4-1 Vs 4-2-1

[rollinfatbudz420]

ok ive never actually seen a dyno prove that 4-2-1's make less power on top than a 4-1 design but ive heard that the 4-1 will have an advantage up high. Do u prefer the 4 into 1 design or the tri y design? I know u import guys dont really care about torque, but its torque that turns the wheels. Does scavenging ever come into play on a motor that is so small? i see the 4-2-1 design as being superior. anyone disagree?

 

[Domeskilla]

Its got nothing to do with torque. Its got to do with powerband.

4-2-1 = low/mid

4-1 = mid/high

Since a Honda makes 90% of its power in vtec, then I'd suggest a 4-1 b/c it flows more for the power range of a Honda. Now if you had an LS, where it doesn't rev past 6500 or so, then a 4-2-1 would be your best bet as far as performance wise.

 

[rsaeini]

hey dumbass, before you post a thread saying that you've never seen a dyno graph to prove a 4-1 makes more power than a 4-2-1, you should go out and do some research first.

...that's the reason you're on the list...

DYNO GRAPH

 

[saturn_boy96]

tocreate torque you have to keep your exhaust velocity up. and the easiest way to do that is to go to smaller piping, thats why the tri y works for torque. but up on top it kills(not a lot ) some horsepower.

with horsepower you want as much air flow as possible, thats why the longer pipes of the 4-1 design allow a higher horsepower figure at peak.

with a header you also need to look at collector size, because a small collector will keep your exhaust velocity up, but it could become too restritive for your engine when its at high engine speed (over about 6500 rpm).

either way were talking about maybe a 3-4 hp difference (at most 10) at 8000 rpm, but were also talking about a 5-7 ft/lb difference at 4000 rpm.

so thats why i say go with the 4-2-1. get the power and get it longer.

unless you've got a supercharger or nitrous, then just go with a 4-1 with the biggest collector you can find.