an upgrade kit from TCI or B&M. Some of these have modulators as well.
Thread Starter
Melting Slicks
Joined: Jan 2005
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From: Madison Ms
sum biatch.......!! Got got in from a late afternoon cruise/hammer session......Running through the gears manually shifting the auto make all the difference in the world!! I felt every bit of torque this biatch has this evening, and then some!! Oh my........
Do have a question...Is there some type of built in protection in the 350Th that will keep it from shifting in high rpm's? I noticed that when I was close to or at redline, it would not shift, but when I eased off the throttle a bit, it would fall right in........
Do have a question...Is there some type of built in protection in the 350Th that will keep it from shifting in high rpm's? I noticed that when I was close to or at redline, it would not shift, but when I eased off the throttle a bit, it would fall right in........
Last edited by MsVetteMan; Jun 6, 2006 at 08:37 PM.
Safety Car
Joined: Jul 2002
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From: St Louis MO
Did you put a shift kit in it? Are you catching 2nd? 3rd?
I put a strong 400 in that 69 Camaro I used to have. The TH350 in it gave up trying to handle the torque one nite. I had it rebuilt and had the rebuilder put a kit in it. It would catch third most of the time.
I put a strong 400 in that 69 Camaro I used to have. The TH350 in it gave up trying to handle the torque one nite. I had it rebuilt and had the rebuilder put a kit in it. It would catch third most of the time.
Thread Starter
Melting Slicks
Joined: Jan 2005
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From: Madison Ms
Originally Posted by Brettmc
Did you put a shift kit in it? Are you catching 2nd? 3rd?
I put a strong 400 in that 69 Camaro I used to have. The TH350 in it gave up trying to handle the torque one nite. I had it rebuilt and had the rebuilder put a kit in it. It would catch third most of the time.
I put a strong 400 in that 69 Camaro I used to have. The TH350 in it gave up trying to handle the torque one nite. I had it rebuilt and had the rebuilder put a kit in it. It would catch third most of the time.
Burning Brakes
Joined: Feb 2006
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From: AL
not too sure about TH350, but the TH400 has a govenor that controls the shift points. it can be adjusted by changing springs or weights. i've had both trannys, shifted both manually, and had rather get them to shift automatically at the right time. i always notice too much delay when shifting manually. this may be what you noticed near redline-if you just kept the loud pedal down, it should eventually shift. . .
take it to a reputable shop and have them adjust. shouldn't cost that much.
take it to a reputable shop and have them adjust. shouldn't cost that much.
Thread Starter
Melting Slicks
Joined: Jan 2005
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From: Madison Ms
Originally Posted by S489
not too sure about TH350, but the TH400 has a govenor that controls the shift points. it can be adjusted by changing springs or weights. i've had both trannys, shifted both manually, and had rather get them to shift automatically at the right time. i always notice too much delay when shifting manually. this may be what you noticed near redline-if you just kept the loud pedal down, it should eventually shift. . .
take it to a reputable shop and have them adjust. shouldn't cost that much.
take it to a reputable shop and have them adjust. shouldn't cost that much.
Advanced
Joined: Oct 2003
Posts: 87
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From: Highland Mi
You can get a governor spring and weight kit from B&M through Jegs or Summit. You can then play with the springs first and get the shift point where you want it. I did this with my 350 trans and got it close to where I want it. Not a hard thing to do, just follow the directions.
Melting Slicks
Joined: Jun 2001
Posts: 2,265
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Just used the B&M spring and weight kit on my 400. With the middle weights and springs it produced a 4800 rpm shift (1-2) was 4200 stock. I just installed the lightest springs and weights. I hope to test soon. My car is not a street car, otherwise testing would already be done. If you decide to modify your governor keep the nose of your car lower (4-6 inches) this will keep you from losing very much fluid. I will post my results as soon as I get to the track, but it'll be a couple of weeks. 
Ron B.
Ron B.
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Joined: Oct 2004
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From: Minnesota
This guy's site has some good info on governors and other 700r4 tuning items.
http://iotech.no/corvette/technical/700r4/index.htm
http://iotech.no/corvette/technical/700r4/index.htm