Using Tac to drive 2 Throttle servos?

[Ranger6202]

Got a new one for you guys. I did do a little searching and i can't find where someone has approached this. I'm putting a 700r4 behind my 6.0 with DBW (currently mated to th400, and am dedicated to the 700r4, so it won't do any good to tell me to put a 4l60 or some other electronic tranny behind it). I'm using a constant pressure valve body from tci so i don't have to worry as much about the correct setting of the shifting cable. I do have a scheme set out to create some bracketry that will actuate my cable off of my pedal movement which will work in shifting my tranny. But, when i go to set my cruise, my pedal won't be moving anymore, and the tranny won't be able to shift on hills and etc.. I know i can just change to a cable throttle body, but i'm determined to make this hard as possible with the DBW still there. Does anyone know if i can can splice into the output signal off of my TAC to the DBW throttle body and drive another servo out of the extra DBW throttle body i have in my garage? What i have in mind is just using another servo to control all the movement of the tranny cable rather than using the bracketry. Anybody got any insight to this? I'm thinking my voltage will hold up, but i'll lose my current and in turn lost correct actuation of both throttle body servos (ie. half the movement due to double the resistance). What say you?

[68GMCCustom]

interesting approach.....I'll be watching from the sidelines.

[clinebarger]

Originally Posted by Ranger6202

Got a new one for you guys. I did do a little searching and i can't find where someone has approached this. I'm putting a 700r4 behind my 6.0 with DBW (currently mated to th400, and am dedicated to the 700r4, so it won't do any good to tell me to put a 4l60 or some other electronic tranny behind it). I'm using a constant pressure valve body from tci so i don't have to worry as much about the correct setting of the shifting cable. I do have a scheme set out to create some bracketry that will actuate my cable off of my pedal movement which will work in shifting my tranny. But, when i go to set my cruise, my pedal won't be moving anymore, and the tranny won't be able to shift on hills and etc.. I know i can just change to a cable throttle body, but i'm determined to make this hard as possible with the DBW still there. Does anyone know if i can can splice into the output signal off of my TAC to the DBW throttle body and drive another servo out of the extra DBW throttle body i have in my garage? What i have in mind is just using another servo to control all the movement of the tranny cable rather than using the bracketry. Anybody got any insight to this? I'm thinking my voltage will hold up, but i'll lose my current and in turn lost correct actuation of both throttle body servos (ie. half the movement due to double the resistance). What say you?

Constant Pressure valve bodies are a BAD idea, You cant expect a 700R4 front pump to handle max line pressure ALL the time, It flat out does not work! Even if you keep putting pumps in it......The firm shifts all of the time at part throttle WILL break something.

From a safety stand point....Messing with the DBW/TAC is not a good idea either, The good thing it will most likely go into "limp" mode & not actuate the throttle very much.

Why are you "stuck" with a 700R4? 4L60E & 4L65E are great transmissions when built right & are based on the 700R4, So i dont see what your gaining besides a headache.

[BR3W CITY]

Originally Posted by Ranger6202

Got a new one for you guys. I did do a little searching and i can't find where someone has approached this. I'm putting a 700r4 behind my 6.0 with DBW (currently mated to th400, and am dedicated to the 700r4, so it won't do any good to tell me to put a 4l60 or some other electronic tranny behind it). I'm using a constant pressure valve body from tci so i don't have to worry as much about the correct setting of the shifting cable. I do have a scheme set out to create some bracketry that will actuate my cable off of my pedal movement which will work in shifting my tranny. But, when i go to set my cruise, my pedal won't be moving anymore, and the tranny won't be able to shift on hills and etc.. I know i can just change to a cable throttle body, but i'm determined to make this hard as possible with the DBW still there. Does anyone know if i can can splice into the output signal off of my TAC to the DBW throttle body and drive another servo out of the extra DBW throttle body i have in my garage? What i have in mind is just using another servo to control all the movement of the tranny cable rather than using the bracketry. Anybody got any insight to this? I'm thinking my voltage will hold up, but i'll lose my current and in turn lost correct actuation of both throttle body servos (ie. half the movement due to double the resistance). What say you?

You have a th400 now, yet you want to switch to a weaker tranny...I get wanting OD but why take a step backward in power handling?
Then you say that you HAVE to have this 700r4, but have no interest in worrying about proper TV cable adjustment. Dealing with tv cables is an inherent issue with the 700r4, the valve body won't save you it will set you back. On top of that, the 6.0 will eventually torch that tranny.

Either keep the th400, get a modern od trans. Your reinventing the wheel, and making it square.

[68GMCCustom]

or...put a gear vendors overdrive behind your turbo400...done.

[Ranger6202]

I'll admit you got me leaning toward the the modern trannies (electric). But I'm not wanting the th400 or the 4l80. I know they're stronger soley on spline input/output, but the rest of the 4l60 can be built just as strong as the 4l80 (once again overlooking the spline input/output). I'm wanting the 4l60/700r4 setup for the lower first gear and of course the OD. This is my hunting truck, so i'm not doing extreme crawling or digging in Moab and probably wont exceed 450hp. I might have to pull a heavy Ford out once in awhile too ;-). I do appreciate the input. You're wisdom is saving me time on the expensive experimenting....OH as for the gear vendors solution....i'm not that rich.

[ls1nova71]

Originally Posted by clinebarger

Messing with the DBW/TAC is not a good idea either, The good thing it will most likely go into "limp" mode & not actuate the throttle very much.
.

This is what I'm thinking will happen too. Not sure how much force is applied to a TV cable, but by putting that load on a throttle body, my guess is it will be too much for it and will go into limp mode.

[68GMCCustom]

Originally Posted by Ranger6202

OH as for the gear vendors solution....i'm not that rich.

DANG! I had to go and look....they are quite spendy aren't they? A good $500 more then I just spent on a brand new 4L85e from GMPP.

[clinebarger]

Originally Posted by Ranger6202

I know they're stronger soley on spline input/output, but the rest of the 4l60 can be built just as strong as the 4l80 (once again overlooking the spline input/output).

This is not true, The 4L80E is substantially stronger than a 4L60E. Ive never seen a input or output shaft on a 4L60E break, Yes the 4L80E is way over used in applications that would be fine with a 4L60E.

Transmissions are rated on torque NOT horsepower.
4L60E's can be built to handle 500-550 ft.lbs.....Thats it, Enough to cover 95% of the trucks on this board running 4L80E's in 1/2 ton trucks

[68GMCCustom]

I've seen 4L60/65/70e transmissions with some heavy duty ratings...but I never liked the 1-2 shift/gearing. Unless you hit 2nd at well over 6k the motor falls on its face waiting for rpm's to come back up. That's why I went from a turbo 350 to a 200-4r...I just didn't spend enough for a good one.

I pretty much believe anything clinebarger has to say regarding gm automatics....but building a 500+hp toy to beat on at the track but now with efi and needing an "e" transmission... I felt I should go the 4L80/85e route.

[Ranger6202]

So if i go with the 4l60, am i limited to certain years that will work with my '05 6.0? i.e. will the electronics hook up to the harness i already have? I know i need to change a few wires for the 4l80 to 4l60 which i have all the literature for. Say i find a 1996 4l60, will that one work, or will i need 2000 and up?

[clinebarger]

Originally Posted by Ranger6202

So if i go with the 4l60, am i limited to certain years that will work with my '05 6.0? i.e. will the electronics hook up to the harness i already have? I know i need to change a few wires for the 4l80 to 4l60 which i have all the literature for. Say i find a 1996 4l60, will that one work, or will i need 2000 and up?

You will need a 300mm 4L60E/4L65E transmission.
98-02 V8 F-bodies.
99-up 1500 4.8/5.3 trucks.
SSR 5.3/6.0
GTO 5.7/6.0

[Ranger6202]

Further enlighten me here. What is the 300mm size indicating? Bellhousing? Torque converter to flywheel bolt diameter?