its 2.5

 

wait so looking at this zzp pipe its a maf AND map relocate...is this also necessary?

i only relocated my maf not the map

 

No, as long as the MAP is still somewhere in between the IC and throttle body on the lower CP it's ok. The pressure will read the same anywhere in the pipe within reason.

 

Smaller diameter increases air speed resulting in a higher MAF frequency & skewing the fuel trims. Could be an issue if it exceeds 12k MAF freq or so. I never found the cutoff point exactly, but I know when a certain freq is reached I've had the throttle close on me. Mine was from a wet MAF from condensation in the IC blowing through.

Get a different larger diameter lower pipe & sell that sucker. I really like the ZZP one for the lower. Ask Vince what kind of freq you logged with the Hahn.

 

when i get my car back from the audio place im gonna measure it to be sure