ceebmoj
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| posted on 26/12/11 at 03:17 PM |
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Replacing air box
I have been looking at cars that have the top of the bike air box poking through the bonnet but preffir a cleaner look. and recently say this air box.
So if I was to make up a new air box to keep every thing below the bonnet line are there any rules to follow? failing that does any one know of a
location to source them from.
Blake
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SausageArm
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| posted on 26/12/11 at 04:12 PM |
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That's from Mac#1 Motorsports, phone number 0114 251 1016
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bobinspain
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| posted on 26/12/11 at 06:43 PM |
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I can't add anything from personal experience (yet), but I have an MK Busa-engined car about to be deliverd to me here in Spain.
If you check out 'Busa breathing,' you'll find responses to the question I posed, which was: is it necessary to cut a hole in the
bonnet of an MK Indy-R to allow it to breathe properly?'
Aesthetics are important to me, but don't over-ride all other considerations. On balance------ well, see what folk in the thread think.
No bonnet hole for me. (for now).
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eddie99
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| posted on 26/12/11 at 06:50 PM |
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These are the 3 points i got about building a Airbox were:
1) Size is king - bigger the volume the better....
2) On the inside of the airbox, you want the tb trumpets to end flush with the airbox, you dont want the trumpets sticking 10mm into the airbox.
3) You want the air to speed up in the airbox, so make the centre/middle section larger so the intake air speeds up, then compresses down into the
trumpets.
Sorry if that doesnt make sense..... I'll explain clearer if needed after the west ham match 
Hope it helps.
[Edited on 26/12/11 by eddie99]
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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iank
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| posted on 26/12/11 at 06:51 PM |
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See this thread for sources.
http://www.locostbuilders.co.uk/viewthread.php?tid=164202
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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Hector.Brocklebank
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| posted on 26/12/11 at 07:24 PM |
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quote:
Originally posted by eddie99
These are the 3 points i got about building a Airbox were:
1) Size is king - bigger the volume the better....
2) On the inside of the airbox, you want the tb trumpets to end flush with the airbox, you dont want the trumpets sticking 10mm into the airbox.
On point 1 Why ?
I thought the bike manufacturers spent a lot of time and money on developing an optimum "volume" of their airboxes so
"bigger the volume the better" would not really be the optimum, when really it might be "closer to what the manufacturer does the
better"
On point 2 again Why ?
As again most of the bike manufacturers spend shed loads of money and come up with data other than Flush see stolen picture below
 
Description
 
Description
Not trying to be funny, just trying to understand the advice being given.
[Edited on 26/12/2011 by Hector.Brocklebank]
Some people can never handle the truth and always try to shoot the messenger instead of taking an honest look in the mirror (its always easier to
blame another than to face reality), but secretly they wish they could grow a pair and be the messenger !!!
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eddie99
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| posted on 26/12/11 at 07:31 PM |
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I got that advice of Andy Bates.
Im sure when he is back from holiday he'll come on this post and give the reasoning. However with regards to point 2, its because having the lip
makes air go up the side of the trumpet and causes turbulence where the air is turning around 180 degrees into the entrance of the trumpet...
Disturbing the rest of the air entering the trumpet..
With regards to point 1. Im not sure the exact reasoning but i presume that bike maunfacturers produce them as big as possible within the packaging
restraints.
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Volvorsport
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| posted on 26/12/11 at 07:56 PM |
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if you have a full rolled lip on the trumpets , they dont have to be flush .
the picture of that airbox will obviously have a lot of dyno time behind it .
www.dbsmotorsport.co.uk
getting dirty under a bus
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mac1ZR
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| posted on 26/12/11 at 08:16 PM |
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The crashed Mac#1 was built by me, i designed the airbox for the K5 GSXR1000 fitted to that car. The airbox was then fabricated by Bryn at Allyfab,
and MAC#1 could possibly have similar in stock
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bi22le
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| posted on 27/12/11 at 02:08 AM |
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My god that's some handy work.
must of been nothing short of real talent to redesign the front of that car??
Track days ARE the best thing since sliced bread, until I get a supercharger that is!
Please read my ring story:
http://www.locostbuilders.co.uk/forum/13/viewthread.php?tid=139152&page=1
Me doing a sub 56sec lap around Brands Indy. I need a geo set up! http://www.youtube.com/watch?v=EHksfvIGB3I
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BobM
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| posted on 27/12/11 at 08:19 AM |
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quote:
Originally posted by Hector.Brocklebank
quote:
Originally posted by eddie99
1) Size is king - bigger the volume the better....
On point 1 Why ?
I thought the bike manufacturers spent a lot of time and money on developing an optimum "volume" of their airboxes so
"bigger the volume the better" would not really be the optimum, when really it might be "closer to what the manufacturer does the
better"
[Edited on 26/12/2011 by Hector.Brocklebank]
No, the manufacturers spent a lot of money achieving the best compromise - bigger is better but they've got packaging problems on
bikes as the airbox sits 'inside' the fuel tank.
Not very Locost but very BEC
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Hector.Brocklebank
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| posted on 27/12/11 at 08:48 AM |
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quote:
Originally posted by BobM
No, the manufacturers spent a lot of money achieving the best compromise - bigger is better but they've got packaging problems on
bikes as the airbox sits 'inside' the fuel tank.
If bigger is better, they would have no air box whatsoever and just have open bell mouths with no air-box, I agree they have packaging constraints,
but there must be a reason that they design convoluted style air-boxes to channel air, just look at Kawasaki's ZX14.
I think that there is a lot more science to it than just bigger being better.
But admittedly in a 7 again there is packaging constraints to consider, but if possible within the packaging area in a 7 it might be best to try and
keep everything as close to stock as possible, where inlet and exhaust are concerned.
[Edited on 27/12/2011 by Hector.Brocklebank]
Some people can never handle the truth and always try to shoot the messenger instead of taking an honest look in the mirror (its always easier to
blame another than to face reality), but secretly they wish they could grow a pair and be the messenger !!!
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BobM
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| posted on 27/12/11 at 08:59 AM |
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quote:
Originally posted by Hector.Brocklebank
If bigger is better, they would have no air box whatsoever and just have open bell mouths with no air-box, I agree they have packaging constraints,
but there must be a reason that they design convoluted style air-boxes to channel air, just look at Kawasaki's ZX14.
I think that there is a lot more science to it than just bigger being better.
Agreed.
I think apart from getting cool air they're trying to get positive pressure but without the turbulence associated with it, hence the narrow
inlets widening out into the volume of the box designed to smooth out the flow.
There are issues around the pulses of pressure generated by the intake too, not that I know a lot about it. Andy Bates did tell me once of someone who
had an aluminium airbox fabricated which was a bit of a disaster as they got a resonance which hit performance big time.
Not very Locost but very BEC
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Hector.Brocklebank
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| posted on 27/12/11 at 09:12 AM |
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quote:
Originally posted by BobM
Agreed.
I think apart from getting cool air they're trying to get positive pressure but without the turbulence associated with it, hence the narrow
inlets widening out into the volume of the box designed to smooth out the flow.
There are issues around the pulses of pressure generated by the intake too, not that I know a lot about it. Andy Bates did tell me once of someone who
had an aluminium airbox fabricated which was a bit of a disaster as they got a resonance which hit performance big time.
I agree with the fabricated alloy part, not being a optimum design.
I think the way to go with an aftermarket air-box for a 7 style vehicle might be to fabricate one using GRP to get some strength just like the OEM
gets with an injection moulded item, and such a design still have a relatively amount of versatility that can still be fabricated by the guy in his
shed.
Some people can never handle the truth and always try to shoot the messenger instead of taking an honest look in the mirror (its always easier to
blame another than to face reality), but secretly they wish they could grow a pair and be the messenger !!!
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:{THC}:YosamiteSam
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| posted on 27/12/11 at 10:17 AM |
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quote:
Originally posted by BobM
quote:
Originally posted by Hector.Brocklebank
quote:
Originally posted by eddie99
1) Size is king - bigger the volume the better....
On point 1 Why ?
I thought the bike manufacturers spent a lot of time and money on developing an optimum "volume" of their airboxes so
"bigger the volume the better" would not really be the optimum, when really it might be "closer to what the manufacturer does the
better"
[Edited on 26/12/2011 by Hector.Brocklebank]
No, the manufacturers spent a lot of money achieving the best compromise - bigger is better but they've got packaging problems on
bikes as the airbox sits 'inside' the fuel tank.
errr - no - manufacturers build everything to a cost first - they just tell you its performance first
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Hector.Brocklebank
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| posted on 27/12/11 at 11:32 AM |
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quote:
Originally posted by :{THC}:YosamiteSam
Err - no - manufacturers build everything to a cost first - they just tell you its performance first
that might be true to a point, But....
You cannot deny that even within those constraints the manufacturers are provably eking out more and more power year after year, so they must be doing
some sort of development (be it in conjunction with their race departments, it dont really matter) as its still pushing things, and money is still
being spent.
Some people can never handle the truth and always try to shoot the messenger instead of taking an honest look in the mirror (its always easier to
blame another than to face reality), but secretly they wish they could grow a pair and be the messenger !!!
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:{THC}:YosamiteSam
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| posted on 27/12/11 at 12:25 PM |
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quote:
Originally posted by Hector.Brocklebank
quote:
Originally posted by :{THC}:YosamiteSam
Err - no - manufacturers build everything to a cost first - they just tell you its performance first
that might be true to a point, But....
You cannot deny that even within those constraints the manufacturers are provably eking out more and more power year after year, so they must be doing
some sort of development (be it in conjunction with their race departments, it dont really matter) as its still pushing things, and money is still
being spent.
think that depends on the car manufacturer and car tho - lol - look at a average car - seems BHP figures are pretty similar as years ago - didnt the
2.0 pinto sierra have around 100bhp? not vastly different - the edge now is in how much more clean and exact the burns are - they have no choice by
law they have to clean it up which i guess works hand in hand
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Hector.Brocklebank
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| posted on 27/12/11 at 12:51 PM |
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quote:
Originally posted by :{THC}:YosamiteSam
think that depends on the car manufacturer and car tho - lol - look at a average car - seems BHP figures are pretty similar as years ago - didnt the
2.0 pinto sierra have around 100bhp? not vastly different - the edge now is in how much more clean and exact the burns are - they have no choice by
law they have to clean it up which i guess works hand in hand
erm we were discussing motorcycle development with regards to the inlet side, and only discussing cars in the guise of a 7 fitted with a motorcycle
engine.....
Some people can never handle the truth and always try to shoot the messenger instead of taking an honest look in the mirror (its always easier to
blame another than to face reality), but secretly they wish they could grow a pair and be the messenger !!!
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ceebmoj
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| posted on 27/12/11 at 04:28 PM |
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Thanks for the feed back guys. Will keep looking round and see what I can see on other cars.
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:{THC}:YosamiteSam
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| posted on 27/12/11 at 05:42 PM |
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quote:
Originally posted by Hector.Brocklebank
quote:
Originally posted by :{THC}:YosamiteSam
think that depends on the car manufacturer and car tho - lol - look at a average car - seems BHP figures are pretty similar as years ago - didnt the
2.0 pinto sierra have around 100bhp? not vastly different - the edge now is in how much more clean and exact the burns are - they have no choice by
law they have to clean it up which i guess works hand in hand
erm we were discussing motorcycle development with regards to the inlet side, and only discussing cars in the guise of a 7 fitted with a motorcycle
engine.....
i digressed - apologeez
pray continue sirs
on same topic tho - my car has the original hayabusa air box fitted with some mods and works very very well. - in doing so knocked 3db from intake
noise as well. - pleased with the install
[Edited on 27/12/11 by :{THC}:YosamiteSam]
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iiyama
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| posted on 28/12/11 at 02:04 PM |
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Built this and havent noticed any drop in performance, although I have yet to get it back on the rollers for a definitive answer:-
Filter sits square to airflow in the scoop:-
If its broke, fix it. If it aint broke, take it apart and find out how it works!
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ceebmoj
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| posted on 28/12/11 at 06:02 PM |
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Very very nice car.
How did you make the air box? Have you done a how to?
also where did you get the cover from?
[Edited on 28/12/11 by ceebmoj]
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phelpsa
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| posted on 28/12/11 at 06:21 PM |
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The larger the airbox, the larger the amount of 'still' air you have to draw from and the less effected one cylinder will be by the
preceding one. That mean the least intake induced torque reduction.
It is however possible to 'pulse tune' the intake like you would pulse tune an exhaust to give a high pressure wave within the airbox as
the valve opens at certain engine speeds. This requires a very specific volume and shape of air box. With modern bike engines this is likely to have
been done for you, hence the advantage of the standard box.
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r1_pete
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| posted on 28/12/11 at 06:28 PM |
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quote:
Originally posted by Hector.Brocklebank
quote:
Originally posted by eddie99
These are the 3 points i got about building a Airbox were:
1) Size is king - bigger the volume the better....
2) On the inside of the airbox, you want the tb trumpets to end flush with the airbox, you dont want the trumpets sticking 10mm into the airbox.
On point 1 Why ?
I thought the bike manufacturers spent a lot of time and money on developing an optimum "volume" of their airboxes so
"bigger the volume the better" would not really be the optimum, when really it might be "closer to what the manufacturer does the
better"
On point 2 again Why ?
As again most of the bike manufacturers spend shed loads of money and come up with data other than Flush see stolen picture below
Description
Description
Not trying to be funny, just trying to understand the advice being given.
[Edited on 26/12/2011 by Hector.Brocklebank]
Point 1, most bike engines are designed to draw slightly pressurised air from the box, the pressure is generated by the forward motion and inlet
scoops in the bikes faring, a the larger the reserve of this pressurised air the smoother the engine will run.
Point 2, if the trumpets protrude, turbulence will occur at their 'rim' and spoil airflow.
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Alfa145
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| posted on 28/12/11 at 06:36 PM |
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How much difference would running without an air box make?
I've never run with a filter on my R1 carbs (on a Xflow) and never had any problems, they're well shielded in the engine bay. It was tuned
withough filters on and put out good power and torque.
I didn't have room to fit a decent depth pipercross filter and only had the room to fit pipercoss socks, which have a high risk of going up in
smoke so I chose to not fit them due to the fire risk and went with unfiltered carbs. Done over 6000 miles now like this and got no issues.
Probably a different scenario for a higher revving bike engine?
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