[Ice]

Thanks fellas for paving the way for those who will com later.

[prof_stack]

What will the K&N filter do for my C5 which has the upswept muffler? 

[douglasmoto]

Prof stack...not sure yet as I've only tested with a standard exhaust. I need you to try it out if you are willing. Give me an address by PM and I'll send one to you provided you will give a full report.

Art

[Ducati Scotty]

I'm curious to see if it will work with a more free flow exhaust too.

Scott

[Ducati Scotty]

Had a thought this morning...  instead of putting a breather on the crankcase vent, maybe just adapt a duck bill from the old iron barrels.  Gotta look into that.  What do you cats think?

Scott

[douglasmoto]

Best way to vent the crankcase on a single is to have a system that creates negative pressure in the case. It's actually really easy to do this with a PCV valve. Singles really create a problem since there's not a piston going the opposite way to balance pressure. It creates leaks and robs power unless it's releaved in some way.

Art

[Ducati Scotty]

I suppose the stock solution of putting the crankcase vent in the air box creates some vacuum.  I suppose I could plumb the vent line to the new filter but the small effective airbox volume could be problematic.

While the duckbill doesn't create its own vacuum, the crankcase expells through it on the down stroke and then can't draw any back.  Unless there is excssive blowby I think you'd have some vacuum created as the piston rises and the duckbill remains closed.

That aside, I'm not too worried about the performance issues.  It's usually fairly minimal going from PCV type to free vented on most engines, and I don't think we have a check valve in stock form anyway.  The duckbill would actually be closer to PCV.  Maybe just one more thing I need to try and see.

Scott

[Sub]

Sorry to bring up this old post, but Scotty, I'm curious if you've had any issues? Can you share some pics with us? What exactly did you do with the breather hose? Maybe it makes sense to start a thread on it?

For everyone else.. Has anyone put a less restrictive intake AND exhaust on the same bike? So far I've only read about one or the other. I'm mostly curious to see if the engine runs a bit lean or rough.

[prof_stack]

Sorry to bring up this old post, but Scotty, I'm curious if you've had any issues? Can you share some pics with us? What exactly did you do with the breather hose? Maybe it makes sense to start a thread on it?

For everyone else.. Has anyone put a less restrictive intake AND exhaust on the same bike? So far I've only read about one or the other. I'm mostly curious to see if the engine runs a bit lean or rough.

My C5 has K&N air filter and the upswept muffler.  It definitely is breathing easier and pulls harder under acceleration than stock.  According to the dyno test (another thead) it is rich at all rpm's.  Getting more air into the box would be helpful.

[Ducati Scotty]

With the cone filter right on the throttle body MPG went down about 10%.  I removed it.  I will put it back on some time and do another test just to make sure that wasn't a fluke.

If it worked I'd just get a breather filter for the crankcase vent as it was I just left if connected to the old air filter.

Scot

[Sub]

My C5 has K&N air filter and the upswept muffler.  It definitely is breathing easier and pulls harder under acceleration than stock.  According to the dyno test (another thead) it is rich at all rpm's.  Getting more air into the box would be helpful.

Oh thats good to hear, you're the first one that I've heard that did both mods. The up-swept still is fairly restrictive though. A buddy has one, so I've heard it!

[barenekd]

I have had the English EFI muffler installed on my G5 for quite awhile. It has a very nice sound without being a excessively loud, but it does offer significantly less back pressure and better running the the stock muffler. It has vented tube about 3/4" in diameter running the full length of the muffler and is open all the way. The tube is wrapped with silencing material.
I just installed the K&N filter that Doug Douglas is offering. It has about 50% more surface area than the stock unit. I only have about 20 miles on it so far, so can't verify what the mileage is doing, but the  bike is idling much more steadily and hasn't seemed to change the mixture much. There is definitely a new growl to the intake noise, though. The backfiring at off throttle hasn't particularly changed, which has always been just an occasional pop. I will get more miles put on and see if there is any significant mileage change this week.
I have used K&N filters a lot back in the old dirt bike days and always found them to be excellent performers, wet or dry. I used to ride a lot of woodsy enduros back east that always offered submarine sections, and never had any filter problems.
This long weekend has put a cramp in my riding time!
Bare