why an airbox?

[tdmf]

I was wondering, what the use is for an airbox. I see these highly expensive performance/race ones in carbon fiber for the 848, 1098, 1198, and so on, which cost 2000, and wondering, wouldn't simple pods be even more effective for race/performance/street race purposes? Do the airboxes have a function? I know the OEM are there to prevent rain going in there, as well as for emissions purposes; but these expensive aftermarket ones???

Thanks for enlightening me

T

[koko64]

Welcome to the forum. It's a great international community.
Go and introduce yourself in the introduction section.

Much has been discussed about this topic and it's worth using the search function to read up on the various arguments for and against airboxes. Which model do you have?

[Mhanis]

I would suggest that since modern MotoGp and World Superbikes all appear to use air boxes, and their ONLY objective is to go faster, that the manufacturers seem to believe the air box is beneficial.

If they believed pods were "more effective for race/performance/street race purposes" that is exactly what they would be doing, especially in MotoGp where the bikes are not production based.

I have no evidence to show the factories are right but I would find it hard to believe that they have spent MILLIONS over the years and never thought to test/compare the difference themselves.

Mark

[koko64]

The reason I asked what model you had was that it will make a difference I think on whether you are better off keeping the airbox.
People have had varying results with both pods and airbox mods, depending on the kits they used, type of mods and tuning applied.

Of course any SBK with ram air needs its sealed airbox. A non ram air model bike can work very well with an open airbox (lid cut open and tuned accordingly). Some people have achieved good results with Pod filters on some two valve EFI Monsters when a good velocity stack is part of the kit (again tuned accordingly).

On older carbed models, open airboxes work well with a jet kit when tuned to suit. Pods tuned to suit work ok too on those older models, but both work better than the absolutely stock, closed airbox and stock jetting.
The stock airbox on a carbed Monster is quite small in volume and inefficient in shape and flow characteristics imo, so that's why pods are not far behind with those models.
Pods are quite popular, people like the clean look, loss of weight and ease of service access.

[ducpainter]

On the Tamburini design SBK's the stock airbox mounts will break over time which indicates the frame is flexing.

The carbon Corse and aftermarket airboxes actually stiffen the frame very slightly.

[koko64]

I think I read somewhere that the odd SP or SPS came with carbon airboxes.

[ducpainter]

I think I read somewhere that the odd SP or SPS came with carbon airboxes.

Yup.

There were some good ones that actually helped. Some were just bling and broke like the stockers.

[koko64]

The strong ones worked like a frame cross member?

[ducpainter]

The strong ones worked like a frame cross member?

I doubt they were that strong.

I also doubt any mortal could feel the difference.

Bayliss, Checa, or Chili...perhaps.

[koko64]

Didn't they remove an actual cross member at one stage to increase the airbox volume? It really helped fatten the power by all reports.

[ducpainter]

Dunno

[Buckethead]

One of the other reasons is that engines tend to prefer a volume of "calm" air, especially at low- and part-throttle openings. If you look at dyno curves for airbox vs modded airbox vs pods, a lot of times you'll see higher numbers down low. As this is where engines spend most of their functional life, it makes sense to design for that use. Sacrificing a few ponies all the way at the pointy end to get a better running bike around town makes for a much more enjoyable riding experience overall.

[koko64]

I'd agree with that.
I like a good airbox. My Gixxer has a beauty.

[xcaptainxbloodx]

In order for our engines to work best they need large volumes of cold still air.

But on a wider notion, in the early 80s race teams started working with resonating air boxes as a way to flow the air for a more efficient detonation.  This is why you see the move from K&N pods to CF airboxes with $$$$$$ development budgets in the late 80s early 90s.

this books has an excellent explanation of how and why. its a bit dated, but it will go a long way to making you understand how horsepower is made and applied;

http://www.amazon.com/Sportbike-Performance-Handbook-Motorbooks-Workshop/dp/0760331839

[tdmf]

Yes, I can see, the airbox can make sense in a race/autobahn bike. I have an 2008 S2R1000 (initially wanted the discussion general and did therefore not mention) and I use it more for in-town/cafe racer/commuter, and the saving of 2kg when removing the airbox and going with pods is more attractive to me.

Thanks