Red Devil

Does anyone have round port Kooks headers instead of the specific D port installed on their ZR1/Z06? Any fitment or performance issues?

chubbs6350

I think that'll be counterproductive, it'll make the airflow more restricted But that's just my opinion Here's a pic of my stock manifold next to my kooks 2"

Red Devil

Thanks! I did speak with Kooks and they did say it would be fine but wanted to see if I could get some real world experience from someone on here that has actually done it.

MTPZ06

Whats the concern here? ARH 2" LT's are round port if I'm not mistaken. Shouldn't be a problem at all...

chubbs6350

Ya I think arh is round actually, I just figured it'd cause turbulence if it wasn't lined up the same but I guess not cause arh is the best system you can buy for our cars

v8sten

as long as there is no interference in the flow (a step up is not an interference) there is no power loss. I had 2" round pourt kooks on my car and my tuner was amazed that I picked up 45 rwhp by installing those headers.