Best next Step to Track Cooling issues?
 

So I'm still having cooling issues at the track, I would like opinions on what my next best step should be.

My setup:
91-1.6
Greddy turbo, RM 2.5 Downpipe, 2.5 Enthuza, and TDR IC, Amsoil 10w-40
BEGI AFPR, Bipes, Hustler's Pink/Red Injector's (NB 1.8's)
Godspeed Radiator, siliconintakes.com fans in parallel, belly pan, shrouding on bottom sides and top of radiator, AC
~15% coolant mix, waterwetter
BEGI Street Reroute (Heater return to upper radiator hose, metal line under the exhaust manifold capped off)

Trackday problem on Friday;
Afternoon, ambient temps ~100°F
This was in San Marcos, TX at Harris Hill Road 1.78 Mile Roadcourse
Top Speed's in the 80's

The first session, I let the car idle for ~10 minutes whilst waiting for the session to begin. I did the warm up lap and had 2-3 good laps before I noticed the temp gauge starting to move. After another lap at 8/10 it was at the 1 o'clock position so I pitted to let it cool down. It got hotter, roughly between the 1:30 and 2:00 position.

Next sessions less idle time meant I got more clean laps in prior to pitting. The third session and fourth session I didn't pit (and kept the heater on the whole session). There were not very many cars so I took it down to 5/10's for a couple laps to cool down and then finish the session strong.

My current options, from most desirable to least desirable:
-Oil temp gauge and real coolant temp gauge or linearize it, find out what temps I'm really running
-Oil Cooler, cutting out spot for the cooler through the belly pan
-hood ducting/vents to increase airflow (I like the price for this mod but don't like the less than stock look)
-Double pass radiator ala M2CupCar

Should I really be worrying about temps ~1 o'clock? This is about as hot as it gets for a TX trackday.

Will an oil cooler effect my temps enough to keep coolant temp down a reasonable amount?

Chris

First, get real temp gauges - a decent autometer electrical water temp gauge is like under $50 from Summit. I've noticed several heat issues with my real gauge when the stock water gauge hadn't even begun to move. "1 o'clock" could be 220 or 250 degrees, who knows.

#1 recommendation from me would be oil cooler. Oil has a much higher thermal capacity (I think that is the right term) than water i.e. it wants to stay whatever temp. it is - it takes longer to heat up than water and once it is too hot, even after you baby it and the water temp is reading OK again, the oil will still be too hot. If you can keep the oil temp cool (within proper range), it will help keep the whole motor cooler - so the water will have less work to do instead of the water trying to do all the work itself, fighting the high oil temps.

-Ryan

Yes.

Well I think a true temp gauge is mandatory.
Beyond the oil cooler another option would be a waterless coolant like those from Evans which should help at least moderately.

shroud the front of the radiator, then try again. Air would rather go around the heat exchangers than through them.

http://i40.tinypic.com/2zhe6pz.jpg
http://i41.tinypic.com/2rr6hz4.jpg
http://i41.tinypic.com/238i2c.jpg
The top is sealed up a the intercooler which sucks...I need BEGi to move my intercooler back 3", until then I'll use the scooper yet to be installed.
whyhellothar
http://i41.tinypic.com/affy3t.jpg

needs more miatas:
http://i40.tinypic.com/166lpck.jpg
edit: vascularity you can only dream of:
http://i41.tinypic.com/2dt3c4k.jpg

Needs more hustler on track.

this is one of the final steps in track readiness. Brake ducting, alignments, and fixed leaking valve are the only phases left. Then, the streets will flow with the blood of the non-believers. If I weren't in Philly right now, I'd be under the car turning wrenches.

It's all shrouded in.

Is that Gary's new shop?

Chris

Cut a hole in your bumper cover....
Attachment 205985

Don't get mugged, that's one dirty city.

Chris

a tranny hooker just offered me her "clean" ass for $50 right when I walked out of my hotel.

Is i totally sealed? If so, then buy a real oil cooler. After that, autokkkonexion hood.


yes

why? It doesn't raise pressure. Do you have a vented hood? Bernoulli FTW!

I love how clean that bay is ^

Of course it raises pressure, you twit. The question is whether you WANT to raise pressure. There is an ideal ratio of mouth area to radiator area, something on the order of 1:3.

I had a hole cut in my old nose. There's no hole in my new RB nose. Take that as you will.

Chris -

If you have a 1:3 ratio (inlet to heat exchanger) and you have shrouded to prevent air by-pass, then the next step in optimizing that particular coolant system component is heat extraction. - Meaning venting. The autokonexion hood, BEGi's hood vents or roll your own.

Another option is to add another component to the coolant system. An oil cooler has already been discussed and sounds like an excellent idea, provided you do not get your oil temps too low during routine driving. (Corky is working on an oil cooler by-pass system, though I'm not certain how close it is to "prime-time"...)


- L

C'mon, its not that bad here!

Is this your way of saying you're not going to be able to afford a track day anytime soon?

Well, it is the city of brotherly love...


What % is your mix of coolant to distilled water? Are you using Water Wetter or that Redline stuff yet?

BTW - I prefer mechanical temperature gauges over electrical because of the fluctuations that can occur in electrical gauges.:2cents:

Edit: Are you using a chin spoiler of any kind to help to create a stronger low pressure area behind the radiator?

It's about 15% coolant mix right now with Redline Waterwetter.

I have the Ratsback racing chin spoiler.

http://vorshlag.smugmug.com/photos/5...53_rHvi5-M.jpg

Oil cooler seems to be the general consensus.

Anyone have any experience with this Moss oil temp spacer:
http://www.miatamania.com/Graphics/P.../904-565_1.jpg
Mazda Miata Parts & Accessories at MiataMania.com

Thoughts on running that with FM's oil cooler thermostat/spacer?

Chris

read up on Bernoulli's law, then get back to me on how surface area does NOT increase pressure.

My tiny Setrab oil cooler behind the '00 foglight hole lowered oil temps by 7*C and water temps by 2-3*C.

24-row with ducting ftw!

Jason, what's the dimensions on your cooler?

Chris

Nice looking ride. You seem to be doing everything else except the oil cooler and the big ugly hole in the nose at this point. My vote is for the cooler. ...as if I get a vote...:)

Thanks, I agree. Plus a big hole would detract from the ~sleeper look.

Chris

What's the deal with the car running so damn hot in the first place??

How much boost/power are you making?

I don't get how your making so much heat that you need reroute, bigger rad, shrouding, spoiler, oil cooler, ect...

I couldn't get my car to come close to overheating on a 20min session (1.7km)short track with nothing but a gs rad and 14" fan, no reroute, running just water..

Anyway I would be doing gauges then a vented hood.

Wait, what? The term is specific heat, and oil most certainly DOES NOT have a higher one than water. If it did, we would all just fill our radiators up with oil, wouldn't we? Neither does Evans NPG, for that matter. Evans works better because it allows the engine to run safely at a higher temp/ cooling system pressure, and it doesn't micro boil in the water jackets, significantly reducing hot spots.

Also, more frontal area will absolutely increase pressure delta across the heat exchangers... How could it not? :laugh: That 200 sq inches on the front of CSpence's car is putting a tremendous amount of force against the standing pressure in the engine bay. The air will make it's way out. You have a great big ass exit for it under the car. Not the best one possible, but it'll certainly work.

Now, Miatamaniac, if you were a local guy who brought me the car to work on, I'd start with making sure the shrouding was well designed and well sealed. It may sound silly, but you'd be surprised what some foam rubber weather seal from Lowes will do. Then I'd do an oil cooler with a thermostat. The RX-7 coolers with thermostats built into the end tank work well if you clean them well. Then I'd look into more significant changes to the car. If it's a track only car, then I'd bust out some sheet aluminum and the air riveter and make some manky hood vents. Big ugly ones with gurney flaps. You're on your own for nice ones for a street car, though.

I'm running only 7 PSI right now.

I see you are in Canada and probably don't ever have to endure 100°F track days. That amount of heat is hard on any car, even stock.

Chris

The same reason that increasing your intercooler pipes diameter doesn't increase manifold pressure. But can increase potential volume.

Apples/ oranges. There's a limited amount of air coming out of the compressor. The charge piping isn't the restriction. Increasing rad inlet frontal area without increasing radiator area would be like increasing compressor output without increasing charge pipe area. Even if the charge piping becomes a restriction (and relative pressure rises as a result) you will still get SOME additional flow.

For the record, I've done track day sessions in a Miata around your power level with a stock cooling system in 110F/ 80% humidity at TGPR without an issue. What thermostat are you using? Are you sure the rad isn't clogged or something silly like that? Big air bubbles in the system? I did rad hoses on a Grand Prix GTP that had to be driven and bled for a week before I got all the air out of the cooling system...

lol, this would drop my oil temps from "massively fucked" to "still fucked"

Sounds like a worthwhile improvement to me!

I need a real temp gauge. Also having temps climb on track days. Lot's of projects to try and improve this but waiting to see if there is a consensus on the most effective route. Oil cooler, venting, shrouding, undertray, rear exit reroute, etc.

Seems like all the guys here tracking cars are seeing temps climb even with big rads and a mix of those mods. Both Curly and I had temps climbing at our track day Sunday and it was only 85 here.

I'm a fan of giant oil coolers.

Take this for what you will. I had a friend take my car for a few laps, the waterpump belt exploded on track at half track, he finished the lap, then brought the car in because "it was making funny noises". The motor lived, I threw a new belt on and finished the day. Had the oilcooler not been there would the motor have survived? Probably not, the head gasket would likely have burned up at the very least.

Yes, my overheating issues on Sunday were very annoying. Only thing I could do was use the bottled water the Porsche club provided to keep my rad full (who needs to keep hydrated, honestly), Blast the heat on full the entire time, drive 8/10 half the time, and 6/10 the rest of the time. Oh, and all of this is with a car that was running pig rich above 6k rpms, so I was short shifting the entire time. I was lucky to see 100mph at the end of the straights, when I was hitting 105 NA.

The reason I was refilling my radiator, was that after about 10 minutes of cooling, I'd open the rad cap and it was dry in there. The reservoir was full (I filled it the day before), and I couldn't get it to transfer to the radiator, short of unbolting it and pouring it in. Is this just a sign of a bad rad cap?

My solution, is flush the system and add only water with a bottle of water wetter, get a new rad cap and make sure it's working, add a gigantic oil cooler with a shit ton of flow to it, and cut a huge hole in my bumper to get more air to the intercooler and radiator. I am NOT going to fuck around with anything small or worry about oil not getting up to temp. The way I drive, I will have no problem heating the oil up after it goes though a 48 row oil cooler.

I dunno, it's pretty wee - 5x8" maybe?

Borrow a laser pointy thermometer, pull the fan plugs, and idle the engine until the temp gauge points to "worrisome" - read the temperature on the thermostat housing - warning, when using an IR thermometer you can't read off of metal surfaces - put some electrical tape on there or some paint.

Dammit. Sitting in slow Dallas traffic today for around 30 minutes (~85-90 ambient), the temp gauge started moving. No AC on. I'm gonna burp it again tomorrow on an incline, but the damm thing is full.

Thermostat, WP and most of the lines are Mazda with less than 30K miles on em. The fans do work and I could tell when they came on in traffic.

Maybe I'll just switch to Evans NPG and be done with it. We'll see how the trackday goes on Friday, should stay under 90 hopefully.

Chris

Changing a running car to Evans is a big old pain in the dick. You have to get absolutely every last drop of water out of the system, which is alot more dramatic than you might think. I'm not telling you not to try it, just to be extra careful with it.

have I missed a thread about this evEns stuff? What is it? Last I heard the best track setup was distilled water with a bottle of water wetter added in. Does this trump that? I'm mostly pissed that my huge mishimoto radiator isnt keeping things cool, and the pathetic little heater core made when I was 8 years old is able to keep things in check. Is this because of where the heater core is getting it's coolant? I need to buy begi's racer reroute.

You aint kidding about price for the EVANs stuff:
EVANS PREP FLUID from Aircraft Spruce
http://www.aircraftspruce.com/catalog/graphics/prep.jpg

EVANS NPG + COOLANT FOR ROTAX ENGINES from Aircraft Spruce

No real threads on MT regarding it Curly. Only a few out of date ones on the pointy forum. It looks like Jason has tested it but didn't fully commit to an endorsement.

Chris

I think there is a really good clue to your problem in this statement. Where do you think the water is going? It is possible that it is going out the exhaust, but lets assume not. So where can it escape? there could be leaks, but I am sure you have covered that. So that leaves one path, past the rad cap, into the coolant reservoir. Is there coolant in there when you stop? I doubt it.

So here is my theory, your coolant is like American beer (FN near water) so let us say it has a boiling point of 220 deg f at zero pressure. Your rad cap, I hope is good and adds 17 psi+- to the system again raising the boiling point, lets say its 250 deg now. For arguments sake, lets say combustion temp is about 1000 deg. That is a huge demand you have put on the coolant in the cyl head. I have no doubt that the coolant is boiling in there, which dramatically increases the pressure in the system. The pressure looking for a way out finds the rad cap and overpowers it, pushing some coolant out to the reservoir, allowing the steam to find its way to the rad cap, which finds its way to the reservoir boiling/blowing the coolant out of the tank. The more this happens, the more steam is produced in the head. Steam does not absorb heat very well, and so cyl head temps start to rise and the problem gets worse.

Yes water transfers heat better than antifreeze. Antifreeze however has a higher boiling point than water. The fix here may be as simple as adding to a 50/50 mix. (that's chemically about the best boiling point you can get with antifreeze) A higher pressure cap if available will also raise the boiling point higher.

Evans coolant has a boiling point of 370 deg f, at zero pressure. The pressure in the head is higher than that due to pumping action and coolant flow. They recommend a zero pressure rad cap, and a higher temp thermostat! The reason for the higher temp stat is so that the temp differential between the coolant and the metal in the head is lowered, allowing it to absorb heat easier. The higher temp of the coolant raises the temp at the rad, creating a wider temp differential to ambient air, thus removing heat easier.

There are other benefits to the higher temp, ultimately increasing the ability to make power and reduce detonation, but that is a much longer discussion.

Ron

I have never used it, but was considering it. I talked to a few guys who were running it, and said it worked well. Then they pulled the motors and noticed it was eating the head. Seems it likes to disolve aluminum.

That's a pretty good write up Ron.

That's weird since EVAN's recommends an aluminum radiator with it.

Chris

Well same ol overheating at MSR last Friday. It would usually start creeping up around 10-13 minutes into the session (heater on and no warm up). So I would do a slowww cool down and try to get one last hot lap in, most times it would be checkered half way through.

I replaced the thermostat thinking it was getting slowly stuck closed. Did a long idle and started getting warm. I also noticed my AC fan (siliconintakes.com 10 incher less than a month old correctly wired in parallel) stopped working.

Next step is pressure testing the system to look for leaks, then a leak down.

Chris

did you do any ducting on the front? Seal it up if its not done already. I may take my car to boostlogic for some metal fab work. I only needed the fan in 2 sessions and I have 30% anti-freeze. What about your oil cooler again?

UPDATE: I had a hole in my Godspeed, it vibrated against an AC bracket. I had it repaired and it was still leaking (I don't think the shop fixed the other hole the first time though). Reinstalled and it was still leaking. I installed the passenger side fan to tight against it and it was making contact with the radiator. Had it fixed again.

I did not notice any overheating on Saturday except when I hit the Hot Pit. This was with ambient temps in the 70s and 80s.

I just bought a digital Autometer coolant gauge and two senders. I am going to test temps for the front and rear with the BEGI racer reroute (heater outlet to top rad hose).

My next step will probably be EVANs.

Chris

Chris,
If the front water neck is blocked-off, don't expect an accurate reading in the front of the head with that nasty water-neck sticking out...no water moves through it. You should make a plate at the head and put the sensor there.

You don't need it though if you block the front of the head because water at the front of the head will always be cooler than at the rear.

Might want to hold off on Evans. I had a prototype radiator in my car at SOW on Friday that was pretty promising. Going to do further testing in 2 weeks, but I think a 30 degree drop is not out of the question.

Maniac92,

Have you sealed the heat exchangers yet so air can't bypass them? Makes a world of difference if you haven't. If you have I missed the thread or post, sorry.

Fixed for ya. What do you have now in terms of ducting?

What are your readings for water and oil on the track? Average and peak?

The front water neck is stock right now. I got an extra one to drill and tap the top for a temp sensor.

I want to see what kind of temp differential there is with the BEGI reroute. I'm pretty sure the T into the top radiator hose is not allowing enough flow through the rear (it should be a Y IMHO).

Is it a double pass? If I went with a bigger/better/different radiator I would probably try one of the circle track double pass radiators that M2CupCar has recommended. It's also the best bang for the buck after the Godspeed/Chinese stuff.

They are sealed ala TrackdogRacing's Intercooler kit. 2 small panels on each side, top of the radiator and bottom of the mouth. While not 100% boxed in, I'd give it a 4 out of 5.

The front is boxed in and I'm running the belly pan as well. Two "hotrod" ducts on the hood behind the radiator would probably yield a significant improvement at speed, I would prefer to not have to cut the hood.

I'm not debating the merits of a proper/ideal reroute. I want to see the actual data for the mods I have now and then switching to EVANs. I don't think that the Miata community has given it a proper shakedown with enough Data to back up any conclusions.

Chris

Although the TDR kit is an improvement...when you seal it up like mine, you get to run in 90* heat without ever turning on the fan...with 300whp.

Do the sealing, and then measure the radiator coolant and air inlet and outlet temps.
I did before changing to the TDR ic, and came to the conclusion that there was insufficient airflow.

Truly sealing those exchangers should make a big change as Hustler states. He's been a big supporter of this. After doing it myself I understand why.

Jason, are you are saying, after sealing you saw decreased flow? Sealing it should lower the pressure in the engine bay giving you a larger differential. Should have seen increased flow.

Http://m-tuned.com

Our Coolant Re-Route is a REAL reroute and will certainly help you in your quest for cool track temps.

We have many happy clients!

No. I've always had sealing, but the TDR ic increased flow big time.