Why do cars lose low end torque with open exhaust systems?

[crazypete]

Interesting. Could this problem be "fixed" with a cam or some 1.7 roller rockers? I dont particularly want to change the power band cause spinning things up to even 5000 rpms invites breakage, especially with a 130,000 mile motor. I'm gonna put in some 4.56 gears and even then, it's 3000 rpms at 80 mph. If I make the valves open more, would that gain back some of the exhaust scavenging. I'll look up exhaust scavenging tonight.

I'm still running in and out of the house. I'm doing "spring cleaning", which consists of spraying the entire underside of the car with 1500 degree ceramic engine paint. Most of it falls off by the next year so spring is when I freshen it up. Once done, I blast the entire underside with tire silicone cause it makes a nice sludge that really protects against rust and makes the car smell like a showroom =) . I have this feeling that I get mad respect whenever I take her to a shop just because the underside is even cleaner than the topside.