I just got my new MCS about 2 months ago & I've finally calibrated my butt dyno to it (I've been blessed "or cursed" with a particularly sensitive posterior dyno) & just today when we finally got some cool temperatures (highs in the low 70s vs our typical summer low to mid 90s) I am noticing quite a noticeable difference in performance. This difference is present in all cars I know (hot air less dense w/ less O2 etc...), However, I think I recall reading somewhere in these forums about how high ambient heat can cause the ECU to dial the timing back. This seems to feel about right, because it is a pretty large difference in performance - much more so than in normally aspirated cars I've owned previously (people w/ blown MINIS who live in cool climates should consider themselves lucky!). Is there any way to overcome this timing dial back? I realize that its to prevent detonation, but is it necessary to dial it back that much even using 93 octane? Has anyone had success with higher octane?

 

huh, i thought the intercooler was just not as effective among other things.

 

Yea, the intercooler would certainly work better when cool ambient air is blowing over it as opposed to hot ambient air. It just seems like the car is Jeckyl & Mr. Hyde - one of the quirks of supercharging I suppose.

 

Quirks? I think JOY! There are a lot of factors to consider; first the S/C is cramming a lot more atmosphere into the engine and as you stated with cooler temps more o2 is reaching the cylinders. Of course the by product of compression is heat however, again as you said the intercooler will be more effective in lower ambient temps. The MCS is my second Eaton powered car and while the Cobra runs 14lbs of boost the characteristics are similar. Love the cool nights when it seems the engine wants to jump right out of the hood.

One of the greatest heat saving mods I did to my Cobra was have the S/C ported. The intercooler on the Cobra sits below the S/C in the intake valley. By porting the S/C it allowed more air to flow directly over the intercooler thereby producing lower IAT. The porting netted me a 20hp increase on the same 12psi pulley. I realize the configuration of the Mini's S/C and intercooler are different but, has anyone ported their S/C. It maybe that the JCW "updated" S/C is ported I just have found any info on exactly what updated means.

 

My brother took his Modified Subaru on a Rolling Road back in February when it was cold ( UK) daytime temp was hovering around zero..anyway he got 401bhp..this weekend he had it RR again..temp was around 23 and he got 365 bhp..big difference!

 

Did you happen to kick off the A/C? The A/C has a big drain on the MINI's little engine.