AU XR8 headers
I've posted this in the DM section as well, but thought others who are not DMs might also have some relevant info/opinions etc.
I was talking to another car enthusiast yesterday about my XR8. He has a mate who owns an AU2 XR8, and instead of fitting aftermarket headers, he took a die grinder to the standard factory ones and cleaned up the ports. Apparently, the standard headers have a lot of welding on the inside of the header pipes (where they join the manifold which bolts to the head). Flattening out the weld "lumps" apparently increase air flow through the headers and is worth up to 5rwkw.
What I want to know is has anyone done this - if so, did you notice a difference.
Can anyone who is mechanically-minded tell me if this is worth doing - I would have thought that die grinding the welds would weaken the headers.
Thanks guys - I know this sounds like a bit of a stupid question, but if it works, it is free horsepower and I won't bother with extractors (can't afford them anyway).
AU1 XR8 Auto 147.9 rwkw (approx 215 fwkw)
AU2 Wagon HAD Auto
17s, Pacemakers, 3" Intake & Pod filter (The Family Hack)
FPV-XR Club ACT