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Location:
Cabramatta, NSW
Registered:
May 2002
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 Tuned length intake and resonance chambers
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Sat, 22 January 2005 05:40
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Was looking for information on tuned length headers to remove the boxer burble from the Liberty and I stumbled onto this page.
The pix are quite funny, but the read is interesting too. They tested the effect length and diameter of the intake pipe had on noise and power.
http://www.mgcars.org.uk/peterburgess/flugelhorn.h tml
http://www.mgcars.org.uk/peterburgess/flugelhorn2. html
It's a good lesson for those who think getting rid of the factory resonance chambers is a good idea.
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Location:
On your mum!
Registered:
May 2002
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Re: Tuned length intake and resonance chambers
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Sat, 22 January 2005 06:44
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Good read. I would like to see the "flugel horn" adapted for street use (maybe up in the air like a truck's exhaust).
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I Supported Toymods
Location:
Sydney
Registered:
December 2002
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Re: Tuned length intake and resonance chambers
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Sat, 22 January 2005 09:32
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I think the moto to that story is don't shove an aftermarket pod filter on an otherwise unmodified factory intake system!
Vehicle manufacturers would have gone to a lot of trouble to get the resonance to noise ratio as tuned as possible and changing the system unnecessarily will decrease performance and possibly increase noise.
Obviously if you have changed something in the system through necessity (e.g. changed the intercooler) then the tuning of the system would be out anyway.
Also tuning the intake like this would mainly be done by the manufacturer to increase power in the peak RPM range... changing the intake "may" improve performance outside of that range... to be able to target the tuning you would really need to be a mathematical genious or go through a lot of trial and error testing (probably both)
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Location:
Brisbane
Registered:
February 2003
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Re: Tuned length intake and resonance chambers
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Sat, 22 January 2005 12:15
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given that this is about induction systems, does anyone have any suggestions for design of intercooler ducting to and from the engine bay (apart from the standard 'keep it short' and 'dont introduce restrictions')?
it would be interesting to see if there's some research/testing of various setups and their impact on power/noise/etc?
i've seen some long (but very large) IC pipes in drag cars, and can vaguely recall an SW20 with extremely long pipes running thru cabin to a FMIC - apart from lag delays, are there any other issues associated with long pipes runs? are the timing benefits of short pipe eroded away by air speed losses from turbulence introduced by numerous bends? ...
my understanding of physics doesn't cover stuff like resonance, acoustics, pressure-wave propagation in air, etc so i'm kind of floundering.
cheers, charles.
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I Supported Toymods
Location:
Sydney
Registered:
December 2002
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Re: Tuned length intake and resonance chambers
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Sat, 22 January 2005 15:14
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Accoustic tuning is something beyond the realms of most people and even most performance workshops.
You would need to spend a lot of time and money to tune an intake system properly and if you change anything afterwards you will change the accoustics again.
Personally I wouldn't even consider trying to accoustically tune anything that is before the throttle body... your time and money would be better spent testing flow on a flowbench as far as I'm concerned.
Even the guys in the article appear to have made a roughly calculated guess at the tuned length of the intake and then cut the pipe say 1cm at a time until they found peak power on a dyno.
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Location:
Menai area of Sydney
Registered:
June 2003
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Re: Tuned length intake and resonance chambers
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Sun, 23 January 2005 00:45
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Get a book called Scientific Design of Intake and Exhaust Systems.
It'll tell you how to tune intake and exhaust using all sorts of parameters such as valve sizes, cam lift, port size, pipe length, pipe diameter, header design, compression ratio, rev band required, power band required, muffler design etc, etc, etc.
Bloody good book - I used to use it to tune motorcycle intake and exhausts. Will help understand the basics like when to use interference type headers and when not to.
Not an easy book to get but absolutely well worth it.
[Updated on: Sun, 23 January 2005 00:48]
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Location:
On your mum!
Registered:
May 2002
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Re: Tuned length intake and resonance chambers
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Sun, 23 January 2005 01:38
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| Scorpion wrote on Sun, 23 January 2005 11:45 |
Get a book called Scientific Design of Intake and Exhaust Systems.
It'll tell you how to tune intake and exhaust using all sorts of parameters such as valve sizes, cam lift, port size, pipe length, pipe diameter, header design, compression ratio, rev band required, power band required, muffler design etc, etc, etc.
Bloody good book - I used to use it to tune motorcycle intake and exhausts. Will help understand the basics like when to use interference type headers and when not to.
Not an easy book to get but absolutely well worth it.
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sounds good - I may try to get a copy through "Bookworks" at Bonds Rd in Punchbowl.
Out of interest; where did you get your coy from?
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