my car is loud and snappy at high rpms with the gutted cat. anyone have this problem? what did you do?

i was thinking about getting a carsound cat. im wondering if it will make a big difference.

should i get a 2.25 cat to match up with my dc header since it has a 2.25 collector pipe? or should i go with a 2.5 to match the 2.5 exhaust? im debating on this.

 

2.5 seems awful big if your car is normally aspirated. I'd go with the 2.25.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TheMirror &raquo;</TD></TR><TR><TD CLASS="quote">2.5 seems awful big if your car is normally aspirated. I'd go with the 2.25.
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considering it was the exhaust i used when i had my turbo kit on, why would i need to buy another exhaust? the 2.5 will do fine.

 

bump

 

Because turbo'd cars need a slightly bigger exhaust then normallt aspirated to relieve backpressure...backpressure is good to a degree in normally aspirated cars, i'd scale down and get a 2.25 exhaust or 60 mm

 

Don't believe the hype, backpressure is never good.

It is fine to leave your exhaust 2.5, I would get a 2.5 carsound cat as well if you are going to make the change - might as well reduce your bottleneck a bit more.

I would try to get a 2.5 collector header one of these days also (JDM DC 4-1, or something like it), it is cheap and should make a difference with your setup.

Most people with Turbo setups run 3" piping, so I wouldn't worry about not having enough hp to fully use your 2.5" piping, you are fine with the exhaust you have.

 

Are you sure your DC header is a 2.25 collector. I only thought they had 2in or 2.5 inch.

A gutted cat is never good. Either a test pipe or a 2.5 highflow cat would be ideal. Either take the stepped design or 2.5 all the way back. You can go from smaller to bigger but not the other way around.

 

you think the cat will help get rid of the high pitched snappiness at high rpms? ill probably go with a 2.5 carsound.

 

It should get rid of a lot of ugly noises, a gutted cat will make your car sound like ****. So will a test pipe in many cases. The next culprit could be your muffler though. What brand of piping and muffler are you running?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by affiliated &raquo;</TD></TR><TR><TD CLASS="quote">you think the cat will help get rid of the high pitched snappiness at high rpms? ill probably go with a 2.5 carsound.</TD></TR></TABLE>
yes id put money on it, a hi flo cat would get rid of the raspyness, my car is raspy with its test pipe but sounds fine with a cat on.

 

cool. thats good to know.

i have a tanabe racing medallion with 2.5 custom piping