In anticipation of a air box mod i ran a test today to see how the CB breaths. I ran with a wide open air-box, no air cleaner, no side cover for about a 2 mile run, expected to have a real lean condition with at least some sort of bog especially full open throttle. To my surprise the bike ran the same as with the air-box closed up tight. Either this bike breathes really we'll or the FI adapts to severe conditions.
Ran open airbox today
- Thread starter CIP57_imp
- Start date
The Spaceman_imp
Road warrior
Wow, that's quite a finding! To go from an OEM filter and airbox to nothing with no detectable difference has remarkable implications regarding mods we're doing.
You really couldn't detect ANY difference at all? Did you get thru the entire revs range?
If only we all had home dynomometers...
You really couldn't detect ANY difference at all? Did you get thru the entire revs range?
If only we all had home dynomometers...
HikerToo_imp
Road warrior
I've never been convinced air intake ( filter mods) would make much of a difference, would engineers really put out a design that has an engine running out of air? And if so, I would think it would only run out of air at max RPM, when it needs the most air, not during normal operation when there should be plenty of air.
Just me, I know others have different opinions and experience.
Just me, I know others have different opinions and experience.
Spaceman,The Spaceman_imp said:
I was amazed, i red-lined 1st and 2nd and could not feel any difference. I was expecting the bike to run like crap. I plan on installing a cat free exhaust and air-box mod before dyno work so figured i would try this out. I remember putting K/N filters on carbs and eliminated the air box back in the day and fuel ( Jetting )was required.
Ridem32_imp
Road warrior
CP. That was done with your reflash ECM ! The amount of incoming air was never to much for the ECM to adj to that's good. Which means that the ECM made the injectors inject more fuel for the more air. Nice 
Michael
Michael
Mike Bee_imp
Running like a top
Are you running with the stock muffler(s)? It's always been my understanding that intake mods like air filters are only a benefit with a freer flowing (after market) exhaust system. If your still using a stock system, making changes to the intake end of things would only net slight, hardly noticeable changes.CIP57_imp said:
~ The Bee
scootarida1_imp
New to the forum
I would have to agree with this. Similar to how most modern cars operate. I would assume though that the fuel corrections were at its upper end and eventually the ECU would learn these new corrections. Not sure of the maximum corrections allowed on the CB1100 however my Subaru would throw a check engine light if the learned fueling exceeded either +-15% adjustment.Ridem32_imp said:CP. That was done with your reflash ECM ! The amount of incoming air was never to much for the ECM to adj to that's good. Which means that the ECM made the injectors inject more fuel for the more air. Nice
Michael
Some more driving around on the CB would determine if this would throw a CEL or not.
Dakota_imp
Running like a top
Thanks for posting these results. This shouldn't be surprising unless the design engineer was incompetent.
Red Mist_imp
Been there
Are you running with the stock muffler(s)? It's always been my understanding that intake mods like air filters are only a benefit with a freer flowing (after market) exhaust system. If your still using a stock system, making changes to the intake end of things would only net slight, hardly noticeable changes.Mike Bee_imp said:
~ The Bee +1
CBXBob_imp
Running like a top
May not have been that much more air. The flow pattern thru the filter maybe more efficient than the unrestricted
flow pattern that has more airflow but is less efficient. Who really knows? Probably not much different because the stock muffler is the restriction, once the filter is eliminated.
flow pattern that has more airflow but is less efficient. Who really knows? Probably not much different because the stock muffler is the restriction, once the filter is eliminated.
Dakota_imp
Running like a top
I hate to beat this dead horse but... Folks assumed that the air filter was restrictive which has now been shown to be false. Why the assumption that the muffler is automatically a problem? The experienced engineer designed the air filter but an intern designed the exhaust?
I see this all the time on the automotive TV shows: lots of money spent on "free flowing intake and exhaust" but miniscule if any gains on the dyno. If you need to have big power increases to be happy, you probably bought the wrong bike.
I see this all the time on the automotive TV shows: lots of money spent on "free flowing intake and exhaust" but miniscule if any gains on the dyno. If you need to have big power increases to be happy, you probably bought the wrong bike.
