FT-86 low temp THERMOSTAT

[rice_classic]

Good info Jamal and good technical write up. It did not appear as if the data there is illustrated in a pressurized system though. Did I miss that? In a 50/50 system, under OEM pressure provided by the pump/rad cap, the standard cooling system can keep the fluid from boiling even at or above 250F. Another thing to consider is the fluid's ability to act a heat sink, so while straight water with a lower boiling point may dissipate/shed heat better, in situations of a heat spike it may not handle the heat as well as a 50/50 system and be more susceptible to cavitation especially around the exhaust ports/valves where the fluid is always hotter then is registered at the temp sensor.

Water Wetter... I won't ever use that again. I now classify the neon pink stuff as snake oil. I used to use in the race car but no more. In most racing organizations Glycol is not allowed so people add WW.

When I drained my radiator/cooling system I noticed this stuff foamed like dish soap water. How can that be good considering the turbulence the fluid sees throughout the system. Any little pocket of air in a mixture that foams like that in a racing application and BAM, cavitation!

Go ahead and put a half gallon of water in a bucket and poor in some WW. You'll see. Everyone goes on and on about.."But Rice, it's a surfactant!"... Yeah, well so is dish soap, doesn't mean I want it in my cooling system.

The Water Wetter made for diesel engines (the black stuff) doesn't foam like the pink stuff does, but it also doesn't have the corrosion inhibitors. If you're going to use WW on a race car, use the black stuff. If you're going to use WW on a street car because you "think" you need to, well you don't. If you're car can't keep itself cool enough in with a 50/50 glycol mix in street conditions you have bigger problems because the factory engineers are smarter than you and designed the engine to be able to cool itself in just about every climate habitable by mankind.

If you're REALLY horny about coolant and you have more money then you can count just go get this:

http://www.evanscooling.com/products/coolants/

[jamal]

Thanks!

No, nothing there is for a pressurized system and I probably should have elaborated on that part a little more. I've been meaning to do a follow up that is more racing oriented that talks about the benefits of higher pressure, bigger radiators, swirl pots, higher flowrates, ducting, etc. Now would probably be a good time since summer and track season are well underway.

I'm not sold on the evans stuff. It's basically just running 100% anti-freeze and I would rather have thermal capacity over boiling point. Just because it's not boiling doesn't mean it's okay to have super high coolant temps. Plus like you said most tracks and racing organizations require straight water anyway.

[Toma]

So did we end up finding a cooler thermostat for these cars? I went to Rock Auto site and none listed.

Looking for a 180 ish...

Thanks

[velin86]

^^^After all that you still want one?

[Toma]

Originally Posted by velin86

^^^After all that you still want one?

Lol. Yes. Of course. 'All that' are generalizations. For what I have in mind, a 30 degree drop in cylinder head temperature will be beneficial. Cold thermostats or even no thermostats with restrictors do have their place in racing.

[FR-S Matt]

I had a 160 thermo in an old LT1 Formula I owned... probably the worst move I ever made. My heater didn't work barely at all and I had nothing but cooling problems on that car, lol. Not saying it caused the cooling problems, but it certainly didn't help anything. I'm not touching the thermostat ever again.

Get a bigger radiator if you want cooling.

[velin86]

Originally Posted by FR-S Matt

I had a 160 thermo in an old LT1 Formula I owned... probably the worst move I ever made. My heater didn't work barely at all and I had nothing but cooling problems on that car, lol. Not saying it caused the cooling problems, but it certainly didn't help anything. I'm not touching the thermostat ever again.

Get a bigger radiator if you want cooling.

Yea I agree. You want to keep the car cool but not at a cooler then ideal temperature.

[DylanFRS]

Whoa... I read the first post in this thread and was all excited to read the flaming and then there was no flaming... I have so many mixed emotions right now... Half of me thinks it is cool that everyone was so understanding but the other half of me thinks that I have seen threads that were far less stupid than this one that got flamed like crazy....

[Toma]

Originally Posted by velin86

Yea I agree. You want to keep the car cool but not at a cooler then ideal temperature.

There is no "ideal" temperature. If you want maximum efficiency and mileage, hotter is better. If they could run an engine at 300+ would probably be best.

If you are octane limited, and want to make as much power on a given fuel as possible under boost, colder is better.

As an example... say your particular engine will tolerate 10 psi boost before becoming octane limited. I have found that ROUGHLY a 30 degree coolant temp drop will allow another 1.5 to 2 psi boost with the corresponding power increase.

Now, the 3000hp Outlaw Drag Radial cars I tune, run ambient temps when they hit the burnout box, and oil temp is pre heated to 140 ish. The Pro Mod Nitrous (gas) cars will often run ice water through the block before they hit the burnout box, but pre heat the oil to also about 140.

I know those examples don't apply to your typical Scion, but I hope it illustrates the need to asses each situation and outcome one has in mind before throwing out a broad generalization.

[cplabaunza]

I'm also looking for a lower temp T-Stat...Had one in my SRT8 Charger and SRT 4 and they ran better IMO...I had to use my DiabloSport programmer to make the fans come on at certain temps in order for the lower temp T-Stat to work when the cars idled...Heat Soak sucked power in both those cars...Ran a lower T-Stat for years no issues...

Be prepared for arguments like the added temps are needed for moisture in the oil to evaporate etc...

[DylanFRS]

Still trying to figure out why a car company would put a thermostat in a car that opens at 190*F if they could put a thermostat in that opens at 160*F and the car would run better.

[Toma]

Originally Posted by DylanFRS

Still trying to figure out why a car company would put a thermostat in a car that opens at 190*F if they could put a thermostat in that opens at 160*F and the car would run better.

Different goals from you and me. They also COULD have given the FRS 250hp, but "we" have to do it for them.

[Toma]

Originally Posted by cplabaunza

I'm also looking for a lower temp T-Stat...Had one in my SRT8 Charger and SRT 4 and they ran better IMO...I had to use my DiabloSport programmer to make the fans come on at certain temps in order for the lower temp T-Stat to work when the cars idled...Heat Soak sucked power in both those cars...Ran a lower T-Stat for years no issues...

Be prepared for arguments like the added temps are needed for moisture in the oil to evaporate etc...

SRT4 totally needed them. Cool night, and they were animals, hot day, and the Stage cars were gutless. Put a colder t-stat, and the performance was MUCH more consistent day to day.

There is merit to the oil argument, but if you can maintain a bulk oil temperature of about 180, that will give localized temperatures that will be enough to "boil off" any moisture, especially if you use it hard. Or you could just change oil more often. This is how I did my Viper. 170 tstat, but use the fans to roughly maintain 185 oil temp.

[DylanFRS]

Originally Posted by Toma

Different goals from you and me. They also COULD have given the FRS 250hp, but "we" have to do it for them.

Getting 250hp out of a small engine is much more expensive than getting 200hp. Making a thermostat that opens 30* costs the exact same amount as any other thermostat. A different amount of wax and a different spring rate is all it is.