3rdgenmaro

iTrader: (9)

If u had to run a 700r4, and due to gearing and track size you would be limited to 2nd gear, would the trans live?
Does a 700r4 get full cooling flow outside of 4th gear (with converter locked up)?

what would someone need to do to assist the trans in living at wot in 2nd?

RBob

iTrader: (1)

Full cooler flow occurs whenever the TCC is locked, 2nd, 3rd, or 4th gear.

Note that 3rd gens came factory with various rear ratios. Such as 3.73, 3.42 & 3.32

RBob.

3rdgenmaro

iTrader: (9)

In stock form does the converter even lock in 2nd? Wouldn't be hard to change though. Or install the valve to remove the lockup feature and provide full flow.

Rule limited to 3.42. The big drop from 2nd to 3rd is a killer for me with 700r4. 2nd gear with my current 3.08 should work out the best with my assumed rpm. Will find out more at practice.

The cooling part is what has me the most concerned.

Looking at the non-lockup valves, Id have to pull the pump to install. Not willing or capable of that at the moment. May have to wire up a lockup circuit. http://www.coanracing.com/PDFS/Insta.../COA-92847.pdf

Tuned Performance

iTrader: (92)

@rbob does $61 mask have 2nd gear lockup settings. I thought it just does low gears 3rd 26mph or so and high gears 4th about 28mph lock.
Or is low gear setting for 2nd and 3rd ?
Looks like the mask has load limits for tps % to unlock as well as speed unlock but no unlock prevention speed.

Btw, going from dextron 3 to 6 makes a huge difference in heat reduction.
My one truck always use to be at 200f with dextron 3.
After going to dextron 6 it's at 100f all the time and 200f hauling a vehicle up a incline.

3rdgenmaro

iTrader: (9)

Cooler will be mounted in passenger compartment with a fan/fresh air ducting.

I'll be running a temp gauge. For practice I may just have to monitor the gauge and see how it goes. Fluid should be starting fairly cold and then running ~4 miles during an event. Toggle switch on during caution/parade laps might help, but that also puts me into having to remember to take it off. I'd definitely need an indicator light.

Looking more into the non-lockup valve, you have to pull the pump and run a non-lockup converter. Not an option at this point.

For the short amount of time, partial flow may be sufficient. Atleast a gauge can help ensure that it isnt heated too much.

I didnt know that about the dex6, thats good to know. Thanks

sonjaab

Why not a old school Turbo 400 instALL?
bOLT IN, cheap and bulletproof !

RBob

iTrader: (1)

It is unmentioned in this thread but it is for racing under a set of rules that prevent drivetrain parts that was not factory.

RBob.

RBob

iTrader: (1)

Yes, it will lock the TCC is 2nd gear. Due to the low gear lock allow which is usually set for 35 MPH or so. Need to pull the stick back into 2nd to get the vehicle speed high enough without the trans going to 3rd.

RBob.

3rdgenmaro

iTrader: (9)

Exactly. Rules require the 700r4.

Just realized though, would have to tune it in I bet. ECM is from a 91 5 speed.

Thanks for the help guys. I do appreciate it. This has been a big learning curve this offseason.

Tuned Performance

iTrader: (92)

Rbob covered all Tcc logic here .
https://www.thirdgen.org/forums/diy-...ad-vs-mph.html

RBob

iTrader: (1)

You do not want to use that PROM with an auto with lockup. The shift light logic will drive the TCC lock output. Which means that the TCC will only lock when the shift light is activated.

Since the shift light is for economy, the TCC will be locking and unlocking when it shouldn't. Can still use the ECM, just need a PROM for an auto car. Or if no lockup is desired unplug the connector on the transmission.

RBob.

Pro Built Automatics

The late 1987 and up valve bodies did not use the 2nd gear lockup. If you want that you will need a late 1987 early 1988 valve body that has the 2nd gear port on the valve body. The later valve bodies eliminated this port altogether. Since you are using a stock diameter torque converter, you would want it unlocked for torque multiplication as when it is locked up there is no torque multiplication. The planetaries get very hot when using 1st & 2nd gear only. We would add tractor or hydraulic oil at a 50/50 ratio or higher and this would keep the planets living much longer as this oil can take much more heat without shearing off all the oil. This worked very well at keeping the transmission from failing. If you run a non-lockup torque converter, you will need the TransGo non-lockup valve to put the oil feed in the right direction. This valve replaces the TCC valve in the pump, and can be installed without removing the transmission.

3rdgenmaro

iTrader: (9)

I would rather leave it unlocked. But the heat issue is what worries me. The transmission I have is an 86, unless somebody at some point swapped in a newer one (I havent looked).

I have heard of using tractor fluid before, but didnt think about it in this case. Forgot all about it. Thanks!

Right now it is a lockup converter. If the transmission doesnt get full fluid to the cooler in 2nd gear, unless it is locked up, Id be willing to swap in a non-lockup converter and the non-lockup valve. Locking the converter really could only occur under caution or parade laps. Basically holding the throttle wide open 90% of time with the other 10% near wot while riding the brakes.

The worst part of it all is that I cant put too much money into the transmission ($400 claim rule including converter), but I have to put in enough for it to live. One risk Im going to have to take though.

Im leaning towards a toggle lockup that I can use if trans does start heating up, or if we get under a caution. Or swapping to a non-lockup converter.

RBob, thanks for additional input.

Is there any other small things I should do? I was thinking of transgo kit in the valvebody and a corvette servo for the 1-2 shift.
Pretty low hp application, but Id like to try and make the trans last and have a good 1-2 shift.

Pro Built Automatics

Add the Corvette servo, and the .282" intermediate/reverse boost valve out of any 1988 and up 700R4 transmission will have one. If you want a firmer 1-2 shift use the .296" intermediate/reverse boost valve. The .282" should do fine. While the transmission is down, use the Borg Warner Hi-Energy 2-4 band and add the Viton input to output shaft seal instead of the white plastic one. They come in all 4L60E's. This will guarantee lube to the planetaries. Grind off the one land on the pressure regulator valve per TransGo instructions. This will increase oil to the planetaries too. The 1986 valve bodies have the 2nd gear port for lockup and use the manual switch that you suggested. Install the temp gauge in the top line going back to the transmission. This will give you real world temperature readings in seconds. You will have to try lockup vs. non-lockup to see what differences it makes. Temperature should be 155F to 190F. Mix Dexron III with the hydraulic oil. Use the Turbulator steels in the reverse input and the low reverse clutch packs. Are you allowed to do anything you want inside the transmission. If you are allowed to do other things, you can remove 3 of the low reverse clutches and 2 of the intermediate clutches and install steels in their place. This will get rid of friction to free up some horsepower. It depends on how serious the racing is here. Run additional clutch clearance in both of these clutch packs. .015" - .020" per clutch being used. .086" 2nd gear band apply feed hole in the separator plate is all that is needed here. DO NOT block the 2nd accumulator.

3rdgenmaro

iTrader: (9)

Thanks Dana. Once I get the initial bugs sorted out, I'll be giving you a call and getting some parts. I appreciate it!

Over the past couple of years the thought of starting to rebuild and modify automatics myself has crossed my mind. I think this will be a good time to start.

BTW, my 88 was rebuilt years ago with one of your street/strip kits. Still running strong!

RBob

iTrader: (1)

I've been testing this on my car as I thought it did lockup in 2nd. Early tests with stock MPH lockup points and then moderately lower didn't realize any results. At the RPM required for the MPH required the TQ was already solidly coupling.

I changed the MPH lockup points to 12/14 (MPH) so the ECM would command a low vehicle speed lockup. It did and the convertor locked, depressing the brake pedal caused an unlock with the jump in RPM. The engine didn't like the 1200 RPM lockup in 2nd, so this isn't something to drive with.

At the same time, this is just one 700R4 model/series. Others may easily be as Dana posted, with the TCC circuit being fed from the 3rd gear circuit. Wouldn't be surprised.

RBob.

3rdgenmaro

iTrader: (9)

IM going to bump this back up. FYI: Temperature has been under 200F with out lockup so far. I do lock it up if we have any cautions. Decent sized cooler in the passenger compartment helps.


I need to firm up the 1-2 shift a lot. Im running 2nd all the time, but on starts/restarts Im in 1st. Lost too much ground trying to start in 2nd. The 1-2 shift just isn't as snappy as it should be.

I'll probably throw a corvette servo and the .296 valve in it before the next race. Assuming it can be done fairly easy.

Dana, is this what I need?: https://www.700r4l60e.com/store/prod...&cat=52&page=1

no new tires

You can run more than 1 trans cooler.

gains:
-more fluid capacity (like 1.5+ quarts)
-more system heat capacity
-more heat dissipation

Pro Built Automatics

Yes, the Corvette servo and boost valves is going to help here? What size is the main boost valve? What year is the transmission?

3rdgenmaro

iTrader: (9)

It is an 86, assuming it was never swapped out.

Based on the car it came out of, it should be completely stock to the car. But the pan has atleast been into sometime in the past, looks like they used rtv to seal up some leaks.

I have never dropped the pan on it.

articwhiteZ

iTrader: (56)

add the 6 pinon front planet making it close ratio.think ya can get them for under $600 now..
there are some good coolers out..

3rdgenmaro

iTrader: (9)

I'll keep the pinion in mind if I ever have to take it down.

Cooler is working good, thanks for the input though. Not having any heat related issues anymore. Just need to firm up that 1-2 shift.