Well it has been 26 hours since my last mod and I was thinking about the M7 cooler thermostat. I know the Mini's love cold weather so will this mod keep the motor cooler = more power?
M

 

I have not done it but every one i've talked to who has loves it.

 

What do they love about?

 

do tell do tell.

 

nothing, don't do it. the ecu wants to know the car is at 195 degrees.

 

My current air fuel is around 11.2 but I would like to lean it out to 12.5. My car is daily driver and only on the street, I don't track it. I want to squeeze a little more power out of it with out going to lean that I blow the car or lose power. If 12.5 is safe then how much wheel hp do you think I will pick up?
M

 

I would be more worried about your crank going for a nice little sunday stroll, than i would be about adding a thermostat and leaning out your car

 

12.5 a/f at wide open throttle is very lean, very bad idea!!! 11.2 to 11.5 a/f is safe. what wideband o2 are you using? i have had the M7 thermastat for a long time now. and have an HKS Fan controller controlling the rad fan to go on at 188 degrees F and off at 179 F. car runs very well in tucson AZ.

 

12's not bad... superchargerd cars like that... i would be on the 11.9 side of 12...

yes make sure you keep a leash on your crank... i know a guy where he didn't and the damn thing just ran away... couple grand later... he was in business again... RIP motor number 1

 

man i don't know, any forced induction motor has to deal with higher inlet air temps and leaning it out puts detonation on crappy pump gas really on the edge. much better too keep it in the mid 11's to be safe. running E-85 this is possible even with c-16 too or 100octane VP Fuels.

 

When I talked to steve about this he was generally positive about the performance gain. I have no idea if the stock cooling system could even keep the car cool enough in the 110 degree CA summers, it'd just basically be stuck open all the time I think. Also keep in mind that if the car doesn't fully warm up you won't pass emissions inspection.

 

I installed one quite a while ago, about a year ago, I think....

First a bit about how the Mini cooling system works. The thermostat doesn't just go all the way open. It kind of rides a open-ish state to keep the motor temp where it should be. The only time I've seen a rise above the 195 or so was running on the track, but that's not too surprising, as I'm pushing the car hard. Temps went up a bit above 200.

If you use the M7 part, the car's thermostat will open earlier, and allow for coolant flow earlier. But the temp is right on the hairy edge of the car not thinking it's warmed up. So if you have cold mornings, you may get an code thrown for not coming up to operating temp.

IF you live where it's warmer, then this may not be an issue. If you do live were it's warmer, it's probably a good idea. If you live where it's cooler, get a code scanner to clear the codes from very cold days, or just put it in seasonally, it's about a 1 hour job, including finding the opener for the beer!

I honestly don't have a clue about performance gains. I have crappy CA gas, and I'm looking for every degree cooler I can run to keep timing retard at bay....

Matt

 

Man it's like everyone ignored what i wrote in my post! i use the HKS Fan Controller to bypass the stock Ecu and control the stock rad fan. therefore during the summer one can have differen't settings in winter. just changing the t-stat alone will have minimal gains in cooling but, the stock fan is extremely powerful and using the HKS Controler really works. in AZ this combo really prolongs heat soak.

 

JSWMCS,

Your theory makes perfect sense. The thermostat functions to restrict the flow of the water/coolant so that it stays in the radiator long enough to remove the heat. If the water/coolant flows too quickly, it does not have enough exposure to the radiator surface (fins and tubes) to dissapate the heat. With a set amount of coolant flow (orifice size & pump capacity), you can regulate the coolant temperature by changing the amount of air flow (HKS fan controller).

The other function of the thermostat is to allow the "cold" coolant to warm to an adequate temperature, before being allowed to flow through the engine and come into contact with "hot" components. This helps prevent cracks developing from exposure to extreme temperature changes.

 

Yes!!

 

OK, I'll bite. Tell us the part number, how to do it and what it takes exactly to get it done, please. I live in Austin, TX. It is not your neck of the woods, but it gets hot during most of the year.

Bomboasy

 

MTH was offering different fan on/off temps, and had found benefit from that. I don't think you were ignored, but a $35 part is a lot easier to do than the fan controller. But I like the fan controller being seasonally adjusted, as then one can avoid codes from colder days....

Matt

 

it was 35 degrees in tucson the other night and i don't get any codes with the fan controller. i did the install over 2-years ago and still no codes. i don't have the HKS part number but i do have 2 extra units left for my other cars.
there are two connectors near the a/c refill tube that you splice into for controlling the fan. the bently maual shows the diag. i did it so long ago i don't rember the wiring. SP engineering sells the HKS Fan Controller.

 

to skin the cat. Thanks for the info!

Matt

 

Randy Webb steered me away from this mod. I don't remember the exact reason, but I believe he was concerned that, due to the lower engine operating temperature, there would be greater likelihood of sludge formation in the motor oil...

I guess if you change your oil often enough, this may not be an issue.

 

Are you talking about the Thermostat or fan?

 

Thermostat...

 

I haven't heard of sludge formation issues on the Mini, like some of the Toyota motors have had.

Matt

 

Sludge, like justice, is blind...

 

Toyota is the only car company I'm hearing that is extending powertrain warrantees because they're loosing motors over it. Something about the size of the oil galleys....

Matt