Pistonkilla1

I have a Greddy FMIC and a Koyo Rad so I thought this should help me out in my problem BUT the famous stock temp gauge will start moving towards the white line! Now I can make it go back down by just not boosting for a while, and then im fine, but when I start pushing the car there goes the needle towards the white line(sometimes)..... Now i know that these engines produce allot of heat because heat is constantly being generated in the combustion chamber because the intake charge is compressed before it reaches the combustion chamber, minimizing cooling effect. So what are my options....... Should I be having these problems taking into consideration I have a FMIC and upgraded Rad?

Thanks in advance!

FD3S2005

iTrader: (11)

FMIC makes it imo a lil worse but only at stops/traffice.. because your blocking the air to the rad. if its happening as you drive then im not quite sure.. just my 2cents

Pistonkilla1

I was going to get the Scoot hood and ill just mod my fans to turn on constant when i have the car on..........

I also have No cats,(DP,MP)so that alone reduced some heat....But still getting hot somehow?????

7-sins

Check fan relays... I just had this happen to me after washing my car.

Does the temp go down if you turn the A/C on? (making the fans run)

Pistonkilla1

The fans do turn on, and I took off my A/C

siris

Check out the cooling thread...Here's a link.
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/big-fat-fd3s-cooling-thread-571088/
When was the last time you fushed the radiator? Did you purge the cooling system? What's the mixture of coolant to water?
Is the radiator properly ducted, I know when I bought my car the previous owner had removed the stock undertray, to improve cooling he said....but that actually raised temps by 4-5 degrees. I replaced the undertray and life is great.

DaveW

At speed, the fans do little to increase airflow, UNLESS the air ducting to the radiator is not sealed to direct ALL of the available air through the radiator. The HD rads (Koyo, Fluidyne) need more airflow than the OE rad to make them work, so proper ductwork is an absloute necessity. The FMIC makes this more critical. The fact that you are seeing increased temps while running at speed under load leads me to believe that the ducting needs to be improved.

Of course, making sure the rad is not partially plugged as suggested above is also something that needs to be done.

Pistonkilla1

Ill flush and make sure that its not plugged, as for the Koyo Rad it has no ducting, its just mounted up vertically behind the FMIC as it should in this tye of setup. It didnt state anything about ducts.......

DaveW

You need to make sure the air coming in can't just escape around the rad - that's a common cause of overheating problems. Just because "it" didn't say ducting is needed, doesn't mean it isn't. "It" may just have assumed "it" was obvious.

I'm trying to be funny, but, seriously, making sure all the available air goes through, not around, is extremely important.

Dave

Pistonkilla1

I know that ducting is a extremely important factor but Ive only seen ducting being used and needed and for SMIC, can you direct me to a setup that has a Standard produced duct and not someone who made a custom duct. Just like they make and sell ducts for SMIC there should be some FMIC, but Ive seen nor heard of none.

DaveW

Sorry, I have an SMIC and a stock rad, so I am no help on that subject. Maybe someone with an FMIC can chime in.

Pistonkilla1

Bump.....Is there ducting for my Koyo rad on a FMIC or is my problem elsewhere???????

bryant

i have front mount and griffen racing rad and dont really have problems??
and i dont have any ducting.





but im in alabama so maybe it is abit warmer where you are.
mine runs about 200 in the city and 185 to 194 on the highway.
my fan runs all the time.

Pistonkilla1

So you have your fans on constant..... For some unknown reason my car is overheating ONLY when I boost the car hard, I took a small trip(140miles) and the car ran very smooth, no problems....

cozmo kraemer

You need to make ducting on your own. Without ducting it is no wonder that your car is overheating. It is critically important. I doubt there are many 'kits' out there you really need to make it yourself. Wander around Home Depot or Lowes and look for supplies that would work well in channeling air. Make cardboard cutouts as a template for the ducting...trimming them till they fit perfectly. Trace the cutout onto some sheet metal (or similar)...cutout the patern and mount into place.

Areas that need smaller amounts of ducting and if you can't really make something out of sheetmetal, you need to get creative and use some medium density foam or thick weather stripping.

If the radiator isn't ducted, the fans pull air through the radiator, heating it. This heated air then recirculates back in front of the radiator and the hotter air is then pulled through the radiator again, thus reducing it's efficiency. So ducting for a front mount is still crucial...if not more crucial than an SMIC setup that can use the stock underpanel as a decent ducting setup.

fdeeznutz

You need to fabricate one. Edit: Cosmo beat me to it.

Pistonkilla1

That's what I was thinking I would have to do. For now till I fab one up, ill just use some 3inch plastic plumbing hose and do like a dual setup that could come from the oil coolers since thats really the only place in which I have room because of the FMIC....

gracer7-rx7

iTrader: (16)

Here is what I did to help this issue:
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/my-radiator-fmic-ducting-mini-project-651168/

Make sure your coolant is in good condition and that the system is properly bled. The FAQ sticky has a good link to how to do that.

Pistonkilla1

Isn't there something like that that they mass produce, some kind of cover that has the company's logo on it as well, it comes in chrome i think, or am i mistaken, cant recall if it was just for looks or served a purpose.....

fdeeznutz

Carbing does make a cover, but it's just that, a cover. Not even close to what ducting will do.

DaveW

The ducting we are all referring to keeps the incoming air trapped so it all goes thru the rad, and hot air from the engine compartment can't recirculate over and over again. 3" tubing ducts may help to cool brakes, but will have almost no effect on improving the airflow thru the rad or the engine cooling.

You just need to make something that does what I and others have said - maximizes the cool air going thru the rad.

Pistonkilla1

What I meant about using the tubes is that if somehow I can get an external sorce like for example the oil coolers passage way from the bumber and route it with the tubing directly to the Rad......But Im going to try to fab something up.

ericgrau

iTrader: (1)

A FMIC makes things worse whenever you boost. If you want to keep the FMIC, consider an even larger radiator (??).
Thermostat might be slowly going bad.
Lisle funnel (search). Only easy and effective way to get air out; other methods are hard and still leave a lot of air.
Foam around radiator and plastic undertray should be in place. There shouldn't be any way for air to go around your radiator. In your case you may want to use sheet metal and silicon or some other way to both provide fresh air and make sure it can't go anywhere except your radiator.
Evan's coolant is expensive but it doesn't boil or need replacing.
One really bad overheat will blow a rotary.

SLOASFK

iTrader: (5)

Is this true? I've never heard of coolant that never needs to be replaced.

Pistonkilla1

+1