K&N replacement for stock air filter

[Guest John Y]

I love free things - maybe my Greek ancestors were goat traders or something like that (keep it clean please!), but I just love getting something for nothing. Thus I'm tempted to fit a K&N replacement air filter in search of *free* extra power - but is it worth doing on my V11?

I have an '02 Lemans, presumably running a closed loop (?) injection (without an oxygen sensor). I have fitted Staintune mufflers (which were free, by the way! ), but I have no plans for a crossover. Will the K&N do any good in terms of performance, or just make the bike run lean? Have any of you fitted a similar filter and can report on the results?

Thanks,

John Y

Australia

V11 LeMans

[jrt]

If you pay for the K&N's, then it ain't free :!: There's always costs- hidden or otherwise. That said, why don't you go for it and see if it works for you? Assuming you pay for the filter, and don't pinch it, you'd only be out 20-30 USD. I don't think I really got that much power out of this conversion on my bike, but the sound is glorious.

 

Cheers,

Jason

[al_roethlisberger]

Hi John,

 

Our bikes are "open loop" EFI systems, that is, there is no feedback to the ECU from the exhaust system on gas content. The ECU makes some assumptions based on the input half of the equation, air-temp, pressure, engine-temp, etc... but the final product, the exhaust, is ignored.

 

This makes for a slightly simpler, but unfortunately less flexible system.

 

So, in that respect, our EFI systems aren't that different from a carb'd bike. That is, if you make enough changes(and "enough" can vary from bike to bike) the static map in the ECU cannot take into account these changes as it assumes its map is still relevant to the equipment, and consequently air/fuel characteristics, as what the factory installed.

 

Therefore, just as on a carb'd bike one might have to change jets, we often have to modify the fuel map of the ECU once "enough" has changed.

 

Generally speaking, if one simply installs a set of exhausts, or a cross-over, or a freer-flowing air-filter, there is no need to modify anything as the stock map was generalized enough to still operate within a safe zone. But add too many things that change the intake and exhaust characteristics, and the bike can certainly run lean or rich...or just not well at all. And even with the most minor of modifications, to get the most from them, it's still a good idea to get the fuel mappings tuned.

 

 

So, will the addition of your K&N in combination with aftermarket exhausts make the bike run lean? Probably. Will it be dangerously or otherwise less efficiently lean?? ...probably not, but you should keep an eye out for overheating just in case. Each of our bikes seems to have thier own quirks, and if for some reason someone, such as your shop, has already modified the map at some point... and it's borderline lean now, adding one more "straw" might just break the back. So just keep an eye on things.

 

 

All in all, I think you'll be fine though. Don't expect tremendous "free" HP, but you might find it having a more soulfull intake sound, and maybe a the torque curve may move around a bit in a positive way.

 

I put a K&N on my LeMans when I still had an air-box, and didn't notice any real difference. Maybe the dyno could have told a different tale, but I couldn't. I liked having it in there anyway though... for no logical reason

 

al

[gthyni]

Isn't it possible to do a poor-man'-s-PowerCommander be just

adjust the TPS to richen the mixture all over the range?

[Guest mcloutier]

Totally off topic, but I would love to hear your review on the staintune slipons.

[dlaing]

If you want the poor man's largest something for almost nothing, try swiss cheesing the top of your airbox.

It is good for more horsepower, more noise, and leaner conditions.

....so you will want to get a remapping or possibly get by, by tweaking the TPS. But keep in mind that tweaking the Throttle Position Sensor will not effect the mixture at Wide Open Throttle.

If you want to save your airbox lid because you are not sure it is a good idea, get the FBF airbox kit. The BMC filter that optionally comes with the kit, appears to be everything the K&N is, ie. Compared to stock, less dirt filtered, but better flow if there are no bottlenecks.

If you get the K&N but keep the airbox lid and restrictive snorkles, you will only let more dirt into the engine. The snorkles are the bottleneck for power.

The combination of no lid and a gause type filter does allow for more power to be developed....or atleast my observation that my bike ran leaner after installing the FBF kit seems to confirm the potential power gains.

Leaner means more air is being drawn in, so that if the mixture is correct, the engine will develop more power.

[Guest John Y]

Thanks to all respondees, you've given me food for thought. I was already considering enlarging the snorkels or, at least, re-routing the intakes away from the hot cylinder head air they seem to be forced to swallow - I was also considering a quasi ram-air setup with the intake at the front of the fairing...

The Staintunes pipes are, without a doubt, the best sounding mufflers I've ever heard: fairly quiet, but deep, at low revs with a magnificent fruity bellow at higher rpm - sweeeet! My local Guzzi guru took my bike for a spin the other day and the sound of him accelerating away was knee-quiveringly glorious. Definitely aural sex... One day I'll get my act together and post a sound or video file for anyone who's interested.

[RacerX]

John, a K&N or BNC filter makes no difference in a stock airbox. Only when the airbox is opened (via whatever means you'd like) will you see a gain. The TPS adjustment is a quick fix, but in no means even come close to a PCIII. - Todd@Guzzitech.com

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