94-00 gasket, no other mods. Engine runs too cool so, no problems. We'll run a fairly fine mesh rad protector screen at Thunderhill to cut aero drag and keep clt temps near 195°

silly question really, but is there a reason you picked 195*? Are you guys running an oil cooler btw (and which one if you are)?

that's the optimal operating temperature.

optimal for longevity I assume? I am just trying to understand why 195 as opposed to any other value, like say 180, or 205?

With my current cooling, I am running at 190-195 on track. We will find out what I end up at when it gets cooler since my Tstat is 180.

195° works for us. Setrab, -10 Aeroquip socketless

My Aeroquip socketless blue hose leaked after about 1-year, through the ply.

We have been using it for many years without issue. We'll keep an eye on it though. Thanks for the heads up.

Hmm, temperature controlled radiator louvers anyone?
Which also close partially at high speeds?
When the temps are low they're shut, to reduce drag...

Prop airplanes have been doing this for decades.
And now the GM Cruze does it too...

I've read an engine's wear rate is dramatically higher when it is warming up/under optimal temps vs high revving at optimal temp.

Yep, and ecomodders have been doing it for a while now. They run the ECT and AFR hotter for more MPG.

Movable aero = points. We thought of that. We can not modify the front bumper skin without taking points either. Rad protector screens are free and the rules do not state what open % or how they are fitted. So we fit it flush with a low open %, just like NASCAR and for the same reasons.

Is a adjustable radiator screen considered "Movable aero"?
I'm thinking about a cable operated screen ("Radiator Curtain shutter" seems to be one term, precursor to the thermostat).
It would in principle be a adjustable aero, but maybe not in the rule book. :)

It would actually be moveable aero and bumper skin modification. Fine mesh screen is the simple solution and achieves our goals. Besides it's not like teh temp swings 60° in one race. We can uses different screens based on checking temps in practice. Not a big deal.

hmmm would running the radiator fan backwards achieve a similar result?

Fan running backward wouldn't reduce aero drag significantly nor protect oil cooler and rad from Honda connecting rod bolt heads. It's not just solving a problem, but trying to maybe solve a few problems with one mod, in the simplest way possible. Eliminate redundancies. Emilio likes elegant engineering solutions.

You guys are funny. Presented with the same problems we were, your gearhead minds all go into overdrive trying to out think the competition and stay legal like we did all year. That aspect is one of my favorite things about racing, particularly enduros. Lots to think about, ideas to try.

If said shutters are behind the radiator, does that count as "aero"?

No, but that doesn't do much to protect the radiator and is far more complex, difficult to implement, test and service than a screen.

Cars from any sanctioning body can run NASA enduro. There only 4 classes for production based cars, ES, E1, E2 and E3. Cars from other series are "mapped" into their respective endurance class. We are mapped in from NASA's own Performance Touring series as a PTD car. So those are the rules we work within as well as the enduro supplement and T25 specific stuff.

Current versions of the NASA rules. They get updated without warning and sometimes randomly so it pays to know where all the latest versions are hosted and check them frequently.

2011 NASA enduro rules
2011 NASA Thunderhill 25 hours supplement
2011 NASA Club Codes and regulations
2011 NASA Performance Touring rules

Knock yourself out.

The Focus does that as well. It would be possible to do with MS3. I'd also set up a condition that kept the shutter(s) open at high speed if coolant > X°. But as Emilio said, not possible with his classing.

Most of the enduro cars I see have a simple, small high flow fan tied to the radiator. No fancy control. No fancy behind radiator shroud. Just a little ducting.

I usually find the race car engineering more fascinating than the race itself.

Well you could have the screen to protect the rad *and* the shutters to improve aero. ;)

Yup. We're using a single 10" Derale fan, no shroud. Set to come on at 200° clt. The Derale weighs about half the stock fan. We have found that the shrouds on Miatas reduce the airflow substantially when the fans are off. The shrouds are good band-aid when you have inadequate ducting. So we just seal off everything to make sure it's all going through the core. The undertray helps a bunch by reducing pressure behind the rad so the differential across the core is good anytime the car is moving. We have yet to see the fans turn on when the car is moving even racing in 90° heat.

OK, we'll build it just for you.

So with the screen is doing it's job reducing aero lift/drag while protecting the radiator and reducing airflow to the required amount for a given event during practice, how would one tune the shutters knowing that the car will overheat unless they are full open?


edit:
It's really easy to get caught up doing stuff just because it sounds cool while losing sight of the bigger picture. In our case, even of the shutters were a free mod, weighed nothing, zero cost, 100% reliable, 1 minute to install.. we would still not do it because we still need a screen and it does both jobs. In race engineering, one has to sometimes pull their ego out of the equation. As a guy with a substantial ego, I have been reminded of this constantly when developing Crusher. You Jason, like to question everyone else assumptions and solutions. It's your raison d' etre and the right frame of mind when building a system. You're also an engineer and suffer from, well, thinking too much.