How badly is power output affected by high temp and humidity?

Alext · 02-05-2011, 06:13 PM

As a percentage, what can you expect to lose from high ambient temps and high humidity eg during summer?

10%/20%?

2kaccordocoupe · 02-05-2011, 06:24 PM

I don't have a percentage for you however this past summer we hit +40 C with something like 90%+ humidity and the car felt like it had no power.

themyst · 02-05-2011, 06:32 PM

Quote:

Originally Posted by Alext

As a percentage, what can you expect to lose from high ambient temps and high humidity eg during summer?

10%/20%?

Honestly, I made 424 whp in 91 degree ambient at 18.5 psi on the dyno. I don't think I'd gain 10-20% over that number if it were any cooler outside.

JayKay335i · 02-05-2011, 06:35 PM

120 degree AZ days. I'm heatsoaked before I pull out of the parking lot. I'd say a good 10% reduction on 91 octane.

Alext · 02-05-2011, 07:41 PM

I been driving around in 90% humidity 100 degree weather recently and it feels like I have lost a bit. But the BMW is a lot better in dealing with the hot weather than my previous turbocharged car which was a Miata. In the cold it would really fly, but once the weather turned hot it would be a dog - really affected.

hipnotic · 02-05-2011, 08:06 PM

shouldn't make that much of a difference

chancejat · 02-05-2011, 08:08 PM

if your stock....it really wont change at all. the car adapts for the heat.

BobS · 02-05-2011, 08:38 PM

My dyno run in my signature was in a 95 degree/ high humidity day. The car definitely doesn't run as strong but it isn't that bad. Get a FMIC, it should help.

Alext · 02-05-2011, 09:00 PM

Yeah an intercooler upgrade is a good idea. The effects of heatsoak on a hot day are multiplied vs a cold day. ECU would be pulling timing like anything.

02-05-2011, 06:13 PM	#1
Alext Banned 155 Rep 2,042 Posts Drives: B M W Join Date: Apr 2008 Location: Everest iTrader: (2)	How badly is power output affected by high temp and humidity? As a percentage, what can you expect to lose from high ambient temps and high humidity eg during summer? 10%/20%?
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02-05-2011, 06:24 PM	#2
2kaccordocoupe Brigadier General 1287 Rep 4,703 Posts Drives: Former ///M Driver Join Date: Nov 2008 Location: The 6ix iTrader: (2)	I don't have a percentage for you however this past summer we hit +40 C with something like 90%+ humidity and the car felt like it had no power.
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02-05-2011, 06:35 PM	#4
JayKay335i Banned 198 Rep 5,046 Posts Drives: ///M323 DCT Join Date: Apr 2009 Location: North Dakota; its best DUHHHHHH iTrader: (1)	120 degree AZ days. I'm heatsoaked before I pull out of the parking lot. I'd say a good 10% reduction on 91 octane.
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02-05-2011, 07:41 PM	#5
Alext Banned 155 Rep 2,042 Posts Drives: B M W Join Date: Apr 2008 Location: Everest iTrader: (2)	I been driving around in 90% humidity 100 degree weather recently and it feels like I have lost a bit. But the BMW is a lot better in dealing with the hot weather than my previous turbocharged car which was a Miata. In the cold it would really fly, but once the weather turned hot it would be a dog - really affected.
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02-05-2011, 08:06 PM	#6
hipnotic Major General 153 Rep 6,603 Posts Drives: e92 335i Join Date: Oct 2007 Location: So. Cal iTrader: (7) Garage List 2008 335i coupe [7.00]	shouldn't make that much of a difference
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02-05-2011, 08:08 PM	#7
chancejat First Lieutenant 18 Rep 310 Posts Drives: bmw Join Date: Mar 2010 Location: usa iTrader: (2)	if your stock....it really wont change at all. the car adapts for the heat.
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02-05-2011, 08:38 PM	#8
BobS Colonel 98 Rep 2,002 Posts Drives: M3 Join Date: Feb 2009 Location: Southern NJ iTrader: (0)	My dyno run in my signature was in a 95 degree/ high humidity day. The car definitely doesn't run as strong but it isn't that bad. Get a FMIC, it should help. __________________ ESS 650 ACM-R Upgrades
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02-05-2011, 09:00 PM	#9
Alext Banned 155 Rep 2,042 Posts Drives: B M W Join Date: Apr 2008 Location: Everest iTrader: (2)	Yeah an intercooler upgrade is a good idea. The effects of heatsoak on a hot day are multiplied vs a cold day. ECU would be pulling timing like anything.
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