Overheating problems!

[Venom]

I am running my 2003 Cobra at 8.5 psi boost with a 2 core fluidyne rad and a 1:15 water wetter coolant mixture. On a cool day (20-25deg) she runs 200-220f on the backstaight, but Sunday at the Barc weekend she was dipping into the 240's again!

Do I get a bigger 4 core rad and custom fit it or maybe a electric water pump to control the flow at higher rpm's?

Any ideas/input on this please...

[ScotcH]

How's your A/F? Are you running lean at all? What kind of coolant?

[Marsh]

Get the hot air out of your engine bay so you get more flow throught the rad. IE an extractor hood or vented fenders. For cheap you can use the hold trick of spacers between the hood and hinges so that the hood sits higher in the back and hot air can vent (doesn't work at high speeds, but does at low speeds).

[Venom]

AF is 11.5, timing 23 total advance (stock) and I am running distilled water with water wetter. The stock Cobra hood is already fitted with some extractor vents... I also have some ducting in place in front of the rad, but there is a few open areas.

[Logan]

Doesn't water wetter ask for 15% glycol mixed with water and a bottle of water wetter as the best mix?

[ScotcH]

Doesn't water wetter ask for 15% glycol mixed with water and a bottle of water wetter as the best mix?

Nah, that's only for lubricating the cooling system. The most efective is water + WW.

[John Powell]

There are those who advise against using distilled water for cooling. I read an article last year (which I can't find because when our computer crashed last year I lost all my bookmarks :mad: ) written by (I think) a chemical engineer from Montreal that said, amongst other things, that distilled water doesn't have the same heat transfer capability as regular water, and because it doesn't contain any minerals, it will absorb them from your engine block and cooling system, thus weakening them. If I can find the article I'll post it as it was interesting reading.

[DECH_92]

Your hood looked like it would work at extracting hot air,
I would get a bigger rad plus block of all those areas where
air can get around the rad.
Bigger oil cooler.
Distilled & water wetter is about all you can do for fluid.
Not sure if electric fan would help except make a bit more
power and remove some clutter but may help the hood extractor
be more efficient.

[Sasha]

my car was overheating terribly - i mean it would overheat to the point of failure within 20min of hard driving.

I added better ducting and got more air into the rad and my overheating problems went away ENTIRELY. Ducting is really the biggest thing.

Also the barc weekend was pretty hot and the track temperatures were really up there, so dont be too worried about that high temp. Try to improve your ducting if you can because thats honestly the biggest thing.

[ScotcH]

my car was overheating terribly - i mean it would overheat to the point of failure within 20min of hard driving.

I added better ducting and got more air into the rad and my overheating problems went away ENTIRELY. Ducting is really the biggest thing.

Also the barc weekend was pretty hot and the track temperatures were really up there, so dont be too worried about that high temp. Try to improve your ducting if you can because thats honestly the biggest thing.


Yes, this makes a lot of sense. Last year on my M3 I was missing a big piece of the undertray, and there was a huge gap below the rad and around it. As you may remember, my car overheaded a bunch of times. This year, I have all the proper ducting in place, and I have yet to see temps over 220, even full out at WGI.

[Mike Basden]

Stupid question, but have you check your thermostat to make sure it's opening all the way? Over the years I've experienced one or two of these. Also check your hoses if they are rubber ones. Check the inner layer to see if they are delaminating at all.

[soloZ]

Hey I saw the Article in the star about your car this morning, I just have one little problem. Do you really have cut springs on your car? this is just something that from a group of people who tell other people to do the right thing like taking there car to the track etc etc and now we are telling people that cutting the springs on a car works and helps make the car handle better?

I personally have seen what a cut set of springs do on a normal road car and I am sure the father that actually owned the car ripped the hid off of his son.(the spring rotated around the spring purch and was half an inch from shredding the tire, the father had to buy new front and rear springs.)

[Venom]

Yes, this makes a lot of sense. Last year on my M3 I was missing a big piece of the undertray, and there was a huge gap below the rad and around it. As you may remember, my car overheaded a bunch of times. This year, I have all the proper ducting in place, and I have yet to see temps over 220, even full out at WGI.

I have some ducting on both sides of the rad but there is still a big gap under the bottom. I left this open for the heatexchanger, but since I dropped the boost down to stock my IT2's are around 160-180. Still high but better than last years 220's.

Thanks for the input, I am going to block in the bottom of the rad and try that first before anything els.

[Venom]

Hey I saw the Article in the star about your car this morning, I just have one little problem. Do you really have cut springs on your car? this is just something that from a group of people who tell other people to do the right thing like taking there car to the track etc etc and now we are telling people that cutting the springs on a car works and helps make the car handle better?

I personally have seen what a cut set of springs do on a normal road car and I am sure the father that actually owned the car ripped the hid off of his son.(the spring rotated around the spring purch and was half an inch from shredding the tire, the father had to buy new front and rear springs.)


I did not read the actual artical before the release and the last thing I want is to do is to make this sport unsafe! I sincerely appologise for that statement and wish I could turn the clock back. I do NOT recommend cutting or modifying springs to anybody in their garage! There was a month backorder to get the rates I wanted at the time so after carefull caculations I decided to go this way. This turned out to be a very complicated mod as I had to make custom spring pocket spacers to hold proper rideheight on all four corners!
Buying the right springs or coilovers is definately the way to go!

[michaelbanovsky]

I did not read the actual artical before the release and the last thing I want is to do is to make this sport unsafe! I sincerely appologise for that statement and wish I could turn the clock back. I do NOT recommend cutting or modifying springs to anybody in their garage! There was a month backorder to get the rates I wanted at the time so after carefull caculations I decided to go this way. This turned out to be a very complicated mod as I had to make custom spring pocket spacers to hold proper rideheight on all four corners!
Buying the right springs or coilovers is definately the way to go!


Riaan,

Sorry some people took those paragraphs the wrong way in the article, but I did qualify what I said about cutting the springs. And I didn't suggest for a moment that the mod was safe. For the record:

(From the article...with emphasis):

"Van Vuuren's first suspension mod was to cut his springs, which lowered the car and improved handling.

Usually this is a no-no, but combined with Bilstein shocks, a front sway bar, caster and camber plates, and custom Delrin bushings, the change has given him a safe base for handling adjustments."


Then again, if anyone here has a car they'd like featured, let me know. Especially if it's as least as fast as Riaan's. ;)


M!

[michaelbanovsky]

And Riaan for the cooling issues...

Do you have the room for a V-mount intercooler? It's commonly used on RX7 drift cars because rotaries tend to run very hot.

Then again, you'd have to remove the stock rad, angle it downward, and place an intercooler at the top to complete the "V". Would improve cooling...and who knows? maybe some more downforce.

V-mount (http://www.kameson.com/RX-7/intercooler3.htm)

If you can't do that, start taking headlights out, then take the hood off, then the front bumper...Or pack the rad with dry ice.


M!

[Venom]

Riaan,

Sorry some people took those paragraphs the wrong way in the article, but I did qualify what I said about cutting the springs. And I didn't suggest for a moment that the mod was safe. For the record:

(From the article...with emphasis):

"Van Vuuren's first suspension mod was to cut his springs, which lowered the car and improved handling.

Usually this is a no-no, but combined with Bilstein shocks, a front sway bar, caster and camber plates, and custom Delrin bushings, the change has given him a safe base for handling adjustments."


Then again, if anyone here has a car they'd like featured, let me know. Especially if it's as least as fast as Riaan's. ;)


M!

No problem Micheal, you tell it how you see it and I respect that. I should'nt have showed you all my little secrects.LOL You get the facts with a little story and some humor (the HONDA comments from me!) to spice things up... Great story, thanks again!

That is a good idea for a radiator setup, but I do not think I have the room for that though. For now I am just going to fab up some thin sheets of aluminum and box in the front.

[slucas]

No one has suggested slowing down the waterpump with a larger diameter pulley.Is this still done or is it passe now?

[malcolm]

if you do run a v-mount, be careful that you are not forcing a ton of air under your car through the rad... might produce a fair bit of lift at higher speeds.

but I agree with sasha: duct it *thoroughly*!!

[Venom]

No one has suggested slowing down the waterpump with a larger diameter pulley.Is this still done or is it passe now?

A local custom rad shop suggested an electric waterpump to slow the flow down at higher RPM's if overheating is still a problem after the proper ducting is in place. That is the same as a bigger pulley and a lot cheaper. He also said a too thick radiator will not always help, what I need is to increase the frontal surface area of the radiator.

[Venom]

if you do run a v-mount, be careful that you are not forcing a ton of air under your car through the rad... might produce a fair bit of lift at higher speeds.

but I agree with sasha: duct it *thoroughly*!!

Thanks for the tip, lift is something I do not need on Mosport.

Ps. Your car was by far my favourate on the track, watching you down 2 and around 3 was a real treat!!

[malcolm]

Thanks for the tip, lift is something I do not need on Mosport.

Ps. Your car was by far my favourate on the track, watching you down 2 and around 3 was a real treat!!

thanks! but yeah, many people seem to think that tilting a rad backward has no ill effects (alone, or in a v-mount)... of course, if the air was ducted out properly, like in the Japanese GT cars, then v-mount would be awesome... however, you'd need to fully redesign the front end of your car to make that work.

Also, when I was helping Sasha with his car, we cut out the hood latch and installed hoodpins so it allowed more air to hit the rad directly. Not sure of the Mustang design, but it's definitely worth thinking about removing any unnecessary objects in the airflow to the rad.