I'm looking for advice on cooler setups. You guys know more about this stuff than me so I'm sending up a help flag

Short summary
I have engine oil and ATF coolers installed to deal with the heat produced by a GTM twin turbo setup. They do OK, but not as good as they can. I'm considering switching to slightly smaller coolers that will get more direct air flow and have enough room for me to install fans for when I'm stuck in traffic / hot weather. Should I keep the current setup which is OK, or switch to smaller coolers in better locations where I can add fans?

Background
My two coolers are Earl's 5" x 13", 16-row temp-a-cure coolers that have 5" x 9" cores (i.e., the face of the cooling surface is ~45 square inches). When the GTM twin turbo kit was installed, the coolers were placed behind the intercooler and in front of the radiator. This placement has worked OK, but isn't optimal in my opinion. In hot weather, I'll see engine oil temps in the 220-240F range if boosting moderately (normal driving temps are fine), and ATF temps in the 220s if I don't take it easy. I previously had a SPAL fans to cool down the temps if they got above 200F, but there isn't enough room to install them in the current location.

Solution?
I can squeeze 10.5" x 8" coolers just below my headlights, but I'm not comfortable with the ground clearance plus I'd have to cut holes in the core support for the fittings (see the two pix below). The safe bet is to go with 7.75" x 8" coolers which have plenty of ground and fan clearance. These coolers have 7.75" x 4" cores (31 square inch cooling faces), about 30% less than the coolers I have now.

I don't have the data to handicap how much cooling efficiency I'm losing with the current setup to decide whether smaller coolers in a better location would be better. I'm hoping someone on here has some experience with this issue and can chime in. Any feedback is greatly appreciated. Many thanks!

 

I think going smaller and adding fans are a step in the wrong direction - fans are only useful below 30mph and if you are generating massive amounts of heat below 30mph you have a bigger problem.

I would move your oil cooler to the place it will get the most passive air flow - don't be afraid to put it back behind your intercooler. Your intercooler won't increase airflow temps as significantly as a radiator/oil cooler.

Might I suggest running(testing your car) without a front bumper cover? to see if the abundance of passive air will keep your oil temps down? If they do than you should focus on optimizing the airflow you have(bumper cover on). If your temps are still high I would look into a larger oil cooler.

 

You might also try some proper ducting. Air will be inclined to go around a cooler that is simply placed in the airflow, and flow through the cooler is what's necessary. A proper duct to ensure flow through the core would go a long way towards increasing efficiency. The duct should be smaller than the cooler face to help slow the air through the cooler.

It seems like cooling was kind of an afterthought on these cars. The nose is pretty tight before adding additional coolers and only the single inlet from the factory. I've thought about adding a pair of the titek style nose ducts and running hose from them to the cooler on mine (currently under the headlight like you're thinking- tru-cool 36 row core exhausting to the fender well). You can pick up used carbon fiber oil cooler duct plates from NASCAR teams pretty cheap off ebay. There are fans for duct hose too if you really wanted fans.

 

Maybe try bigger coolers 8n the current location..16 row is tiny...I have the same gtm/tt setup, coolers behind IC but they are 48 row each setrabs.

 

hey guys, i really appreciate the responses!

@ bealljk, I agree regarding going smaller. the reason i want to put the fans back on is its very congested out here, and when you get caught on a hot day, you're helpless in trying to keep temps down. traffic routinely gets so bad that it takes 30-40 minutes to move a mile - i'm not exaggerating, its happened to me twice in the past 2 months.

my coolers are currently located behind my intercooler so they don't get direct flow (i should have posted the pic below for clarity). but like you said, its not like the I/C is heating up the air as it passes through under most conditions. i will just upsize my coolers as you and ogie suggested.





@ kilogram, thanks for the tip on ducting. my current coolers are behind the I/C so I don't have room for ducting, but if i relocate the coolers thats that way I plan to go. I cut vents in my wheel well liners a few years ago to aid in flow as well.

@ ogiehooker, yep, they are kinda small, but worked well when I was supercharged (and the coolers were right behind the side vents in my bumper). As you and bealljk suggested, the best route probably is to just go with larger coolers but keep them in the same location.

Btw, I saw your setup when I started researching this topic and immediately got envious. How are you coolant temps with such large coolers in front of your radiator?

 

Isn't this going to drastically effect your radiator's ability to cool?

It's my understanding that you never want an oil cooling radiator in front of any other radiator or intercooler.

 

This statement should be taken with a grain of salt...I would never put an oil cooler infront of your intercooler but you should factor in that your thermostat is restricting your coolant-cycling, so yes, putting your oil cooling in front of the radiator may not be optimal but isnt the end of the world either. Kilo hit it on the head that having airflow forced through the cooler will improve efficiency.

I ran thermostat-less as I'm fighting some cooling/bleeding issues right now and (per my haltech) I couldnt keep my temp above 135degrees (granted I have a much larger capacity radiator) it opened my eyes to the importance of the thermostat.

Another thing to consider, depending on how big of a priority you put the balance of the car is the amount of weight you are adding to the front of your car, especially adding weight ahead of your front axle.

 

When I was SC'd, I also had coolers by the reflectors (now vents) which were ok.
With the FI setup, I took extra precautions regarding cooling when building my car..everything ceramic coated/antifriction coated internally...converted to HR style cooling system, 54mm radiator sprayed with heat emitting coating, water/meth for COOLING, not a power adder. The oul coolers themselves were sprayed with BBE, heat emitting coating as well, which you could do if you use the current coolers still behind the old reflector openings. You could also make "shark gill" slits like Jaxter did at jtran to open up air flow (see jaxters thread).

I have 2 naca ducts on my front bumper that have3" ducting to each side of the radiator, behind the oil coolers...a bigger oil cooler will help with oil cooling and reduce load on the water cooling system.

The extra weight on my front end was compensated for by moving the 40 lb battery to the trunk.