Thanks WarBaby... I got a million questions just like that one!!Haywood - I'll take a quick stab at it. Although nobody ever does it this way with stock cams, stock compression, etc., a "proportional" increase of bore and stroke relative to the stock bore and stroke dimensions is a matter of scaling if the related components (valves and ports) are equally scaled up to match the increased flow demands. By "scaling", I mean a 10% proportional bore/stroke increase in total displacement would yield an approximate 10% power increase: 1300 cc (160 HP) X 10% = 1430 cc (176 HP). A 20% proportional bore/stroke increase: 1300 cc (160 HP) X 20% = 1560 cc (192 HP). As mentioned, it is never done this way but a realistic power estimate depends upon too many variables--cam profile, compression, air/fuel ratios, head mods, revised timing, and so forth. There are many dyno charts on display at various Busa sites that show the results of the myriad "big motor" modifications available. Such a question...
Exhaust Myths vs Reality
- Thread starter WarBaby
- Start date
This one should be pinned it took me a minute to find it again
May i assume therefore..... the bigger the pipe diametre the better?[/QUOTE]
Not necesssarily. It depends on what kind of power enhancement you want from an exhaust system. If you install tubes that are very large in diameter, you may have great peak power but the low-to-mid range portion of the powerband will suffer because the gas flow velocity will drop severely. It might help if you focus on the part about flow velocity vs flow volume in the original post. It's all about design compromises to achieve a given performance objective.
Not necesssarily. It depends on what kind of power enhancement you want from an exhaust system. If you install tubes that are very large in diameter, you may have great peak power but the low-to-mid range portion of the powerband will suffer because the gas flow velocity will drop severely. It might help if you focus on the part about flow velocity vs flow volume in the original post. It's all about design compromises to achieve a given performance objective.
Orange_Busa
Registered
OK, since the X-pipe in the factory design was a bad idea, what would you say about the HMF X they use in there dual systems? Bad idea or a better design? Thanks.
ps. Great post also, has alot of people thinking now I would asume.
Wow!! Thanks for explaining all that!
I have a sound questions for you
I have the full titanium 4:1 pipe, and it works well but sounds to quite, I can't hear it on the highway.
I plan to open up the can and wrap 1/3-1/2 of the internal perforated tube with sheet metal, this should make it sound louder.
If I cover the section near the tip, or near the engine would it have any change in sound??
Thanks in advance
P.S. Any other idea's using my existing can?
I have a sound questions for you
I plan to open up the can and wrap 1/3-1/2 of the internal perforated tube with sheet metal, this should make it sound louder.
If I cover the section near the tip, or near the engine would it have any change in sound??
Thanks in advance
P.S. Any other idea's using my existing can?
bbbsleeper
Registered
WOW, So basicly exhaust velocity and volume will make my bike go faster, cool, OK.
Tom ... I have this same question. When the tuner mapped my HMFs, he commented that their X design was an improvement over the stock pipes. After reading your excellent post, I'm starting to get a clue about exhaust now. Thanks much !!
Brian ... your bike is Sweet !!
Sorry for being slow to respond. For some reason, I haven't gotten email notifications about the last few posts.
OK, since the X-pipe in the factory design was a bad idea, what would you say about the HMF X they use in there dual systems? Bad idea or a better design? Thanks.[/QUOTE]
X-Pipes have their place in the scheme of exhaust designs and, on dual muffler systems, they can broaden the powerband (more power below the HP peak). The factory crossover design was probably a cost-induced compromise.
Wow!! Thanks for explaining all that! I have a sound questions for you I have the full titanium 4:1 pipe, and it works well but sounds to quite, I can't hear it on the highway.
I plan to open up the can and wrap 1/3-1/2 of the internal perforated tube with sheet metal, this should make it sound louder. If I cover the section near the tip, or near the engine would it have any change in sound?? Thanks in advance
[/QUOTE]
Yes, covering some of the sound-absorbing holes inside the muffler should make it louder.
Tom ... I have this same question. When the tuner mapped my HMFs, he commented that their X design was an improvement over the stock pipes. After reading your excellent post, I'm starting to get a clue about exhaust now. Thanks much !![/QUOTE]
Cross over pipes can be a good thing for dual systems when properly designed and correctly located. I am sure that HMF's design is far superior to the factory X-pipe crossover. This can aid low-to-mid range gas scavenging which creates greater torque. More torque is always a good thing!
If you visualize an exhaust pulse as a colume of gases moving rapidly through the exhaust tubes, it is easier to imagine what is happening inside the exhaust system. Clearly, a gas colume just wants to get out of the exhaust. It has mass and therefore inertia. The fewer restrictions it encounters, the better. Imagine the gas colume having a smooth, tubular path with gentle bends, no collisions with other gas columes, etc. vs. sharp bends, baffles, and turbulence etc.
OK, since the X-pipe in the factory design was a bad idea, what would you say about the HMF X they use in there dual systems? Bad idea or a better design? Thanks.[/QUOTE]
X-Pipes have their place in the scheme of exhaust designs and, on dual muffler systems, they can broaden the powerband (more power below the HP peak). The factory crossover design was probably a cost-induced compromise.
Wow!! Thanks for explaining all that! I have a sound questions for you I have the full titanium 4:1 pipe, and it works well but sounds to quite, I can't hear it on the highway.
I plan to open up the can and wrap 1/3-1/2 of the internal perforated tube with sheet metal, this should make it sound louder. If I cover the section near the tip, or near the engine would it have any change in sound?? Thanks in advance
[/QUOTE]
Yes, covering some of the sound-absorbing holes inside the muffler should make it louder.
Tom ... I have this same question. When the tuner mapped my HMFs, he commented that their X design was an improvement over the stock pipes. After reading your excellent post, I'm starting to get a clue about exhaust now. Thanks much !![/QUOTE]
Cross over pipes can be a good thing for dual systems when properly designed and correctly located. I am sure that HMF's design is far superior to the factory X-pipe crossover. This can aid low-to-mid range gas scavenging which creates greater torque. More torque is always a good thing!
If you visualize an exhaust pulse as a colume of gases moving rapidly through the exhaust tubes, it is easier to imagine what is happening inside the exhaust system. Clearly, a gas colume just wants to get out of the exhaust. It has mass and therefore inertia. The fewer restrictions it encounters, the better. Imagine the gas colume having a smooth, tubular path with gentle bends, no collisions with other gas columes, etc. vs. sharp bends, baffles, and turbulence etc.
wizard
Never Forgotten
..warbaby, this ws an excellent presentation, and also you keep track of the follow-ups questions an' all, thanks!
1) So, if I understand correctly ther is NO exhaust system that can give torque to the entire rpm range (mainly below hp peak) AND add a few ponies to the peak point..
2) Which is the full exhaust system that YOU would recommend for more torque and what are the mods on ecu and/or shafts that would be necessary? I am talking particular here, so if you don't want to "expose" your preferences to common view, I will understand..
3) Weight of the standard system IS an issue! (..along with the heavy wheels, but that's another issue altogether..). I am willing to go for a full exhaust 4
1 system just for the less weight benefits alone. The HMF's I particularly liked but they use two cans. Should I "trade" the extra weight of the HMF's for the lighter single-can system, and how can I preserve the TORQUE (this is what I 'm after, couldn't care less about more "peak" hp power, too dangerous here in Greece to ride on those rpm ranges.. (..oh, well, occasionally maybe.. )
Thanks for an informative review, and if your time permits some answers to the above questions..
1) So, if I understand correctly ther is NO exhaust system that can give torque to the entire rpm range (mainly below hp peak) AND add a few ponies to the peak point..
2) Which is the full exhaust system that YOU would recommend for more torque and what are the mods on ecu and/or shafts that would be necessary? I am talking particular here, so if you don't want to "expose" your preferences to common view, I will understand..
3) Weight of the standard system IS an issue! (..along with the heavy wheels, but that's another issue altogether..). I am willing to go for a full exhaust 4
Thanks for an informative review, and if your time permits some answers to the above questions..
Not sure if its a BDE gen3, I bought the bike with it on. It is the full tatanium one with the titanium can.
The bike has 14,000 KMS (8,000 ish miles on the bike)
Not sure when the pipe was put on
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