UNBROKEN

iTrader: (1)

chimmike

Well, the cutout will be after the cats...so i'd expect a lot more volume. Performance gain? I don't know. I used a qtec many years ago and it was great, but slow....maybe they're a little faster now.

OCMike

iTrader: (1)

Do I understand correctly with a blower when you reduce back pressure you also reduced boost. So you can offset that by running a smaller pulley.

Is this a true?

Mike

LTNBOLT

That would be correct.

w00t692

Boost may go down but you won't lose horsepower. Boost is just the amount the air is being compressed before the motor can ingest it. If you're supercharged and you do some mods for airflow and boost goes down, you've GAINED power generally.

chimmike

I'm not sure you reduce backpressure all that much using cutouts after the cats. I would imagine the mufflers are a pretty good flow-thru design, unless you're using (IMO) crap baffled (flowmaster type) mufflers.

Scott91370

Why put them/it after the cats? I had one on my Eclipse and it was before the cat. Literally my exhaust was 17" long. They're not huge gains but it was 18hp/tq at the wheels. Bang for the buck it's not a bad price.

I'm looking for a set of pipes to install on my truck so I can experiment with cut outs before the cats. I want to have an extra set just in case things don't go right.

UNBROKEN

iTrader: (1)

chimmike

Last thing you want to do is put a cutout between the cats. Like unbroken said. Now, on my 3.5EB I've seen the cats immediately following the turbo...there's no way a cutout would go between the turbos and those cats anyway

Scott91370

Edited: Maybe I don't understand what you mean by flow over O2s

Isn't the cat about a foot away from the turbo? At least on the 15-17? Plenty of room.