Hi

Im new here on the forum
And also kinda new of all that car tuning stuff.

I have a question though.
The collectors on the hytech header long tube are 2.5" but is that the Inner diameter? Or is 2.5" the outer diameter of the pipe?

I was told that its not good to have a bottle neck in the exhaust system. Why not?

My skunk2 megapower is closer to 2.25" inner dia. And 2.36" outer.
So I was wondering if I should get it exchanged with the skunk2 megapower R wich has 70mm piping/2.75" outer. That will be very close to 2.5" Inner diameter.

Sorry for my english it might not be the best, Im from Denmark I hope you understand my question.

Best regards Rasmus

 

2.5" OD

 

Kronn: Thanks alot

What about that bottle neck from header 2.5" - 2.36" Is it really bad? Or are we talking about maybe 1-2hp difference

 

It's bad. Don't do it.