what would be the average gain with replacing stock parts with new high flow cat, cat-back system, and new headers?

plus on a side question, how easy is it to do "bolt-on" parts? given i have never touched serious tools im my life

 

The full exhaust including the cat may be around 20 hp. Some bolt on's are easier then others as far as doing the exhaust it would be easier to have a lift of something but just remember _lefty loosey-righty tighty_

 

its not bad some exhaust bolts might be hard to get off and might be seized. Just take you time and if you have problems post on here and we will try to help.

DEF

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DXDOHCVTEC &raquo;</TD></TR><TR><TD CLASS="quote">The full exhaust including the cat may be around 20 hp. </TD></TR></TABLE>

More like 6-10hp on a good day...If a naturally aspirated car makes 20hp from an exhaust swap, they must have had a bannana in their tailpipe.
Not even the manufacturers make such wild claims...

"brand x makes up to 12 hp". But then actual dyno testing shows only a 7 hp increase.

 

yea. 20hp i skinda pushing it. Maybe 10 with some good stuff!

 

Oh my bad...Yeah I was talking about if there were a banna in the tailpipe. You will have to take that out then you will feel the hp increase : /

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DXDOHCVTEC &raquo;</TD></TR><TR><TD CLASS="quote">The full exhaust including the cat may be around 20 hp. </TD></TR></TABLE>

Are you talking about a Supra or WRX? Even then you are pushing it.

i/h/e will give you 6-12, based on your application.

 

best way is to replace any maintenece parts first
plugs, wires, h20 pump, etc