700R4 Transmission expert needed
Thread Starter
Racer
Joined: Jul 2004
Posts: 434
Likes: 0
From: Santa Barbara Minnesota
700R4 Transmission expert needed
I drove my 86 C4 with the new "Raptor 700R" auto/trans. for the first time today. It seems to shift way to early. I have the 52 mil. BBk throttle body. On my previous 700R we relocated the pin for the cable below the original location, this really increased the pressure and it shifted really hard, and also blew up. But it shouldn't matter at WOT. right? it's shifting at about 3600rpm., it should be at least 5000rpm. Is that in the accumulator, valve body?
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Though moving the TV cable head may have some small effect on WOT shifts, it's mostly effects part throttle shift points and shift feel.
To raise WOT shift points you will need to add small weighs to the governor, behind the round dome on the left side of your A4. You can get a B&M governor recalibration kit from Summit that has a variety of weights and springs along with complete instructions for around $35.
To raise WOT shift points you will need to add small weighs to the governor, behind the round dome on the left side of your A4. You can get a B&M governor recalibration kit from Summit that has a variety of weights and springs along with complete instructions for around $35.
Thread Starter
Racer
Joined: Jul 2004
Posts: 434
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From: Santa Barbara Minnesota
To raise WOT shift points you will need to add small weighs to the governor
Thanks, sounds right. I'll probably have the Performance Shop that installed it adjust it, the shift cable isn't adjusted correctly either. They did the Dyno / chip on a Mustang Dyno. Thanks, Chris 
Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by #70SM2
How do you adjust line pressure? 
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Instructor
Joined: Jun 2001
Posts: 132
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From: Monroe Washington..the State
Well some good points here. You must rebuild the correct geometry before you go on.
From there I would go down and purchase the correct "Corvette" Governor. I have the part number sitting on my Tool box at work. I have torn into a few of the Rapture units and often they just have a stock V8 truck govenor.
Good luck!
From there I would go down and purchase the correct "Corvette" Governor. I have the part number sitting on my Tool box at work. I have torn into a few of the Rapture units and often they just have a stock V8 truck govenor.
Good luck!
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Le Mans Master
Joined: Aug 2000
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From: Australia
Check this out for a indepth view of what the TV cable can and can't do.
http://www.tvmadeez.com/article/index.php
Note the comment:
The TV cable used with the 4L60 transmission should not be thought of an automatic downshift cable. The TV cable used on the 4L60 controls line pressure, shift points, shift feel, part throttle downshifts and the detent downshifts. The function of the (TV) cable is similar to the combined functions of a vacuum modulator and a detent cable.
http://www.tvmadeez.com/article/index.php
Note the comment:
The TV cable used with the 4L60 transmission should not be thought of an automatic downshift cable. The TV cable used on the 4L60 controls line pressure, shift points, shift feel, part throttle downshifts and the detent downshifts. The function of the (TV) cable is similar to the combined functions of a vacuum modulator and a detent cable.
Thread Starter
Racer
Joined: Jul 2004
Posts: 434
Likes: 0
From: Santa Barbara Minnesota
What the TV cable can and can't do.
Thanks alot guys, some really good info here. I've sure learned a lot about this 700R auto tranny. The TV cable has been returned to the original position on the BBK throttle Body. I understand now that my previous mechanic was totally wrong in lowering the TV pin position! to adjust the shift characteristics & timing.
I have a call into Raptor about the governor, to make sure it is a "Corvette Governor". I also understand now that the springs in the governor control when it shifts! I actually have the old Governor here, as someone on the course found it when the old tranny "Grenaded". It actually blew the governor out of the tranny.
Luckily I was on an AutoCross course in Hollywood Park going about 60mph. in a fast corner when it blew, the fluid coated the tires and I had a pretty wild spin and short lived Fire. But there wasn't anything to hit accept rubber cones! .. Thanks again, Chris
I have a call into Raptor about the governor, to make sure it is a "Corvette Governor". I also understand now that the springs in the governor control when it shifts! I actually have the old Governor here, as someone on the course found it when the old tranny "Grenaded". It actually blew the governor out of the tranny.
Luckily I was on an AutoCross course in Hollywood Park going about 60mph. in a fast corner when it blew, the fluid coated the tires and I had a pretty wild spin and short lived Fire. But there wasn't anything to hit accept rubber cones! .. Thanks again, Chris
Thread Starter
Racer
Joined: Jul 2004
Posts: 434
Likes: 0
From: Santa Barbara Minnesota
Correct Governor installed
Originally Posted by TwoFast4Lv
Well some good points here. You must rebuild the correct geometry before you go on.
From there I would go down and purchase the correct "Corvette" Governor. I have the part number sitting on my Tool box at work. I have torn into a few of the Rapture units and often they just have a stock V8 truck govenor.
Good luck!
From there I would go down and purchase the correct "Corvette" Governor. I have the part number sitting on my Tool box at work. I have torn into a few of the Rapture units and often they just have a stock V8 truck govenor.
Good luck!
I also would add, I had a nasty "clunk" from the rear everytime I put it in gear, I pretty much replaced everything, new rear end, 373 gearset, ujoints, bushings. It all went away with new transmission. Somehow it must have transfered down the driveline, I was 100% convinced that it was in the rear of the car.
Thread Starter
Racer
Joined: Jul 2004
Posts: 434
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From: Santa Barbara Minnesota
My First Website
Originally Posted by USAsOnlyWay
Chris, I just got the picture of that grenading 700r4!!!
Holy @#$@!!!
Hope this one works out better for you!
Holy @#$@!!!
Hope this one works out better for you!
Just ordered B&M Recalibration kit from Summit, $28.
I've just started figuring how to make a Website, mostly AutoCross now, Check it out: http://members.***.net/interpilotfilms/
Team Owner
Joined: Apr 2004
Posts: 36,040
Likes: 4
From: All great change begins at the dinner table Ronald Reagan
I learned a lot about the 700r4/ from this webite link:
http://www.ptsxtreme.com/main.asp
Go to: Forums & you're in. While a lot is about 200r4, you'll see 700r4, th350/400 + more.
http://www.ptsxtreme.com/main.asp
Go to: Forums & you're in. While a lot is about 200r4, you'll see 700r4, th350/400 + more.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by #70SM2
Well, we got the correct Corvette Governor installed. It shifts better but still to soon at 4500rpm. Now I know where it is and how to remove it. Question? what springs will make it shift later, say at about 5500-5800rpm. range. Lite springs or heavier springs? Any tricks to install.
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Thread Starter
Racer
Joined: Jul 2004
Posts: 434
Likes: 0
From: Santa Barbara Minnesota
Too bad you bought a governor.
I called "PATC" the Raptor builders & they priorty sent me a new Corvette Governor free. So I have an xtra + the one that was ejected from the old tranny. In a conversation with Summit Tech. this morning they seem to think the shifting of the Governor will be different with "Lower Gears". I have 3:73". I hope I can get it right!
I've spent 9 years playing with this car, 7 in the shop! This is now like getting the spelling right on the icing on the Cake! I see the springs appear to be color coded, the new Corvette Governor has a purple & white. So they are different springs on each side?
I'll be running the car this weekend at California Speedway, if I don't get the shift points right, I'll manually shift. The National Champs are usually there! I think we're ready!!
I've spent 9 years playing with this car, 7 in the shop! This is now like getting the spelling right on the icing on the Cake! I see the springs appear to be color coded, the new Corvette Governor has a purple & white. So they are different springs on each side?
I'll be running the car this weekend at California Speedway, if I don't get the shift points right, I'll manually shift. The National Champs are usually there! I think we're ready!!
Thread Starter
Racer
Joined: Jul 2004
Posts: 434
Likes: 0
From: Santa Barbara Minnesota
B&M recalibration kit arrived today
Originally Posted by CFI-EFI
Swapping a governor in a trans is not an exact science, if the trans isn't built exactly like stock. The governor pressure has to overcome kick down pressure and vice versa for the shifts to occur. Actually, that new governor is pretty much "on the money" for an rpm limited L98. Lighter weights and heavier springs will delay the shift points. It will likely take some experimenting with that B&M kit, before you get it the way you want. Too bad you bought a governor. You could have accomplished the same thing, modifying the old one.
RACE ON!!!
RACE ON!!!
The part about the springs is where I'm a little DumbFounded. The new Corvette Governor came with a purple spring on one side & white on the other, being that purple is the stiffest. Should I just try adding lighter weights first? (Glad I don't do this or a living) I just break cars, I don't fix them!