I'll be building a d16z6 this winter. D16A1 pistons, ef-1 cam and retainers, mild headwork, custom intake manifold, and hopefully hondata. I was looking into headers, and I see the bisi and an-r as the only decent options. I noticed that the an-r has a 2.25" collector. Is this the norm for a "hardcore" d-series header? I would think that even on a 150whp d series, that 2.5" would be beneficial.

 

You cant run A/C with the bisimoto header

2.25"is just fine for an all motor d series

 

i would go with an-r you can get a 2 1/2 if you need it

 

the powercore header is also 2.25"