PDA

View Full Version : exhuast question


s13240sx
02-13-2003, 08:44 AM
Im looking at gettin a new cat-back exhaust, But i want something that i wont have to change when i do my motor swap.
Ive been looking at the apexi dual n1, the gt spec exhaust, or the gp sports spec R dual


S13240sx

russian
02-13-2003, 09:34 AM
if you swap to turbocharged engine you will be better off with 3inch piping, but 2.5 still will do. I would consider best 5zigen Fireball miracle with 3 inch piping but once again 5zigen is my personal preference.

Jeff240sx
02-13-2003, 11:42 AM
Exhausts are chassis dependant, not engine dependant (unless you swap in a CA). But for the KA and SR motors, the exhaust will fit.
That said, since you will be going turbo, you'll want 3" piping. The N1 Dual is huge, and looks like it will work wonders. It's also dual 2.5" piping, which gives much more exhaust area and volume than a single 3" piping. IMO, it'd be better for your NA ka (untill you swap) also, since each pipe diameter is smaller, so you'll retain torque. But... if you want sound, then get 3" piping.
-Jeff

s13240sx
02-13-2003, 12:03 PM
sorry didnt pharse is well i was wanting something with out to much back pressure for the sr swap. Im mainly lookin bewteen the gp sports dual and the apexi dual n1 to keep a little bit more stock look in the back, and as far as sound im more worried about performance for the turbo motor that is as long as it doesnt sound like a bumble bee :D

iggy
02-13-2003, 12:16 PM
Originally posted by Jeff240sx
Exhausts are chassis dependant, not engine dependant (unless you swap in a CA). But for the KA and SR motors, the exhaust will fit.


exhaust will fit even if you swap in a CA. i dont see any reason why it wouldnt fit? like you said, exhausts are chassis dependant, not engine dependant..

russian
02-13-2003, 12:20 PM
hmm maybe i dont understand something so expain to me

N1 dual echaust has dual piping and 2 mufflers, ok i see but how does it make more airflow if it joins into a single pipe by the cat?? i mean headers connect into single pipe at the collector, single pipe trough cat then (if you have dual N1) it splits into 2 pipes. I just dont see how that gives you a bigger gain over single piping. i could understand if the piping was dual all the way starting from headers, but its not.

maybe im wrong but i think it makes sence... :) i think lol

Dousan_PG
02-13-2003, 12:22 PM
Originally posted by iggy
exhaust will fit even if you swap in a CA. i dont see any reason why it wouldnt fit? like you said, exhausts are chassis dependant, not engine dependant..

ca exhaust dont fit exactly same.
alex chang (mav1178) had tested this theory out before

USDM chassis and JDM chassis are slightly different as well.

most wont run into a problem unless you are buying a really OLD exhaust

Dream240
02-13-2003, 12:31 PM
From what I've read about the designs the dual exhaust profile does decrease backpressure even if it doesn;t start until after the CAT. The two pipes work together to drain gases at double the rate of one pipe.
For example, if you had a straw with one opening on one end and it split into two on the mouth end you could still suck more fluid through the straw at a faster rate. I'm not a scientist but it has to do with physics.
So basically, even though you don't change the size of the pipe until the CAT, you ARE decreasing back pressure on the whole due to dual pipes after the CAT. Thus increasing power. In one of last years Import tuner power pages, they used the N! dual and mentioned that it gives high end power without sacrifing mid-range torque like the N1 single. I can't remember which month it was.

Hope this helps.

russian
02-13-2003, 02:19 PM
hmm.. sounds good. although i dont trust "import tuner" :)
thanks

Jeff240sx
02-13-2003, 03:39 PM
Originally posted by iggy
exhaust will fit even if you swap in a CA. i dont see any reason why it wouldnt fit? like you said, exhausts are chassis dependant, not engine dependant..

As said before, the exhaust will NOT fit using a CA engine. The downpipe goes out further, and won't line up with any 240sx chassis exhaust. You'd need a silvia exhaust made for the CA.
For instance.. look at this:
http://www.blitz.com.au/100147.php#100148 and scroll down to s13 silvia. All SR exhausts have different part numbers than CA exhausts.
-Jeff