?backpressure?

C

clubredsilvia

Member
- Alright. I'm NA-KA right now and i have an apexi n1 "style" 3" catback, and a testpipe. Now i'm going to buy a nice 4-2-1 header. Will there be a significant loss in power from the lack of back pressure? Should i run a CAT again? Is there anything that a lack of back pressure can hurt (like exhaust valves/anything)? I've talked to a lot of people about this subject and some people said KA's don't need significant back-pressure, and that only honda's do. Then some people said that i will lose top end power. I'm confused.
 
no when you open up the exhaust path like that you are going to lose low end power and gain top end power
 
Minimal back pressure with optimal velocity is how to make power with the exhaust. Most of the changes in your powerband will occur from the header design in na application. As long as the cat-back is free flowing with minimal bends, you shouldn't lose torque b/c of size. I'm willing to bet an increase in power across the board with a 3" cat-back.
 
Back pressure is never EVER desired. The after market exhaust header can loose bottom end power because the exhaust pulses are not timed to work with in that rpm range, poor cylinder scavenging. The altered dimensions of the aftermarket header will yield better cylinder scavenging in the upper rpms to make more horsepower. Do not run a catalytic converter if you are searching for horsepower. A well designed header will provide a more productive power band then what the factory has installed for city driving. The change in power band will depend on the header dimensions. For your instance, buy a header and try it. If you would like to try a different header to find a different power range then search for one with different dimensions. Some headers will provide more low end torque while retaining the same top end, others will specialize in upper rpm power and there will be a loss down low. Test and tune.
 
You must log in or register to reply here.
Back
Top Bottom