Agreed. A lower temp thermostat should be the last thing you do to troubleshoot cooling issues.

i was going to make the undertray myself thisweekend. i figuered i would just buy everything and not worry about the cooling after all these are bought

It's your money to waste as you see fit.

honestly i dont really see it being a waste of money. this car when i bought it was very run down. so ive done new suspension, rebuilt the motor, it has now a koyo rad and now it will have the fans and thermo and also it has the hard rubber lines. and the fans are programed to turn on sooner. after the tray im done spending money on this thing. i still need to finish my firstgen rx7 lol

A lower-temp thermostat is a waste in almost any scenario.

One thing to remember is that fans on track at track speeds probably aren't helping anything. If they're coming on when on track you probably have another issue. Fans are really used for 0-30mph to help pull in air and aid cooling. Above this speed the ram air affect is meant to take over and naturally cool things down.

Yep. Especially a $60 one.



True to a point, but it depends on the particular fan setup and how the shroud is designed. There is a thread on here somewhere, wherein I tested running both fans on low vs. no fans driving up to 60mph in the heat of a Texas summer. Surprisingly, the fans helped with cooling up to about 55mph--nearly double your theoretical number. I would try to find it, but photo storage was not durable back then, so my charts and graphs would be missing.

so basically what you guys are saying is that i shouldve just done the undertray and the foams.... ok lol dam it

Pretty much.

Always fix what you know to be broken FIRST. If that doesn't solve the issue(s) you are seeing, then start troubleshooting and replacing/upgrading parts.

ok guys,

i have bought new fans, and i installed new foam around the rad, still no undertray but will install all this weekend. new undertray, thermo and fans. i will update you guys

OK. Please do. Until you have an undertray, data above about 40mph is meaningless.

I though I'd update my progress on cooling. Water temps are lower lately, but there's still some room for improvement. I saw 215-220 on track on Monday at Autobahn. If I cruise around at 90%, temps are around 200. Once I really get on it and spend more time at high RPMs, temps go up. If I back off, it'll drop 10-15 degrees within a few corners.

I think the pump is just churning at high speeds. So I bought an S2 pump to put in. Hopefully I can get that done before I go to Mid-O in two weeks.

I'm sure the fact that the engine makes more power at higher rpm has something to do with it !

I would add : if you are seeing 220 on an aftermarket gauge (think i saw you mention this earlier) that reads 10-15 degrees higher than the stock sensor ...you are probably running at the optimal temp already .

What's the ECU saying about the water temps?

ok, installed the FAL fans and new thermo. wow what a difference

This kind of remark does nothing to help anyone ... How about some actual meaningful test results ?

How quickly do your temps drop during cool down lap (do you even get a cool down lap in TT?)?

After a 20 minute session on Autobahn South, my coolant drops to ~185°F in under half a lap. My oil temps drop to the 190°F in roughly the same time frame.

i went from sitting in traffic and reaching to 215 to now 190.

i coast at 170-180 compared to 185-196

I wouldn't be happy about the cruise temps ...too low IMO.

Water drops by 10-15degF pretty much immediately once I start a cool down or just relax a bit. But never under say 200. And sitting still in the paddock temps will stay around 210.

I feel like something has to be wrong, here. I just have no idea what it is. I've literally replaced the entire cooling system, except for hoses.

The S2 water pump didn't help at all. Saturday the car was cooler and rarely hit 215, but ambient was relatively low, in the 70s. I had 215-220 in the warmer temps on Sunday.

^ I have just re-read all of your posts. According to what you have done, you should be running cool as a cucumber! I have 2 thoughts and am otherwise stumped:

1. Are you absolutely sure you have ALL the air bled from the system? Run the engine up to temperature with the front on jackstands and the coolant bottle cap off. Massage the top radiator hose after the thermostat starts to open to force air out. This might take up to 1 hour. (Some people cut the jiggly thing out of the thermostat on track cars. This helps bleed the system at the expense of taking longer to reach operating temp, but that might actually help you while sitting in the grid.)

2. If you removed the rear hood gasket, that could have created problems for you. That is a positive pressure area where air is forced in from the base of the windshield. It could be working against your hood vents. Where are your hood vents located? They have to be in the right locations to work.