I've got some questions for motorsport cooling gurus. I'm not finding help in the "advanced" forum. It's sad... that forum used to be so good... but now the BOV questions have seeped in there too. No place is safe.

https://www.evolutionm.net/forums/en...ml#post7072066

Basically I want to know how to estimate the air velocity through an average radiator.

I just picked up a mishimoto radiator and I'm obsessed w/ maximizing cooling since I've had some serious heat issues lately. I've sealed off the area in front of the radiator to maximize flow through it, I've re-routed and reprogrammed the ICS to spray on the radiator, I've got the ralliart thermostat, the 1.3 bar cap, and the oil thermo killer and removed the AC. I'm going to test that this month at Hyperfest, but I wanted to theorize about the fans a bit. Please see the link above.

 

I've some info and some questions. The only way i've seen, if your that concerned about it like your part list depicts, is to build a duct for it and get a bumper, like the C-West, that has a much larger front/center opening.

Now my questions on topic:

1. I recently removed my heat shields from the mani down to the stock o2 in an effort to allow air to come in and cool these objects. In doing so I think I cranked my rad temp up 50 deg because my last track weekend - the oem block sensor was reading slightly below "normal" but the upper rad sensor (using 42draft's housing) was reading up to 250 deg coming out of the rad, is it the turbo (all oem) that's doing it? I'm running water + water wetter so it shouldn't be that different, and actually run cooler then AF + water. I remember being at Barber in the 100 deg day and it wasn't near that. I also added more wetter after a few sessions but no change (knowing that it breaks down eventually).

2. Has anyone rigged up a dual fan with a manual switch yet to suck through the rad and blow on the engine? For those of us that don't have AC anymore, it seems that - even though technically the "ac" fan should kick on on it's own, it's **** on a bull because it mostly just sits there.

 

Wow, good info here. I 've had to remove my heat shielding too and I just recently fabbed up a really ghetto aluminum shield that will hopefully keep the manifold heat away from the rad. I'll see if it works at Hyperfest this month. A few things:

1. How are you getting separate coolant temperatures? When I log coolant temps I see the same as the temp guage inside (~260F at the max.. which scared the crap out of me)

2. I know why my temp went up. For some reason I would boil over so much that the overflow tank would overflow and spill out, and when the car tried to suck it all back in there wasn't enough. I'm fearing a HG problem but I'm not sure. I've done compression tests and checked oil/coolant and the head studs... they all indicate that everything is okay. I had to install a tube that went from my overflow up onto my windshield to see when I was overflowing. VERY VERY HELPFUL.

3. In this thread ( https://www.evolutionm.net/forums/ec...onditions.html ) I'm trying to find out if we can use ECUFlash to change the parameters around the AC fan. Right now I've just got my AC fan coming on every time the puller fan comes on. I'm trying to figure out if that's a good idea or if I should just remove it. (which is what the initial thread in the advanced forum was about)

Edit: btw the radiator is as "ducted" as possible and my bumper is very open. ...my dremel made sure of that.

 

Good info indeed. I had plenty in my overflow so I know I wasn't spilling it out onto the track. But for my gauges, the stock water sensor (i think) is on the back of the block somewhere under the intake manifold. My second gauge feeds off of the 42draft design upper water housing. Look at their site for it. This gives me the conditions inside the motor and the condition of the water as it leaves the radiator. So technically it should be the opposite - I wish I had someone to hold a laptop and log but I didn't at the time. But glancing over at the gauge seeing the needle near 250 i was bout to freak too. You got pics of your setup? (use something besides fliker/photobucket if ya can, cause I can't see those at work ).

So

1. Does water wetter work, I'm not sure it does because I was still cookin.

2. We REALLY need a dual fan kit to suck through the radiator

 

This one?


Does it come with the sensor?
(One thing I just noticed is this: If this sensor in this position showed high I would tend to think it's because you've got vapor in the system. That is the highest point I believe, so you get an air bubble anywhere, it would be there. And remember steam can get much hotter than water can.

I'm not convinced that water wetter does much more than eat up rubber and plastic. Water wetter seemed to leave a lot of of black goop in my reservoir and on my radiator cap. I've decided not to use it anymore. I'll see what 50/50 does at Hyperfest. I was going through water wetter and water like crazy last time out.I had to refill every time I came back into the paddock.

I don't have any current pictures. When I do I'll try to post em up.

 

Ya that's the housing, but I'm using prosport's gauges, so the water gauge has the same size thread as 42's housing. In looking at a recent pic I took of the engine bay, that housing actually sits about 1/2" down from the filler neck. I can see your point where because of the design of the housing, you "could" get bubble/steam in the top because the water would flow underneith it. But the gauge probe is about 1/2" long so it's gotta be in the flow. That and I had it on about 6 other weekends and was seeing opposite temp readings. I'm blaming the wetter and the lack of heat shields I think. There's gotta be an alternative to wetter that some track ***** has used? Royal purple's stuff?

 

Getting a nice aftermarket radiator can work wonders if it is an all aluminum construction efficient design. On the 8/9's you guys have some serious radiant heat hitting the back side of the radiator.

Check out those new DEI Titanium T3 Turbo shields:

http://www.gohtsn.com/article_1196.shtml

I think Dave Buschur did a quick review on his own forums and after seeing it in person on someones car at Watkins Glen I bought one too. It will be on the car in a couple weeks but it looks very promising. It doesn't quite fit the new Garrett GT3076R exhaust housing because the turbo is a monster but a small cut to allow attaching the internal WGA and it should work just fine.

Wrapping the exhaust manifold/headers and downpipe will also work wonders to reduce radiant heat and they sell that titanium wrap as well.

Running Redline water wetter also helps improve the radiators efficiency as does increasing the water to 60-70% with 30-40% being coolant. If you can run just water and water wetter withoit and risk of freezing it will be even more efficient.

Sometimes you can get engine compression pumping pressure into your cooling system under higher boost when your engine is really hot. This is due to head lift and stretched head bolts allowing the head to move slightly and the weakest points in the head gasket start failing. What sucks is that doing a compression test usually shows that everything is fine because as soon as you get off the boost the head seals up again. Daily driving is usually fine buy any extended boosting forces coolant out of the system like nobodies business. The solution is a new head gasket with ARP or other brand head studs. Making sure the head isn't warping under high heat is also a good idea if you have had issues like that for a while.

Hope that helps!

 

Good ideas. Not for me though because i'm using stock everything. Also using low boost (23) with arp studs already. I think the only thing you can do for the oem is coatings or wrap. Coatings being better obviously. I pm'd and left a message with Chad @ CBRD to ask about a radiator designed to use the oem air duct and a dual fan setup. We'll see if he can help.

 

I did install a new (Mishimoto) radiator and I'm switching from water/water wetter back to 50/50 water/coolant. My exhaust is heatwraped but I did have the shield off previously so I have a makeshift shield on there now. I'll see what it does.

I also am running 23psi and ARP headstuds already. If I still get overheating this month I'll look more seriously into a new head gasket. I was fearing head lift, but I can't see how that's happening as all of my ARP head studs were still super tight.

 

Didn't help... pretty sure it must be the HG. Dun dun duuunnnnn.

 

Your collant should be running right around 200 degrees F....What are you oil temperatures ? How old is your radiator and have you flushed it / tested it ?

You want to wrap the manifold and keep the heat shield on (IMHO) - retaining the heat there is good...I don't believe for road racing applications that you would need to get tricky with the fans on a stock / stock like turbo setup.

 

That sucks, sooo it's an oppertunity for forced upgrades? Is anyone running that dual fan shroud that mitshimoto is selling?

 

Agreed. I shouldn't need all this for the power I run so something is def. wrong. I just notices yesterday that I have an exhaust leak that is blowing on the radiator... maybe it's superheating the coolant... I dunno. I'll try to fix that, then I'll run at VIR this month and see if it helped. If not I'll have to do the HG.

lol, nope not time for internals. I need someone to buy my wheels so I can even afford to to do the hoses and HG!! I'd like to go higher compression... but I'd settle for reliablilty.