While you're waiting for the undertray to arrive, you should be running 100% distilled water plus a bottle of Water Wetter, and disconnect the signal wire to your ac compressor. Once you do that, turning your AC on (and having the cabin fan control in 1 or higher) will turn on both your fans, which should bring those temps way down at low speeds, and may help at highway speeds as well.

C

You still running the FMII setup? I'm going back to NA, and if you like, you can have my undertray, which is already cut for an FMII, cheap, and I'll buy the new one off you. My car is off the road pending an engine swap, so this could be an immediate solution for you.

C

I am already running fans in paralle. I followed hakunas guide over on m.net. it help but still. I bet the undertray will fix it because Savigton said so. Just a waiting game at this point. I also ordered stage 2 fan shroud from fm this morning just cause. I read lots of reviews and to be honest the mishis blow lighter than the stock fans. Originally I only got them because when I was na I couldn't fit the intake that well on my 91 at the time. The fans were ok most of the year when I was still na. My friends gonna buy my mishi fan.

I don't trust cheap aftermarket fans either. I took the time to trim my stockers so they'd fit with my Koyo55 & FMII, after being less than impressed with the Partzfinder strap-on fans.

Try the AC trick though - just disconnect the compressor trigger wire, and your fans will turn on from the AC button.

C

I do find it funny that my 93' at 10psi in 118 degree weather with no undertray, 1 fan, koyo radiator doesn't go above 180 on the highway or in stop and go traffic even when pushing it hard.

Is that using a stock fan?

That is with 1 slim fan. As far as I can tell it's a no-name fan, held on by those push through zip tie things.

This is the that I recommend to get to help burp coolant. I am not saying I do not think the missing undertray is the issue, this funnel will just make burping in general much easier.

you should be running 10:90 antifreeze:water.

and put your undertray back on and seal the mouth.

90/10 vs 100% distilled + Water Wetter, which one reigns supreme?

C

at that point, you have bigger issues.

???

I believe the consensus is that pure water provides superior cooling performance, but that for street cars, adding some antifreeze is necessary for corossion protection.

In my non-turbo '90 (with no undertray, stock radiator, etc) I run appx. 30% antifreeze.

Water has better thermal conductivity than coolant, and Water Wetter, Purple Ice, etc advertise that they cover the corrosion & lubrication issue.

C

Unless I misread the first time, you are running 10% water and 90% antifreeze; just the opposite of what you want.

How is it possible to use 100% water and then add water wetter on top of that??? Your radiator would be overflowing and shit!!!

If you want the ABSOLUTE BEST COOLANT POSSIBLE then fill that fucker with 100%compressed liquid ammonia. No shit.

But in the real world, water is the best coolant because of its high specific heat (liquid ammonia has a 40% higher specific heat at 212* :P ), water wetter does indeed add a level of corrosion resistance, but the primary purpose of water wetter is to break/reduce the surface tension of water which results in greater surface area contact between metal and water at the molecular level...apparently.

Edit: Put your undertray on.

if he's having issues with 90% water, he's going to have issues with 99.9% water + 0.1% wetter.

Every post that doesn't include the words "put your undertray on" in this thread makes me cry at night.

I wonder how many people actually use the undertray. I'd imagine a lot of turbo'd people do not with the extra cutting required (horrible excuse I know). I fully "intend" to run mine as I know the benefits. But I bet there are a lot of people who "intend" to put it back on too.

Is that the correct order?