SoarerGold

Wat is the ideal piping size from my headers back on an sc400 pm me with you input please. I have heard its 2 1/4-2.5 if so Wat is the best size for optimum flow

t70 supra

iTrader: (-4)

Optimum flow is 2.5" what exhaust were u getting

Kira X

iTrader: (24)

2.5 inches is pretty good. It's not too big and it's not too small. Personally, I'd go with 3.5 inch straight pipes on the 1UZ. Are you getting mufflers too?

Sohconthis

lol suggested 2.5 but you would go with 3.5? why?

I say 2.5

Kira X

iTrader: (24)

I have 2.5 inch, but I have an NA SC300. I've always heard anything over 2.5 inches would hurt your performance if you weren't boosted. I think 3.5 on a V8 would sound really nasty though.

Sohconthis

yeah if youre not worried about some low end loss it could sound menacing or just too loud depending on the driver

Kira X

iTrader: (24)

I would imagine it being annoying on the 1UZ. My friend has straight pipes in his LS400 and it's loud inside the car, and that's with stock size piping. 2.5 would be good enough as it wouldn't be too annoying if you have some sort of muffler.

Sohconthis

yep. i think best setup on a 1uz is 2.5 from headers -->xpipe-->muffler of choice

ashtray

iTrader: (12)

Since he said PM him with input...does that mean he wont be checking in on this?

TheRonTom3

iTrader: (5)

I wonder what the optimum single exit exhaust size is on the 1uz 3"?

ShibbySC4

Why would you want to do a single exit on a 1uz, that seems odd to me. Curious enough to how it sounds. Now, will running straight pipes throw any codes or cause any problems? A check engine light? My friend's got an ls400 with really bad cats and the muffler shop told him not to run straight pipes cause the v8 lexus cars were "acting weird" afterwards.

TheRonTom3

iTrader: (5)

sounds just like a v8 no different. single exit exhaust saves a bunch of weight and to my it looks better

Durrby

iTrader: (3)

On my '99 I have the IMF headers and 2.25" piping from there back with an x-pipe in the middle, no cats/resonators with the 5zigen fireball mega mufflers. It sounds great on start up and idle but is loud as hell just driving around. This setup caused me to have 2 codes because of the cats not being there. One is "catalyst efficiency below threshold" and the other is for an o2 sensor.

Kira X

iTrader: (24)

That's what I've always heard. My friend was told the same thing about his cats on his LS400. I've seen people get rid of their cats, but I don't know if it throws any codes out.

It does save a lot of weight. My dual exhaust was way heavier than my new single exit. Single exit looks better if you have the hole in the bumper filled. I hope to get mine done soon.

I bet that sounds pretty sick. Does your car run any differently with the cats removed and do you have any sound clips?

Durrby

iTrader: (3)

I don't think it feels any different. I'll have to take a better vid with an inside/outside perspective, but here's a couple for now.

http://www.youtube.com/watch?v=h6okQ...eature=related
This was with just the the 2.25" piping, x-pipe and mufflers

http://www.youtube.com/watch?v=ye2d8yREJPo
My weak *** dyno run with the headers added

http://www.youtube.com/watch?v=j3lGubtdeTA
little rev while driving around