Ok, the mods..

Race ported, barebones engine.
PFC
GReddy T78 GT79wheel
Fluidyne Rad..
GReddy FMIC
..those are all that i think matter..

Anyways, I'm having a major heat issue, and i'd like to see if anyone has any suggestions on how to fix it, is dealing with it currently, or whatnot..

Cruising at about 65-85mph in ambient temps of 90-95F 50-100% humidity.. i see 104-110C watertemps on the PFC. Its quite bothersome, because i can't get into it.. the more i boost, the more heat i get, and the hotter my temps rise. The map i'm running isn't lean or anything.

I made a duct today to go over the radiator, as i feared air was going around it.. it dropped the temps 3C, but i still see about 108C on the highway.

Will installing the heat shield on the hotside of the turbo knock any temps off? Do i need to do a better job ducting elsewhere? Different thermostat? Vented Hood?

It just seems as though the heat has nowhere to go.. if i turn my heater on, i can get the temps to drop instantly from 108C to a drop of about 103-104C. So just a few degrees.

Any input would be greatly appreciated. The car is just so uncomfortable to ride in.

 

oh and fans are set to turn on at 86C.

 

Hows the tuning? Richen it up a bit and that might cool of the exhaust temps which might cool off over all temps.

 

Take out the AC condensor =)

It blocks the radiator and air that goes into the radiator as well.

BTW, are you running a 2 row or 3 row FMIC? Also is the T78 a water cooled or oil cooled turbo?

 

before you pull out the AC =)....

Try changing the thermostat or your coolant, try using a different mixture with more water than anti-freeze and see how that goes before doing anything else to the car. Or see if there is anything blocking the radiator that isn't too obvious. All those could drastically increase your water temps

 

2 Row FMIC, oil cooled T78.

Coolant is pretty much 60water/40coolant.

i'm going to get an aftermarket thermostat.. that opens at 75C.. see if that makes a difference.

My a/f is pretty rich as far as i know.. i can richen it up more.. can't hurt..

any other ideas?

 

I have the billion thermostat that opens up at 65 C and to tell you the truth, it wont' help cool your car down on a hot day.

maybe your water pump has cavitation or something...

 

any way to check for that?

 

where can I get a lower temp Tstat for a 91 13bt??

Im interested

 

www.jt-imports.com

tell jason you want the billion one

 

Or to go napa and ask them. they have a bunch that fit 13b's in stock.

 

i put some insulation on the bottom of the radiator.. seems to be working.. i'll know more later when i can get her on the highway again.

 

Is the belly pan on the car???

 

yeah its on the car, but there was space between it and the bottom of the radiator, so i put some insulation on the bottom to close the gap.. i'll know more when i get her out in the heat of the day.

 

doesnt the belly pan removed help cool of the car some?

 

The car will run hotter without the belly pan. Air is going to take the path of least resistance so it will flow under th radiator without the pan on. You have too much coolant in there. I run about 80% distilled water and 20% coolant. Water transfers heat better. The only reason you want the coolant is to prevent corossion and freezing. I have a similar setup to yours and on a 100 degree day I'll get up to about 103-104 degrees C while cruising with the a/c blasting. 110 is pretty hot. 115 and you are damaging the motor. You could also try a bottle of redline water wetter.

 

Pete, I have the EXACT SAME setup as you. Same turbo, everything. Anyway, I too experienced the same heating issues and I'm in Naples (about 10 degrees warmer on a consistent basis). Mine wasn't quite as severe, only getting up to about 103 degrees. I have a fluidyne.

First. Seal that f*cker all the way around. I used that thermotec insulating blanket stuff...basically it's fiberglass insulation with reflective foil on both sides. I sealed the bottom, top, and both sides as best I could.

Second, change your coolant as suggested. Run about 70% water, 30 coolant, and add a bit of Royal Purple Purple Ice which basically removes the water's surface tension and promotes heat transfer.

Third, get a 16lb. radiator cap. It makes a big difference.

Fourth, make sure you "burp" your cooling system after refilling it to get some of the trapped air out. Run your heater when refilling it. Fill the radiator SLOWLY which will allow the air to escape. Oh when I mean burp, you need to do it when it's hot. Just crack the cap (use a towel) enough that the coolant "almost" comes out. It makes the air bubbles come to the top. Also, try using an air seperator tank for a bit. I don't use one btw...

Fifth, insulate that turbo and EVERYTHING around it. Thermotec makes a turbine housing wrap which works very very well. Much better than a heat shield. Also insulate your heater hose. It runs right by the turbine/downpipe.

You also may want to consider the installation of an additional oil cooler if you have a touring/PEP model with only one oil cooler. 2/3 of cooling in a rotary are done through the oil. And the T78 is an oil fed turbo only. So you're making the cooler's job twice as hard.

I've done all the above and I kid you not, it sometimes takes forever to get the car above 80 degrees Celcius. I usually run about 84 w/o the A/C on, about 87 with it on high. On the highway, cruising at say 90 or 100mph, it'll reach 93 with the a/c on full blast. Made a huge difference! Good luck and let me know if I can help further.

 

Oh, either www.jegs.com or www.summitracing.com for the above thermal supplies. You can get the radiator cap at Pep Boys. As suggested, change the thermostat to a new unit too. But stick with the stock temp because the PFC is programmed in such a manner that there's a bit of fuel correction until the proper temps are reached. And oil temps must reach a certain range to work as designed.

 

Hey rx7tt95, could you take some pictures of ypur handy work. Sounds like you did a really good job of coolong off your engine bay.

I've heard bad things about the turbo wrap. My engine bay is hot and I think I'll cause more damage not covering it in the the long run.

 

Thats what i'm working on currently.. it seems the more i seal it the more the temps drop. Still gets warm..

Quote:

Second, change your coolant as suggested. Run about 70% water, 30 coolant, and add a bit of Royal Purple Purple Ice which basically removes the water's surface tension and promotes heat transfer.

Third, get a 16lb. radiator cap. It makes a big difference.

Fourth, make sure you "burp" your cooling system after refilling it to get some of the trapped air out. Run your heater when refilling it. Fill the radiator SLOWLY which will allow the air to escape. Oh when I mean burp, you need to do it when it's hot. Just crack the cap (use a towel) enough that the coolant "almost" comes out. It makes the air bubbles come to the top. Also, try using an air seperator tank for a bit. I don't use one btw...

Yeah i don't have the AST anymore either, and i have a 16lb cap. I'll dump my coolant and go for a higher ratio of water this time.

Quote:

Fifth, insulate that turbo and EVERYTHING around it. Thermotec makes a turbine housing wrap which works very very well. Much better than a heat shield. Also insulate your heater hose. It runs right by the turbine/downpipe.

You also may want to consider the installation of an additional oil cooler if you have a touring/PEP model with only one oil cooler. 2/3 of cooling in a rotary are done through the oil. And the T78 is an oil fed turbo only. So you're making the cooler's job twice as hard.

I've wrapped a lot of things in heat reflective tape and insulation as well.. i'm a little skeptical of the heat wrap on the turbo and downpipe because of the rusting issues.. i'd rather ceramic coat.

And my car is a touring model, and i'm probably working that single oil cooler to death.. i think i'll end up getting a MOCAL or GReddy upgrade unit or dual units.. either way, seems like its something that needs to be replaced.

Quote:

I've done all the above and I kid you not, it sometimes takes forever to get the car above 80 degrees Celcius. I usually run about 84 w/o the A/C on, about 87 with it on high. On the highway, cruising at say 90 or 100mph, it'll reach 93 with the a/c on full blast. Made a huge difference! Good luck and let me know if I can help further.

Sounds great, looks like i've got some work to do.. i'll keep you updated!

 

A FMIC blocks about 70% of the bumper inlet so you dont get as much air to cool everything off. That last 30% that makes it in there needs to be used VERY efficiently to keep your coolant temps down. At the least you need to block everything off so the air is traped and has to go thru the radiator core.

The best thing would be to form some type of air duct for your radiator (somthing similar to a smic duct). I think Brian at BNR fabed something up that attaches to the belly pan. I havent seen it yet but he told me it helped a lot.

STEPHEN

 

Ceramic is definitely better. I didn't have that option at the time (long story) so I used wrap instead. I had my turbine housing wrapped and when I put in the new motor I damaged the wrap. BIG DIFFERENCE in radiated heat. I have a heat shield on there now which helps a bit but not much. On a recent jaunt across the state to S. Beach, I opened the hood after arriving home (at night) and the turbine housing had a nice glow going...nothing too dramatic but glowing none the less. I figure I'll be replacing everything before corrosion sets in anyway so i wasn't worried about it too much.

I'll try to take a few pics of what I've done but to be honest, I've had no luck in being able to post pics on this forum for months.

I forgot to mention (although it's in my sig) that I have a FEED front end....larger opening plus there's a small, perhaps 2" slit at the bottom which the front mount does not cover. Perhaps this is helping with my lower temps as well.

 

update: finally got distilled water and water wetter, its made a huge difference at night time.. now the hottest i've seen was like 88C... so i'll have to see what happens during the day.. i'm trying to duct the radiator as best i can too.

Also plan on getting some R1 oil coolers.. since my single old oil cooler is kinda smashed up from rocks..

 

Thanks for the update! I usually don't see one of those.

X...

 

better get a 3 row. that 2 row wont last.

IMO id get a trust. there front mount sits more to the passenger side so it doesnt block THAT MUCH OF THE AIR GOING INTO THE ENGINE!