header and hi flo cat

[hemz86]

If i put a 4-1 header and a hi flo cat on my 98 dx but keep the stock piping except for my muffler what if any hp gains will i have and how much louder would it be.

[89CivicHatch]

you won't gain much because your using your stock piping, if it to small of piping then all that air is going kink up inside and your air won't have no were to go.

[itstock]

Try farting through a straw, then thats your answer. But seriously, you have to open up the rest of your exhaust to see any noticeable gains.

[puffy]

Get the header and de-cat as well as the rest of the system at the same time and you may well see upto 12-15hp increase...

[S Q A D]

headers .. hi flow cat .. piping .. and a race muffler .. would kick ass .. in the air flow and hp/tq department .. and why the hell would you keep your stock piping ?? that makes no sense if your changing out the cat and exh. manifold .. why make the exhaust flow freely from the motor .. then restrict it as its on its way out .. ?? sounds like you just wanna make your car louder ... :roll: if you want a loud dx .. cut the pipe and leave no muffler ...

[DOG]

Tried to fart through a straw last night and it didnt quite work.lol.

If your going to spend the money on a decent header and cat you might as well get better piping and a decent muffler. At very least a decent oem ex muffler from a junkyard.
Do it right.

[Rexinre]

^^^^ THEY BOTH ARE RIGHT!!!

[dragman99]

well, you open up the pipe that fart is going to be a loud, wet, stinky one. i'm not going to argue this point because everyone will disagree with me but, your killing your backpressure which will in turn kill your bottom end(no pun intended)on a basically stock motor.

[DOG]

I agree that you will loose a little bit of your low end tq. Its a give and take depending on the size pipe you use on a given application. I would hope that someone with a basically stock engine and minor mods wouldnt want to put on a large 3" diameter pipe.

[S Q A D]

if they did ... then .. they need to taught a lesson ... dont be a dumbass and rock race pipes on a stock d16 !!!

[dragman99]

i don't think he needs more than 2" pipe. i actually think if he ran the stock pipe he would benefit more from it. but the only way to find out is try it.

[hemz86]

Well i was thinking i would get the header and the hi flow cat and then like 2.5 in to the muffler, which is aftermarket already, but the thing is i don't want a high pitched crackle like some of the rice around here. My muffler has the stock pipe running to it and the stock resonator, so maybe i can run the 2.5 to the resonator and from the resonator or what b/c i don't want it to be load and crackly. Also 4-1 or 4-2-1 i know the age old question but what is really gonna make it the fastest if i'm only at the I/H/E stage.

[sgvridgerunner]

Why fart through a straw when you can light it on fire :lol: :lol: :lol:

[S Q A D]

no matter what stage your at ... get ALL of the piping redone with bigger piping if your gonna do it ... and if you dont have a ricey and crappy muffler .. then you wont get that ricey crappy muffler sound... most cars only sound bad cause they have shitty 39 dollar mufflers on them nowadays .. so if you spend money on the quality of your muffler .. then expect a quality sound .. 4-1 is better imo .. better gains ... at any stage of tuning .. both are improvements over stock ...

[dragman99]

dude, 2.5 inch pipe is going to sound like shit on a n/a 4cyl. i don't care if jesus makes that muffler. i'd recommend 2 inch pipe which is almost pointless because stock is 1.75 and it's not crush bent. i'd love to still have my stock pipe even with my 12:1 c/r. back pressure is IMPORTANT to a 4 cyl. car. why kill the bottom end when it doesn't have any anyway.

[S Q A D]

then go ahead and get your 2 inch piping ...

[kommon_sense]

Rule of thumb is about 60hp per square inch of exhaust piping. So a 2" exhaust will handle 200hp and 2.25 will handle about 240hp. So 2-2.25 would be ideal on a n/a 1.6L sohc.

[S Q A D]

i know what the " rule of thumb " is .. we've had this exhaust discussion many times before ..

[gloryhog]

I have a ractive 4-2-1 header to a powercore cat to a greddy evo exaust and it is 2.25 , I am very happy w/ it I feel like i gained some good horsepower especially after 2500 rpms and this is on a sohc zc vtec.