Turbos at Altitude

["Kaklikian, Gary" <Gary.Kaklikian@Compaq.com>]

At risk of reiterating the obvious, I finally had the chance to drive an
Audi turbo - the same Audi turbo that I normally drive at 5000+ ft plus - at
sea level. And yes, altitude does make a difference, not so much in top-end
power, but in low- and mid-range torque. 

I recently drove to the QClub event at Road America , and can confirm that
there is a substantial improvement in throttle response and torque at sea
level vs high altitude. Also, detected occasional pinging under load at
lower rpm's at sea level which I never noticed here at high altitude (even
with 93 octane vs the 91 we get here); used octane booster at the track just
to be on the safe side. Also, the car - 4000TQ - idled about 400 rpm higher
at sea level, even after repeated fiddling with the CIS frequency cycle.

Wally - this probably explains why you thought the chipped S4 you drove here
in Colorado was slower (at least at legal speeds) than your stock S4.

As to the event at Road America, well, all I can say now is -- the traction
of these cars in the rain (with the center diff locked) is Incredible !  I
have never before had the opportunity to drive so fast in the rain, yet feel
so safe and never reach the car's limits.

Gary Kaklikian
86 4kcstq
86 5kcstq