Interesting. I thought they were cutouts that you could un-cap and bypass the second mufflers. Backpressure tubes makes some sense though.
|
|
LinkBack | Thread Tools | Display Modes |
04-25-2009, 11:40 AM | #16 (permalink) |
The370Z.com Sponsor
|
Interesting. I thought they were cutouts that you could un-cap and bypass the second mufflers. Backpressure tubes makes some sense though.
__________________
MikeBonanni.com Twitter: http://www.twitter.com/MikeBonanni Facebook: http://www.facebook.com/MBonanni36 Function > Form |
04-26-2009, 03:23 AM | #18 (permalink) | |
Enthusiast Member
Join Date: Mar 2009
Location: Irvine, CA
Posts: 340
Drives: 2011 FX 35
Rep Power: 250 |
Quote:
Correct me if im wrong here, but wouldn't narrowing the piping to increase exhaust velocity be more effective than adding "backpressure" tubes. |
|
04-26-2009, 09:00 AM | #19 (permalink) | |
A True Z Fanatic
Join Date: Jan 2009
Location: Behind enemy lines
Age: 54
Posts: 5,995
Drives: People to drink
Rep Power: 32 |
Quote:
__________________
"There are no small accidents on this circuit." -- Ayrton Senna 316.8whp & 248 ft/lbs (Dyno Dynamics) | 319whp & 256 ft/lbs (DynoJet) (04/23/10) Stillen G3 CAI, CBE, Pulley / F.I. LTH / GTSpec Ladder Brace / Setrab Oil Cooler / UpRev-tuned by Forged Perf. |
|
04-26-2009, 01:46 PM | #21 (permalink) | |
A True Z Fanatic
Join Date: Feb 2009
Location: US of A
Posts: 2,842
Drives: Answers
Rep Power: 33 |
Quote:
Thanks for the pic post as I wonder whether the 5Zigen does not have a similar setup when viewed underneath with the extra cans atop the actual mufflers? Can you please fly your private jet to Japan and find the answer for me? Inquisitive minds want to know. (Now watch AK smoke me on finding this out first.)
__________________
( Click to show/hide )
Last edited by SoCal 370Z; 04-26-2009 at 02:15 PM. |
|
04-26-2009, 03:57 PM | #23 (permalink) |
Enthusiast Member
Join Date: Feb 2009
Location: Ohio
Posts: 412
Drives: 16 Cayman GT4 Red
Rep Power: 220 |
A side note on HKS. I believe in the most recent Grassroots Motorsports Magazine they tested several exhausts for the 335i and the HKS exhaust was their pick.
__________________
16 Cayman GT4, Carmine Red, Buckets, PCCB etc. |
04-26-2009, 04:48 PM | #24 (permalink) |
Enthusiast Member
Join Date: Dec 2008
Location: so cal
Posts: 449
Drives: _
Rep Power: 17 |
I believe those extra canisters on the HKS are for sound reduction and avoidance of drone.
"Backpressure tubes"? Forget what you've heard, but backpressure is a bad thing and kills power. Initialgemini had it right, as exhaust velocity is key. The key is to match pipe diameter to give the greatest exhaust velocity with the least amount of backpressure and of course matching to your power band. A narrow pipe will have greater velocity at low RPMs while a wider pipe will flow better at high RPMs so a well-designed exhaust will take this into account and should have a correct balance. Last edited by sensi09; 04-26-2009 at 04:51 PM. |
04-26-2009, 06:28 PM | #25 (permalink) |
A True Z Fanatic
Join Date: Jan 2009
Location: Behind enemy lines
Age: 54
Posts: 5,995
Drives: People to drink
Rep Power: 32 |
There's no need for separate piping if all you're looking to do is reduce sound -- that's what in-line resonators are for. Now, I want to be clear here. I am not vouching for the effectiveness of using separate piping for backpressure, I'm just explaining what the intent behind the design is. Personally, I think they're gimmicky. But believe what you want to believe. It doesn't make an ounce of difference to me.
__________________
"There are no small accidents on this circuit." -- Ayrton Senna 316.8whp & 248 ft/lbs (Dyno Dynamics) | 319whp & 256 ft/lbs (DynoJet) (04/23/10) Stillen G3 CAI, CBE, Pulley / F.I. LTH / GTSpec Ladder Brace / Setrab Oil Cooler / UpRev-tuned by Forged Perf. |
04-26-2009, 07:30 PM | #26 (permalink) | |
Enthusiast Member
Join Date: Mar 2009
Location: Irvine, CA
Posts: 340
Drives: 2011 FX 35
Rep Power: 250 |
Quote:
|
|
04-26-2009, 11:16 PM | #27 (permalink) |
Enthusiast Member
Join Date: Dec 2008
Location: so cal
Posts: 449
Drives: _
Rep Power: 17 |
From the marketing of the HKS hi-power exhaust, these extra canisters are for sound reduction and tuning. In this regard, they are similar to resonators. Search for "dead chambers" for more info on this.
|
04-27-2009, 08:26 AM | #28 (permalink) |
A True Z Fanatic
Join Date: Jan 2009
Location: Behind enemy lines
Age: 54
Posts: 5,995
Drives: People to drink
Rep Power: 32 |
Hmm...well that makes the design even worse, IMO. Extra piping = extra weight. If the right sound can't be achieved with the normal in-line resonators and mufflers, that's just not good. Just my 2 cents.
__________________
"There are no small accidents on this circuit." -- Ayrton Senna 316.8whp & 248 ft/lbs (Dyno Dynamics) | 319whp & 256 ft/lbs (DynoJet) (04/23/10) Stillen G3 CAI, CBE, Pulley / F.I. LTH / GTSpec Ladder Brace / Setrab Oil Cooler / UpRev-tuned by Forged Perf. |
04-27-2009, 01:21 PM | #29 (permalink) |
A True Z Fanatic
Join Date: Nov 2008
Location: Columbus, OH
Posts: 1,940
Drives: Mag. Black 2009 370Z
Rep Power: 705 |
With regards to the SACLAM unit, it looks to me as though the HUGE resonators up front are what cures the drone, and the extra piping out back prevents the loss of backpressure.
Now, the HKS unit shown above looks like it serves both purposes by incorporating a "dead-end" with a resonator attached to it. Also, backpressure isn't bad if its used correctly. For N/A applications, you need backpressure to prevent the loss of torque in free flowing exhausts. If you have too much though, then you will lose power. Think of it as a glass of red wine a day. In moderation, its actually good for you, but in excess its not. Horsepower and torque are both important IMO, and not just horsepower.
__________________
|
04-27-2009, 01:36 PM | #30 (permalink) |
Track Member
Join Date: Jan 2009
Location: Snoqualmie WA
Posts: 973
Drives: 03 996TT Porsche
Rep Power: 606 |
Hard data is what really would convince one way or the other...............where's the comparitive dyno chart, that and the weight numbers?
__________________
Buddy Revell: "One man's sooner is another man's later" |
Bookmarks |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
STILLEN 370Z Dual Exhaust System w/pricing | AK370Z | STILLEN | 25 | 01-03-2011 08:49 PM |
Greddy exhaust system! | DJcuetip | Nissan 370Z General Discussions | 17 | 08-02-2009 06:13 AM |
Is the Nismo Exhaust System Available? | Dino 54 | Exterior & Interior | 4 | 04-02-2009 09:48 PM |
Tubi exhaust system! | tvfreakazoid | Intake/Exhaust | 8 | 01-28-2009 03:51 AM |