eanda9000

I traded my summer automatic C5 for an S4 8 months ago. Wanted a car that could be driven all year around. The funny thing is that in Denver I think that the S4 feels faster then the C5. It has 100 less horse power. I am guessing that it has to do with the fact that turbos work better at altitude. The workmanship, materials, and radio were all really subpar. Like some sort of cheap toy. The C5 did not ensire confidence in hard cornering, it had a tendency to skip. It did have grip. S4 feels way heavier in the corners. I drove to Calif. and the C5 was like a differnt car almost, it had so much more power.

I am thinking that turbos are a must for speed in Denver. Any thoughts.

Dean
Totally Stock Silver
Thule Bike Rack

Ted K

think makes it feel faster. Turbos at altitude also have a HUGE impact.

eanda9000

Any idea how huge huge is? If NA then do you take a 30% power hit as opposed to a 15% hit if turbo?

ChrisH

no power at all until a really significant altitude. The turbos don't care what the external air preassure is (within limits) and just cram air molecules in until the over boost control kicks in. With a normally aspirated motor you loose power because you have less air mass (fill the cylinder minus any vacum losses) and also less fuel thanks to modern fuel managment systems so you cannot help but lose power.

Ted K

since cars run on air (gas is just the catalyst that starts the combustion - most people don't know that for every gallon of gas, you burn like 80 gallons of air) if the air is 15% less dense, you should lose 15% of your horsepower. But that's just my guess, not very scientific.