So, i installed my new Koyorad seeing as how the stocker wasn't cutting it here in arizona, of course i did some reading. I just find it funny that when they advertise these things they say will drop right in without major modification, i do consider having to bend/cut into metal to be slightly major, but either way i got it done, and now driving with it being 105 degrees outside, under normal driving with the frequent WOT , i stayed at 95C and never once went any higher, compared to the stock where my average was about 100-105C

 

It's all worth it in the end. If you do some searching on the forum though u'd find that the koyo requires things like bending or refabbing brackets to make it fit. Don't worry I had to go through the same thing.

 

which koyo did you use......standard or nflow?

 

I went with the nflow , yeah I had to bend the brackets then trim a bit of metal so the screws would sit flush, fun times though , I still have that annoying clicking so that's my next project. Though I think worse then installing the radiator is after when you sit there biting your nails looking for coolant leaks haha

 

There is nothing wrong with the stock radiator. You would have been better off spending a few extra hundred dollars on a PFC, borrowing a Datalogit, and setting the fans to come on at ~85C. I have never seen higher than 87C no matter how high the ambient temperatures were or how hard I have been driving the car.

 

Nothing wrong with it? Yea except those plastic endtanks that like to burst after 17 years of Arizona heat... Replacing the rad was a smart move, and the next one should be to get the PFC and turn the fan turn-on temp down like you said. But I wouldn't have told him that the new koyo was a waste of money, it's preventative maintenance.

 

I have to agree that the stock rad is a pos. My stock rad was probably going on 17 years of use also. All it took was a ride to gym and back one morning and next thing I know I find coolant leaking from the plastic end tank. Replaced it with a fluidyne and had no more leaks and temps were always low from then on.

 

agreed, the KOYO is worth the money, for the 300-400 bucks for one anything that drops temps on these cars is great. i have one, and in the past heat wave when i took the car out i saw 95 on the PFC and when its cool i get no more than 85. which in my opinion is well worth the money.

 

I have a PFC already, the radiator was kinda my last thing as far as reliability mods, thanks for the fan info, I'll be sure to set the temp lower so the fan kicks on earlier, well after I find someone with a datalogit haha

 

I think that several guys in Tucson have datalogit. I know of a few in Phx also. Even with lower coolant temps, be careful of Summertime WOT blasts if your intake charge temps are over 50C, which they USUALLY are if running a small IC. Are you still running stock IC and DP? What kind of intake temps have you been observing?? You guys have been getting HAMMERED by rain.

 

I don't get why folks have trouble with these radiators. I just installed one in a car with a m2 medium and m2 cf intake and trust me that's one of the harder setups to get a good fitment.

I simply trimmed the upper side of the front plastic grill/duct to allow radiator to sit lower flipped the rad brackets tapped them down with a hammer, DONE. Took about 3 hours.

The best tip for refilling is to disconnect the tb coolant hose and push it up under the brake lines so it's vertical or pointed at the sky then topping off while you're buttoning everything up until some coolant comes out of the TB coolant line. Reconnect the line and you should be good to go.

 

You must have a very conservative tune and some good ducting

In the car I just installed the n flow I was seeing some fairly high temps in town with the ac on, the n flow reduced temps by about 5c under similar condition. However this car is a little rocket so the timing is probably pretty high causing it to run a wee hot.

 

You're crazy. The stock radiator is a pos time bomb waiting to fail, like many other stock parts on these cars. Mine was leaving plastic flakes in the coolant.

 

My Koyo dropped right in (after my stock radiator's endtank began leaking). I guess I got lucky, because all I had to do was push the 2nd oil cooler line back a little. No clipping, bending or...anything.

 

IF you're using a box style intake and aftermarket m2 variety smic you must flip the brackets and trim the ducting.

Or possibly you're missing the front grill and didn't know you flipped the brackets lol

 

I have a stock intake box and Blitz SMIC, and I DID flip the brackets, but no trimming. I just pushed the duct forward a tiny bit.

 

I am running 14psi sequential with all the usual bolt-ons and ~11:1 AFRs at high boost/rpm. Stock ducting. I have the first fan set to come at 85C and the second at 87C.

I am not sure how much of an outlier my car is - I have always been surprised at how well temperatures are controlled. I have never seen above 87C no matter how high the ambient temperatures or how hard I drive it. Obviously, on a track may be different story. (I do see 100C+ after a short stop with the engine off, but it returns to normal in seconds.)

I should have been clearer - what I meant that there is nothing wrong with the stock radiator in terms of its cooling abilities. The reputation that these cars have for a poor coolant system is related to the fans coming on way too late IMHO. The stock radiator size is fine for anything but the most wildly modified cars. I will eventually change my stock one but plan to get a stock-sized aluminum replacement.

 

I'm not referring to the smic duct but if you were able to push the front bumper grill/duct forward it must be broken or not fixed to the bottom of the bumper. If you leave the bottom sway/radiator mounts alone you'll need to trim a good 1/4 inch however if you bend the bottom mount down a bit I'm sure you could get away with a little less trimming but possibly jeapordize some ducting fitment or cause other problems. It's a very snug fit I'm probably a mm or so away from the condenser.

 

You have a freak of a car if you're able to keep temps at 87 with 14 psi on twins, that's just crazy The fans don't do a damn thing on the highway or when flogging it around the country side.

 

Nah, i got a Blitz SMIC and an aftermarket downpipe, yeah last night i was out and i think i went through a puddle that almost went up to the bottom part of my door , If you could, would you point me in the direction of those guys with the datalogit if you know them off the top of your head

 

Don't understand setting fan threshold at 85°C. The stock thermostat begins to open at 80.5 - 83.5°C and is not fully open until 95°C. (1994 Workshop Manual, page TD-4.) If the fans come on below the full-open temperature of the thermostat, coolant flow is limited by a partially-open thermostat. The fans are doing the cooling work that should be done by the water pump. Unless you are also running a lower-temperature thermostat, I don't see the point.

 

As long as I'm moving, I rarely get above 90 C with a fluidyne.

Anyway, the stock radiator WILL fail....it's just a question of when

 

Hey Fritz, I too rarely see over 87 with AC off or 91 with AC on regardless of ambient temps my self Twins are pushing 14PSI here too! The M2 airbox, KoyoNflow, proper ducting and gap filling and more importantly my second Oil Cooler have drastically reduced my temps!

 

You might IM toyzzz. If he doens't have the datalogit software he would likely know who in Tucson has it for the FD.

 

Ha!Take it from a 70-year old... eventually EVERYTHING wil fail. It's just a question of time.