one of our Corvettes we race is a C4, last year....

Engine guy I am... Automatic transmission guy I am not:-)

RWHP 398
RWTQ 405


Any quick fix to keep form burning them up?

 

700r4? If so....MAKE SURE the TV cable is properly adjusted......it is the lifeline of these transmissions.....it controls pressure within the valve body.
Use a giant trans cooler as well....but you knew that.

Jebby

 

Putting on the GIANT trans cooler this weekend...

I have always run manuals in my cars... middle son runs the auto in his corvette,,, so I am asking for my son Chris... he has had the trans "built" 2 times now to take the power, but he keeps eating them up... I will have him ask about the TV cable, as I know nothing about that..
Thank you..

 

Is he burning them up or breaking parts?

If he is burning them up, it is a pressure problem probably created by not adjusting the TV cable properly.

There are constant pressure valve bodies available so that the TV cable adjustment is not so critical. There are also larger billet servos available to put more pressure on the bands. Bands and clutches are available with more aggressive friction materials to hold better. slipping makes heat and kills the bands and plates. Also, the really good bands are wider than stock and require a new drum to clamp onto. If a used drum is installed with these high performance bands, they will fail.

If things are breaking, there are stronger sprags, drums, planetary gears and shafts available.

The first 700R4 I had behind the motor in my signature when it was in my 80 Vette was built by a friend of mine. He put the good clutches and bands in. He upped the pressures in the trans and putt better sprags in it. I broke it after about 3 days. My friend, now passed, built great trannys, but it should have had all the gears, drums and shafts upgraded.

My second trans I bought from George (gkull). It is a Art Carr 700R4 built to handle 850 HP. George beat the snot out of it for quite a while and I beat the snot out of it for about 4000 miles. It is going to get beat in my 75 Vert if I ever get it back from the body shop.

Mike

 

its a 4l60. not an r4

 

Same tranny, just electronically controlled. He may be able to up the pressures with a tuner such as HP Tuners.

Mike

 

4L60 is a later version of the 700-R4. Is your builder setting up the clutch packs at minimum spec clearances? Shift kit made by? Using Kolene Steels and red friction discs? Removed the cushion (wave) plates from the packs? Like V2 pointed out- all of the sprag clutches are updated as is the sun gear and planetary gearsets.

 

Tranny cooler is a must. Blew out 3 qts racing uphill in first. Installed tranny cooler. No issues.

 

I suppose 7000'+ hill sides will do that.......

 

God I love this forum...

 

Yup. Mt. Palomar. Look It up. Popular drive on Sundays. Bikes to Lambos.

 

I'm glad that I'm not the dead tranny guy.

Typical 700r4 hp hop up kits are not made for real performance motors. Manual down shifts will kill any auto tranny not setup with full manual/no kick down auto shifters

Deep pan. Big cooler, and tv cable setup with a pressure gauge help you need the 26 vane pump and high hp hard and soft parts

 

do you see transmission temperatures above 200?

 

You need AT LEAST a B&M #70297 trans cooler with the fan.... and you may need an additional plate style cooler as well. Make sure to NOT run the trans fluid through the cooler in the radiator...That will just heat up the trans fluid more. You need to keep the trans temp below 200* at the MAX.... 150-160* is a lot better. Heat kills the 4l60.

RPM Transmissions in Indiana are the kings of the 4L60. I would definitely consult with them if you want to build one that lasts.

 

Yes, just bypass the cooler in the radiator and get the biggest cooler you can.

 

Thx guys... His brother DannyBlake10 chimed in and is also watching the thread... He is helping with the transmission..

Yes, just burning them up... fast.. they do not last long.

 

Call Ron at TRC Transmission in Chatswroth long time racer
Tell him what youre doing, how its being driven he will get it right the first time never broken one he has built yet.
Those things fail all the time behind stock motors really need to put some work to make them right. Ever consider a 4L80e?

 

thing to remember with the 700r4 is to low of pressure will smoke it very quickly, not sure anyone has ever damaged one with to high of pressure.

 

Along the way I picked up a MONSTER engine oil cooler, and it's about a foot square and over an inch thick.....

I use it on my 200 4r in the '72 vette, 350 engine about 350 hp....fuel injection...

I can drive on FLORIDA freeway at 80 mph, pull off on to a traffic light, stand in traffic on a bright day easy 100f temp outside in my back yard, I"m thinking that street is about 600f, being black ASSfault....

at any rate I pull into the garage and put the IR temp gun on the pan.....

130f.......can't bitch.....

 

Paul, you can sink $3000 into the tranny and another $1200 into a TC and quality cooling system and the 4 speed OD tranny can take on 800 hp and never get hurt.

But the conclusion I came to after doing all that and putting in a bullet proof 4.11 rear end assembly is that those transmissions have bad gear spacing and an auto burns up about 25 hp over a manual.

Drag racing to auto give you the stall and instant shifts. for road racing it has too many negatives. I bit the bullet and pulled all the money I spent and did the logical thing.......... you have to get a 5 or 6 speed setup for 600+ foot pounds and never look back. I originally looked at full road racing sequential trannies in the $8000 class and then trimmed it down to the $5000 ish Keisler RR package. All SFI and light weight rotating assembly with blow proof bell housing