ROB'S SS

i vote all 3 inch also

justin sutton

All 3".Why would you want to come out of your muffler with 2 1/2 " turndowns?

John98LS1

iTrader: (6)

I just installed my Hooker LT's yesterday. I have 3 inch collactors on the lt's, what do you think i should go with 3 inch pipe or 2'1/2 inch pipe?? i will have a x-pipe and buillets, thanks for the help

Nasty N8

iTrader: (33)

3" to the x-pipe and 2 1/2" after. Thats plenty.
Nate

jeffrey G

go all 3'

John98LS1

iTrader: (6)

why would i want 3inch all the way?? isnt that a little big? thanks

2000LS1

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by coolguy:
<strong>why would i want 3inch all the way?? isnt that a little big? thanks</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">In theory the x-pipe should have enough scavenging effect to make up for the increased pipe size.

John98LS1

iTrader: (6)

i dunno i need more proof guys, why wouldnt 2-12 inch work??? i figure that plenty, **** theses cars only have 1 3 inch pipe 99 % of the time

Corey R.

iTrader: (4)

flowmaster says 2.5 is good for up to 400 HP.

also remember as the gas cools down, it condenses and gets smaller, hence you can use the smaller pipe towards the rear.

FASST

If you're still stock displacement: 2.5"...that's what I've got on my dual setup. There are a bunch of guys out in Phoenix running with dual 2.5" making great power; it's plenty. Too little back pressure will lower your exhaust velocity. That my friend, is a bad thing.

BTW, of all the people that responded with 3", how many of you are actually running a dual 3" setup?

<small>[ December 16, 2002, 10:10 AM: Message edited by: FASST ]</small>

SSHOTROD

iTrader: (5)

im running duel 3", maybe alil big for stock cars but at least you have room to grow. made a big difference on my car, it revs freely up to redline and better throttle response.

Z06PSI

iTrader: (33)

I actually have a 3" dual setup. Planning for the future heads/cam with nitrous. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

<small>[ December 16, 2002, 10:34 AM: Message edited by: redrumss ]</small>

justin sutton

I have dual 3" on my car.It is a bolt on car with a small shot. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Rpm2800

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by FASST:
[QB]Too little back pressure will lower your exhaust velocity. That my friend, is a bad thing.

QB]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">???
I'm not so sure too little back pressure will lower velocity. I think back pressure would hurt velocity.

Now PIPES too big can hurt velocity. So velocity could POSSIBLY suffer from 3 inch pipes depending on the combo. But Im not sure back pressure will increase velocity. I think it's just that the smaller pipe(too a point) will have more velocity. Not that back pressure increases velocity.

LS1Fbrd

Coreys right, with bigger pipes your ehaust gases cool and condense ( becoming heavier ) causing power to be wasted pushing the heavier gases out. You want your exhaust to be hot to the end.

John B

iTrader: (10)

Exhaust pipe size is one of the most mis-understood elements of hod rodding. Take a look at the exhaust pipe size in my signature and tell me if you thing velocity suffers when you see my RWHP & RWTQ numbers through this exhaust system and it goes all the way out to the back of my car!

Cody Brooks

iTrader: (2)

there is no need for any restriction after the headers dual 3's will work just fine. the only power you may loose from an exhaust that is too free flowing would be low end power. but you will make up for what you lose low end with what you gain high end. exhaust pipe size is one way to tune the engine to make maximun power at a certain rpm range. example big = higher rpm range power, small = lower rpm range power.

dual 3 inch pipes through an x-pipe will work as good as long as you don't mind losing a small amount of low end power.