I was wondering if anyone is using one of these? I have one I can pick up for under $50 and was curious if I should get something larger like a 25 row. Right now all i have is a single stock cooler so i assume that this would be an improvement. Do I need the thermostat with this one?

 

The CWR oil cooler kit uses Mocal 19 rows. I'm running two of them in that kit. The Mocal cooler does not have a built-in thermostat like the stock cooler(s) (I'm not sure if the passenger [LHD models] side stock cooler has a thermostat built-in, but the driver side one does). Mocal makes a separate thermostat you can use, as do several other companies. What threads are on the cooler? The coolers used by the CWR kit have AN-10 male threads, but I know the coolers are available with several different thread options. Normal price is around $135-ish for the cooler. The rest of the parts (lines, fittings, thermostat, etc.) make up the bulk of the cost of the kits.

-Max

 

the Crooked Willows are 19 rows...really nice. The fins are beefy so they don't bend like the stockers...

If I remember right from the parts diagram...the R1 has a thermostat in the drivers cooler....if cold...it bypasses just that one cooler allowing only the other one to work...so the system is in series...

If you add it to your system u probably need to add a thermostat...but plumbing it for me was a PITA....mine failed in this area costing me my second engine...

 

Yup this one is AN-10. I have a box of fittings and about 6' of line lying around. I am wondering how much of an improvement only one cooler would be. Wondering if I should spend the extra cash (maybe $100 more than this) and get a larger one with more rows.
You wouldn't happen to have an extra one of those CWR ducts would ya

 

I sent mine back to duane to trade for duct that fit the 99 spec front...

 

A single 25/4 row mocal type with proper ducting and t-stat would be my choice for street/track use with stock bumper. Stock duals each have a 150F bypass t-stat, so no coolers used at winter start-ups.

The right duct can be worked into a dedicated cold air intake, and center mouth is for rad and intercooler only. Just don't think an extra 10F drop in oil temp at the track is worth the added high pressure plumbing, esp using right synthetic oil.

 

I have a single 25 row Mocal and the total cost was close to $600 but does not include the brackets will I have have to fab myself.

 

Yeah, 19-row Mocal. Buy it!

 

34 mocal is like $280

 

I'm going to watch my oil temps when I get my car back and potentially remove the second cooler and use the passenger duct for an intake. I just got the idea from your post. One of the local RX-7 owners here used to have a nice custom intake that grabbed air from there. It would be nice to be able to use that spot if the extra oil cooling isn't needed. I'll be running synthetic and had my rotor faces coated with a thermal barrier, so perhaps my oil cooling needs will be low enough to use that spot for an intake.

-Max

 

Cool. Just seal right duct for a session. 2nd series exch'r will always be less efficient than 1st. I always thought twins would be more effective in parallel, but single is simple. Interested in your results.