I'm wanting to get a header for my car and wanted to know the difference between a 4-2-1 and a 4-1. I see the difference but what does it do performance wise. Would I be able to tell a difference with one? Thought about a DC Sports. I have an 02' Civic EX 1.7 L.

 

4-2-1 will give you a better kick sooner. but lose HP at top end speed. good for street racing

4-1 will give you more hp at top end speed, close to redline. it's used for drags or any type of straight a ways

If u like to rev your car while switching to every gear go with the 4-1

 

never heard the loss on the 4-2-1...i'll have to look that up.

but please...do a search before asking anything. nowadays only three questions are ever asked:

1. 'whats the difference between 4-1 and 4-2-1'
2. 'what is better, turbo or supercharger'
3. 'CAI or SRI'

 

the difference really is minimal. i have back to back dynos on them, and its really dang close.