24 June 2013

Change of plans. After doing a lot of thinking and reading, the decision was made to change to an oil-to-coolant heat exchanger and electric water pump. I was beating around the bush, not confronting the reality that a turbocharged engine has special needs. Adding the oil cooler was good but didn’t have enough airflow, always a problem when mounted aft. I almost bought a small radiator fan for it but it seemed like a band-aid on top of a band-aid. It turns out that Lotus Elise owners (a similar drivetrain arrangement) also have high oil temperature, especially when running the supercharged model in warm areas of the country. Somewhat surprisingly, the stock Lotus has front-mounted oil coolers and the engine has to push oil through about 12 feet of hose, something I don’t want to do.

The owners swap in an oil-to-coolant heat exchanger near the engine which transfers oil heat into the coolant, putting more stress on the radiator. To deal with that they install the biggest radiator that fits. The reason for me also adding the electric water pump came from a racing buddy who swears that Honda water pumps don’t work well pushing water all the way to the front of the car and back again. I asked how he knew that, since he only worked on FWD cars. I also asked that if that’s a problem on FWD drivetrains mounted at the rear, why don’t they all have electric water pumps… never really heard an answer. I’m also reminded of how, without a thermostat, my engine ran at 150 degrees F on the freeway, which indicates to me that I have plenty of coolant flow. (To be fair though, that was at an ambient temperature of about 60 deg F, so figure running at 100 deg in the desert is 40 deg higher, which would increase that to 190 deg, before adding the heat-exchanger.) It may be overkill but at the same time I’d hate to tow the car 100s of miles to a trackday event (never mind the entry fee, gas, motel, and food expenses) and have it overheat. Assuming this works well, there’s not much else from preventing running a trackday event, other than it unfortunately heading into the hottest part of the year around here – the car might be fine, not so sure about me!

Oh, and a good thing happened during a test drive yesterday… the realization that I’m much more comfortable with the car; the extreme trepidation about things falling off or breaking seems to be lifting. Speaking of pushing the car, I’m curious whether it can leave the line in second gear… probably, though the clutch might not be too happy. Doing so of course means no shifting all the way to 60 mph, and we all know how important that is 🙂 Once the issue with oil temperature is cleared up there’ll be more interesting videos 🙂