funglenn

iTrader: (10)

I must say I just moved from Colorado Springs (my old house is at 7000 ft) to San Antonio, Texas (700 ft) and the difference in the performance of my car is night and day!

I am now actually happy with the 250's response/acceleration. Def getting a new exhaust still, but now will stop lamenting that this car is slow--i feel like it gained 30 horses!

Just had to share--I am soooo Happy!

Kurtz

iTrader: (1)

More than 30... a car at 7000 ft in say 65 degree weather, 29.92 humidity, and a dewpoint of 40 the engine is only producing about 76% of rated horsepower.

Same weather at 700 feet is about dead on at 100%

IS250 is rated at 204 hp.... * 0.76=155.04 engine hp.

fraga

Awesome...but why on gods green earth would you move from Colorado Springs to San Antonio...were you forced at gunpoint...

Bichon

I'd be curious to see how Kurtz arrived at that number. I'm not doubting him, but his figure doesn't jibe with the estimate of 3% power loss for every 1,000 feet that I've always heard.

If I lived at that altitude, I'd definitely be driving a car with a turbocharged engine. Turbocharging largely compensates for the change in air density.

Kurtz

iTrader: (1)

http://wahiduddin.net/calc/calc_hp_dp.htm

iRyan

iTrader: (7)

Oo man enjoy it now bec in a month or two ur gonna say damn this car is slow...lol...it happens

MpKSonic

I also live in Colorado Springs and the altitude definitely sucks in terms of automobile performance, especially on 'hot' summer days. Of course our hot summer days must feel like the South Pole to a hot summer day in San Antonio. lol. Forced induction is a big advantage up here. My 350 runs even, if not slightly faster, with my friends stock 2009 WRX for reference.

funglenn

iTrader: (10)

Yes, my wife's turbo charged volvo never missed a beat!

iRock

iTrader: (12)

Oh quite a change in climate. Congratz on the performance improvement.

MpKSonic

My previous car was a 1.8T Jetta, so I know both ends of the spectrum.

Toymota

I don't know what you mean by "29.92 humidity", but I assume you mean the atmospheric pressure. 29.92 inHg is the standard pressure at sea level. You lose about 1 inHg for every 1000 ft so at 7000 ft, you will only get about 23 inHg. That's 76% not taking into account the temp or humidity. So yeah, that's a lot less air going into a normally aspirated engine even at full throttle and a lot less power.

Initial G

iTrader: (38)

Congrats on the improvement without spending any real $$$. You might feel a little difference with an aftermarket exhaust, but not much. You'll just notice/hear a sound improvement. What exhaust are you looking to purchase?

Kurtz

iTrader: (1)

Ack, yeah, typo, 29.92 pressure... but the 76% does take into account temp and humidity, hence why the calculator asks about the dewpoint and the temp.

http://forecast.weather.gov/MapClick...d2=-104.76&e=0


And FWIW, the pressure right now in Colo Springs is 30.03...

Toymota

Careful. That barometric pressure is already adjusted to sea level. But I took a look at the calculator you posted, and it asks for Altimeter setting, so using the sea-level adjusted barometric pressure there would be correct.

Masciaman

lol this whole conversation made me laugh