More fins per inch, IIRC. I'll check with Brandon, he did the testing.

 

I LOVE those outlets. Just awesome.

Why bother to pop the mesh in and out on an outlet though? Just leave it out. I can see the point on an inlet . . . . ??

 

The conjecture here and elsewhere about the Superstat confused me as much as anyone. What was needed was either a specific flow rate test or field testing. We couldn't figure a simple controlled test for flow so we set up a field test. We tested the Superstat against the standard tstat in the reroute on track. We found the Superstat ran several degrees cooler and recovered faster on cool down laps. The Superstat is now standard in our reroute.

 

A heavy canopy of "grandfather" oaks necessitates it. Huge tree debris issues. Mine isn't a full time track car and I don't want that crap underhood.

Ten seconds later:

 

Awesome thread. I may be one of those unfortunately perpetuating the whole "VVT/MSM heads don't need a reroute" thing, because I had measured a max delta of 2 deg C between the front and rear of the head.

I kinda missed the point and I think the reroute is as much about getting more coolant to circulate rather than just keeping temps even.

Those WRX vents look awesome, great find!

 

One of the few reasons I'd love to have a naturally aspirated car: custom forward-slant radiator, duct entire exit out the hood.

-Ryan

 

That would probably be overkill on a stock sized radiator. My current setup of a VVT motor w/ '99 head gasket, ducted CX racing radiator, BEGI reroute, and vented hood has no problem during 15 min sessions at Atlanta Motorsports Park in upper 80 degree temps. My fan is setup to run at 190 and it wouldn't come on until after I parked the car after a cool down lap. I need to setup my AEM to log temps to see what they are through the session though.

 

When I say naturally aspirated, I'm not envisioning stock-ish miata power levels

I'm more of the mind that if I'm going to design/make something, I want it to be able to handle anything I can throw at it. 15 minute stints at 80* may be a decent representation of the average HPDE miata's use, but it's a far cry from what I'd use as a benchmark for 'anything I could throw at it".

I would worry more about a sub-optimal system than a too-optimal system. That's what the thermostat is there for. Make the cooling system as ideal as possible, then let the thermostat regulate as necessary.

Also, there are advantages to ducting all of the heat exchangers out the hood beyond just the cooling system (think aero).

Ideally, I'd duct everything out the hood. In my particular situation with relatively large intercooler and radiator, plus seperating the airflow for each so they both get unimpeded flow, I've settled for ducting the intercooler all out the hood and ducting the radiator down the transmission tunnel and out over the top of the diffuser. I like this solution in my particular case though because it helps move the heat of the exhaust which would otherwise affect the transmission's temp due to the flat bottom.

-Ryan

 

Ahhh yes. Live Oaks. I remember those. I still find Live Oak leaves in strange places on the Silver car (it started its life in the Houston area).

 

My car is mildly boosted and street driven. Maybe one HPDE a year. No reroute, and I'm running a 1.5 year old 16mm Koyo OEM style plastic radiator. My plan for this year was to monitor coolant temps, and decide from there whether or not a reroute was needed.

I'm using a short sweep Autometer temp gauge with the sender mounted in the heater hose running out of the head to the heater core. So far I haven't broken 210* and I only hit that when doing some spirited driving through mountain ranges during 80*+ days.

Is this a valid or invalid way to test if the cooling system needs upgraded?

 

I found these posted on another forum today and would be ordering a set if I didn't already have some louvers on the shelf waiting to be installed. It's a cool idea and they're reasonably priced. He has a few different options that could work well on a miata.

Roadster “Oversize” Side Vents

 

I don't think it is valid - I can drive around the track at 7/10ths and heat is not a problem, and I would have to be doing some pretty crazy stuff on the street to be going as fast as I do at 7/10ths. If I push the car harder then it gets warm quickly.

 

It's valid data, but you need to interpret it correctly. Let's call it 5/10th (maybe) on a track on a cool day. The data is saying that the coolant coming out of the front is ~190 while that from the rear is ~210. So, even at a mild operating condition, you're generating a cooling imbalance -- it only gets worse from there.

 

JoeP thermostat comparison:




It's a nice feature to have that mesh pop in and out.

 

That's a pretty cool idea. I might have to make something similar that is shaped for the miata hood...

-Ryan

 

I've been talking to our sheet metal guy about just that, actually. It would be nice to have a drop-in vent that was shaped to fit in the right spot and avoid as much bracing as possible. I like the way this guy built the louvers, apparently the sheet metal folks use the same technique on an industrial application.

 

Whats with the fear of cutting the cross braces? Yeah it makes the hood floppy when its up and removed the spot the stock hood prop goes to, but with a couple of properly adjusted aerocaches + the venting = less hood rise and ripple than the stock setup at speed.

 

Would this be an appropriate place to discuss reversing the flow?

I took an initial stab at it using a stock radiator and remote water pump. It seemed to work pretty good, but there are some hefty flaws that needs attention.

 

Nice summary of info Emilio. I third the conduction/convection corrections.


keith, how did you determine these pressures. Some sort of in vehicle testing of from a CFD type analysis?

 

I've got templates made up for the NA hood and could do the same for the NB..
Would be a short run though, sadly anything involving cutting your car up only appeals to a small niche of the community.

-Ryan