89 replies to this topic

[al_roethlisberger]

There's certainly some small degree of religion about this topic depending on who you ask , and I've seen some of the dyno tests out there. But unfortunately many of those have a couple of other variables in play at the same time such as exhaust x-overs, etc. that make it hard to ascertain what is contributing or impeding performance where.

So, for those that have ridden, tuned, or have bikes where you've tried modifying the stock airbox with something like Fast By Ferraci's lid eliminator and you've run with the K&N filter pods off of the TBs.... I'd love to hear your thoughts of the benefits and tradeoffs for both.

I am sure both work fine based on a number of people that have had either, but I wanted to try to get this info and comparison in one thread for myself and anyone else that might have the same questions and interests.


thx!
al

[guzzi323]

I thought a long time about this before I decided to 'core' my airbox lid. I like the look and simplicity of K&N's but just about everything I've ever read about the subject says that engines like to breathe from large still masses of air. That's why airboxes keep getting bigger and bigger on sportbikes. Individual filters make the engine breathe in what is typically a messy, turbulent buch of air (Kind of like breathing with your head stuck out of the window of a car going 80 MPH.) Once I thought about it in those terms, the 'big pile of still air' theory made much more sense.

Of course I don't have any V11 feedback to offer because I had to take my bike in to the shop right after I cut the lid and I haven't even had time to change the map.

Once I get it back and play with the map I'll submit my vote...

-johnk

[jrt]

Hi Al (and all),

Don't know if it's fair to make this comparison without dyno measurements and statistics. Too many variables. I do have pods on my bike, but not out of zealotry, rather just that's the first mod that came out. They, whoever they are, reported the airbox mod after I had already cut up my intakes. Still, I like it. It looks good- opens the frame up a bit, and it sounds great.

John, I like your reasoning on modifying the airbox. It makes sense- laminar flow air has much better drawing power. We use it in labs (laminar flow hoods) where we work on extra nasty bacteria and viruses. mmmmm, bacteria and viruses....
The other concern I have about pods is that they might draw in water more easily in the rain.

Cheers,
Jason (sorry, couldn't vote- I cant make the comparison)

[dlaing]

I voted for the airbox because of the evidence here Doug Lofgren's dyno tests
But the evidence is not conclusive, just suggestive.
Theoretically I think the air box will produce more power on average throughout all the rpms, because it is a two into one system and the restriction of the filter is shared between the cylinders.
However if the total surface area of the pods is significantly more than the area of the flat filter, I would say that the pods should flow better, especially at high RPMs.
I think the ultimate set up would be two forward facing ram air boosted pods with a tuned crossover.
I went with the FBF kit because I am lazy and it works better than stock.
I like the fact that I do not have to reposition the air pressure sensor anywhere, and I don't have to do anything about the oil breather.
What do people do with the oil breather tube???
What I like about the pods is that they are easy to remove, they look slick, and they allow easy access to the shock absorber and fuel lines.
Also, in Moto Euro Magazine's article on the FBF tuned V11S, they say that Feracci says, "I can gain another 7 or 8 HP by fitting separate filters to the throttle bodies," "We are working on that as we speak"
Perhaps I should have gone with pods....

[Dirtybill]

The bad thing about pods is on the Guzzi they need to be supported or you run the risk of too much weight on the manifolds and a result of cracking. I don't like the look of safety wire running off of the pods and I have no scientifc evidence to back the "turbulent air flow" theory up, but I think it holds water.......so to speak.

I did mods on my Sport one at a time and all the results are seat of the pants, but, I started with the shop unhooking all the pollution crap,this was done at day 1 so I'm not sure about its affect but I did ride a friend's Sport with the pollution stuff still on it and it seemed underpowered and had rough idling. I then added a power commander, then pipes and tuning the PC. This is where I started to notice a big difference as the bike ran better everywhere in the rev range. Then a K&N in the stock airbox and played with the PC settings. Seemed to want to rev even more. Next, I went to a crossover and had to really play around with the PC, especially in the upper rev range. Big difference in top end power. Made a frame and hold down clamp for the K&N and removed the airbox lid, ran lean again so adjusted PC and now it runs great from idle all the way past 8000rpm. It literally leaps out of slow speed corners and will cruise at 150kph (around 90mph) effortlessly.

I had pods on my TDM850 a few years ago and on a trip into Idaho as we were gaining altitude, the rain started turning into sleet. It was getting very cold. My bike started misfiring and running like it had dirt in the fuel. Either water was getting into the pods, which I don't think was happening, nor do some Mechanics I've talked too, or the carbs were freezing up. Carb freezing is a problem for bikes and especially Kawasakis in the UK for riders who ride all year round. I think on the TDM, as it had a large airbox, the box itself helps prevent this.

For whatever its worth though, living in the Pacifc Northwest, with the amount of rain, temperature changes thru mountain passes and the variable weather, I'm going to stay away from pods, and wouldn't they be drawing in warm air on a Guzzi anyway?

[TX REDNECK (R.I.P.)]

I have the pods...cuz it looks kewl !l

[gthyni]

2 non-technical reason to go with pods:
1. looks - pods looks more like a race bike and without the airbox
you get a lighter more classic italian sportbike look.
2. sound - I have a K&N on my BMW car engine. Sound great when you accelerate.

Technical:
An engine runs on air (with a little petrol added), on a four-stroke
engine we would want free non-turbulent flow as possible of cold air.
(Cold air is richer in oxygen and have bigger mass per volume than warm)
I am sorry to say that a reliable freeflowing non-heated airstream is
difficult to find on a bike, so we need a compromise.
Most racebike goes for pods since it is easy to maintain and gives a
reliable free flow of air (and saves weight too).

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?

[jrt]

snip....
Also, in Moto Euro Magazine's article on the FBF tuned V11S, they say that Feracci says, "I can gain another 7 or 8 HP by fitting separate filters to the throttle bodies," "We are working on that as we speak"
Perhaps I should have gone with pods....

That brings up another good point. You can always go from a modded airbox to pods, but not the other way.

Cheers,
Jason

oh- I don't think the pods need to be supported- they weigh next to nothing, and are quite stiff on my bike. If I see evidence of cracking the manifold, it's probably time to replace it anyhoo.

[al_roethlisberger]

I'll be very interested to hear FBF's testing with pods on their project bike since they market an airbox lid eliminator, and it has seemed to work out well for them and others up to now.

Victor? ...what's the deal?

al

[guzzi323]

I'll be very interested to hear FBF's testing with pods on their project bike since they market an airbox lid eliminator, and it has seemed to work out well for them and others up to now.

First they sell us their airbox kit, then convince us that their pods are better??

Even if they have dyno runs with and without the pods it won't be definitive because with the pods you're not in a real world environment. The pods are just drawing from an even larger still air mass (the room) than with the airbox installed. Of course it'll make more power on the dyno that way...
Unless FBF runs their pod kit on a dyno in a wind tunnel we'll never know.
Ya know what I mean??

I'm not saying it's bad or wrong or any such thing to run pod filters. I'm just saying that dyno runs are an artificial environment and just because a computer says your fueling is correct on a dyno in a room doesn't neccesarily mean it'll be correct in the real world.

[gthyni]

The pods are just drawing from an even larger still air mass (the room) than with the airbox installed. Of course it'll make more power on the dyno that way...
Unless FBF runs their pod kit on a dyno in a wind tunnel we'll never know.

Hmm,
since the pods is closer to the engine they will suffer from more
from the engine heating the air around them on the bench
than in real life too.
So it will be hard to tell if pods has an advantage or disadvantage
conpared to the air box when running on the bench.

[jrt]

Wind tunnel? We don't need no stinkin' wind tunnel. Just stand next to the bike with a hair dryer

Sorry,
Jason

[dlaing]

Just stand next to the bike with a hair dryer

Are you talking superchargin'?

[dlaing]

RamAir is the way to go!
image from http://www.guzzisti.it/

[gthyni]

RamAir is the way to go!

Wow,
that was UGLY
I wont even tell you what it reminds me of since this is a family site

Another reason not to go for ramair beside the technical doubts.

If you really need more air and are not afraid of "uglifying" your poor
Guzi why not go for turbo charging.