Oil coolers, what are you using??

StephenB

StephenB

New member
I am thinking of making a few upgrades to my oil coolers in the next few months. currently stock the RX8 has 2 oil coolers on each side in the front bumper. I am thinking aftermarket ones made for racing must be more efficient and offer better cooling... any suggestions?

Also what are the benifits of a thermostat in a purely racing application? do we need it, and if so what temperature setting?

Stephen
 
earls, mocal, setrab type are all very good and available in a huge variety of sizes and shapes with fitting up to -12AN, sometimes larger. fluidyne makes some seriously nice kit, too, but in limited varieties. I think the setrab and mocal have less pressure drop than the earls, but the earls is far cheaper and still very good, and has the most sizing options to fit just about anything. we have earls in -12 on the MR2s and they fix the cooling issues we were suffering from...where's that koolaid smiley... oh yeah, wrong board. don't use the tube/fin or B&M style (sold by a million companies as their own) stamped plate stack. waste of time.

the real key is to get as much cooler as you need. if you get too much, then you might need the oil thermostat. otherwise, a racecar shouldn't need one. Changing viscosity can change operating oil temps somewhat, and changing temps often requires changing viscosity, too. are the stock coolers not keeping up?
 
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I much rather love the B+M plate style, actually; have had it in my 924 for ages. A number of guys use 'em in the DSRs, in fact. Much cheaper and more robust than the uber-expensive Mocals etc.

In the 924, it's a similar location as the RX8, sounds like - up front, corner, in front of the front left wheel. It's been in a number of tire walls and gravel traps, thanks to the new/current driver (oh, yeah, and me once or twice too). It still works great, just have to poke out all the gravel on occasion.

Excellent cooling too, IMO - car works great in 95 deg heat. With the 924, it's the 8.5x11" size... YMMV...
 
StephenB said:
I am thinking of making a few upgrades to my oil coolers in the next few months. currently stock the RX8 has 2 oil coolers on each side in the front bumper. I am thinking aftermarket ones made for racing must be more efficient and offer better cooling... any suggestions?

Also what are the benifits of a thermostat in a purely racing application? do we need it, and if so what temperature setting?

Stephen
Click to expand...

Run the water thermostat but use a 160. Not sure why you would need new oil coolers if the stock ones are clean and properly ducted, they work great. What temps were you seeing that make you want to change?
 
Steve, I know you have a ton of experience with these so thanks for jumping in.

I have around 210 for water temps and I am seeing close to 250 for oil temps.

That seems pretty high to me. I have swapped out the oil coolers with a second set of stock ones, including all the lines just to see if that made any difference. I am not using one of those racing beat adaptor things near the oil filter I purchased an adaptor from autometer and I am getting my temps from the sender on the side of the block down below the air intake towards the very bottom. I also swapped out the autometer sender just to check to see if it was reading wrong.
 
230 - 235 is normal in the summer but 250 is a little high. I would check the air/fuel ratio and see if it is a little on the lean side. Most of the temp from oil is from the spray on the inside rotor faces so combustion temp is a big factor.

I always pick up my temps at the filter to see what the motor is being fed, but you should be close. Shoot the coolers with a heat gun to see what temp they have when it is hot. I would want to see that both coolers are getting the same circulation and not bypassing.

Are the coolers sealed to the nose opening?
 
great idea on checking the temps of each. I had the factory shrouds before but I also had my break ducts in the foglights. I am going to remove those from that spot and duct that entire opening to them and seal them. I think that will work much better with a lot more airflow going to them. The ducts can easily fit in the bottom area. I know the mazdaspeed bumper has nice huge openings for the coolers so I think I need to take advantage of that entire opening.

Do you think my temps are higher because of where I have the sender located?

Stephen
 
I have the Oil Filter adapter if you want one. Im getting 235-240 oil temps on my car with the giant first gen cooler mounted under the radiator.

V3.0 will have a first gen cooler in front of an ISC giant radiator with an ISC front airdam sealed up. Everything should be cooler with that and some actual carb tuning to richen it up.

Dan
70,77,79 IT7

Yes I have 3 of them, wanna try one?
 
StephenB said:
great idea on checking the temps of each. I had the factory shrouds before but I also had my break ducts in the foglights. I am going to remove those from that spot and duct that entire opening to them and seal them. I think that will work much better with a lot more airflow going to them. The ducts can easily fit in the bottom area. I know the mazdaspeed bumper has nice huge openings for the coolers so I think I need to take advantage of that entire opening.

Do you think my temps are higher because of where I have the sender located?

Stephen
Click to expand...

Let me check and see if I still have some of the custom plates I made for under the filter area. We made some with less restriction than most on the market. Problem with the RX8 is you are in the 9000+ range far more than the 7 motors. PM me if you want with a phone number and I will give you a call with a few things to look at.

Do not overlook pulling brake duct air from the sealed area in front of the radiator. Also check the area behind the coolers as pressure inside the fender wells will actually push back the airflow.
 
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