Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

What is air deregulation?

Discussion in 'Technical and Troubleshooting Torque' started by Cruisin Nurse, Apr 19, 2016.

  1. i picked my 2016 Yamaha Stryker up from its first service and the mechanic gave me some advice. Yeah like I would know what he was talking about.
    he said the manufacturers deregulate the air flrow and that it impedes performance. He said he do do something small that would help or he could replace the enclosed filter with one that is exposed like on the Harley's which would improve my bikes performance.
    I don't know what to do

  2. sounds like he wants to replace your discombobulator with blinker fluid...

    but seriously, he probably said or meant they Restrict the air flow.

    air filters are not that likely to actually reduce performance.. they usually flow pretty good as standard (with some exceptions)
    exposed filter... no need, unless you specifically want that look.

    some comparisons with different mods in the following link
    Ivan's Performance Products
  3. I would not worry too much about changing your air filter to anything else.

    I'm quite sure that Yamaha did a bit of homework and lots and lots of testing to decide on the placement, size and flow characteristics of the standard original fitted air filter.

    Theoretically you might get a slight performance increase with better (less restricted) air flow but I doubt if you would be able to notice the change in real life.

    Unless of course you really WANT to modify and bling up your cruiser. Then all sense is irrelevant and you get the shiniest, blingiest exposed filter.
  4. The only thing you will gain with a freer flowing air filter at partial throttle openings (ie the vast majority of street riding) is more intake noise. The only time you gain any actual power is at high revs and wide open throttle. If you WANT the induction roar, by all means spend the money on the open air filter, but you will also need to spend more money on re-jetting if the bike runs a carburettor or re-mapping if it's fuel injected to get the mixture right to both prevent lean running (and engine damage) and to gain anything but noise.
    Personally I wouldn't bother, you won't gain any real power output, but if the noise and look are what you want then it's your bike and your money.
  5. I thought you bought that bike to restrict performance.
  6. actually, I take that back.

    grabbing and overlaying the Ivans graphs, for stock ECU, with stock air filter or "LAC air filter", shows a pretty decent improvement (LAC = LA Choppers looks like pretty much any other generic K&N type filter)
    note this is with non-stock exhaust

  7. So why would the stock bike be sold as it is ?
  8. laziness? emissions?

    but much more likely is noise emissions..
    • Agree Agree x 1
  9. Only on corners....lol
  10. A free flowing filter AND a free flowing exhaust will of course make more difference than just one or the other, but it still needs re-tuning to take advantage of the changes. Either way, nothing happens until 3,250rpm out of only 6000.
    • Like Like x 1
  11. Agree, manufacturers have a lot of things they need to design for. A lot of bikes have strange little power blips in their curve to pass noise emission or pollution emission tests in various testing regimes.
  12. If your quote is accurate I've got no idea.
    Many of the Yamaha cruisers have a fairly restricted air filter assembly and the stock filter is restrictive too.
    I think it helps emissions and their reliability. As they rev fairly high then the more air they can get then the greater risk of them leaning out unless you put in larger jets.

    Changing the standard filter to a high flow filter will help a little, and that doesn't effect the filter housing.
    You'll need to get it properly tuned though, and maybe rejetted to suit.

    Or you can change the whole lot if you actually want to boost the performance.
    Then you'll definitely need rejetting.
    At low revs/cruising speeds it will definitely improve cooling and fuel economy.
  13. He was saying something about as the filter is completely enclosed the only air it is getting is hot air. By allowing to get cool air it is better.... Ok, I guess...lol
  14. I haven't had much of a look at the Stryker air filter/cover assembly but on most of their other cruisers they only have small inlet holes right back on the engine. Yes, that means they do tend to suck hot air and will be affected, particularly in hot weather.
    Getting more air to the filter, and keeping it cooler is definitely a good thing, but do you want to get it tuned / dyno' and rejetted to suit ?
  15. If you want improved performance get an FZR
    • Agree Agree x 2
  16. there's a fair few threads around saying that K&N filter in stock airbox, and holes drilled in stock airbox, do not help much at all, and that replacing total works much better (but is also much louder)

    also gotta think about what happens in wet weather..

    the ECU may have a fair bit of range still available, may not need retuning as you are not changing the volumetric efficiency of the motor, just decreasing the vacuum at the intake (which will be measured by the MAP sensor).
    exhaust can change a fair few things about what happens during exhaust valve opening which can change VE, so more likely to need retuning for that. but still may be ok (better to check with wideband O2 sensor)
  17. Disagree. The Stryker will have a resonant airbox, as do the vast majority of cruisers, so freer flowing air will in fact add more horsepower in the mid range and provide nothing in the high/peak range.
  18. #18 Cruisin Nurse, Apr 19, 2016
    Last edited by a moderator: Apr 24, 2016
    Ok, it all was going good when you said "the ECU may have a fair bit of range still available". After that all I got was white noise.......Lolol

    No thank you. Just bought a bike....
  19. You can think of it from your expertise as a feedback mechanism like any of the Homoeostatic mechanisms in the human body. These mechanisms on the bike measure air temperature, oxygen levels in the exhaust and provide feedback to adjust the fuel and air flow. Just like the human body there is generally a wide range over which that adjustment can work.
    • Like Like x 1
  20. #20 oldcorollas, Apr 19, 2016
    Last edited by a moderator: Apr 24, 2016
    ok, engine is an air pump.
    on intake side, maximum air pressure is 1 atmosphere (14.7psi). any restrictions between free air and the intake valves will reduce it below that, but freeing up the intake can only do so much..
    ie, if you have 1 or 2psi pressure drop across airbox, that's all you can get.

    it doesn't change how the engine eats the air, just gives a bit more to eat :)

    pressure in the exhaust can be much higher than 1 atmosphere, so you have much more potential of changing things there, and that will change how the engine eats the air (err.. like giving it a larger colon :p sometimes a larger colon won't keep things in when they need to be kept in :p ) anyways...

    scroll down for some pics

    first pic opens up the hole at the back of stock airbox plate.

    second shows the K&N filter above the modded hole

    Full Air box Mod - Page 3 - Yamaha Star Stryker Motorcycle Forum

    that probably makes much more sense, but all I got was homeostatic something or other :)

    can see it here (video, mute sound first) the intake tube extends into the airbox = tuned for noise