Originally posted by liquidX:
Originally posted by DemonSVT:
For every 10 degrees cooler the engine runs it requires 1 less octane point. (I.E. more boost, timing, etc per octane from pump gas)

You wonder why I could run my race program until the mean heat of summer... Well besides good tuning

Even now I switch to it if I'm driving at night.

What difference is that on a stock or mail order chip car. Not much if any.

For ref
Stock t-stat starts to open at 190-192.
Stock fans are 216/224.





BTW, Tom, thanks for the corrective and informational post. Who needs a car forum when they have friends like you?

Okay so let me get this straight. Right now my SCT tune and program has my main cooling fan coming on at 200F, and shutting off at 180F. I will need a 180F thermostat in order for the dF to be compliant both from the fan and the thermostat in synchro correct? Stock is 192/195 at Autozone, and the Mustang one I have in the box here is 160f, but they also provide a 180f one as well. 3 Choices, and I need to pick one by Friday. Thanks guys...

XL





Not exactly.
Stock runs like 225 turn on and 210 turn off or something like that. The ultimate temp you can go without coolant boilover is determined by the cap. THe higher it can get the better it sheds heat but the more pressure....yada yada.

You already have it then go ahead and run it. It isn't going to change much unless you are in a cool climate already.
Having the fans come on at 200F is no big deal either other than you don't use the cooling system to its max potential due to the whole heat transfer thing. I would use a 220-200 range myself.
Again, the t-stat will be the minimum operating temperature for your engine. The engine will run warmer most of the time except cold start and highway cruise with cool ambient temps.
This is the only reason I give credence to what Demon was just saying. It may allow him a little more timing under certain conditions but only when the engine temp is lower than 180 and that doesn't happen too often. For the most part I think it is a placebo and that it was more likely his combustion chamber prep and his tuning that allowed the better timing numbers.

So if I didn't already say it, you will be fine with the setup you are going to except in the afore mentioned initial startup, cold start/cold temp emissions and with the lower fan turn on temp and the slightly slower rate of cooling associated with it.

Just remember that your cooling fans will be running all the time now except in very cool weather and you may end up having to replace them due to the reduced longevity.

Don't you ever wonder why they put higher pressure radiator systems in cars? THey have been raising the pressure on radiator systems consistenly for almost 100 years as engines advanced. THey are now up to 20lbs pressure wheras 30 years ago they ran 6-10lbs.

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black