man my fc (s5) is losing power in first gear at about 6500 rpm, all i have done to my car is gutted the cat., added intake, and took out the secondary butterflies but i havent removed the shaft yet. could it be that the shaft is causing turbulance?? i dunno, please help!! https://www.nopistons.com/forums/pub...IR#>/dunno.gif



keegun

there is not enough back pressure to open up the secondaries, is you're air pump working correctly?

It's the exact dame thing for me. I have a header and a presilencer (no cats), and a cat-back, also an intake. Your problem is exactly the same as mine. You don't need backpressure to open the 6 ports on an s5 (I have one too), the air pump does it. Check you solenoid valve, make sure it works and turns on at the right rpm (about 3500). Should be the one with the brown sticker.

I think I have a vacuum leak, I'm going to have it checked out soon.

yea its probably your 5&6 ports, although most dont support this, but you can wire them open,

youll lose a bit of low end(under4k) but youll get your high end back. .02

vacuum leak would be at lower rpms

it is weird, i tested it 3 times today and 2 out of the 3 it did it, but 1 time it didnt, im not sure what to do....

aux ports.

well what can i do to fix it? https://www.nopistons.com/forums/pub...IR#>/dunno.gif

if it is in fact the 5 and 6 ports, then wire them open, if yours is s5, on the s4 you have to use a strong tie wraps, to keep them open