since we're seeing more and more Evolutions and STis on the road how about an IC spray? Both come with one stock. The Sti's is an automatic even.

my newest interest is KDs dual rad setup.

 

Fan mod, lower fan cycle on temps, reduced battery size and pulled tray, pulled stock airbox so the radiator breaths better. Never over 100C (85C in winter, 92C summer).

 

I've seen people rig up their windshield fluid system into a fairly decent intercooler spray system.

I don't think this will make much a difference in engine temps but it would certainly held intake air temps under harsh conditions.

 

i did a write up on how I did it but the pics disappeared

https://www.rx7club.com/showthread.p...ar+wiper+spray

 

Just curious, what ambient temp you get these reading at?

 

so if the pullys made temps lower at higher rpm would the temps be higher at lower rpms? (water is moving slower)

 

~50/50 water/coolant
pfc set to turn on fans at 90 deg C
~half a bottle of water wetter
stock radiator
new waterpump (i think) and all coolant lines replaced when i had the motor done

i have never seen over 91 deg C yet, even in hard driving conditions. cool season tho.

chris

 

DamonB, do you still have your write-up about the electric waterpump from the Porsches? I tried looking for it but no luck. I'd like to make a subscription to that thread so if you can link me it would be great .

Jeremy

 

The 110C temp was on the track a few years (VIR) ago in 104+F ambient conditions. God it was hot that day. Typically on the track I will see around 100-105C pushing hard at 12psi on stock port with original stock twins.
Street driving engine temps it doens't matter what ambient is. On hot days it cycles between 87 and 95C but never above 95C when the fans kick to high and this is only rarely - as in I can't remember when it last did this.
This past weekend in ambient temps of around 50F the max engine temp when driving was around 67C. This actually is too cool and I don't like running the car like this. Poor car thinks it's constantly in warm-up mode, eg., constant high idle. Hope this answered your question.
Crispy

 

My car is still pretty stock except the downpipe and AST. I've replaced upper and lower rad hoses, ast hoses, and turbo coolant hoses, done the fan switch mod, use 70/30 mix and water wetter, along with an aftermarket water temp gauge. My average crusing temperature at 80mph in the summer is 185-190. Idling in traffic with the fans on it hovers around 185.

 

Hmmmm Yes good point you got me on that one. Had the parking lights on and the fan on 4. Motion was very slow, probably 10kmhr or so.

Nobody seemed to reply to my question about the air con. It's got my head in a spin. In my opinion running the air con has two competing effects.

1. The fans will kick in and help lower temps, good in stop/start traffice.
2. heat will be dissipated from the condenser piping, located in front of the radiator, increasing the temperature of the air that flows through the radiator and decreasing the radiator efficiency.

Some claim that running the air con helps keep their coolant temps low, while I've noticed that in steady driving at various speeds, it increases my water temps. Maybe stop/start traffic is different, but I fail to see how. Even with the fans on there would be less airflow than driving at 60+kmh

Anyone care to elaborate?

 

the thing with the air conditioning is that people remove the relay so that it isn't actually on but the fan controller thinks it is. that way you get the fans to come on but the AC doesn't actually run so you don't get the negative effect you pointed out.

 

Think of the AC in this manner. AC is removing heat energy from the interior of the car and dumping it as waste energy by "radiating" it from the condensor to the exterior environment. The hotter the interior of the car is the more heat is going to be radiated (rejected to the environment) from the condensor. I would think that once the interior of the car is cooled down to a comfortable level the amount of heat energy removed from the interior of the car to maintain that comfortable interior temperature will not be much and therefore the amount of heat being "radiated" (rejected) from the condensor will also be relatively small.

In essence the condensor is NOT going to be preheating the air entering the radiator significantly once the interior of the car is cooled down. Caveat, if you live in Arrizona and on a 110deg F day this may not apply

I would also like to add that, in my case, lowering the condensor (or for some removing it altogether) may not be to eliminate this "preheating effect" but moreso to allow a clear unrestricted airflow path from the nose of the car directly to the radiator itself. Dare I say it, akin to the FMIC vs SMIC debate.

FWIW
Crispy

 

For those in traffic that just rely on the stock 221F 1st fan trip point for cooling, running with AC establishes an equilibrium water temp that is cooler than 221F. If they just ran the fans manually by 'tricks' or miata switch, they would run as cool or cooler that with ac on, and with much less usage of the fans.

 

That wasn't me. Not sure what thread you're referring to?

 

No, at lower RPM, your water is flowing a bit slower due to the larger circumference of the pulley but does not affect heating issues. At higher RPM with the stock pulley, cavitation has a high chance of creating itself at the pump due to a smaller circumference pulley. I.E. When at a track, you're up at the higher RPM range 95% of the time. Going WOT and then back off, and then WOT jerks/spins the stock waterpump pulley so fast that it creates cavitation at the fins not pushing any coolant, which disrupts your cooling flow. Getting a larger pulley will inihbit more efficient flow at the higher RPM range also reducing the effect of cavitation.

Jeremy

 

It's true that fluid speed is an important variable. I ordered some custom air-to-water coolers recently for a 500MW generator/motor. The supplier engineered them specifying flow rate, inlet temperature, fin density, tube diameter, number of pipes (size of core), overall size, thickness, etc. ALL of these variables interact, so that making any one parameter larger doesn't always make for a lower outlet temperature.

Slowing coolant flow results in the coolant spending more time in the engine absorbing heat, but then more time in the radiator and getting cooled. Without lots of data about the system to do a thorough analysis, you just try it and see what happens.

Dave

 

If you are at 7 k on the track doing this, the w-pump is still at same speed, not much jerking at the impeller.

You are right in that cavitation due to pump/system design and high speed will disturb flow. This would show up as a head (presssure) loss at the pump discharge, which would normally be well above the t-stat relief point. It would be informative to install a pressure nipple in the pump cover,at the dischrge location, and monitor discharge pressure at the track vs engine rpm, with stock pulley. Should be able to detect cavitation by a sudden pressure drop there.

 

I belive that was PomanFerrari who did the whole deal with the electric water pump.

Going back to what one person said about the copper radiator, RonKMiller (Where the hell is he?) had done a write up about the avantages of a copper unit over other's.

 

I don't know for sure why the waterpump underdrive pulley helped so much but the fact is that it really did make a large difference in keeping my FD continually cool. I ran the same track at the same ambient temperatures and my FD got too hot after about 4 laps. I then later ran the same track at the same temperatures and my only modication was the underdrive pulley. I ran cool all day long.

 

wait, i'm confused... does turning the a/c on help keep the car from overheating??
this doesn't make any sense

 

the a/c doesnt come on they remove the relay or the entire thing. when you hit the a/c button it tricks the car and make it idle up and the fans go full blast. so it will cool the car down.

 

ahh... i see. pretty cool, thanks

 

.

 

Its FREE? Damn I was getting like 5miles to the gallon less on a tank with the A/C on, thats why its in the shed hehe


MY MODS

Vented hood
Upright Koyo Radiator
99Spec 5 and 7 blade fans
Air removal system 2 extra hoses my own design

That about sums up cooling mods

I run currently from 88c----96c