martin500
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| posted on 27/1/18 at 03:57 PM |
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air box
I have been having problems getting the noise of my ZX9R phoenix down to an acceptable level and am getting a lot of induction noise which I think is
being picked up when testing the exhaust so I decided to build an air box, this will also have the advantage of forced cold air to the carbs.
The engine is fitted with a piper cross PX500 air filter so I decided to make an air box that would fit over that air filter and mount to the PX500
back plate.
I started with a filter frame mounted to a wooden bade then glued on foam to start shaping, the picture below is version 1, you can see the piper
cross filter frame.
I then covered it with filler, sanded and painted before applying lots of coats of mould release wax and used it as a mould to make the air box
I was not happy with the the shape of the first air box when I fitted it to the car and it didn't really have enough height at the rear for the
air filter
So I made version 2 which l think looks better and has more room above the air filter
I now need to decide if I am going to fill and paint it, take a mould off it to make a new one which will give a better external finish or just leave
it as it is, but I shall try it out first once the weather improves.
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tims31
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| posted on 28/1/18 at 07:39 AM |
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Nice work, can I ask where you got the moulding foam from?
I think once you have completed the design and its working it would be good to finish the outside surface off too.
Build: http://www.martinsfurybuild.co.uk/
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Andy B
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| posted on 28/1/18 at 09:10 AM |
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If the airbox works to create more airflow, which it certainly looks like it will, you are going to run in to a big issue with fuelling.
As you are running carbs, you will be forcing lots more air in but no more fuel, this will cause big leaning out of mixture. To make it even mor
difficult, the airbox pressure will be variable dependant on speed so the fuel compensation needs to be variable too
You can try linking the float bowl vent pipes into the airbox so the pressure works on the fuel in the bowls and pushes more fuel up the jets if there
is a pressure increase.
When we tried that years ago we got very choppy carburation and eventually had to mount the entire carburettor inside the airbox so that all circuits
worked in the same pressure at any given point in time
Hope that helps
Andy
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martin500
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| posted on 28/1/18 at 09:32 AM |
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quote:
Originally posted by tims31
Nice work, can I ask where you got the moulding foam from?
I think once you have completed the design and its working it would be good to finish the outside surface off too.
I was looking for foam over the christmas break so could not find ay styrofoam so i bought some blocks of flower arranging foam from Hobbycraft, it
worked ok but was a bit fragile.
Martin
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martin500
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| posted on 28/1/18 at 09:36 AM |
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quote:
Originally posted by Andy B
If the airbox works to create more airflow, which it certainly looks like it will, you are going to run in to a big issue with fuelling.
As you are running carbs, you will be forcing lots more air in but no more fuel, this will cause big leaning out of mixture. To make it even mor
difficult, the airbox pressure will be variable dependant on speed so the fuel compensation needs to be variable too
You can try linking the float bowl vent pipes into the airbox so the pressure works on the fuel in the bowls and pushes more fuel up the jets if there
is a pressure increase.
When we tried that years ago we got very choppy carburation and eventually had to mount the entire carburettor inside the airbox so that all circuits
worked in the same pressure at any given point in time
Hope that helps
Andy
Hi Andy,
The ZX9 utilises ram air with the float bowl vent pipes linked to the air box on the bike to balance the pressure, I have done the same so hopefully
it should work ok.
Martin
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Christof
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| posted on 29/1/18 at 03:01 PM |
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Nice work!
I happen to be doing the same thing, currently posting on the JPSC forum.
saw your method (using the backing plate) on a lotus forum, but I just used a spare piece of alumnium for a backplate.
Mine's under the bonnet so will leave it rough gf painted black like yours, but I'd p38 yours and make it pretty!
Hopefully I won't have ram issues, the dcoe vent holes (assume these are c12mm holes near the ram pipes) are inside the box, but it is fed from
a bonnet louvre, albeit through a filter etc.
Was looking at hobbycraft foam, but went for expanding foam inside a box. assume you glued some of the foam bricks together. expanding was ok, albeit
with some cavities and made quite a mess.
 
Description
[Edited on 29/1/18 by Christof]
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martin500
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| posted on 29/1/18 at 08:28 PM |
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quote:
Originally posted by Christof
Nice work!
I happen to be doing the same thing, currently posting on the JPSC forum.
saw your method (using the backing plate) on a lotus forum, but I just used a spare piece of alumnium for a backplate.
Mine's under the bonnet so will leave it rough gf painted black like yours, but I'd p38 yours and make it pretty!
Hopefully I won't have ram issues, the dcoe vent holes (assume these are c12mm holes near the ram pipes) are inside the box, but it is fed from
a bonnet louvre, albeit through a filter etc.
Was looking at hobbycraft foam, but went for expanding foam inside a box. assume you glued some of the foam bricks together. expanding was ok, albeit
with some cavities and made quite a mess.
Description
[Edited on 29/1/18 by Christof]
It seems like a popular winter past time!
I may yet make a box that comes back under the bonnet to be fed cold air from a bonnet opening but with the carbs pointing up in the air the shape
will be a bit more involved, I have some sheets of styrofoam at work so lots of material to play with, I just forgot to take them home for christmas.
On the mk1 I glued the foam with a hot glue gun but this caused problems rubbing down so i used evo-stick on the second one.
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theduck
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| posted on 30/1/18 at 11:32 AM |
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Making an airbox is currently on my todo list too, nice to see how youve done it
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Christof
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| posted on 5/2/18 at 02:31 PM |
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thought i'd hijack this thread again and show the finished article
 
Description
[Edited on 5/2/18 by Christof]
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