Ran open airbox today

[CIP57_imp]

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.

[The Spaceman_imp]

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...

[HikerToo_imp]

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.

[CIP57_imp]

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...

Spaceman,
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.

[DAC]

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.

This has always been my suspicion as well. I have seen, somewhere in the webz, that airbox mods and filter types don't add any benefit. Certain "high flow" filters may actually allow more dirt into the intakes.

[Ridem32_imp]

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

[Mike Bee_imp]

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.

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.

~ The Bee

[scootarida1_imp]

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

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.

Some more driving around on the CB would determine if this would throw a CEL or not.

[Dakota_imp]

Thanks for posting these results. This shouldn't be surprising unless the design engineer was incompetent.

[Red Mist_imp]

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.

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.

~ The Bee

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.

~ The Bee +1