89 replies to this topic

[Murray]

Airboxes are getting bigger for one main reason to difuse niose engines make all sorts of sucky slurping nioses when they breath in. I have pods fitted to my carbed 1100 sport I cahnged the carbs at the same time however one thing it does do is shorten the intake tract significantly the V11's with thier snorkle nose have pretty well no ram air effect even the earlier 1100 sport/daytonas it had a marginal effect at best (intakes weren't ideally placed. But with a number of vehivles I have found that a shortened intake tract increase response and mid to low end torque where as a long one will give top end power F1 cars an few road vehicles have variable intakes to get the best of all worlds. So K&N's pods would be my suggestion at least you get a nice intake whistle to !@## everyone off with.

[Paul Minnaert]

What you must do, is use the plastic cone that's going into the airbox, and mount the pod on that. Mounting the pod directly onto the Tbody won't do it. I have my pods on the plastic cone. So the length is the same. For me, the pods were estethical, and pracitical, as I have no place left for the box. I hope the police won't get me for to much sound, but things are getting worse here in europe, especialy parts of germany and switserland, where the swiss thake the whole bike, and then see for yourself that you get it back from the police
But I think I have to experience it myself, before I take action. At the moment I have a silencer under the gearbox made!

[emry]

I have just removed my airbox lid and made a bracket to keep the filter in place; ala FBF. The only seat of the pants differnce i noticed was more intake noise. A plus in my opinion. Most modern sportbikes loose significant average power when the air box is removed, due to the increase of turbulant air and the shortening of the intake tract. This often moves the tuned area of the intake out of the rpm range of the engine.

But with a number of vehivles I have found that a shortened intake tract increase response and mid to low end torque where as a long one will give top end power

Actually the shorter the intake tract the better top-end and the longer intake tract will produce better lowend power.

Check this for more info.
Intake tuning

[gthyni]

Actually the shorter the intake tract the better top-end and the longer intake tract will produce better lowend power.

Check this for more info.
Intake tuning

Excellent read, if a little car centric.
A sport motorcycle has more radical cams and works at higher RPMs
than a car engine.

I went out and measured
I estimate the intake from valve to airbox the column is
about 23cm (9"),
which with a pod directly on the injection unit is reduced
to about 16cm (just above 6"). The intake lenght would
be reduced by 30%.
A moderately shortened manifold and the freer airflow of PODs
should theoretically give more power in the higher RPM range.

[Dirtybill]

Most racebike goes for pods since it is easy to maintain and gives a
reliable free flow of air (and saves weight too).

Wrong. With FI, most if not all race bikes I've seen, are using specially made and shaped carbon fibre air boxes.

Ram-air:
Destroys aerodynamics (not that if makes much difference on my V11s sans
fairing). More important it is unreliable and make it hard to map the FI.
How do you simulate the effect of ramair when running in a bench mapping
you PowerCommander?

The same way ZX-12R and Haybabusa, as well as other owners do. The FI will still measure out the correct amount of fuel with varying amounts of air coming into the system. I think you're comparing ram air with carbs instead of ram air with FI. Big difference.

My SP-1 was mapped on a Dyno and it has ram air. Ran fine wether the ram air came into effect or not.

And the bit about supporting your pods I have to attribute to the Head Mechanic and Service Manager at my local Guzzi shop.

I think you maybe getting carb with ramair confused with FI with ram air.

[Dirtybill]

I had the airbox removed at the first service. FBF filter gives great intake sound, the plugs run clean, there has been no spitting or backfiring, the idle never surges or varies and the filkter is reusable. All seat of the pants valuations.

Do you realize we probably live about 10 minutes from each other? Are you the owner of the burgundy LeMans I've seen at the bookstore/restaurant in Ft Langley?

There's another lower mainlander on here too. "Januz" is from North Vancouver.

[gthyni]

>Most racebike goes for pods since it is easy to maintain and gives a
>reliable free flow of air (and saves weight too).
Wrong.  With FI, most if not all  race bikes I've seen, are using specially made and shaped carbon fibre air boxes.

To clarify,
a was thinking amateur racing,
not MotoGP where carbon is cheap
and you do not need filters at all since the
motor is rebuilt for every race.
The "airbox" is then a tuning device to optimise the flow
and length of the air column as described in the excellent document at:
http://www.grapeaper...intaketuned.cfm

>Ram-air:
>Destroys aerodynamics (not that if makes much difference on my V11s sans
>fairing). More important it is unreliable and make it hard to map the FI.
>How do you simulate the effect of ramair when running in a bench mapping
>you PowerCommander?

The same way ZX-12R and Haybabusa, as well as other owners do.  The FI will still measure out the correct amount of fuel with varying amounts of air coming into the system.  I think you're comparing ram air with carbs instead of ram air with FI.  Big difference.

My SP-1 was mapped on a Dyno and it has ram air.  Ran fine wether the ram air came into effect or not.

And the bit about supporting your pods I have to attribute to the Head Mechanic and Service Manager at my local Guzzi shop. think you maybe getting carb with ramair confused with FI with ram air.

My point was (even if it was clear enough)
I do not think ramair does any real diffence in real life,
it is more a marketing gimmick.
If it had a significant effect it would create problems.
Even an advanced adaptive engine control computer
like the one on BMW M-technic sport cars has limits
to what parameters it works within. It works to adapt to
the natural variantion in temperture, humitity, petrol
quality and altitude, but if you do significant changes
to the flow in intake or exhausts it too has to be remapped.

The problem with ramair (if it works) is that it is not predictable
which would make it impossible to map the FI in an optimal way.

The difference between carbs and FI is a finer granuality in the
"mapping" and a certain degree of adaptivity in the FI unit
(but as said within limits).

But my main point again ramair was that:
I think is mostly hype with no real life effect.

[emry]

I remember reading a article in Performance Bikes I think that tested air pressure of the air box at speed and then simlated the pressure on a Dyno. If I recall below 120mph no effect. Above it began to make a little but never made more than 2 or 3. I was on one of the early zx-11's.

So. Yes it works. But it really is hype since most of us would never get to use the beneifts...what little there is.

As for fuel control. Most motorcycles that use ram air and are fuel injected just have a Manifold Pressure Sensor which would correct for any pressure gained from the ram effect. Older carb bikes just referenced the fuel bowl vent to the air box thus pressure was equalized and proper fueling was maintained.

[Dirtybill]

Sorry, I disagree. My RC-51 (SP-1) used a flapper valve in the front intake hole of the fairing. This valve would open at 8000 rpm and a significant kick in the pants could be felt from the ram air. Rumours had it pegged at another 8hp on tap.

The VTR (aka Firehawk) which is also a Honda V-twin does not use ram air and there is no significant kick at any rpm. I owned a VTR also.

The 1986 1000 Ninja used a similar ram air method but with no valve. The long intake runners ran from the top of the airbox to the front of the bike. At the time, this was the fastest production bike you could buy. Again, a kick up the arse could be felt at higher rpms.

I owned one of those bikes also.

I don't really care about all the technical jargon. Engineering mistakes are full of it and Mechanics (something I do know about) are required to repair those mistakes. I hope that's "clear enough".

[al_roethlisberger]

OK, well I guess I've decided to go for a "hybrid" solution for now

The reason I was asking about the differences in solutions, is that I "accidentally" had some of the correct K&N filters on-hand for a pod conversion, and I came across a used airbox for about $20USD. So I had all the ingredients to do some experimentation.

Personally I really like the idea of pods because of the simplicity, the sound, and the look... all of which I liked when I had them on my FJ1200. But in contrast to most people's tastes who like the pods, I like my airbox side-covers and didn't want to expose the frame and bits above the red side-plate.

So, I did what I know a few other people have done, but have never seen photos of. I removed the stock airbox, and made some brackets from the remains of my spare airbox, and some aluminum stock.

In my opinion, this really opens up the area under and around the frame, and can only be a "good thing" for airflow and cooling. Plus with the airbox gone, I have the potential to relocate the fuel-pump on top of the frame(next project).. or at least somewhere a bit further from the cylinders. But again, most of all, it gives me a bunch of space to reroute some wiring, etc... away from heat, and out of sight with the airbox removed.

So, now I have my two pods, under my side-covers, so this adds some weather protection, plus I'm going to add the triangular piece of plastic to the swing-arm to protect the transmission breather, pods, and rear shock. With all of this, it should actually preclude any major concerns about water and the pods. It should provide at least as much protection as my FJ had, and I never had any water problems.

So following are a couple mock-up photos. I have to still fine-tune and nicely finish the aluminum, etc... But I think it looks fairly spiffy.

P.S. What/where do you do with the oil breather hose that was hooked to the airbox? This is the hose that comes from the banjo fitting on top of the spine at the very front of the tank.

Attached Files

•  pod_top.jpg   26.03KB   274 downloads

[al_roethlisberger]

The bottom and rear of the airbox are actually gone as well, basically the only remaining part of the airbox is the same shape as the side-covers so that they could be bolted to them correctly, with the remaining carcass of the airbox providing material to which to fasten the aluminum bar-stock.

So the pods should get air cleanly from all around, and even inside the side-covers there is an inch or more of clearance on the side by the cover.

Attached Files

•  pod_left.jpg   39.85KB   194 downloads

[al_roethlisberger]

I'll post some photos tomorrow night of the whole cover assembly off of the bike so you can see more clearly how it's attached and built.

Attached Files

•  pod_right.jpg   55.57KB   122 downloads