Overheating on the track and radiator question
 

I'm in the middle of the second session at TWS yesterday and on the front straight I relax my grip and check my gauges, just like I was told to when I started out. Except this time the temperature gauge is almost all the way to hot. One lap or two prior I had put two wheels off and felt a clunk, but didn't come in.

So I'm thinking that I broke something, am leaking coolant, and limp back to the pits. By that time the temp was normal and I can't find a leak.

Go back out and after a couple of laps the temp is up again. So for the third and fourth session I ran the heater and just coasted down the front straight in 5th. The temp would rise but cruising in 5th would bring it back down.

This is my third summer doing track days so it's not just the fact that it is summer. However, here are the changes since last summer:

1. 93 octane tune

2. 275/40-17 r-comps

3. driver mod

4. temp got over 100

Could the fact that I'm faster (I hope!), the r-comps are shorter, and the tune allows a higher redline mean that the car is at higher rpm's for a longer period? Add in the 100 degree temp and the car simply overheated?

Since the car would cool down so quickly I'm assuming there isn't anything wrong with the cooling system, however what could I check?

It seems like I just need more cooling. One of the Mustang racers recommended the Mishimoto aluminum radiator from Americanmuscle. He said that the Ford Racing part has plastic end caps and the Fluidyne is much more expensive. Anyone familiar with this part?

-Wayne

Wayne,

This might sound a little dumb and newbie-ish but how is your coolant new, old, replaced? When I tracked my car I put in some Water Wetter. That helped my car but I think it did run a little hotter then usual and cooling off fast once I let it idle for a few minutes after a session. Some of the other track guys might be able to give you some better solutions.

http://www.redlineoil.com/products_coolant.asp

If you were dropping fluid you would of gotten the meat ball flag while on the track so I doubt you broke anything but if you bent or deformed any of the radiator louvers that can effect how well it cools. It will be fine on the street but, as you know, when you are on the track you are asking a lot more of your car then the usual daily driver does.

I have been having overheating problems as well. I installed an electric water pump not sure if this has anything to do with it or not but I am replacing it with a regular but high flow water pump as well as changing my thermostat. My brother told me that possibly the thermostat went bad.

My temperature used to sit at around 192 - 198 degrees as per my Aeroforce gauge. Now it is around 210 and will work its way up to 220 so there is definately something that has changed in my cooling system.

So I am going to replace the water pump, install a 160 degree thermostat, flush the coolant and replace with purple ice.

I am also going to check that the fan is working properly. I was going to upgrade my radiator but I dont hear of folks having issues with their stock units so figure that I must just need to fix a minor problem. My brother is usually right so I wouldnt doubt it if the thermostat is my issue.

Oh and my track temps have been at 244, went into limp mode twice and the car shut off on me once. I think my car may be trying to tell me something...

Wayne,

I have had great luck with the Mishimoto radiators, and I would recommend upgrading to an aluminum rad regardless of whether or not that is what is causing you to overheat. However you definitely want to get to the root of the problem first. Have you noticed any fluid leaks since returning from the track?

Bunch of points -

1. Check and/or replace your radiator cap. They are cheap ($6 or so?). They tend to go bad and not hold pressure, allowing temps to rise. I keep a spare in my trailer.

2. A vented hood will serve you much better than a bigger radiator. It's a matter of airflow, not the surface area of the radiator. The vented hood will also reduce lift up front, giving you some more front grip.

3. A chin spoiler will help get air to the brake ducts and the radiator.

4. Unless you are in an area that has freezing issues, run almost straight water with Water Wetter. Water is thinner, and will flow faster as well as give off it's heat faster. You will also pick up a pony or two. A high flow water pump is not the answer.

5. When in doubt, run the heater. It's only 30 minutes. Suck it up sissy.


HTH

Nasty nasty - run the heater in Texas in the summer!

Last time I was at the track up here in the great white north I had the AC on for a few laps at the end of the day! :)

Thanks for the other good suggestions. I'm running the CDC front spoiler and I think it helps.

I've looked at vented hoods but so far haven't bitten the bullet. In my case with the SC the underhood temperatures seem high when running around town in stop and go driving. Some one keyed my hood badly a while ago so that will actually make the decision to go to a new "easier" as it will cost about the same to fill and fix the stock hood or a new one.

Further to your point about a vented hood helping to reduce front end lift I was wondering at what speed you start to notice the lift. At Mosport my top speed on the back straight is 130 MPH (6250 on the rev limiter in 4th) and when I start braking the back end is a little "squirrely" until the speed comes down. Could that be due to back end lift?

I have the mishimoto and love it. I dont track it but I still do notice a diff on the street. Takes a bit longer to get to normal coolant temp level. The fact that its almost double the thickness will help in dispersing heat better.

But I agree with the guy above. Track cars generally run pure water w/ water wetter. Keeps temp much lower then coolant.

This is exactly why I don't do DE's from June to August. It's just way too hard on the cars and the drivers. When I tracked my STi in the summertime, the heat soak was so bad that I didn't have any power in the front straight at TWS. In addition, my pads wore much more quickly with the crazy Texas heat. What finally convinced me was a friend blowing the engine on his Mach 1 during a July event at TWS. He didn't even look down at his gauges until his engine seized on a shift. The only exception I make is the night event at TMS that I've done the last few years in August. It's pretty hot when we begin at around 6; but by the time the sun goes down, it's much more tolerable.

-Edward

PS: One thing that I found on the STi was that running my 93 tune resulted in my EGT's hitting 1850F just before braking for T1 at TWS during the summer. Running my 91 tune brought that down to 1725F. So it may be worth looking at dialing back the timing.

Sorry to hijack Houston's thread but I had a question. What sort of speeds do you hit at your tracks? I've been thinking of getting a chin spoiler; but someone here had a CDC one that started dragging at speeds over 120 in just a couple of laps.

Thanks,
Edward

Thanks for the replies and suggestions.

The radiator is on the way and I'll get a new cap. I'm trying to keep the car TTC and CMC2 legal, so no front splitter or vented hood.

I WAS running the heater during the last two sessions and the car still overheated.

Are there any issues with the aluminum radiator and/or engine if I run only the Water Wetter without antifreeze?

The 91 vs. 93 tune might be a good idea. I'm at the track on Friday for some more practice and will take the tuner.

- Wayne