2low4snow

How Much affect does Altitude have on how much boost your car runs with a chip???

Blue2

I'm at 7500' and I still notice a big difference between stock

Swank4

I go from sea level (San Francisco) to Lake Tahoe fo skiing (~6,500 ft) my boost gauge shows a few things:
1. At idle, the vaccuum is about -15 in Tahoe versus -20 at sea level.
2. Boost kicks in at much lower throttle inputs - probably to compensate of lack of air.
3. Max boost is a few lbs greater. In fact, even with my stock chip, I max at about 8-9psi at sea level but got it to spike to 11psi and hold 10psi when in Tahoe! Temps were all between 40-55 degrees.

I'm assuming the computer is asking for more boost from the turbos to compensate for lack of oxygen.

sym//S4

It takes a little more RPM, perhaps 300-500RPM before full boost is made compared to sea level. Then the little K03's run out of air more quickly at altitude(6,000ft where I'm at) compared to sea level. There just isn't as much oxygen up here and the turbos begin to operate outside there efficiency range. That being said I see 15-17PSI tapering down to 10-11psi in the high RPM(5600+). Similar to what people see at sea level.
Chipped cars still run well at altitude but the top end is not as strong.

Killer Bee

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sym//S4

Colorado or NoCal?

Killer Bee

your picture just struck me as "familiar" looking.