I have a similar setup on my NA vvt '93. Keeps oil temps to around 220 or less on track in ~98+ ambient Texas weather. I'm thinking a nice, small electric fan will really help improve efficiency since it's seeing air after the radiator. That is my next plan, and I'll wire it on a switch so I can compare on the same day.

Do report back how that works, I have considered it but I dont really want to add complexity if I dont have to.

I’m close to having real data on this double-fan setup as well. They are 2A, 147 CFM each from Summit Racing. Had this on my previous build but did not have a real temp gauge to show actual drop in temps at that time. Waiting in line to get the dyno tune and 3” DP/exhaust built right now. Have it wired on a separate circuit to program the on/off as I want to.

https://cimg2.ibsrv.net/gimg/www.mia...71f133fa6.jpeg

There are a few ducting options in the market, too lazy to look for you more than 1 but there are cheaper ones too
https://www.demon-tweeks.com/us/revo...ct-kit-343114/

Since this is a great thread I am adding my take on it (Well, my awesome mechanic's really)
13 row setrab with -10an 60 deg up top and a straight one down.
Used Russell 632160 for the hose lines and had just enough.

https://cimg9.ibsrv.net/gimg/www.mia...776b1899ba.jpg
https://cimg8.ibsrv.net/gimg/www.mia...1e4db0f6f1.jpg
https://cimg1.ibsrv.net/gimg/www.mia...2812ec3452.jpg
https://cimg2.ibsrv.net/gimg/www.mia...86f2788187.jpg

^
You're going to need to sheath that oil line with split loom and keep a close watch on it to prevent it from sawing into the intercooler pipe/hose.
Stainless steel braided hoses are nice but they MUST not rub anything!

Ditto the warning on routing stainless braided hose. It's a buzzsaw to what ever it touches.

I cut a short piece of radiator hose to act as a barrier for my oil cooler lines.
https://cimg1.ibsrv.net/gimg/www.mia...ac195099b8.jpg

https://cimg3.ibsrv.net/gimg/www.mia...d9ab7141b8.jpg
Has anyone mounted his oil cooler laid flat in the mouth? I currently run a 25 row cooler behind the 50 mm aluminium water cooler, fully ducted to the radiator. The intercooler is located 25 mm before the radiator and covers the lower half of the radiator. Everything is fully sealed to the mouth opening.

On track I see water temps of 90-93° C and regular oil temps of 100° C, taken at the oil drain in the pan. However at the Ring I see brief moments of almost 130° C when 320 whp are running free for 30" on an uphill straight. So I wonder if I could improve my cooling.

My idea was to switch to a smaller 19 row cooler, but mount it horizontally before the intercooler. So it wouldn't be a V setup but rather an L setup. It would be attached to a Dibond plate, again fully sealed so air needs to pass through the oil cooler and then exit into the gap between my splitter-ish underbody panel and the radiator ducting l, and from there exit the engine bay together with all the other hot air from engine bay

I don't want to dump the air into the fast air underneath the splitter

100c is actually too cool, 130c is only 266F......barely getting up there honestly. You sure you're not looking for a problem to fix?

The Trackspeed kit we all know, love and recommend uses a Mocal thermostat @ 205°F, which is about 98°C. Your comment would indicate these are setup to run way, way too low an oil temp. I can assure you they are not.

Sure, but most folks aim for 220-250 degree oil temps though. Gotta get above the 212 degree boiling point for the water vapor to boil off.

I consider 100-105 to be perfect, but 130 might be on the edge. Am I overly cautious? Maybe, but just because you're paranoid doesn't mean they're not after you.

Just like the thermostat in your cooling system, oil thermostat it sets the minimum fluid temperature. The maximum is set by the amount of heat going in and the ability of the system to disperse or reject that heat.

If the thermostat is set to open at 205° you'll find your actual temps are a bit higher in practice. Here's an image I snipped off the web:

https://cimg5.ibsrv.net/gimg/www.mia...f7ec0c08c4.jpg
This is for the Improved Racing oil thermostat ( High-Flow Engine Oil Cooler Thermostat FSM ) to give you an idea of what I'm talking about. This behavior is common in all wax pill/motor thermally regulated systems.

This is how Vegas is setup. Works well. Exit has to be behind rad or it won't flow well. Rock screen or deflectors a good idea to protect fins. Some OEM oil coolers are configured like that.

Thanks for the confirmation of my idea Emilio

I have a similar setup, a 25 row setrab mounted where the A/C fan would go. This is behind a 50mm core rad that is well ducted and sealed to the front bumper, though I do have large hood vents.

I had noticed that my oil temps weren't as good as I'd expected, so thought I would put a temperature sensor right behind the radiator to see what temperature of air, the oil cooler is actually getting.

See the plot of a 15 minute session below, admittedly this session wasn't as fast as the car could go, but still ~10 seconds/lap under the UK spec miata pace, at 170kpa = 265hp and 1160kg total.

https://cimg2.ibsrv.net/gimg/www.mia...d2766856a4.png


The air temps out of the rad were around ambient +30C. My ambient temp sensor appears to heat soak a little on track (and definitely in the pits!). Ambient according to the weather report at the time was 14C.

Still, oil temps of almost ambient +100C is a lot, more than I'd like. The data suggests this setrab would be capable of ambient +70C given ambient air, which would be more than enough for me. Or put another way, taking air from behind the rad, needs an oil cooler sized 40-50% larger, assuming the airflow is the same (big assumption!)

I'm tempted to move my oil cooler, which would allow a second radiator fan to shed heat faster when a session get's red flagged I can't do sufficient cooldown, but that's another topic....

Yup, as we would expect. Rad behind low mount A/A intercooler is OK but even then, we place the FMIC sorta below the rad and with enough gap for air to flow over IC to bottom of rad. Air exiting rad, if its doing its job, is damn hot. Not suitable for much other then tweaking air pressure over the hood.

Oil temp hit 300F at California Speedway this weekend. It was crazy hot, 108 air temp. My car is a stock engine 1.8 NB. Has aluminum Koyo radiator that's properly ducted but no oil cooler. That oil temp was measured at the filter sandwich plate. With the Trackspeed kit no longer available what is the best off the shelf solution for a track only car? I am considering the Fab9 25 row Setrab kit. Any others I should look at? I'd rather not piece it together unless it's going to be significantly better and/or cheaper. Probably going to mount it in the fender well, have a full undertray so the steering rack location won't work. I could put it in front of the radiator if needed.

Best to have a decent race shop take a look at your setup. OTC cooler kits are a great concept, but usually they're a compromise at best in my experience. Mocal sandwich plate, then custom order the straight/45/90/etc fittings that best fit your application, then nylon braided hose of the correct length to avoid trigger wheels, accommodate mounting locations, avoid reroute hoses, work with filter relocations (which no one in this thread should own), etc, etc, and you've got a well functioning cooler setup.