BackPressure? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Drift Style S14 · 10-22-2001, 12:52 AM

Hey i read in a previous thread something about the Duel N1 exaust. Now i was wondering, wouldn't the Duel N1 kill all backpressure on a N\A engine. So wouldn't the Single N1 be better than the Duel? Oh and who sells some good quality, low price front and rear Strut Bars? thanks

*LanceS13* · 10-22-2001, 10:17 AM

The combined cross-sectional area of the Dual is almost the same as the cross-sectional area of the Single.  I don't see where the Dual has any real advantage over the single.  Someone correct me if I'm wrong, but I figure if the cross-sectional area is the same, the same amount of gas should be able to pass through each with the same resistance...no matter how many pipes that cross-sectional area is split into.
For front and rear STB's check out www.rollhard.com .  You can get both for around $100.

Freak Leash 240 · 10-22-2001, 10:31 AM

No, the N1 dual actually creates more backpressure thant the N1 single. Now it might not make sense but check this out:
• The N1 is a 3" pipe.
• The N1 dual is the equivalent of a 3,25" pipe, only split into two similar size pipes.

So the dual will have slightly (not much) more top end than the single simply because it flows more gas volume, BUT it retains bottom end because the increased contact area (more pipes) makes it more restrictive.

*LanceS13* · 10-22-2001, 10:56 AM

You know, Freak Leash, you're absolutely right...that does make sense.  The Dual, although having the greater cross-sectional area has roughly twice the contact area.  I'm not sure how that increased contact area would affect top end, but low/mid range should see benefits.  (I'm still doubting whether those benefits justify the extra $130 for the Dual...anybody got dyno charts?)

Drift Style S14 · 10-22-2001, 04:10 PM

well even on a N/A car the duel and the single N1 would be too much. You stated that the pipe on the n1 is 3 and on the duel 3.25? well wouldn't a N/A benfit more from a pipe that is 2.5 ? no wait 3 inchs might be ok....

S13Grl · 10-22-2001, 04:13 PM

N/A four-cyllinder should benefit from about 2 1/2 inches, I think. Four-cyllinder f'n non-turbo.

*LanceS13* · 10-22-2001, 04:26 PM

The 240 having a pretty large displacement for a 4 cyl. and practically no top end responds pretty well to the 3" piping...and then when you go turbo, you still have adequate piping.  However, if you intend to stay n/a, you might be better off with a slightly smaller piping (maybe 2.5-2.75").  The 3" still doesn't hurt performance on an n/a KA.  My N1 gave my car a top end that was virtually non-existant stock.

matic 240sx · 10-22-2001, 10:03 PM

i have a dual magnaflow muffler with a custom made 2.5in pipe from the cat back.  i had it put on with my injen intake at the same time.  after driving my car for about 1 hour that day, so once on i noticed a good bit of difference.  now i added my cold air extension and still noticed the difference.  im getting bigger fuel injectors soon and then im going to a 3in pipe.  and i think it will still benefit.  it seems like im holding back something when i hit it sometimes.  if you really want to see a difference in back pressure and no back pressure.  remove your whole exhuast system and take it for a drive.  ive done it, the KA24DE sounds like a v8 on crack.  and my car was stock and there was not a noticeable difference in performance.  but i guess it all depends on mods and what not...

BlankFlip · 10-22-2001, 10:18 PM

don't know if this helps, but it's from their site.

Retain the same peak HP of the single N-1 while improving mid range torque, Mid to high-end power.

N-1 Dual Mufflers are a variant of the popular single-tip N-1 Series Mufflers. The N-1 Dual piping splits into two smaller diameter pipes just after the catalytic converter and flow into a pair of 120mm canisters. The canisters are polished off with aggressive 90mm tips. The use of smaller piping diameter helps retain more mid-range torque. The Dual N-1 does not sacrifice peak horsepower because the dual pipes can handle more exhaust gas volume. Piping is treated with high-temperature titanium particle coating, and the canisters and tips are constructed of polished SUS 304 stainless steel. Optional 90mm Super Silencers can be used to reduce noise levels by up to 7 decibels.

nebody know the different piping sizes for the n/a n turbo versions?

10-22-2001, 12:52 AM	#1
Drift Style S14 Zilvia Addict Join Date: Sep 2001 Location: ............ Age: 42 Posts: 602 Trader Rating: (0) Feedback Score: 0 reviews	Hey i read in a previous thread something about the Duel N1 exaust. Now i was wondering, wouldn't the Duel N1 kill all backpressure on a N\A engine. So wouldn't the Single N1 be better than the Duel? Oh and who sells some good quality, low price front and rear Strut Bars? thanks

10-22-2001, 10:17 AM	#2
LanceS13 AutoX Junkie Join Date: Jun 2001 Location: MS Age: 43 Posts: 2,044 Trader Rating: (0) Feedback Score: 0 reviews	The combined cross-sectional area of the Dual is almost the same as the cross-sectional area of the Single.  I don't see where the Dual has any real advantage over the single.  Someone correct me if I'm wrong, but I figure if the cross-sectional area is the same, the same amount of gas should be able to pass through each with the same resistance...no matter how many pipes that cross-sectional area is split into. For front and rear STB's check out www.rollhard.com .  You can get both for around $100.

10-22-2001, 10:31 AM	#3
Freak Leash 240 Leaky Injector Join Date: Sep 2001 Posts: 134 Trader Rating: (0) Feedback Score: 0 reviews	No, the N1 dual actually creates more backpressure thant the N1 single. Now it might not make sense but check this out: • The N1 is a 3" pipe. • The N1 dual is the equivalent of a 3,25" pipe, only split into two similar size pipes. So the dual will have slightly (not much) more top end than the single simply because it flows more gas volume, BUT it retains bottom end because the increased contact area (more pipes) makes it more restrictive.

10-22-2001, 10:56 AM	#4
LanceS13 AutoX Junkie Join Date: Jun 2001 Location: MS Age: 43 Posts: 2,044 Trader Rating: (0) Feedback Score: 0 reviews	You know, Freak Leash, you're absolutely right...that does make sense.  The Dual, although having the greater cross-sectional area has roughly twice the contact area.  I'm not sure how that increased contact area would affect top end, but low/mid range should see benefits.  (I'm still doubting whether those benefits justify the extra $130 for the Dual...anybody got dyno charts?)

10-22-2001, 04:10 PM	#5
Drift Style S14 Zilvia Addict Join Date: Sep 2001 Location: ............ Age: 42 Posts: 602 Trader Rating: (0) Feedback Score: 0 reviews	well even on a N/A car the duel and the single N1 would be too much. You stated that the pipe on the n1 is 3 and on the duel 3.25? well wouldn't a N/A benfit more from a pipe that is 2.5 ? no wait 3 inchs might be ok....

10-22-2001, 04:13 PM	#6
S13Grl Married to the Mob Join Date: Dec 2000 Age: 44 Posts: 3,670 Trader Rating: (0) Feedback Score: 0 reviews	N/A four-cyllinder should benefit from about 2 1/2 inches, I think. Four-cyllinder f'n non-turbo.

10-22-2001, 04:26 PM	#7
LanceS13 AutoX Junkie Join Date: Jun 2001 Location: MS Age: 43 Posts: 2,044 Trader Rating: (0) Feedback Score: 0 reviews	The 240 having a pretty large displacement for a 4 cyl. and practically no top end responds pretty well to the 3" piping...and then when you go turbo, you still have adequate piping.  However, if you intend to stay n/a, you might be better off with a slightly smaller piping (maybe 2.5-2.75").  The 3" still doesn't hurt performance on an n/a KA.  My N1 gave my car a top end that was virtually non-existant stock.

10-22-2001, 10:03 PM	#8
matic 240sx Join Date: Jul 2001 Location: las vegas Age: 42 Posts: 798 Trader Rating: (0) Rides Gallery: matic 240sx Feedback Score: 0 reviews	i have a dual magnaflow muffler with a custom made 2.5in pipe from the cat back.  i had it put on with my injen intake at the same time.  after driving my car for about 1 hour that day, so once on i noticed a good bit of difference.  now i added my cold air extension and still noticed the difference.  im getting bigger fuel injectors soon and then im going to a 3in pipe.  and i think it will still benefit.  it seems like im holding back something when i hit it sometimes.  if you really want to see a difference in back pressure and no back pressure.  remove your whole exhuast system and take it for a drive.  ive done it, the KA24DE sounds like a v8 on crack.  and my car was stock and there was not a noticeable difference in performance.  but i guess it all depends on mods and what not...

10-22-2001, 10:18 PM	#9
BlankFlip Nissanaholic! Join Date: Oct 2001 Location: The Future Posts: 1,627 Trader Rating: (0) Feedback Score: 0 reviews	don't know if this helps, but it's from their site. Retain the same peak HP of the single N-1 while improving mid range torque, Mid to high-end power. N-1 Dual Mufflers are a variant of the popular single-tip N-1 Series Mufflers. The N-1 Dual piping splits into two smaller diameter pipes just after the catalytic converter and flow into a pair of 120mm canisters. The canisters are polished off with aggressive 90mm tips. The use of smaller piping diameter helps retain more mid-range torque. The Dual N-1 does not sacrifice peak horsepower because the dual pipes can handle more exhaust gas volume. Piping is treated with high-temperature titanium particle coating, and the canisters and tips are constructed of polished SUS 304 stainless steel. Optional 90mm Super Silencers can be used to reduce noise levels by up to 7 decibels. nebody know the different piping sizes for the n/a n turbo versions?