9krpmrx8

iTrader: (46)

Okay Guys, I actually did this Install today on REDRX3RX8's 2007 GT Auto. He came into to town for a track day at Harris Hill and after having his tranny replaced a couple months ago after a track day we thought it would be a good idea.

I read 09Factor's excellent DIY here:

https://www.rx8club.com/series-i-do-yourself-forum-73/diy-cooler-install-112522/

I did it a different way though and think it's easier to pull the battery and intake and go through the top. There really is no reason to go under the car or remove the bumper to do it. REDRX3RX8 made the brackets to fit the factory rock guard and that was a really smart idea, it worked perfect. So for those of you with older Auto's, you will need the factory rock guard t do it this way.

Anyway, hope this helps you Auto guys keep things cool on the track or if you live in a hot climate.

http://www.flickr.com/photos/9krpmrx8/5462875379/
http://www.flickr.com/photos/9krpmrx8/5463477176/
http://www.flickr.com/photos/9krpmrx8/5462875681/

09Factor

Alright another way to install a Trans cooler! After Mazda came out with the rock guard i wish I had it at the time of my install. Oh well. You did a Great job on REDRX3RX8's cooler
Thanks for the kind words.

invasion08

iTrader: (7)

What were the before and after tranny temps?

9krpmrx8

iTrader: (46)

I believe on his return trip he saw a 10F drop but that was all highway and he is using the Scangauge II to monitor. It would be easy to add an inline tranny temp gauge, I am not sure where the sensor is that the factory PCM monitors tranny temp.

He has seen tranny temps of 235F on the track and he doesn't even track in extreme Texas heat like some do. That is very close to putting the car in limp mode I think.

REDRX3RX8

Here I am guys.

Yeah, its hard to tell on the temps because I wasn't stressing the car on my drive home on I10.

I10 has a 80mph speed limit so I set cruise on that (got 23mpg), and when I climbed a steep hill the water would climb from approx 179 to 184, and the ATT (auto trans temp) would stay at about 174.

Previously it appeared that as soon as the thermostat opened at 180 deg the ATT would immediately follow up to the water temp; in 30 minutes of creeping rush hr at 70 deg ambient, I saw 203 deg f ATT max; and on the track before my cooler the water would be 207 max (just corrected, Ha!), but the ATT would be 235.

The PCM is supposed to put the tranny in limp mode when it hits 249, so the track is the only place I'm worried, but I don't use car in hot weather much either.

Right now I'm claiming 10 deg f lowering which is plenty good to take the edge off for a $50. mod.

After March 6th I'll have the answer for the max on my next track day.

Silver_Surfer

I know I'm responding to and old thread but have you tried switching the lines around? It's my belief that the fluid should climb up the cooler, staying longer in the cooler allowing the fluid to be cooled longer.

REDRX3RX8

OK, good input, and this thread needs update anyway.

With this configuration, my trans got up to 242 deg on another similar 70 deg track day ( different track but also technical).

So I got the biggest cooler that would slide through the front without trouble : Derale 13103 from Amazon $42. which has two more rows of fins.

I haven't tracked yet, but I've driven hard on the Texas 8 April 2nd with ambient 98 deg or so, and the ATF was running 203 max with the water at 220 deg.

I was driving home around the tripple digits on a deserted hwy for awhile and both temps were 193 deg so I think I've got enough cooling.

Funny thing is: when I got home and checked the temps on the in and out metal lines the top was reading 158 deg and the bottom 172, so we accidently switched lines to your recommended configuration.

It seems like I'm getting enough cooling that the water temp rise is being held back some so I like it until I test Nov 19 at track day.

So, if this configuration doesn't keep the trans from ever hitting 230 deg, I'm thinking of plumbing the hoses parallel so the ATF goes through the two coolers at the same time instead of through the factory then the Derale.

40w8

Update!

Driving down I10 to my last HPDE at 80 mph without AC, the water temp ran around 175-177 deg f which should mean the thermostat had the water flow turned off, and the fluid coolers were doing the cooling.

The atf temp was around 155 deg with outside temp around 70 deg f, so this cooling mod is not only a trans saver, but an engine saver.

On the track on a 70 deg day, the water hit 213 deg tops, and the trans temp kept rising slowly until after about 15 minutes temp rose over 230 to about 244 deg f. On the track I hit about 90 mph, then brake hard to 30 mph which seems to build heat more than other tracks that are 90 down to 50.

So I have a very good total system cooler that is plenty to save the trans and engine which doesn't apply to manuals trans RX8's.

Silver_Surfer

Great details! What is your final set up? Plumbing?

40w8

40w8 is REDS alter ego, but anyway I left the plumbing alone with the 18,500btu cooler plumbed after the stock cooler in the water radiator.

The water hoses were switched accidently when the bigger cooler was installed, so the hot atf out of stock cooler enters the BOTTOM like you suggested.

it's a very neat install if you follow the first instructions, and it works good enough not to keep messing with it.

If I did it again, I think I would split the ATF to go parallel into each cooler, then, rejoin just before the trans.

If you have a auto, why don't you try that and give us data.

Silver_Surfer

Mine is routed same as yours. Wondering because I was talking to people who said why use the OE radiator cooler with the AM cooler or run it through the AM cooler and then through the OE cooler. I have the fan relay mods so opted your route.

btw: did you try different ATF fluids? I'm using Redline ATF ever since installing the cooler so not really sure of the improvements if any.

40w8

The dealer filled it with Toyota T-IV fluid like the Aisin book says.

I haven't even checked the level, but did fill the cooler with some T-IV when installing.

Oil is oil unless it's ATF which the wrong kind can easily ruin an auto, so I'm not brave there.

40w8

Every cooler instal says to plumb after the OEM cooler in the water radiator, but it would seem to be better to split it with 3 way so two coolers have flow in case one gets blocked.

when I measured that 14 degree difference, the hotter was 172, and without the cooler the temp would likely be 186 deg on a 98 deg day. the AC was on and I could feel the air across it.

I don't see any way to manipulate more temp decrease except to maybe turn the heater or ac on the track to flow air across the fins.