Air Filters-good performance gain?

[c_noble]

Im considering getting a performance air filter for my curvey SV, i have a standard. Will i notice much of a performance gain, or am i better of saving for a can? thanks

[NedSVS]

If you go for a K&N or standard BMC that dont require rejetting then you aren't likely to notice much difference. Even with a dynojet stage 1 kit you probably wont notice much. A stage 2 kit (Factory Pro, JHS racing or Ivans) will give a noticeable boost in mid range and a little at the top too. Ideally you'd wait and do your exhaust at the same time as stock and aftermarket exhaust will almost certainly need a slightly different setup.

[jonnygman]

i have a bmc race and a micron exhaust it goes well and the sound off it is great especially when nailing it if you go for the race/rs you will have to do summit with the jets but the race as well as the micron delta oval+ only needs slight tinkering

[northwind]

Any filter/exhaust combination that doesn't need new jets is basically not doing much... All you're doing is getting more air in and getting the spent charges out faster, and then adjusting the fuel to match- so if you don't need any more fuel, you're not shifting much more air. A lot of SVs run rich as standard so there's some room to maneovre.

IMO either do it right or don't do it at all- a bike with a quality race system and a K&N should need rejetting just as badly as a bike with a Race RS, just that it won't get half as much benefit. Just because the bike feels OK doesn't mean it's not lean- in fact, the SV tends to lean out most dramatically at about 6000rpm, and a flat spot there doesn't feel bad- it actually makes the peak feel stronger as instead of going from, say, 50bhp to 70bhp in 3000rpm it's going from 40bhp to 70bhp. Feels great, because the brain feels the contrasts not the actual power. A lot of people bump up the needles to try and compensate for undersized mains- not really the way to do it, you're treating symptoms not cause there and it'll leave you rich lower down.

When I rejetted mine properly for the first time, I was sure I'd lost a load of power up top... All I'd actually done was lose the flat spot and therefore the contrast, I'd actually gained power on top but it didn't feel like it.

So, either leave it alone or fit an RS or desnorkelled other filter, and rejet to suit. The power gains don't really justify the cost or effort regardless for a street bike...

If you do want more power for the curvy, think cams... Cheaper and easier for better results, most of the time.