comon sense says a FMIC will restrict the air flow to the rad its why i dont bother with FMIC in TT's

 

thanks for the useful info :rolleyes2

 

check your fans. mine started doing that and i found out my pass fan was kaput. both of them should turn on with the AC on.

 

I'll check it out, I was thinking about hot wiring it so they both kick on at the same time anyways

 

Check out this post by Trevor: http://www.3si.org/forum/showthread.php?t=235667

 

I've seen shrouding work wonders on the road course where you get the same slow rise in water temps as you're seeing.



It also helps to vent the underhood heat as someone else mentioned. Road Race Engineering uses it on all their cars to avoid overheating.

You could also try just "boiling out" the radiator. A radiator shop can do it very economically and straighten any bent fins at that time as well.



If it were me, I'd get the radiator boiled out and install shrouding. Cheap and you don't have to cut any of the exterior up.

 

Also why in rx-7s when you have an FMIC you go with a much larger radiator. Heat+rotary=badbad

 

How did RX7s get into the conversation here?

 

Do you still have a stock radiator? Try going with a KOYO and a 170 t-stat.

 

well yes that's pretty obvious, but I'm not going to throw $500 at something to "try" it when it's not even overheating that bad, I'd like to weigh my other options first

 

For whoever mentioned the fans, your fans do not working while you are driving as they would restrict flow.

Tom you have a 1st gen RT/tt and there lies your problem.

You have to open up the front area some and there are not many bumper options for the 1st gen rt/tt since our headlights are different.

I know eventually I will have a larger setup than these DSM SMIC's can handle and when that time comes I will have to cut on the stock bumper and go to town with some bondo. I was thinking along the lines of cutting on the center dodge grill section, the fog lamp section and reinforcing the cuts with bondo, then repainting the whole thing.

Should be a nice increase in airflow and wouldn't look to bad when its all said and done. Also for know you could look into a aftermarket hood to let that heat out somewhere. Possible cowl induction hood.

Stock our cars generate alot of heat under the hood, with more hp comes more heat, and you need a place for that heat to go.

 

I just want to point out something that many people on this forum don't seem to understand. A cowl induction hood will not let heat vent from the engine bay. The answer is in the name: "Induction". The area right in front of windshield is at high pressure, therefore if you have an opening there it will ram air INTO the engine bay, not out. That was the entire point of cowl induction. Vents have to be at least 12 inches from that area to be effective.

 

Surprised no one mentioned trying a coolant system flush. They aren't ridiculously expensive...I think the local place charges $70 or so for one. There could just be some gunk built up that is restricting optimum flow. Checking the fans is also a good idea, but I would definitely get a flush before buying a koyo.

 

Why not just go with a lower thermostat?

 

Why not fix the problem instead of throwing random solutions at it?

 

Are your lower ducting/cowling on under the car? If not, get it on there. Leaving this off drastically reduces airflow through your radiator.

It doesn't sound like you want drastic fixes since you say it is only running a little hotter than you prefer. So if you push a little more air through your radiator that should do you fine. Right now I imagine your radiator shroud is gone. So.........a lot of air is going around your radiator because that's gone (they make a big difference and is why they're there!). Try and fab up to close the areas that the air escapes around the sides, etc. This won't help for overheating while idling but it sounded like your overheat complaint was during driving.

Your fans will run until you hit 50mph at which time the ecu will turn them off. That's approximately when the air being forced through exceeds what the fans can "pull".

If you have an overheat problem while idling, or under 50mph, or want to have the ability to cool more when you slow down/stop - you can change the temps when your fans come on high. Personally I think the best way is with a fan controller (example - HKS Fan Controller). Then rather than let the ecu control the temp settings the FC'er will handle it. Lowering when you go into high can allow you to get a jump on the overheating sooner and usually keep it in check. The stock ecu has fairly high temp settings for both fans coming on high. Further comment is hard because you do not state exact temps you are dealing with or desire.

Changing your thermostat to a lower one (180 to 170) isn't going to make any difference in 220+ temps (which I am of course assuming you are dealing with). Either will be wide open in the 200 degree ranges.

Venting the heat from the engine won't show you much difference either. The problem is in the flow from your radiator due to the FMIC blocking it and even more so the removal of the duct/shroud that used to direct all the front air through your radiator (and is now esaping out the sides, bottom, etc). You need to CLOSE it up more not open it. Opening up more will just further disrupt the flow of air from the front and through the radiator.

Flush? Fans working? Well I am assuming your coolant system is in proper condition and your fans work so I won't address the basics.

Also remember that water cools better than antifreeze. Do you run 50/50? If your driving habits/area weather temps/and where you keep your car (garaged?) will allow - try dropping it from 50/50 to 70/30 (70% water). Or a ratio that will still provide freeze protection (or boiling in summer). You'd be surprised at how your temp control will recover/drop.

Anyway, those are some random thoughts for you.

 

Don't EVOs run a fmic stock? How did mitsu deal with it blocking the radiator?

 

Uhhh, the car was engineered with it on there rather than aftermarket addon. I think the major problem w/ aftermarket FMIC is the removal of the shroud and air just flows around the radiator then (and FMIC too actually).

 

you sure its not just the thermostat on its way out ? when i replaced mine i put them in a pan of water and heated it up - both opened at the same time but the old one didnt open so far.

mike

 

might be, I haven't had a chance to start troubleshooting yet

 

Heres a picture of some random Evo.

 

As mentioned, shrouding to force air through rather than allow it to go around the FMIC/radiator will make a significant difference. so will using a vented hood (not and induction hood).

The purpose of the hood is to use the low pressure air flowing over the hood to extract hot air from the engine bay creating a low pressure/partial vacuum area right behind the radiator. The Evo hood and the authentic Pit Road M hood both do this quite well and so does the Top Secret style hood. The Evo and PRM hoods both have the forward vent placed optimally to make use of the airflow to create this low pressure area in the engine bay helping suck air through an FMIC, the radiator (and the a/c condenser if you still have that).

Try the shrouding first. If you're overheating only slightly, this should make the difference (and it's the cheapest option). It's also free to pull the thermostat and make sure it's opening fully in a pot of boiling water. As mentioned a lower temp thermostat shouldn't make much if any difference in that temp range. The stocker should be fully open already.


Max

 

CJbyrons post mentioned a whole bunch of other things but the first thing he mentioned is probably a lot of the issue.

Put your airdam back on below the radiator. Removing it doesnt make you more aerodynamic.People actually install much larger ones to help with aerodynamics and traction at the top end of the drag strip.


Anyways, being in constant boost is going to cause you to overheat...especially if you are in constant boost and not moving very fast (try driving up a long steep hill in boost).

 

well I put the stock ducting back in, had to hack it up a little bit to make it fit, but it's still overheating when I thrash it, I guess it's time to get a koyo and a ford taurus fan

 

I would look into Trev's thread because once you remove those ducting air dams you are not forcing air through, air will just find the fastest passage around which will be the sides not through little holes in your FMIC and Rad.
-John

 

soon to get a FMIC and will be looking at this thread later

bumpo

 

koyo fan ftw but why a taurus fan?

 

it's one of the best flowing fans out there, something like 4500cfm

google it

 

my car still likes to over heat after boosting hard for a while.
IPS TD05 Kit
Koyo Rad
Flexalite Fans
Stock T-Stat
GTPro FMIC
no ducting
99 Cut up.

Im going to be getting rid of the flex-a-lite fans because they block off over half of my radiator, and going with two big fans in front between the FMIC & Rad, as well as a lower temp T-Stat, and lots of ducting.

 

What exactly do you call overheating? Temps?

I'd try the ducting first, bet it does a world of difference.

 

after half a lap at nurburg my temp gauge was pegged

 

i see youre in michigan, what % water/antifreeze mix are you running?

 

nah I'm in belgium, the climate is about the same though, only winter isn't as bad

not sure what my mix is right now, probably somewhere around 50/50 + royal purple's purple ice

 

i dono man i have never had over heating issues in my car, im running a 4 inch thick core. stock radiator/fan, stock T-stat. u positive u dont have a coolant leak somewhere?

 

100% positive, it always cools back down after I stop running it hard, and the coolant level hasn't dropped at all

 

im having a similar problem except on my car if i slow down after a little while of driving it(say speed bumps) then the temp will creep up until i start driving it then it goes back down. Im clueless because it seems to be a random issue since the previous time i drove it around it didn't do it.

Have fmic, t stat, pwr rad. and stock fans. Any ideas? What would happen if i didn't run a t-stat(im in fl)?

 

Your problem sounds like fans not working. The car will overheat pretty quick if the cars not moving and the fans dont work. Also, the ductwork thats in front of the radiator that we have to remove to put the FMIC in helps keep airflow velocity high at lower speeds so the fans do not have to work as much to keep the car cool.

 

The lack of air flow was my problem! I put in a monster radiator and flexalite fans and it made no difference. You have to block off any air recirculating from the motor and put in some duct work to get fresh air flow to the radiator.

 

koyo and 1.3bar rad cap came today, I'll be installing the radiator this weekend most likely, then I'll go rag on it on the highway to see if my overheating issue is solved