I just went full BPU yesterday (18 PSI). I changed the plugs to NGK 3330 & the car hesitates or flat spot between 3500-3800 RPM. It is kinda it loses power @3500 but suddenly it's back to normal @3800. My car has 44,000 miles and it is the first time boosting it. This happens most noticeably in 1st gear. I do feel some hesitation on the car when I try to a maintain certain speed. One strange thing is that the car's exhaust is quieter (don't know why) and the BOV can really be heard now.

I am new to this so every advise will be much appreciated.

Thanks ahead,

Raul

did you use the free fcc mod or a bcc or fcd?
If you did the free mod you will have a pressure drop right before 4k rpm because the 2nd turbo doesnt get prespooled (and you will greatly reduce the life of that turbo~try the ttc mod)
also you might want to do the 12v fuel mod to prevent detonation around that same spot in the rpms. (go to www.mkiv.com for intsructions)

Interesting! I have a similar issue somewhere b/w 3K & 4K rpm in 1st. My '97 TT has some BPU's... downpipe, TRD exhaust, HKS EZ BC, APEX S'AFC (untuned & zeroed at both lo & hi rpm), but NO BCC (yet). I plan to have a Greddy BCC installed within the next couple weeks & i'll let you know if this problem goes away. BTW, when it flattens / loses power i also get a very distinct 'drone' from the exhaust system. It's entirely unclear to me whether its running rich, lean, or ok(?). Well it's not OK, but i have no idea right now what to do to resolve it.

- Rob

no nockin = not lean. you smell alot of fuel in the air its rich. the BCC will fix the problem