Hi all, got my Pacemakers on today, a lot more power about 2500rpm.
Just wondering if I need to take it back because when I boot it I get a hissing noise coming from the headers..

Is this normal?

Headers tend to be noisier than the stock system, because the tube walls are thinner. It could be a gas leak though, needs investigating.

I get that sound as well, although not with pacies but with Advance Headers. Yea im guessing its due to decreased thickness of tube walls.

i think you should be fine, keep an eye on it or if concern, take it back to the exhaust shop and ask them to have a closer look.

however, i did notice my exhaust being slightly louder after installing a set of pacemakers

The hissing seems to be decreasing now, so either I'm getting used to it or it's a bedding in thing.
Man, I really didn't think extractors would make that much difference! but I guess when you've already got a K&N filter and straight through exhaust it helps :)
For the first time I'm actually getting pushed back in the seat :) :)

Heres a tough one - spray some soapy solution around the hissing sounds and see if you have a leak. Or ignorance is bliss - like my leaking inlet manifold.

Heres a tough one - spray some soapy solution around the hissing sounds and see if you have a leak. Or ignorance is bliss - like my leaking inlet manifold. to add on this.. the exhaust should bubble up the soapy water, the stufff you wash your dishes with is fine... put it in a cup and paint it on with a paint brush

. . . . while its cold, then fire it up and look for bubbles. Also, check the torque on the manifold nuts. The flange mounts and gaskets may need some heat/cold cycles to settle in. Don't overtighten them, I think its 25 nM, it isn't much, the studs are in the alloy of the head.