Black88Z

1: trans cooler or no trans cooler? I thought they were better than just using the radiator but after doing a bit more research I found it may be the opposite... something that stuck with me the most is "if you had a red hot piece of metal and wanted to cool it as quickly as possible, would you leave it in the open air or dip it in water?" I saw some very valid reasons why leaving it hooked up to the radiator is better than a trans cooler, but would like to see what others think.

2: is there a difference between the 700r4s in early fbodys vs later years? I have an 88 iroc and I got a spare dipstick from a 1992 camaro and the dipstick "full" marks were in different spots (I think they are both the same length, don't remember for sure though."

3: I've seen different answers to this, so id like to see if anyone can give me the correct one. What's the stock stall on the 700s converter? It is 12" right? Id like to get a 10" converter, maybe even a slight stall but nothing major.

4: (general questions) what's the best "high performance" tranny fluid I can put in it? I'm having it rebuilt in the nxt few weeks (went out) so I want it done RIGHT. I'm having a shift kit installed, vette servo. I'm looking into a deep pan too (worth it? Necissary for racing?) I know they carry 11.5qts stock, seems like a lot.

sofakingdom

iTrader: (1)

1. The cooler in the rad is HIGHLY effective. There are several problems with it though: it puts the heat into the engine coolant, and it then relies on the rad itself to remove the heat, which if your cooling system is already compromised somehow, can create a problem; it's sized and designed to move a certain amount of heat and that's it, which if your transmission generates more heat than that, might not be enough.

2. There's kind of ALOT of different dipsticks for ALL transmissions, over the years of the production lifetime of a trans. Typically it's either to make it fit into some chassis arrangement that is introduced after the trans was; or, to reduce mfg cost. In general, as long as the stick and the tube are a match, and it fits your car, it doesn't a whole lot matter which one you've got.

3. Depends on the motor torque. A 305 will stall around 1450 or so, a 350 1600 or 1700.

4. I doubt it matters much. Find out from your builder if he has any requirements or whatever and stick with that, at least at the start-up. Totally SUX to have a warranty issue and have to pay for it anyway because the builder isn't happy with the fluid you used. Wouldn't worry so much about the pan: about 6 quarts or maybe a bit more is in the converter at all times. A lot of times the deep pans cause more trouble than they're worth; clearance issues, scraping the ground, etc.

danclemts

iTrader: (1)

Can't argue with Sofakingdom, I added a car filter adapter inline to my rad cooler, bit more volume, bit more cooling with the slip on fins (pic below). heat is the biggest enemy of a trans, cooler is better. Higher stall will get you off the line quicker, but creates more heat and you lose gas mileage and dd'ing it can be annoying. You may feel differently
I use Redline fluid, I think any modern synthetic fluid will be fine, assuming it complies with any mfg/warranty requirements

Reid Fleming

iTrader: (2)

You need to factor in surface area and comparative temperature. Just saying that water cools better than air in itself isn't true. After all, when I'm hot after being outside and I have the choice of:
a) Standing underneath a ceiling fan blowing 75° room air on me
or
b) Sitting inside my hot water tank (120°)

I'll take the air cooled ceiling fan any day.

Let's take the surface area. My transmission cooler is 11x12" of dedicated cooling. Solely for the transmission. The radiator on the other hand just has a pencil size tube that runs up/down for the transmission line to run to. And it's shared with the engine's heat.

Then we have to factor in ideal transmission temperature is about 160-180°. But your radiator may be sitting at 200-220°. Now running your transmission through the radiator and then to a transmission cooler will in most cases suffice. But by bypassing that hot radiator and going straight to the cooler, you don't end up getting boiling hot fluid trying to cool the already warm transmission.

What happens in a traffic jam? You're sitting there idling, watching the coolant gauge rise up. The transmission isn't heating up too much if you're stopped. It will get hotter if you're constantly inching forwards though (slipping the converter). With the radiator bypassed, you're going to be getting the radiator fans sucking air through the cooler constantly while avoiding the heat soak from the radiator. If it gets worse and your car overheats, your transmission (with the radiator bypassed) doesn't have to worry about nuking the transmission fluid. You also don't have to worry about the line inside the radiator breaking and getting antifreeze in your transmission and transmission fluid in your radiator.

Therefore, I recommend bypassing the radiator if you live in a southern climate and/or if you only drive in the summertime. Running it through the radiator and then to the cooler is better for northern climates as well as winter driving. Because the radiator helps speed up getting your transmission temperature from (cold) ambient up to full operating temperature. Worst case scenario would driving in -30° weather down the highway with a bypassed radiator. Your transmission fluid would turn into gel.

Now even saying all of the above, I will admit that running a transmission cooler either bypassed or through the radiator first, either way is a good idea. Transmission coolers are cheap and they can save you a lot of money in the future. I think all automatic vehicles in Texas should have them. Whether they're high HP Corvettes or low HP Civics.

The important thing is to get a "stacked plate" cooler instead of a "tube and fin" cooler. Tube and fin are a series of U-shaped bends. Bends = higher pressure. Pressure = high heat. A stacked plate on the other hand is like a mini radiator for your transmission. A stacked plate also has MUCH more surface area for cooling at all times than a tube and fin. You can see the difference in the picture below. While the picture is in reference to A/C condensers (parallel flow is the same as stacked plate), the same holds true for transmission coolers.



I run a Long Tru-Cool transmission cooler. I like this particular model because it has a built in bypass that keeps the transmission fluid from being cooled by the cooler until it warms up enough to warrant being cooled. This allows me to drive the car during those rare Texas mornings when it's at freezing or a couple degrees below without any issue. I do not run it through the radiator at all.

http://www.transmissioncoolers.us/ca...cool-thin.html (Mine is #4490)

People run 4000 RM stalls with this transmission cooler with no worries. And it handles the city traffic of Houston during the summertime just fine. I think the issue of bypassed radiator getting a bad rap comes from people putting undersized tube and fin condensers on their cars and seeing no change or higher temperature. But a good sized stacked plate will drop the temperature very nicely. The other problem that comes up is that people will install the transmission cooler directly on the A/C condenser with push pins. A bad idea as the A/C condenser will run 140-180° temps when the A/C is on. So your A/C performance goes to hell and so does the transmission cooling. (I have a small air gap, just barely enough to squeeze a finger in there. The A/C still blows air in the 30's. So no issue there)

Stock stall is going to be a 12" at around 1600 RPM. If you want a stall, I would recommend a 2600 RPM minimum and spend the extra money on a GOOD brand (Circle D, Vigilante, Yank). They offer better driveability and are built with better clutches, better materials, etc. They will last. The money saved on a lesser brand always results in the same thing. Worse driveability, burnt clutches and then when it takes a dump, it breaks your transmission.

The 1988 and newer 700R4 transmissions are stronger than the 87 and earlier transmissions. I couldn't tell you what is different though. The odd thing is that GM allowed the 87 and earlier ones to make the full throttle shift into O/D. While the 88-91's (except for B4C police cars) would not make the shift into O/D at full throttle. Sometime mid 91, they went back to allowing the shift. A different plunger and sleeve will allow the shift. I suspect GM did this mostly for trucks towing as well as lower HP cars. Wanting to make it so they couldn't burn up their overdrive with anything more than 2/3rds gas pedal. (More than 2/3rds and it would shift from O/D back to drive or stay in drive) The Corvettes always had the ability to make the full throttle shift into O/D.

I wouldn't bother with a deeper pan. These cars are low enough as is. And the cooling isn't necessary unless you're getting into mega heads/cam setups.

Fluid? Whatever your builder says. I don't believe in the "high tech" fluids.

MikeT 88IROC350

This is some good info here, gotta bookmark this one for future reference. I need an ext cooler for sure. I have PI Vigilante converter, spec'd at 2800-3000 stall. I went a little aggressive since i was hitting the strip, and wanted it to be done once, ready for future mods. It certainly helped my 60' times for sure. But now, after a few years, i am thinking this high stall converter is putting heat into my engine coolant. I know it is. I run a 170 tstat, and it ran cool before the converter upgrade. Now when i load the engine, like go up hills, the engine coolant goes up for sure. Doesnt really get above 200, but more than what the system can handle, i think. I did get a 4-plate tranny cooler installed in the rad, when i had that rebuilt.
So is this Tru-Cool tranny cooler kit easy to install? I like the variety of sizes to choose from.

Reid Fleming

iTrader: (2)

Hard for me to say honestly. I had it put in at the same time as the TransGo. The shop told me it would be 2 hours for the shift kit and 1 hour for the cooler. They billed me for 3 hours total.

MikeT 88IROC350

So do you agree that i could benefit from an ext tranny cooler? I thought of trying this project myself, but if i have the tranny shop do it, it would be done right. I just know my converter is putting heat into my engine coolant!