I love it every year when fall gets here......just because my mini loves the colder temps. I know it's because of the cooler intake charge, but man....it sure is great while it lasts.

If I had to guess....I'd say that my car picks up 10-15+hp when the temps get down into the 40s...vs. 80-90 degree temps in the summer time. I wish there was a way to keep that power all year round.

I have a meth injection setup on my car......but to be honest, it doesn't feel like it gives any more power when it's on....and I know that's supposed to cool the intake charge quite a bit. It's not even comparable to sucking all of that 40 degree air through the IC.

Anyone else notice that big gain power when the air temps fall?

 

+1

Early morning driving is the best

 

Same here! My clutch has been on way out and wouldn't hold on Map B of my Manic tune so I've been driving Map A without issue. Lately its been about 40* in the morning by me and clutch slips in every gear. I can get through 3rd in the afternoon without issue. Temps have a large variance in power on turbo cars, hence why water/meth is very popular.

 

I was going to post that exact same thing......when my clutch started slipping last year, it was in the fall when the temps were in the 40's. It would slip in just about all gears. Later in the day when the temps go up into the high 60's, it was hard to make it slip at all.

 

Yes, my R58 JCW loves the cold weather on its intercooler.

 

I was hoping for a pretty healthy power boost after I installed my meth injection setup....something similar to the power my car picks up when it's cold outside......but nope, to be perfectly honest.....it didn't gain any power at all. I was pretty disappointed.

 

I cannot feel the difference temp makes, 10hp is gonna be hard to feel. But the gains are real

Data logs from this past weekend at carolina motorsports park, with and without meth, air temp was ~50 degrees

 

Well, it's simple physics. Cold air is denser, more molecules per cubic whatever hence the value of a CAI. Airplanes fly better and the worst part, golf ***** don't go as far.

 

I definitely feel the difference. Living in the hot, humid, swampy Hell of Florida, when the cooler weather comes, my MINI get perky, and noticeably so.

 

" golf ***** don't go as far. " I thought it was just my swing

 

I know that meth injection reduces your intake air temps.....but I can't feel mine when it's on. I can definitely tell when I'm driving my car in 40 degree temps vs. 80 degrees temps. HUGE difference in power.

 

this is exactly what meth does, have you data logged to make sure you are seeing temp drops? IAT is a standard obd2

 

from my logs.. most of the 'power' you are describing when its cold is from timing advance lower in the RPM range due to the IAT.. ECU pulls timing back down once boost comes on.

*when its hot out (+85f ambient) - timing advance is ~half of what ECU adds when its colder (below 60f ambient)

**ive logged up to +38.5 degree advance in ~58f weather before boost

 

I inject the meth after the intercooler right before it goes into the cylinder head. I don't think you would see that on the IAT sensor.....

I'm not saying that meth doesn't' drop intake air temps....I just don't think it's as dramatic as pulling cooler air through the intake...AND having cooler air rushing through the intercooler. And, like others have said.....that cooler air coming in through the air filter is going to get the "tune" to advance the timing to make more power......you won't have that timing advance if you are just injecting meth right before it goes into the cylinder head....the intake air temp sensor is still measuring the outside air/intake air temp.

I guess if you had a tune setup just for meth....that would make more of a power increase.

 

that's where I do too, and I definitely see it on the IAT sensor just look at the logs I posted, it's a huge drop in temp when I run meth

I do not tune for meth but I dont really see a need to as the ecu does it on it's own due to the lower temp

 

Where is the IAT sensor located? I thought it was in front of the IC.

 

I agree, you won't feel the difference. If you do, it's placebo effect.

 

From meth injection, or when the outside temp get down into the 40's? When the motor makes enough power to slip the clutch when it's 40 out....but not when it's 75 out......that's not a placebo affect.

 

i thought it was built into the MAF, if you look at my log with meth, water droplets are getting on it and causing spikes

can we log the timing? if we can via obd2 I'll add it so I can see what it's doing meth vs no meth.

 

tmap does both, it's on top of the intake manifold, after the throttle body & supercharger horn

 

2012 JCW
2nd cat/res delete
91oct
50f IAT



You can see timing @ ~0 as soon as boost tips in, with just a few degrees negative at ~15psi. Also - AFR's like to sit closer to 11.8-12.2 @ WOT when IAT is low like this Ive noticed. When I first saw this, I was running an E30 blend.. so I ran new logs on 91oct (as above) and saw roughly the same boost levels/MAF reading/timing/IAT. I think the ECU doesnt like to boost as much when the MAF reading is high from the colder IAT. Once IAT is ~80f .. i see boost up to ~19psi, but have NEVER been able to see this when IAT is 'cold'.

 

r53 does not have this problem, boost is fixed with rpm

 

Yeah, but theres other factors for horsepower besides boost pressure. Very rough summary is the colder the air the more dense the oxygen in it, more oxygen more power. So using random numbers here, 40* outside air at 10psi will make more power than 80* outside air at 10psi due to density of the oxygen.

Noticeable on the butt dyno for both supercharged and turbocharged vehicles in the winter.

 

Don't be too excited. In most of the "Union", the fuel station switched to winter blend. My Mini get a bit tipsy.

 

Winter blend is not making you more power lol. If anything it would be less, as the difference is the chemicals used during winter allow for a lower evap point, and they are cheaper.