Wide Band Fuel Air Meter, as good as Dyno?
 

Giday guys,

Im wanting to ask the 'veterans' here opinion on AFM tools in conjunction or instead of using a Dyno run. Not just a basic AFM tool but ones with the data loging capability such as the Innovate Motorsports LM-2 units.

From what I can tell it essentially used the same principle to 'map' fuel/air delivery across the rev range. It just excludes the rear wheel Hp out of the graph.
Now correct me if Im wrong but if fuel/air are being delivered effectively that should equate to optimal performance, right?
Additionally the graphed lines will tell a tuner, even a back yard one exactly where the flat-spot or under/over fueling is occurring as the lines cross or diverge, thus indicating which jet/screw position or potentially items further upstream (i.e. filter) or down stream (i.e. exhaust) is causing issues.

Happy to hear from anyone who's used them and can talk with authority on the use of for tuning purposes.

Plus! for $230 for a AFM its far more cost effective than the usual $700 we pay for Dyno runs (at least here in Australia).

Your thoughts gentlemen :)

*ouch!*

As a comparison here in the UK you'd be looking at paying £30-£40 ($55-$70) per dyno run.

Tell me about it!.. it almost like we have to pay a 'carbon tax' just for having our bikes tuned!

While this does seem like a good idea in theory, and you are correct that it does tell you the same AFR info as a dyno, theory doesn't always tell the whole story.

When I was dynoing fuel injected bikes/ATVs years ago, we initially started tuning with a "perfect" AFR in mind. A magical number that the publications said was ideal, and best for the tune.

What we found was that some engines wanted above that AFR to produce maximum HP, and some engine wanted below that AFR to produce maximum HP.

There are some who tune to AFR, but my results have shown they are most likely leaving HP on the table. Our objective was always to tune for max HP at various throttle opening percentages (25%, 50%, 75%), across the RPM range.

It seems as if this will give you the ability to tune to AFR, but that is not necessarily max HP. So in my mind this is not as good as a dyno tune, though it is some sort of reference for you, if a dyno is out of the budget.

James

Im doing a http://www.zeitronix.com/index.html 2 band Zt-3 Wideband Kit and Zt-2 Wideband Kit install right now.. So Yes I think it's a GREAT tuning tool.

My Dyno runs are free (well beer and time) but they are still far fewer then I would want.. and dependant on others and a shop.
On a VTR, where there is a separate carb and intake path for each cylinder, and a MIXED exhaust gas from both cylinders out the pipes .I believe two O2 sensors (dual band) are required. Most motorcycle dyno set ups do not even have dual band exhaust gas capabilities... They will just put the sniffer in one pipe then the other... great for a twin that uses two complete separate exhaust pipes head to tip, or an inline 4... not good for a VTR.

I just picked up a used set of headers, and will weld in the O2 sensor bungs monday, then off to the ceramic coater they go.

I've been running a narrow band meter for years. It really helps, no question. With carbs you are dialing in by steps - you only have increments of jet sizes, etc. Even with the narrow band you can determine if you are way off base or at least close. Not good enough to maximize power but plenty for my purposes.

Interestingly, I've found it is a good indicator of when the plus need replaced!

This is all good info guys. Glad I asked..

Will have to check out that Wideband kit you've mentioned there..
Also can you tell us more about the ceramic coating? I don't want to diverge too far away from the original question posed, but, if I have to go installing bungs in the exhaust anyway having it coasted might prevent premature rusting.

:iagree:


Cheers for that.. Suspected it might be the case with the dark-art of performance tuning.. From what Im reading it certainly sounds like having the thing fueling consistently is a step in the right direction and will at least give a Dyno Tuner a head start when making fine adjustments to gather those dropped pony's left behind with component changes.

Cheers.

Ceramic: I'm using Nitroplate for mine - High Performance Ceramic Header Coatings - Nitroplate

James

You've really peaked my interest in this.. Would be keen to see the results when its done.

I'll have pictures up soon. My finished exhaust is in a ups box in the garage :)

James

Hows it going?
 

Hi Marquez,

Just wanted to see how the install of the AFR meter was progressing?