Hellgate
Wizard
Okay I've tried to stay out of this, as I've sworn to myself never to enter an air filter or oil thread as the majority of the time the perspectives are subjective.
Airflow on a flow bench has very little to do with the actual and potential hp of an engine.
First take a look at Motoman's article on port sizing: -=MototuneUSA Motorcycle Performance Roadracing Superbikes & Wild Girls I think you need to create an account to read the article.
Second this quote if from a friend of mine who own's a motorcycle shop and is considered one of the better tuners in the US:
The "What's in the AF1 shop" Thread - Page 238 - ApriliaForum sponsored by AF1 Racing, inc.
"I have K&N filters in a couple of my engines, but most I keep the stock filter. After almost a decade of dyno tuning I have yet to see an actual gain on a modern sportsbike from a low restriction filter and often a tiny loss. I assume this due to a diminished resonant effect in the airbox since the filter "backflows" air as well as it does let it into the box to began with. Resonant frequency is determined by several variables including total airbox volume which is the volume from the filter to the intake valves of the motor. Now exceptions to this general rule are made for cruisers, especially Yamaha cruisers with their TINY little air filter, replacing it with a low restriction unit definitely makes power. The SXV and RXV are another example of anything or nothing being better than stock.
I suppose the thing we have to remember is that we do not care at all about big "flow" numbers, we care about charge trapping efficiency. This is what makes power, bigger holes and less restrictive filters will definitely win on a flow bench, we are not driving/riding flow benches.
In general sportbike airboxes seem to be very well designed and thought out from the factory. The Honda CBR1000RR is no exception but this was the first and only time I have ever had to actually read the instructions to install an aftermarket intake filter...."
Here's another quote from him:
"I personally think that stock paper element filters are the way to go for most applications because their filtration is indeed FAR superior to wire and gauze or foam type materials. Tiny particles do matter over long periods. I have seen inside some pretty interesting bike and car engines over the years from AMA to F1. There is but one common theme, they either run a paper element or no filter at all (maybe a wire mesh screen). On my old 1999 Mille I did a dyno test with full EGA on the stock filter, EVO, K&N, a Foam one I made and none at all. The dyno graphs all directly overlaid one another as did the mixture trace lines.
Filtration is key for a filter and this applies to oil filters as well. I only use paper element oil filters in engines I build and service as those "washable" stainless mesh oil filters have not fared well in terms of filtration in independent testing, the only place they seem to do well is in the testing done by the people marketing and selling them. Dirt bike guys love the washable oil filters, especially KTM guys where they have two or more to replace every few hundred miles."
Airflow on a flow bench has very little to do with the actual and potential hp of an engine.
First take a look at Motoman's article on port sizing: -=MototuneUSA Motorcycle Performance Roadracing Superbikes & Wild Girls I think you need to create an account to read the article.
Second this quote if from a friend of mine who own's a motorcycle shop and is considered one of the better tuners in the US:
The "What's in the AF1 shop" Thread - Page 238 - ApriliaForum sponsored by AF1 Racing, inc.
"I have K&N filters in a couple of my engines, but most I keep the stock filter. After almost a decade of dyno tuning I have yet to see an actual gain on a modern sportsbike from a low restriction filter and often a tiny loss. I assume this due to a diminished resonant effect in the airbox since the filter "backflows" air as well as it does let it into the box to began with. Resonant frequency is determined by several variables including total airbox volume which is the volume from the filter to the intake valves of the motor. Now exceptions to this general rule are made for cruisers, especially Yamaha cruisers with their TINY little air filter, replacing it with a low restriction unit definitely makes power. The SXV and RXV are another example of anything or nothing being better than stock.
I suppose the thing we have to remember is that we do not care at all about big "flow" numbers, we care about charge trapping efficiency. This is what makes power, bigger holes and less restrictive filters will definitely win on a flow bench, we are not driving/riding flow benches.
In general sportbike airboxes seem to be very well designed and thought out from the factory. The Honda CBR1000RR is no exception but this was the first and only time I have ever had to actually read the instructions to install an aftermarket intake filter...."
Here's another quote from him:
"I personally think that stock paper element filters are the way to go for most applications because their filtration is indeed FAR superior to wire and gauze or foam type materials. Tiny particles do matter over long periods. I have seen inside some pretty interesting bike and car engines over the years from AMA to F1. There is but one common theme, they either run a paper element or no filter at all (maybe a wire mesh screen). On my old 1999 Mille I did a dyno test with full EGA on the stock filter, EVO, K&N, a Foam one I made and none at all. The dyno graphs all directly overlaid one another as did the mixture trace lines.
Filtration is key for a filter and this applies to oil filters as well. I only use paper element oil filters in engines I build and service as those "washable" stainless mesh oil filters have not fared well in terms of filtration in independent testing, the only place they seem to do well is in the testing done by the people marketing and selling them. Dirt bike guys love the washable oil filters, especially KTM guys where they have two or more to replace every few hundred miles."
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If it opens up a mean growl as well I'm all for it but I don't want to mess with my mixture yet...I have no PCIII and have other things to do before I start mucking with performance.
