matty

for the past year my car has been running warmer than it used to. i am seeing 94 degree temps when i used to see 87-88. 5-6 yrs ago i changed the power fc to make the fans come on at 87 and really it never went much higher. all of a sudden i see 94. should i replace the t-stat?

also i am curious, at what temp reading while on the track should i do some cool down laps at? i am guessing 105-110 somewhere?

gracer7-rx7

iTrader: (16)

Last time you changed coolant? Have you tested voltage of the coolant?

matty

i changed coolant at kd last fall.

not sure what u mean voltage of the coolant? you mind explaining?

gracer7-rx7

iTrader: (16)

when coolant goes bad, it conducts voltage and can be tested with a voltmeter.

Might want to double check your fan settings on the PFC and verify that they are coming on at those temps. Otherwise, maybe it is you t-stat. Might also run a strong stream of water through the rad fins. You'd be surprised how much dust and crap accumulate in the fins.

I think on track, I think I've read threads where they say to slow it down when you see 105 C. 105 C = 221 F.

IRPerformance

iTrader: (41)

Partially clogged radiator or sticking thermostat, or a slight blockage somewhere.

FearNoPiston

iTrader: (17)

hmmm my car always stayed at 82c all day long then one day driving it just started going up and fluctuates much more now. maybe I should flush and run some water through.

theorie

iTrader: (31)

clearly you're all missing the REAL reason.... GLOBAL EFFING WARMING

if you want to know why your engine is running warmer, go ask al gore, i bet he'll give you a reallllll scientific answer.

pfff what a joke.

anyway, i would agree with Ihor: partially clogged radiator or sticking thermostat, or a slight blockage somewhere.

my car has been running a little warm lately (88-ish). i partially flushed the coolant tonight and got a some goopy brown stuff out. now the car runs at a solid 85c.

2RotorsNaDream

iTrader: (7)

I never get how so many people here get 87º temps daily. I just replaced my stock radiator with a Koyo radiator, all my coolant is brand new, my thermostat is brand new OEM, and I have a FMIC. My car is always at 89-94ºC when driving on the highway and when its sitting in traffic it regularly goes up to 99-100ºC and then goes back down to 95º and keeps fluctuating back up to 99-100ºC again. I dont get how other people get such low numbers on this forum. Maybe because my PowerFC doesnt have the fans set to run at a lower temp.

gracer7-rx7

iTrader: (16)

^That is b/c you have a FMIC. I was never able to get temps under 90 C when I had my Greddy and lived in NY.

Fritz Flynn

iTrader: (263)

If you opt for an FMIC in order to keep the temps down you'll need to change your front bumper, have it professionally ducted and add a large single cooler or some duals. Once this is done you'll have no problem keeping your water and oil temps normal and your charge temps will be outstanding.

FMICs are very good mods for these cars if done properly because they keep the charge temps really low and reduce the chance of detonation by a wide margin but most people just bolt them on with no concern for ducting etc....

IRPerformance

iTrader: (41)

Agreed. I never had temp issues when I tracked my car. I ran a greddy r-spec front mount and mazdacomp radiator, R1 oil coolers and a 180 degree thermostat. I had a 99 front end and ducted air under the front mount to the radiator.

matty

fritz care to respond to when i should slow down on the track?

Fritz Flynn

iTrader: (263)

At 110c (i believe at 245f the death con 5 alert is heard) any higher and you risk damaging the aluminum housing because it cools/expands faster than the irons causing them to warp which of course leads to a bad seal between the rotor aluminum housings and irons leading to our precious rotary becoming a steam engine with low compression

Ideally you'd like your FD to run at 200F, both water and oil on 100 degree day of flogging and no lifting. My current car will run 190 water and 225 oil on a 100 degree day which I'm ok w/ but I really need to duct my oil coolers asap. I do run mobil 1 15 50 and when i change it every other track weekend approx 500 miles it's still gold and not black so I think things are ok.

VERY important, never ever let your intake temps go to 70c no matter how well your car is tuned etc..... IMO you shouldn't go above 55c and this is just as important as worrying about your water and oil temps because your engine will die a quick death if it detonates.

2RotorsNaDream

iTrader: (7)

Thanks alot for that, I have the Feed Type II R replica front bumper from Shine so the front opening is pretty big. I guess I'm going to try to run a duct from underneath to the radiator like you did and get an R1 cooler for the passenger side. I also need to get an undertray ASAP, thats probably a big reason for the high temps. When I bought the car it didnt have an undertray and I keep forgetting to buy one. My charge temps are beautiful though haha.

Fritz Flynn

iTrader: (263)

Don't buy a stock undertray and take the car to a professional fab/race shop and they'll take care of the duct work for you. Probably cost between 250 and 500 but the OEM undertray is 189 from Malloy and won't work well w/ an FMIC. Make sure both oil coolers are also ducted well. Once this is done you'll be very surprised at the difference and your intake temps will also improve

Monsterbox

iTrader: (6)

ducting doesn't matter as much as you guys think it does unless you are moving. When you are sitting in traffic in 100F ducting doesn't do sh*t. FANS are what matter. Why doesn't anyone think about upgrading to summit racing or some universal double CFM fans. Install a switch and this should make a huge difference and should be much less money than 500 dollar professional ducting.

GoodfellaFD3S

iTrader: (213)

My R1 (recently refurbished dual oil coolers) has a 99 undertray, blitz fmic, fluidyne rad, and deleted a/c and p/s. Temps on the street are typically 82-83 this time of year here in the NYC area.

Even down at Deal's Gap when I was constantly boosting over the 11 mile route (318 turns so probably 300+ wot pulls), my temps never went above 92 degrees. I think the low backpressure 4 inch full exhaust helps alot.

gracer7-rx7

iTrader: (16)

Your blanket statement isn't true. How much it helps depends on your setup.


The problem with FMICs (particularly in traffic when the car isn't moving) is that it leaves the radiator w/o a direct source of fresh air. The Greddy FMIC is a particularly good example here. Not as bad with other setups. The radiator winds up just sitting there underhood instead of in the bumper opening. When the fans engage, it mostly just pulls hot air from underhood through the rad.

Most radiators (aka heat exchangers) are designed on the assumption that the air flowing though them is colder than the medium flowing inside of it. If you are recycling HOT underhood air through the rad core, the coolant inside of it just gets hotter. It probably won't get cooler than the air flowing through it. The engine bay also heat soaks further making the underhood air hotter and it spirals from there.

Adding some 'ducting' to seal the top and sides of the rad so that air gets pulled from the bumper opening through the IC and A/C condensor helps quite a bit. Helps both when the car is stopped/driving slow in traffic as well as when moving actually.


With a SMIC, the ducting doesn't help as much when stopped in traffic. Then again, you rarely see hot coolant temps with a SMIC compared to a FMIC. When moving (particularly when hustling on track), the ducting/sealing of the radiator helps to force air through the rad core instead of around/under it. Air flow management further improves an already reasonably efficient design.


With a V-mount setup, both the rad and IC get direct fresh air. So from that perspective, it is an even more efficient design.


We are mostly off topic at this point since Matty runs a good radiator and SMIC. Ihor's advice was the best on this thread in directly addressing his problem.

matty

because we dont care what heat the car is producing when its not moving. we care about when it is moving especially for track guys.

matty

its nice to see some of you guys are still around. anyways i plan to spray down the rad this weekend. will let u know how it works out. but i'd be shocked if thats it.

if it doesnt i will replace the t-stat. should i do the napa 180 degree one or the stock oem one? does anyone have part number the napa one?

1QWIK7

iTrader: (33)

I have a FMIC and my temps are always under 195-200F.

As soon as i see it approaching 190F, i hit the fans, ONLY when im idling. Once i start moving, i turn them off.

If i keep the fans on all the time, ill never see temps above 200F. And recently i have been doing 45min - 1 hour driving trips, its been pretty warm lately.

I do have the ducted headlight cover and a 99 front though, maybe that helps with airflow.

matty

also i should add that this only happens when its warmer out, say 75 plus. the car will get up to 94 then cool back down to 87. the thing is this it used to NEVER get to 94. it would just get to 88 and sit there. does that sound like a failing t-stat?

Monsterbox

iTrader: (6)

well, I still believe a major factor in cooling is the CFM of the stock fans.

The stock fans were designed for the super thin joke stock radiator. When you add something thick like a nice large thick koyo you end up with major heatsoak. At least thats whats happend to me. On the stock radiator in traffic my car would sit fine at 180F. Now with the Koyo it SLOWLY creeps up to 190+...I can tell its heatsoak. I have a SMIC with an aluminum SMIC duct (although this aluminum probably adds to the heatsoaking as well). I also have installed carpentry foam around the sides of my radiator.

Moving on the interstate my radiator temps are just fine unless I am going up and incline or running between 80-90mph (oddly it heats up to 190 at this speed where as 55-60mph it cools down go figure).

However, in traffic, with my fan switch, the car just doesn't cool down nearly as quick to 180 as it used too. Its entirely livable as long as you don't idle for 45 mins or turn the A/C for too long in 95+ ambient.

Overall, I believe the stock fans are underpowered for the thickness of a Koyo radiator, especially with a FMIC in front of it. (Only if you consider 200-225F too hot) The fans are having to pull air through ALOT thicker metal.

IRPerformance

iTrader: (41)

I have two cars at my shop with very similar setups and motors. Both have aspec turbo kits (35r and 500r) koyo radiators and IRP motors with similar porting. They both have IRP oil passage mods but no coolant passage modification. 180 degree thermostats. Both have mocal dual oil coolers. The main difference is one had a front mount intercooler, the other a vmount. The vmount car runs about 84-85 degrees while the one equipped with the front mount runs about 92. Both cars have ac and all accessories as well. Stock fans. The hottest I've gotten the v-mount car is about 95 and that was in traffic on an 85 degree day with ac on. The stock fans when in good shape are actually not too bad on the high setting. The multi-speed relay system is an over-engineered waste. Upgrading them never hurts however.

Rollogic

iTrader: (1)

What CFM's do the stock fans produce?

What kind of ducting work have you guys had done? Have you done it yourself...any PICS?

I think upgraded fans WITH ducting is the best solution. I totally believe in overkill for cooling. I am going to purchase two upgraded electrical fans...especially since the driver side stock one fried out on me.