ok i have a ls/vtec build thats getting ready to be swapped into my integra
my question is what time of exhuast piping should be ran i kept the stock muffler and piping for sometime as a bit of a sleeper look but i dnt wana restrict the motor with the new setup
has a blox intake manifold, stock throttle body (for now), pr3 pistons, ls rods with arp rod bolts, machined block and head,dc sport 4-1 header(which i might change to a better one later down the road to one that has increased velocity exiting the exhuast ports on the head
i do realize velocity will be higher from a smaller diameter piping
and wider diameter will have better flow at high rpms
the car is being built more for auto-x and road racing more then it is for 1/4 racing

im thinking of running the usual 2.5(63-64 ish mm) diameter for the setup unless i can benefit more from a different setup
im not looking to purchase a HIGH dollar cat-back only for the reason that
if its going to be daily driven and a weekend racer the piping would either get abused from speed bumps or who knows maybe get a little beat up if something goes wrong road racing
but by all means i would atleast take the effort to not piece together 20 autozone exhuast connecters
i just think it would be better to get a an exhuast made for 2-300 dollars mandrel bent that if anything get torn up a certian section can replaced over doing that to a 500-700 cat-back

 

look into a cutout to keep your stock exhaust

 

SMSP makes a twinloop muffler thatll work real well and he supplies DIY exhaust kits as well.

 

hmm...i never thought of a cut out or twin loop system...both are actually not bad ideas now that i think about it

 

Quiet, high flowing. Can't beat it!

 

intresting! i too am building an lsvtec and want to keep the stock exhaust with the e cut-out. How would this effect the tune of the motor? i have s2s2 cams and a tri y header also, i would like to drive with stock exhaust on and use the e cut out when im at the track. would this cause any problems with the motor and tune as far as making it bog or excessive back pressure?

 

i dont really like the sound of E-cut out for road racing. For 1/4 yeah sounds nice.

But driving with E-cut out isnt like running Open exhaust&headers' Sooner or later ur motor will lose compression?

 

Wut?

 

what the **** did you just say?

c'mon son..wtf.

 

When did SMSP start making twin loop cat back exhausts?

 

i was asking if e cut out make u lose compression?

if both of u are mr. smartass can u answer my question?

 

No, it won't make you loose compression. Why would you think that?

 

3 inch piping, with a large 18 inch resonator and a vibrant flat black muffler.

 

i was just wondering thats all.
i heard running no muffler = no back preassure
and slowly burns ur valves or loose Cp etc etc.
well sorry and thanks for the reply

 

Not true, nothing of which you said, is.

 

You're believeing alot of myths right now..having a e cut out has nothing to do with losing compression.

 

settle down turbo, you made your point.

 

i think thats gonna be your cheapest/most power/most effective, but i would imagine its gonna be pretty loud

 

Its not loud, resonators serve a purpose.

 

Not really trying to make a point, just point out the guy obviously has alot of reading to catch up on, over the years.

 

Backpressure is NEVER good. What you heard about burning exhaust valves is partially true. Also running open header on a low compression motor can prove to be difficult. The term that relates to this phenomenon is called scavenging. You need scavenging. Scavenging is what helps the spent exhaust exiting the head actually make it out of the head. Running too little of an exhaust can reduce this effect. Bigger is not always better. If it was we'd all be running around without an exhaust manifold bolted up at all.

The term backpressure is often confused with scavenging. One you need, the other you don't.