exahust piping?

[Nebraska240sx]

what size is the piping on a stock 90 240

[Former_240_s14]

I would have to say 2 and a half, or two and a quarter.

[Nebraska240sx]

so could I leave my pipes stock and add an N1 and not be rice?

[Former_240_s14]

I wouldn't be a 100% sure, but it shouldn't be a problem, but if you do go bigger you would have better airflow for your exhaust. Redrocket has a full 3 inch exhaust from header back with not cats. Makes a HUGE difference.

[drifter]

I wouldn't be a 100% sure, but it shouldn't be a problem, but if you do go bigger you would have better airflow for your exhaust. Redrocket has a full 3 inch exhaust from header back with not cats. Makes a HUGE difference.

But it's probably louder than a guy with a pink shirt and neon green pants....depends if you're going turbo or not (which in this case, I'm guessing not)....2.25-2.5 is plenty loud enough and good enough for airflow as well. Three in. pipes are good for turbo!

[driftaholic]

my '91 had 1-7/8" pipe

[singlecamhonduhkilla]

ummm 2.25"is not ur stock piping.. its more like 1.75" because when i changed out my piping on my 89 240sx coupe the custom mandel piping that i put on to it compared to stock was way bigger(new vs. old) so yea i would suggest getting a 2.25" piping. i have it connected to a pos non-stainless steal magnaflow muffler.. and it sounds pretty good and good airflow..joe

[drifter]

Oh good, you guys....I did it right...my exhaust is the HKS Hiper with custom mandrel bent 2.25' piping...looks and sounds great! Also, has sufficient amount of backpressure....

[Tino]

"Bigger" does not equal "better flow".

As you increase the diameter of the piping, velocity is going to decrease. This will in turn decrease scavenging action at the exhaust port on the head, reducing performance.

For a NA four cylinder car, 2.25" piping is all you need.

exactly... it's not the size that counts... its the flow.:boink

[Exar-Kun]

K, actually I can provide a,link all about exhaust back pressure and stuff, lemme go find it...

heres a good one:http://www.z31.com/myths.shtml

-chet

[singlecamhonduhkilla]

who cares.. in my opinion i wouldnt get a muffler and put it on stock piping.. its too restrictive.. just get the 2.25" piping with it.. sounds way better and is better flow..joe

[Exar-Kun]

yeah K, its meant to dispell the myths the "you need backpressure" statement was meant to be a myth.

anyways, it does provide some good info for n00bs, although some points migh be over simplified.

-chet

[Nebraska240sx]

I haev seen a kit for the N1(comes with muffler, and piping, i think it was 2.5), but I want to keep lowend power to and sound good, so what do i do the kit was $585?

[drifter]

Sorry K...I guess I had no idea what backpressure was all about...but I did read that thread by that Honda guy and it made more sense to me now....thanks

[Exar-Kun]

the apex-i N-1 exhaust is 3" piping.-chet

[ninjak84]

So should I be puting 3" piping when my N1 (single, not dual) comes in?I don't exactly know what size to go with, but I'm for sure going to replace the stock piping (just for sound )

[Exar-Kun]

as far as I know, thers two version of the N-1 muffler: a N/a and a Turbo version, with the turbo having 80mm inlet(3") and the non turbo having 65mm (~2.75") or something like that.

like K said, without a turbo or serious modification 3" piping is really almost overkill for a 2.4l engine. I plan on running a turbo, so I went ahead and did it with a full n-1 cat-back anyway.

so piping diameter would vary with what you plan on doing with the car bro.

-chet

[Nebraska240sx]

not going turbo dor a long time, but 2.25 seems to be the favorite, size so I should get the 65mm and the N1?

[Nebraska240sx]

how many cc is the 2.4l ka??

PIPE DIAMETER GUIDELINESSome basic exhaust pipe diameter guidelines for non-turbo cars are as follows: 1,500cc-2,000cc engines : 2-inch2,100cc-2,500cc engines : 2.25-inch2,600cc-3,000cc engines : 2.5-inch

[Nebraska240sx]

uuuuuuuummmmmmmmmmmmmmmmm **** you, have a nice day

[driftaholic]

2.4 is a round figure to start with though. the KA24DE is actually 2393cc (and i doubt if THAT's exact either). KA24E is 2376cc. pretty much the same for all motors. sure beats saying you have 2.393L

K-Car i like your math. i ALWAYS switch from metric to standard cause it works much better. i hate multiplying and dividing by 10!

[UncleBen]

by the way, redrocket has 2 1/2" piping, not 3". i dont kno if someone already said that, because i didn't read all the replies. i just wanted to let everyone know that.

[slw240sx]

ahhahaaha, K car you kill me. i suck at math, infact i flunk out during intermediate alegbra. and i knew that one... and i hope he doenst take that conversion to heart, i mean damn metric to standard back to metric. i never even thought to do it that way ill have to right that formula down for future referances for when i get a motorcycle

[Exar-Kun]

K why did I get this feeling you were about to show the CFM used by the engine at a given RPM to determine how big an exhaust pipe has to be to flow that vlaume with minimal back pressure?

that was in "auto math handbook" that I ahve laying around here....

-chet