what size exhaust piping should i go with?

[Coutts]

ok so i've done some research and a local shop said he can crush bend 2.25" aluminized piping to a muffler that i would supply for $109. i dont care that its aluminized i wont have the car long enough to have it rust out. i know all of you are going to say mandrel bending is better, no s**t but nobody around here can do it, and im not about to go drop nearly $500 for just a catback.

i've got a mild ls/vtec build:

stock b18b1 block
b16 head with ITR cams and valvetrain
ITR intake manifold
stock LS exhaust manifold (For now, im also on stock civic ex exhaust right now so i deff need to change this).
autozone diy short ram intake
gsr trans with a quaife lsd
untuned on hondata s200

So since im crush bending should i bump it up to 2.5"? or is 2.5" too much (dont want to loose all of my back pressure). Right now im leaning more towards 2.25" piping but what do you guys think? i personally think crush bending isnt as bad as people say, everybone bitches and moans about it because they bought a $500 catback blah blah i dont care. also no im not buying an ebay catback. i would need to have w/e catback i buy modified to meet my cat coming off the LS header (integra cats are longer than civic ones, therefore ther would be a gap of a couple of inches between the cat and the rest of the catback), so it woudl be easier to just have a shop run piping. $109 doesnt sound bad at all so what do u guys think?

 

[Scorchsta]

Go with the 2.5". Back pressure is your enemy not your friend. You're problem with going to big would be that the exhaust could cool too quickly and slow down before it exits the pipe. You won't have this problem with the 2.5" piping though. Especially with crush bent.

 

[EG-Owns you]

2.5 is just fine i used to run 2.5" on a fully built b20 with gsr quife lsd to s**t scooted but i dont run a full exhaust now that its a track car

 

[Jersey8]

yea go with the 2.5

 

[ryan89crx]

mandrel 2.25" would flow plenty for that motor

 

[Coutts]

alright i got it done today. sounds awesome IMO. i just had him run 2.25" piping from the cat back to a fart can my friend gave me. surprisingly its got next to no rasp (only at high rpms) and its loud as crap. very very deep so this fartcan is pretty good lol. i deff can feel a power boost in it compared to stock, and i got 2 kills tonight woot.

v6 auto mustang - train lengths from a dig and roll

built gsr swapped 98 coupe - train lengths from a dig (my quaife > his open diff), 2 lengths from a roll.

 

[Kaotic_Zeus]

v6 mustangs are easy kills,

 

[Kaotic_Zeus]

i would of seriously went with 2.5, with that motor setup.

 

[Coutts]

i would of seriously went with 2.5, with that motor setup.

well to be honest it looked like the guy might have ran 2.5" piping so that he could stretch it out to slide together, either way its loud, deep, sounds good and gave me a little boost in power.

pics:

can looks big but its sounds good. ill get a sound clip up tomorrow for you guys. this is without a resonator btw too. i was so shocked at how it sounded. im guessing the fact i still have a cat is also contributing to it sounding good.

 

[vjf915]

(dont want to loose all of my back pressure).

Apparently you DIDNT do your research. Back pressure is BAD, you DONT want back pressure. You want to hit the point where you have NO back pressure, but dont have a big enough exhaust so that the exhaust cools down before it exits.

 

[Kaotic_Zeus]

that canister is not big lol

 

[Coutts]

(dont want to loose all of my back pressure).

Apparently you DIDNT do your research. Back pressure is BAD, you DONT want back pressure. You want to hit the point where you have NO back pressure, but dont have a big enough exhaust so that the exhaust cools down before it exits.

either way dude it works fine now, alot better than before with the stock exhaust. i dont know why everyone is telling me to go with 2.5" piping, thats way too big for this setup. this is a mild ls/vtec setup, its a completely stock block with a built head, its not going to be making any crazy power so it will be just fine with this. with a good header and a tune it should see 170whp.

 

[slowcivic E G]

from what i can see in that last pic those bends dont look to bad, 2.25 might not be doing too much harm, but also, i cant really see the rest of the exhaust.

 

[Coutts]

i have a feeling he might have just put 2.5" piping in. when i got the quote when he repeated it to make sure i heard everything he said 2.5", and also it looks like its 2.5" piping (looks more like my friends 3" piping rather than something smaller). either way it works fine for me and what i need. and yeah the bends werent as crushed as i thought, im very pleased with it. i spent $130 on everything and its just how i wanted it.

 

[Jersey8]

nice man!

 

[mylovehx]

you should see my canister, buckeyes deff rule