IS F at altitude
 

Hey all, looking into getting into an IS F but I have concerns about the N/A engine at Denver altitude or greater (10,000 ft). I was hoping to get some owners who drive them at altitude to give me their opinions. I'm concerned about it feeling sluggish especially going up to the mountains.

I had a friend who sold his E92 M3 because he felt like it was too slow at our altitude. I also heard of people complaining about their RS4 (maybe altitude and carbon buildup) I currently have a mildly modified STi which is a little less susceptible to altitude due to the turbo and I don't want to downgrade in performance.
IS Fs are pretty rare so a test drive is also rare plus it's difficult to gauge on a 20 min drive.

Thanks

The NA engine does struggle a bit at altitude vs boost but with full bolt ons it still puts the smack down on majority of the evos/sti/bwm/mustangs around town.

I was looking to keep it stock.
Is it pretty disappointing then?

Yes, if your going to keep it stock it will struggle and wheeze a little like an asthmatic going up to the mountains. It's such a different beast when it's FBO and it compensates some for altitude but still loses about 82 hp @ the crank compared to sea level.

It's not as bad in town @ 5,280 +/- but when you head up into the mountains it will start to lose power especially if you want to keep it stock.

I'd say forced induction or a Tesla for altitude especially for a lot of mountain driving....... my 2 cents

Thanks professor. I'm aware that the the partial pressure of oxygen is lower therefore less power can be made through combustion.

My point was how it feels. You could have a 600 hp car at sea level and have it make 500 hp here and it's still freaking fast.

OP ^^^^^^^^^^^^^^I sent you a PM if you had any further questions other than what has been said on this thread feel free to contact me

how it feels is going to be completely subjective, so yes, you should try to drive one.

Mine isn't sluggish around town. It's a V8 this is one of the best for NA setup around here, that's why I went this route. Then again, I have'nt driven mine up the mountain yet. I just got it. I drove a 4x4 four cylinders up the mountain before this so I'm sure I won't be disappointed with this.

I'm in vegas which isn't as high as Denver, but, we are a lot higher than Cali. But the car still feels good, it just feels better at lower altitude.

I don't know if someone higher than us can chime in and help, but its a V8 so its not going to get "slow"

Fixed. That's exactly how it's gonna feel, after plugging in your 10k ASL reference to an air density calculator. If you want elevation performance, stick to FI.

Btw, '14 CTS V-Sports are becoming quite affordable - there was even a Jalopnik blurb to that effect recently. With tune they'll make ~430whp and won't be nearly as impacted by the thinner air. It's no Lexus, but not a terrible option since RWD seems to be an acceptable platform to you.

To make it easier, just go test drive another V8 with similar power, 10-15 Camaro SS/11-17 Mustang GT. They are fairly similar in weight and power and you'll be able to tell if it's weezy or not at that altititue. I'd venture to say if a 420hp ISF is brought down to IS350 levels at 300HP or so, that's still plenty quick and you'll have the V8 sound and great 8 speed to boot. ATS-V or S4 or 340i or something similar would be my choice if you want to stick to FI.

My bone stock ISF did not like elevation at 6000ft in New Mexico and Arizona during my roadtrip to and from California/ Kansas. I'm really used to the power at Sacramento and Wichita, elevation is pretty low compared to the mountains.

I guess the full bolt on guys have said differently, which I wish I got to experience. Go for the RR Racing Supercharger! :D