Just what is it about the stock air filter that makes for the modifications I read about. I don't see anything that could/should be improved.

Rich

Less restriction, better breathing....
better breathing, more power,... goes hand in hand with less restrictive muffler and carb rejet.

  You can get more high end power but then you lose low end power,So if you drag at the strip then the high end power works. If you want to pull strong from 40 mph in high gear you only need the jetting.

Part of what air filters retain are petroleum contaminants as are found in industrial air pollution, exhaust from other tailpipes, etc.  These oil based contaminants cannot be blown out of any filter with an air pressure hose.  They must be removed with the appropriate chemistry, which is why you cannot re-use paper air filters, and which is why KN tells you to use a filter oil otherwise their filter will be ruined.

As for less filter restriction= more dirt being a crude rule of thumb, that is an unsupported assumption.  Here is yet another test showing that the more air that gets in, the more dirt also.

http://www.bobistheoilguy.com/airfilter/airtest1.htm

In addition, it is not possible to determine the effectiveness of an air filter's ability to retain dirt by just looking to see how much dirt it has captured.  Their are far too many variables to consider, such as the environment in which you use it, contaminants that have passed through the filter without leaving stains on the filter, amount of time the filter has been used and so on.  This is why filters are tested in labs using controlled conditions and very expensive equipment.  Home testing is a guess, at best.

What causes you to think about it is the first time you need to replace it and they hit you up for approaching $50 to do so.  That's $50 every couple of years ...

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Is there anything wrong with the stock Suzuki filter?  No, it is balanced with the rest of the Suzuki system, it is relatively restrictive and it does a good job of stopping dirt for a fair period of several years.

Improving on it is a matter of opinion and trade off.  Those who want more hp are going to want to rebalance the engine with less exhaust restriction and less intake restriction (with changes to carburetor to accomodate this increased air flow rebalance).

A moderate rebalance for a new rider is to use the stock muffler and increase the air flow through the intake system, this can be accommodated without a rejet through white spacer mod and air screw tuning.  I rode like this for years and was quite happy with it.

Then I ground my muffler cover plate mounting bracket in half and knocked the welds on my muffler mount loose as a result of that, so I chose to replace the stock muffler with a Dyna and started on the chain of pure hp modifications.

The bike is not easier to live with, it makes more noise but it does seem to get out of its own way faster.  Mine isn't a virgin any more so I am continuing on down the hp path by slow degrees, taking my time and doing it slowly keeping my eyes open.

The hp path is a fiddler's path -- some of the road bumps on the way are increased oil consumption and an eventual case of piston slap noise and various motor rebuilds, some of which are needed and some of which are hobby driven.

Serenity ran a stockish motor for 56,000 miles with no real trouble with a stockish set up, so please let's not try to say the hp route is the "trouble free" route -- it isn't.

On the other end of the spectrum is REX, who seems to be apart more than he is together.  But that's his nature as an experimental test bed.

Where you fall in that spectrum tends to change with time.  I was a stocker type person, but as my stock bits broke I went cheap and handy on the replacement bits which has gradually put me on the hp path.

dasch wrote on 09/13/09 at 04:37:10:


Same here.  

i just desnorkled and left the cover of the airbox with a a stock air filter. the bikes sounds and rides very different. for the better of course.

sure, what do you need?  1,pop of the seat  2,grab rubber snorkel that goes to the airbox which is under the seat 3, pull upwards and it comes out.

i also removed the side cover of my airbox, where you get to the filter

1 remove seat 2 remove right metal panel 3 remove plastic air box cover 4 insure filter is in place 5 put back together

i pulled the idle screw out 1/2 a turn to compensate

since doing this i have got a lot more induction noise, and a much better overall sound, i was disappointed with the dyna muffler untill i did this, now im very happy with it

but today i intend on pulling the whole air box and installing a round k&n filter

i hope it doesn't mess the sound up!