fatman

Here’s the deal. I just got my 89 camaro running on all 8 cylinders and hit the track. We ran a 12.993 with a 1.7 60’ time. We had a 104-105 mph trap speed. After looking over the time slips we decided to move from a 750 vacuum secondary Holley to a 700 double pumper. The car seems to flatten out through the middle of the pass. We rebuilt the carb and mounted it last night. I need to change some linkage and vacuum lines around. We are running a turbo 350 and I wonder if I need to invent some linkage for the kick down. This carb does not have an arm to attach the cable to. If I do not care about the kickdown feature do I still need to hook this up to enhance or maintain internal pressure on the transmission? If it doesn’t I can forget this linkage. If I do not hook it up and have softer shifts then I will build some linkage. Are there any trans guru’s out there that can help me out or link me to a site that will tell me? Thanks in advance!

sofakingdom

iTrader: (1)

No, you don't need that. All it does, is yank the trans down into a lower gear when you floor it.

Use a RED STRIPE vacuum modulator. Not a pink stripe, not a green stripe, not the big black can; small gold can, RED STRIPE. There's no particular application you can look up and get the right one for sure; just open the box and look. It has a certain amount of adjustability built into it, a screw in the vacuum fitting hole. Adjust it in about ¼ turn increments for the shift you want.

jr. gearhead

the purpose of the cable, as you may or may not be aware is to control the shift points in the trans. w/o it hooked up, the trans will shift very early and will not allow the engine to get into the power band that it needs. having it attached will allow the throttle pressure circuit in the trans (what the cable is connected to in the trans) to modulate and balance the governor pressure resulting in a higher shift point. yes, the 350 trans has a governor, but it has nothing to do with top speed control of the vehicle. the governor also has springs in it that allow fine tuning of the shift points as well. for all out drag racing i would suggest a full manual valve body mod that forces the trans to stay in the gear you put it in till you shift it. some even allow the auto functions if the shifter is in 'drive' and manual control in '1st' or '2nd'. i would suggest hooking it up and seeing if that corrects the problem at hand. there is one thing to make sure of though. the linkage needs to be 30mm center to center for the correct ratio and travel in the cable. let me know if there's any other ?'s

sofakingdom

iTrader: (1)

No, it isn't.

In a 350, the thing that controls the shift points, is the combination of vacuum modulator (engine load) and governor (vehicle speed). The cable is ONLY for kickdown.

That's why its official name is "detent cable", not "modulator cable", like a 700.

jr. gearhead

you're right about that...it was late (for me) when i wrote that. the 350 has the detent and the 700 has an actual part called a throttle valve. leaving it disconnected in a 350 and it just won't downshift. leave it disc in a 700 and you'll smoke it quick

fatman

So do I need to hook the kick down cable up or can I just leave it disconnected? I am not being lazy but this car will not be street driven very much. Just a few more races this year and it could be hooked up this winter but I will expediate the installation if we need it to protect the tranny. Thanks!!!

Blackroc86

You don't need the kickdown cable hooked up on a TH350 trans. Like Sofa said all it does is shift the trans down when your foot is on the floor.

jr. gearhead

the kickdown does two things, both of which relate to near WOT. one is to cause the downshift, the other delays the upshift. my advice would be to hook it up and see what happens. i use it on mine.

Blackroc86

Be sure to adjust it properly if you hook it up. It sucks big time if it keeps you in second gear on the track.