How hot does your Rb run?

[y3llows14]

Mine seems to run pretty hot. It gets up to 97* celcius in the city as shown on my power fc commander. But my needle on my cluster doesn't even go towards the halfway mark; and I dont hear coolant boiling when I come out to check it. Other than seeing how hot it gets, the car runs fine and pull like crazy. Any ideas?

A little info on my car : RB25DET with upgraded turbo (gt3251),tial wastegate w/open dumpipe,gtr fmic, dual 12 " fal pushers, and Koyo radiator w/ Nimso cap. Carbon fiber hood is also raised and vented.

So Im wondering if you guys are running this hot. If yes, what did you guys do to help cure this issue?

[Yellow4g63]

Mine hasn't over heated on me yet. well I shouldn't say never since I haven't driven it long. I did drive it over to my friends place to install the fans and it didn't bubble over. I installed some felxa lite 220 pullers. (note to anyone else with a RB20 swap. Don't get the pullers the P/S pump won't fit.) I'm going to trade my friend for his pushers and remount the fans. I'm on the stock KA radaitor with smic and stock turbo for now. The FMIC will block flow to the radaitor so it will run a lil hotter but shouldn't be too bad. I haven't installed my pfc yet so I can't give you any temp #'s right now. Did you swap in the KA temp sensor on the RB motor? Thats what I did on mine.

[y3llows14]

No...it still has the Rb25 sensor. I think Im gonna buy a Ka one and see what happen or might just end up getting a water temp gauge from autometer to make sure. The thing is I dont see coolant boiling or extra coolant in my overflow can, which gets me kinda iffy on this thing.

[Imissmyturbo]

I have an RB25 with an RB25 cluster. My temps on the PFC comander show 85-91 while cruising on the highway and when it's warm out (over 65 F) the car will go into the high 90's. Once it shows 100 on the PFC moniter the gauge will start to climb to the 3/4+ range. You won't here any boiling till atleast 100 C since that is when water boils and since I have some antifreeze mixed in as well It won't boil till it gets even hotter. I didn't run pure water in the summer but now that it is getting below freezing, I am now running some antifreeze with my water.

Now on cold days it seem like it takes along time for my car to get to opperation temp. I think my thermostate needs replaced.

Another thing about my temps is it seems like once the coolent heats up it doesn't want to cool off. I am running the stock KA radiator with 2 10" pullers. They come on at 91 C.

[fly240]

rb25, using stock 240sx radiator, cluster, one 14 inch fan, drove for 300 miles on high way, the stock water gauge meter go to half. it does feel hot, but didn't have any boiling or smoking. Now i'm adding one more 12" fan and the water meter never go up to half. It stay on c or only move up alittle.

[y3llows14]

Just got back from Vegas trip. Boy was that expensive. Anyways, thanks for the input guys, I guess Im runngin a tad hotter than what I should be running then. Ill be checking the thermostat out when I have the chance. Im thinking the the gauge cluster might be wrong because it is sending temperature in Celcius instead of fahrenheit.

[NISMO_RB25]

yep, pick yourself up a 240 sending unit. There were two types, so make sure you get the one that is for the gauge and not one that is for the light.

I got the wrong one the first time, and when I started the gauge it would peg the gauge. Now with the new one it works fine.

Helpfull tip from Mckinney was to run 80% water/ 20% coolant and use the additive 40below.

I have dual 12 pushers and the koyo, no overheating problems.

[BoostFab]

my upper intake pipe tends to heat soaked...

[FAST-DATSUN]

DO NOT trust the stock gauges get a good aftermarket water temp and oil pressure (direct reading ) on your car to keep your RB alive longer big radiator, oil cooler and good fans are the key to long life....

[Vkoslak]

Check out the latest Sport Compact Car. They talk about cooling the "Project Silvia". I know its an SR, but most of it should be applicable or at least give you some good ideas.

I particularly liked the oil cooler.

[krayton]

SHROUD!

not sure if anyone posted that, but ill put that up on the very very high list of cooling equipment.

ive ran through just about every setup for cooling.

i have no heating issues till i start drifting (but who doesnt)

my final attempt to keep the rb cool will be the koyo with pullers and a shroud.

the 2nd best so far was the stock radiator and 1 puller (since thats all i could fit.)

note: this is also with a condensor and intercooler blocking that air flow

[y3llows14]

I havent driven the car long enough to see how hot it will go up to, but when hitting the freeway for a couple of minutes, it begins to drop to like 92 *C . The weather out here is pretty cold too---around 40* F.

And I just ordered a coolant temp from autometer, should be here pretty soon. Havent have time to look at the sensor nor the thermostat though, so its up to the RX300 to take me to school.

My flex a lites are shrouded and covers up all of the Koyo.
Modified by y3llows14 at 1:43 AM 12/3/2004

[accel junky]

Ice Cold.

[y3llows14]

Got the autometer gauge install a couple days ago, which gives me bad news. Im running out!!! The power fc was accurate. What do you guys think could be the problem? Heres what I did so far for cooling issues--Koyo , dual 12" FAL pushers,Nismo cap, vented carbon hood,raised hood,large bumper openings(fmic is kinda in the way though), new sensors, thermostat, water wetter, and bleeding the cooling system. Ill do a compression and leak down test whenever I have the chance.

[Imissmyturbo]

I wonder how the water flow is through the radiator. If you can get ahold of a non-contact thermometer you can take a few temp readings in your system. Does the temp just keep climbing? Where is it leveling off at now?

[y3llows14]

When at idle before I drive it---it stays steady at around 78*C. When driven---it keeps climbing up, which makes me pull over. So I Turn off the ignition for around 3 min, and temperature drops like 10* C. This $hit is weird. Its so freaking cold out here too--35*F---which is 1.7*C.

[Wulfgang]

That's pretty cold. I would guess that your FMIC is blocking the air, but if you are overheating at only 35ºF, then that does not seem so likely.

So maybe you've got a flow problem. Take that new coolant temp sensor you bought and put it on the OUTLET of the Koyo. Then warm up the car and take it for a drive in cold weather. If you get temperatures above 140ºF or so, then your flow should be ok. But if you get temps down near the air temperature, say below 60ºF, then you know you aren't getting any water through the radiator.