Straight Piping

[quikstr13]

my freind just got Straight piping on his car but he wanted to know if he would still pass smog??? as long as he put the cat... back on???

 

[formby]

in some states youll need atleast 3 bends

 

[get_nick]

this is why you do emissions BEFORE new exhaust or motor swaps. also another reason why you keep the stock exhaust and don't weld on the new one.

but to answer your question, odds are it wont pass.

 

[jimboburgess]

hooray central PA and sight inspections.

Mechanic: does your car have a cat?

Me: yep it's right there (points at cheap racing cat off ebay) see?

Mechanic: Oh, ok it looked like a resonator to me.

Me: (thinking, yeh that's what it is but i have the box it came in saying otherwise) nope, it's a cat, here's the box it came in.

 

[quikstr13]

does straight piping even give you HP???

 

[get_nick]

does straight piping even give you HP???

on turbo'd cars it does. if you dont' have any back pressure on an NA car you will lose a lot of low end torque.

 

[formby]

you can have back pressure and still use straight pipe....

its all in the diameter of pipe and the type of muffler you use

 

[UnluckyOne]

Formby is absolutely correct. Back pressure tends to be dependent on the size and type of muffler you use. On my ED civic I used a straight through Magnaflow muffler with 2 and 1/4 and the low end was near the same while I was able to accelerate faster at higher rpms/speed.

 

[quikstr13]

i know im stupid at all this stuff because ive only been racing for two/three month... so u you guys maybe tell me wat back pressure is...? i might have a better idea...? wat if i was to keep the stock muffler tip???

 

[get_nick]

i know im stupid at all this stuff because ive only been racing for two/three month... so u you guys maybe tell me wat back pressure is...? i might have a better idea...? wat if i was to keep the stock muffler tip???

back pressure is the flow of exhaust leaving the engine. on an NA motor, you need a little backpressure for engine compression. with a turbo motor, you basically want all the exhaust gone as fast as possible. just get a regular exhaust for your application. keep your cat and your muffler. test pipes really don't do that much anyways and you wont likely pass emissions with it.

 

[formby]

back pressure is the flow of exhaust leaving the engine. on an NA motor, you need a little backpressure for engine compression. with a turbo motor, you basically want all the exhaust gone as fast as possible. just get a regular exhaust for your application. keep your cat and your muffler. test pipes really don't do that much anyways and you wont likely pass emissions with it.

+1

the cheapest way is to buy the mufflers of choice[ magnaflow, flowmaster] then you take the car to a muffler shop and have them copy the oem set up.

 

[quikstr13]

thanx