I'm trying to find a tranny cooler that will cool the ATF enough to keep my tranny from hurting itself. I found these 2 that I like but need some opinions on size and thicknesses. http://www.summitracing.com/parts/BMM-70273/ http://www.summitracing.com/parts/HDA-678/ I know to stay away from the tube and fin because they aren't as efficient but have no idea where to go from there. Thanks, Chas

if you are going to place the cooler in front of the rad.
i would use the 678 if you have space as it is thinner
and air will flow through it easier-if it won't fit,the
other one looks up to the job too,as long as the radiator
cooler is still in use.Also would be good to have gauge
to monitor what temps the tranny runs at-old B&M
trans temp gauge i have in my dodge has yellow zone
that starts at 220*,red zone at 240* overcooling the
tranny can increase wear and reduce performance

So what size is optimal for keeping the right temp without overheating? I currently drive in 50*-80*+ temps throughout the summer.

get the biggest that will fit IMO. Typically you can never overcool a trans. I buy the 28k rated ones, aka the biggest TCI cooler on the market. My trans temps with bigger stalls and the radiator fan running have all been in the 175 range.

i agree, get the biggest one you can afford/fit
if you are worried about over cooling, run the fluid from the trans, into the cooler, then into the radiator, then back to the trans.

if you have a radiator with no cooling lines, just get a stonking big one and forget it.

honestly though, too big is hard to do and too small could potentially cost you a new trans

I'm sure you mean run the fluid from trans into the radiator, then the cooler and back to the trans The fluid would actually get heated up by the radiator since coolant temps are usually 195-210 whereas we're shooting for under that by 20 degrees at least.

exactly, but trans temps are in the 300* range when they get hot.
say you live in north dakota but do a lot of towing or have a high stall converter with no lockup
the air temps will cool the fluid to a much lower than desireable temperature, so if you run the fluid thru the cooler first, then the radiator, you will lower the radiator temperature, lower the trans temperature, but not let it get below an operating temperature of just above engine temp.

say the fluid out of the trans is 280*
the radiator alone will get it to say, 240*, just for arguments sake
the radiator is at 180*
your trans is in trouble... big time

now add a cooler
trans out is 260*
into radiator, and 220* out
radiator is 180*
into cooler and out 140* (big cooler example)
this is fine, and the trans out temps have been lowered, but 140 is verging on too cold for operating temps, and the temps will get colder int the winter and when you are not driving hard

if you run it reversed,
trans out 265
into cooler, out 185*
into radiator, out 180*
radiator is 175* due to less demand on main cooling system.
trans out temps are slightly higher, but the overall effect is to use the dedicated trans cooler to do most of the work, and the radiator cooler (which is small by the way) to be used to stabilize the temps.


at least thats the theory that was explained to me by an engineer, and a car guy (two separate guys)
i pulled the numbers out of thin air, so dont take them as scripture, just the idea

oh, and i am using a thermostat lower than the stock 180 or whatever it is... 170 or 160 is fine

when installing temp Guage,Temp Guage always inline from tranny.before radaitor. or in pan..

this is not VOODOO Guys

im up in washington state.and ran a B&M 3500 9" none lock up converter in a B&M 700R4 with 4.10 gears in the rear, with a 11.1 383 SBC.

from radiater to cooler 9" x 12" tube and fin (works fine)ENG running at 190 deg
always remember to make sure it's(the cooler) as Big as a dinner plate.


and the tranny temp Guage never gets above 150 deg. IN THE SUMMER
even at the track!

if your tranny see's 300deg, it's time for a new tranny.. or Guage...lol
as that oil will start to burn up at 300deg..even at 225. for 10 min it's on it's way out
and would go from red to Brown in color..and smell burt..

your tranny might still run at 260 deg..but not for long..
worked at aamco when i was a Kid(15 to 18) doing R&R and
putting them together...and played with heat on them to see how long.. if it's a race car only doing 10 sec runs every 10 min your fine.
But thats it!! has it will never see that temp.

the cooler you keep it the longer it will last..thats the rules!

175 deg temp in a auto tranny will get a life of ball park 60.000 to 80.000

anything above 200 you will smoke it before it's time

KEEP it under 160 and all is good!
NOTE: flashing it at the track or on the street a few times getting it up to say 180 deg if fine..it's not living there for more then 10 min!
(been there do that..lol)

go dig up some Books on Putting them together and check it out.
look at the test done on the Tranny Fluid (Oil), when it stops doing its job,... so do the parts its there to help...

but them iv never smoked a tranny,
i have busted parts in them.(R&R parts and back in it go's)
my 89 Chevy truck iv had for 20+ years now..pans never been off.
fluid still looks new..why is that?..it's never been over 150deg.
leaks now (dip stick & pan)..and i add Ford type F.. best stuff to use.
NOTE: see how B$M Guage gaps at 160 thats so you know your moving into a Uper heat zone ok for short trips towing/racing stuff.
when your fluid starts to turn Brown (should always look Cherry red)
but when it starts to turn..Flush it out! install fresh stuff..

now also see how when it hits 220 it's yellow..see the short gap from yellow to Red! Notice: red from 260 to 350..notice its red..
you dont want it there.. thats why it's red.


but thats just Me

this is all wrong No trans temp is in the 300 range, etc. From the trans to the radiator to the tranny cooler and back. In fact if it is only driven in warmer climates and/or a bigger stall just run it into the cooler if you wish.

a tranny cooler remote mounted with a adjustable thermostat fan switch with a fan mounted on the cooler. NO problems 100% recommend

I think i will be going this route. I don't have a tranny cooler in my radiator so there is no way for me to do the above mentioned. So optimal is 160* so that is what i will shoot for with a temp activated fan switch...



Thanks
Chas

you can run cooler, it's ok..but with stop and Go driving ya 160 is the norm.. if you running just the tranny cooler you might see lower then 160
THATS FINE! the cooler the better..

its better to have a external cooler for the transmission, because the car gets about 220* and because stock cars have the built in transmission cooler in the radiator so id imagine the transmission fluid gets up to 220 as well. Point is the stock radiator actually slowly kills the fluid. Its better to separate the two. On Gm truck, ck2500 and up have a power-steering cooler built in the radiator i think. Our cars have a power-steering cooler its that metal pipe at the base of radiator, Just a tube, for 20 bucks a better cooler with fins can be mounted as well for the power-steering. Both power-steering and transmission fluid is virtually the same. In fact ive read people used power-steering for top off for transmission, and vice versa. Theres even complete guides to convert the transmission to straight power-steering fluid. same stuff, but lil different and ones dyed. You could try to search on this site for the debatable ideal temp for transmission. also a temp-gauge on the return line or something. Not advice but some direction.

Thanks for the help ill keep it in mind.

Thanks again,
Chas

If you're really concerned about overcooling your ATF, you might consider finding a brazed cooler like the first one you linked ( I prefer inverted flare fittings over hoses and clamps ). The one I use is made by Transgo and has graduated tube orifices. The first couple of tubes are normal i.d. and then the rest are restricted more and more as you go down the tube stack. Your ATF has to become viscous enough from the heat to travel through the restricted tubes thereby regulating the flow. My 700 runs around 125 with a deep B&M pan.

Your other option if I may is to find a Hayden Transmission Oil Thermostat http://www.summitracing.com/parts/HDA-163/ or something similar

I know Summit states Engine Oil, but read up on it on the Hayden site
http://www.haydenauto.com/upload/Hay...il-coolers.pdf page 68

I should add that our daytime temps here right now are around 10C and I run my ATF only through the external cooler. I don't know what summertime temps I will get as I have only installed the Trans Temp Gauge this Winter.
The Trans was installed with the Pan and so on a year ago in November and ran Great through last Summer's 25-30C heat.