Does anyone have experience with any of the stock mount aftermarket radiators on the market? I have a dual stock parallel oil cooler setup in my NA FC S5 STL race car with all the -10 AN lines and secondary mounting points already built so I am hoping to stay with 2 stock mount style oil coolers. The stock ones served me well but they now both have cracks in the bungs resulting in slow leaks so it is time to replace them. Obviously I see a bunch of options when I Google, but does anyone have any direct experience with what's on the market? If I can find something new for a reasonable price vs. rolling the dice on couple used OEM ones I'd prefer to do that.

Thanks for any info.

 

I have been using the oil coolers that are sold on ebay for many years on race cars and road ones with no problems on race cars i fit 2 to keep the oil temp lower . Under 90c

 

I tried a pair of the knock off ebay oil coolers on my car plumbed in parallel. They were were crap compared to the stock coolers I had been using. Maybe I bought the wrong ones. The problem is that it is impossible know if the ones I bought are properly baffled to be a true dual pass cooler like the OEM coolers. Also, I don't know if they have turbulators in the tubes like the OEM cooler do.

So after allot of research, I went with an single Improved Racing MHX-248 triple pass cooler https://www.improvedracing.com/mhx-2...il-cooler.html It works as good as a pair of OEM coolers and it simplified oil cooler plumbing.

https://www.rx7club.com/build-thread.../#post12473577

 

That is a really nice oil cooler option, and very nice thread you pointed me to. I also saw in your thread that someone mentioned the CSF 8066. I hope they respond with their experience. Maybe with decent ducting it too can be a viable alternative to my dual setup for $300 less. If not, I am starting to lean towards the MHX-248.

 

Thanks! Agreed, a pair of CSF 8066 coolers might be a good option as well.

Regarding the MHX 248 cooler, It might be worth asking Improved Racing if they could put a bung for the return line in the top or side of the third tank. That would avoid the tube that runs through the first and second sections of the cooler for the return line. The person I spoke to at Improved Racing in 2021 was very helpful.

 

Yes, I saw your mention of relocating the bung on the other thread.

You don't think a single ducted CSF 8066 could do the job?

 

Picked up a car a few years back that had a ebay unit. Inlet/outlet on the same tank with no baffling. Looked almost just like a oe unit. You could run a wire right through and come out of the other. I cant say for sure if that was the reason for the failure of the engine but bet it wasn't helping.

 

If the CSF 8066 is the same size as an OE cooler, it won't provide enough cooling in my experience. I tried this with an OE cooler when I was running my car in Improved Touring. The ducting made no difference. That is when I went to two OE coolers.

At that time we had a bunch of E Production RX7s in KC. Several of them were running an OE cooler plus a Ron Davis radiator with a built in Oil to Water cooler. I think they had everything plumbed in series. That worked okay but eventually the radiators stared leaking internally plus the series plumbing effected oil pressure. Pretty soon all of them were running two OE coolers in parallel. Back then there were lots of OE coolers laying around or for sale on eBay. So it was easy to do.

 

So I have the CSF cooler on my 1st-gen EP car. It has worked well as a replacement option to my stock unit that was squashed at an off-track excursion. It even survived my big front-end shunt into the tire wall at last years Runoffs. I would add that I have a very large radiator that keeps my water temps at 170-180 on normal days. So this oil cooler doesn't have as much work to do. I also race mostly in the West Coast in Winter/Spring so external conditions not that big an issue. It doesn't have a thermostat but since it's a racecar, hasn't been an issue. I do like the -10 fittings, mounting was pretty easy as well.

Probably not as nice as the MHX, but less expensive. If I damage this one, I would feel fine with replacing with the same unit.

Scott, now that you are retired, I hope to see that car in action a bit more!

 

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highly recommend the Improved Racing t-stat assembly as well

https://www.improvedracing.com/high-...hermostat.html
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I spent too much time thinking about this. I decided to go with the MHX-248, no thermostat, and will fab some mounts with isolators and ducting to separate the path from the nose to oil cooler.