Silk Road Extractors 16v -> 20v

[slipp]

I'm currently considering purchasing Silk Road type 2 (4-2-1) extractors for my 16v 4AGE.

Down the road I intend converting to a 20v (black top) 4AGE. I was just wondering whether I will have any problem with the header?

Thanks in advance for any help.

[drift kid]

Depends on their design, some companies use a "universal" 16v/20v header flange and some use model specific, do some research and find out, even if it is model specific they can be modified to fit as it is only the two most outer studs that are different

[Matt]

The 16v flange won't bolt straight up and it is difficult to extend... if anything buy a 20v one and notch the sides to make it fit, you can't do it the other way around.

[hayashi]

It looks like all the manifolds for 4age's made by SilkRoad come drilled and slotted to suit both 16v & 20v heads. So you should be fine when it comes time for your 20v conversion.

[slipp]

Awesome, thank you hayashi!

[LittleRedSpirit]

Sure you can, I did, I just had to face the flange.

[Sam-Q]

better make sure the inside diameter of these pipes is more than 34mm or else it's going to step down on a blacktop which wouldn't work too well.

With a common 1.6mm wall thickness this means you want an outside diameter of 37.2mm or more. In imperial a 1.5" pipe will work which is 38.1 by memory