Tmclaurin

Ok I've read through countless articles on here about this and the entire x-pipe dual exhaust benefits etc. My state does not have emissons or anything like that so I'm not worried about that. I have a 91 ls400. I just want to run dual pipes from the cat back splitting from a Y. I read about using different sizes for different setups but none about a true straight pipe back from the cat. I would want to take the cat out and run the pipes straight back but afraid that may hurt performance.

OneJay

iTrader: (14)

I cut the exhaust after the stock Y-pipe and ran a 2.5" Vibrant resonator, and split to dual 2.25" pipes. I think most people that go true dual do 2.25" with an X or H pipe.

Tmclaurin

Was there any loss or gain in power? I mostly hear about people losing some low end torque, but that may be because of a bigger exhaust piping size becuase you said the resonator you put in was a 2.5 aplitting to dual 2.25

OneJay

iTrader: (14)

I didn't notice any difference in power. At most, I'd guess you'd see a gain or loss of 3-5hp in either direction. Not really enough to notice.

dicer

The only thing it hurts is any resale value. To replace that exhaust with OEM is over $3000.

timmy0tool

iTrader: (7)

2.25" to an x-pipe then mufflers of your choice is the consensus around here. the cats are high flowing and leaving them on would not hurt performance so why spend the money removing them (unless you want unnecessary loudness). what's your goal with the car? even with a very thought-out designed catback, horsepower gain would be very minimal as with any exhaust modification.