spdpug98
|
| posted on 30/5/16 at 06:48 PM |
|
|
Fitting Shorter Airbox - BEC
I'm finally thinking of putting my MNR to proper use and hill climbing it, as thinking I might retire my little 106 at the end of the year
I have seen quite a few BEC's running original air boxes cut up to fit under the bonnet, with some owners saying it's improved
performance. I have been looking at getting an R1 air box in but have had to remove basically all of the upper part (pic below) would it be worth
running the box like this as not much space above the central inlet trumpets, my plan was to run the air in, in front of the centre trumpets by
cutting a hole and glass fibre'ing a piece of duct in - can anyone offer any advice
My Blog: http://spdpug98.wordpress.com/
|
|
|
|
|
Rosco86
|
| posted on 30/5/16 at 08:23 PM |
|
|
I can't really answer your question but could you just use a foam filter?
My Build Thread
|
|
|
spdpug98
|
| posted on 30/5/16 at 08:29 PM |
|
|
quote:
Originally posted by Rosco86
I can't really answer your question but could you just use a foam filter?
I'm already running a foam filter, was hoping to see an improvement going for the original air box plus reducing the induction noise down
My Blog: http://spdpug98.wordpress.com/
|
|
|
Rosco86
|
| posted on 30/5/16 at 08:34 PM |
|
|
Ah ok, would it be easier to make a fresh box from some aluminium sheet? Or a fiberglass one?
My Build Thread
|
|
|
hkp57
|
| posted on 31/5/16 at 06:15 AM |
|
|
Do a search for member cosmick on here, he has just done a box for my Hayabusa, different box but I am sure the same technique could be applied.
He cuts the plastic and fusion welds it back together, here is a before and after shot from his archive.
 
Description
Fleet
SKC Raptor R - Hayabusa
Toyota C-HR Hybrid Limited Edition
Honda VFR1200 CrossTourer
DCT
Marlin Roadster 1800
Mercedes Vito 116 Sport
|
|
|
spdpug98
|
| posted on 31/5/16 at 07:11 AM |
|
|
Thanks, I'll have a look - starting to think I'll stick with the foam
My Blog: http://spdpug98.wordpress.com/
|
|
|
Andy B
|
| posted on 31/5/16 at 05:03 PM |
|
|
We have done a lot of work with airbox design and matched exhaust systems. To be honest it is largely due to gains from a new airbox that the Arion is
so much quicker in the RGB races this year.
Here's a few pointers that may help.....
Volume before filter can never be big enough on a Bec
Always try and build from grp or plastic over alloy - it resonates and can cause interesting characteristics
The stand off area above the bell mouth is crucial and reducing height to lid will seriously affect power
Keep inlets relatively small on the body and taper them up in n diameter to the airbox
An airbox will always work better in terms of power delivery on a Bec than an open filter
Use the biggest area of filter material you can - it's job is twofold - to filter particulates but also to work as a damper trimming out
turbulence
On a seven shape car a good area for intake is on the nose one on the corner where vertical meets horizontal surface
If you can achieve ram air pressurisation (and it is possible) small increases give big gains but tend to come in high up the speed range
A downside to achieving ram pressure is the motor can feel a little flat after braking and reapplying throttle as energy is used making the stall d
air flow again
A closed throttle dump valve will help keep air flowing to stop this symptom
Use the he smoothest bore I take you can - ribbed flexi hose creates lots of detrimental turbulence and can negate airbox gains - in o e case a 5bhp
loss
For this reason it is jaw important to build a good intake as airbox
That's about all I know about that - hope it's useful
Andy
|
|
|
spdpug98
|
| posted on 31/5/16 at 07:45 PM |
|
|
quote:
Originally posted by Andy B
We have done a lot of work with airbox design and matched exhaust systems. To be honest it is largely due to gains from a new airbox that the Arion is
so much quicker in the RGB races this year.
Here's a few pointers that may help.....
Volume before filter can never be big enough on a Bec
Always try and build from grp or plastic over alloy - it resonates and can cause interesting characteristics
The stand off area above the bell mouth is crucial and reducing height to lid will seriously affect power
Keep inlets relatively small on the body and taper them up in n diameter to the airbox
An airbox will always work better in terms of power delivery on a Bec than an open filter
Use the biggest area of filter material you can - it's job is twofold - to filter particulates but also to work as a damper trimming out
turbulence
On a seven shape car a good area for intake is on the nose one on the corner where vertical meets horizontal surface
If you can achieve ram air pressurisation (and it is possible) small increases give big gains but tend to come in high up the speed range
A downside to achieving ram pressure is the motor can feel a little flat after braking and reapplying throttle as energy is used making the stall d
air flow again
A closed throttle dump valve will help keep air flowing to stop this symptom
Use the he smoothest bore I take you can - ribbed flexi hose creates lots of detrimental turbulence and can negate airbox gains - in o e case a 5bhp
loss
For this reason it is jaw important to build a good intake as airbox
That's about all I know about that - hope it's useful
Andy
Andy
Thank you that's very helpful, I'm not sure if I will have enough air space above the centre trumpets as the lid / top will only be a
couples cm's above them. I could always trim them down, I assume Yamaha put them in longer to smooth the airflow as the entry point was centre
of the box
My Blog: http://spdpug98.wordpress.com/
|
|
|
Andy B
|
| posted on 31/5/16 at 08:47 PM |
|
|
We use shorter spun alloy bell mouths on the Hondas - improve mid to top end power and allow lower airbox without compromise - think we do a set for
your engine as well - what model/year is it
|
|
|
spdpug98
|
| posted on 31/5/16 at 08:51 PM |
|
|
quote:
Originally posted by Andy B
We use shorter spun alloy bell mouths on the Hondas - improve mid to top end power and allow lower airbox without compromise - think we do a set for
your engine as well - what model/year is it
That could be a plan it's a 2003 R1 (5PW I think)
My Blog: http://spdpug98.wordpress.com/
|
|
|
