I have just had my 2004 Sunfire fitted with a ceramic coated Pacesetter header, Magnaflow cat/muffler, thrush glasspack, and 2.25" tubing.

However, and perhaps those of you with this same header know of this, the Pacesetter header suddenly goes from 2.25" to 1.75" at the end of the downpipe (or whatever it's called), so my exhaust guy had to fashion a little section that goes from 1.75" back to 2.25". In effect, there is a small section of my exhaust.. about 2-3 inches or so.. that is 1.75", and the rest is 2.25". Is there a reason why the Pacesetter header has this sudden narrowing to 1.75"? And does this in any way affect performance? If so, is it desireable to cut out this small 1.75" section and fit a 2.25" pipe into it, so as to keep the entire system at a continuous 2.25"?

Thanks in advance,

Matt

I would have your exhaust guy remove the 1.75 section it is a restriction to the flow.


"Racing is life Everything else is just waiting"
Phil

That's what I was thinking. I'd like to hear from someone here who has the Pacesetter header installed, I know there are a bunch of members here who have it. It just seems like such a silly thing for pacesetter to do without having a good reason...

Thats what you have to do, get your exhaust guy/shop to cut just before the point where the piping shrinks to 1.75" and then basically put either a stainless steel piece of tubing between the downpipe and catalytic converter or maybe a resonator, not too sure bout the resonator since I dont use 'em.

Alright, I'll get that done then. I'm curious, however; is the performance hit from this 1.75" section of pipe noticable at all on a dyno sheet?

If your exhaust system is 2.25" and you have a small 1.75" piece then the exhaust flow will only be as good as the 1.75" section allows. Basically, if you want good flow and slightly better numbers then go with a complete 2.25" system. Make sure the exhaust shop uses stainless steel if they have to add any piping onto the system. Just my suggestion tho.

Matthew Housser wrote:Alright, I'll get that done then. I'm curious, however; is the performance hit from this 1.75" section of pipe noticable at all on a dyno sheet?

it probably wouldn't show up on a dyno, but it's more along the lines of having the satisfaction of knowing your exhaust is flowing at it's maximum instead of feeling like it's restricted.

Yeah, it's kind of bothering me just knowing that the 1.75" piece is there, when I went through all the trouble and money of having a 2.25" system made for me. I'll have it cut out tomorrow. Thanks for the advice.