Exhaust and a/f mixture question

[Maelfyn]

Okay, the new HS header is installed. Will this affect my a/f ratio? It's only exhaust so logically I can't figure how this will affect my a/f mixture since my header is after combustion.

Wondering if I have to reconfigure my s-afc. Also while I'm posting, will a pulley affect it either? Seems like a stupid question and I'm guessing no :)

[Slant]

top. i wanna know too.

[Unity112]

Yes your a/f mixture will be affected. During valve overlap, there is a stage where your head basically becomes a vacuum. The more effective the header, the better your car will be able to scavenge the exhaust gasses out of the cylinder, and draw in more fresh air. Depending on header design, your a/f mixture will either be greatly affected, or won't be too affected.

[autxr]

Yup, what Unity 112 said. Header and exhaust can make a big difference in how the engine breaths. The pulley shouldn't make a significant difference.

Scott