Pod Air Filters

[jmnjrpa]

The

one thing you left out. Any jetting advise is on the assumption that before mods you had it jetted correctly. If you do not, then obviously you can't be helped. But i get your drift anyhow.

[T99Ford]

That is a BIG assumption

[MrOzz]

...if you are really concerned, dyno it with an A/F sniffer, and you will know exactly what it is doing.

What is a A/F sniffer? Air/Fuel ratio?

[T99Ford]

Yep. It is a probe that is put in the end of the exhaust pipe that measures the air/fuel ratio of the bike in real time while it is running. (Had to be careful how I phrased "probe up your tailpipe) Your printed dyno sheet will show you what the mixture ratio is at a particular load and speed, and also compare that mixture against an ideal. It is pretty slick, since it tells you exactly what is really happening in real time conditions. It is the only way to go for exact tuning. I have seen varied prices on a dyno run. I can get it done here for about 20-25 dollars, but not every where is that cheap. It usually takes a couple runs to get everything sorted, but is the ONLY way to get spot on results. Everything else is just "pretty close" although some guys get "really pretty close.

[MrOzz]

Yep. It is a probe that is put in the end of the exhaust pipe that measures the air/fuel ratio of the bike in real time while it is running. (Had to be careful how I phrased "probe up your tailpipe) Your printed dyno sheet will show you what the mixture ratio is at a particular load and speed, and also compare that mixture against an ideal. It is pretty slick, since it tells you exactly what is really happening in real time conditions. It is the only way to go for exact tuning. I have seen varied prices on a dyno run. I can get it done here for about 20-25 dollars, but not every where is that cheap. It usually takes a couple runs to get everything sorted, but is the ONLY way to get spot on results. Everything else is just "pretty close" although some guys get "really pretty close.

JAT

I noticed that you can get a air/fuel ratio meters. From what I can tell they are around $150.00. Can you use something like that to tune the bike? If so what would you look for? I think I would need to install a O2 sensor? What would the proper air/fuel ratio be?

Also has anyone done this before?


Thanks

Ozz

[psycoreefer]

Problem is that then you have to have a way to also measure and record load, RPM and throttle position to make that A/F data really useful. Sure its a little better then the "seat of the pants" measurements most of us make but still not nearly as good as a dyno pull.

[T99Ford]

What Psyco said. All the data of the dyno run works together to let you know the useful real time operating conditions of the engine.
Now, an A/F gauge tapped into your exhaust (or exhausts if you have two) will tell you the same thing, provided that you are able to monitor your tach and A/F gauge, and be able to correlate the two so that you know the A/F ratio at any given RPM under a constant load. A dyno does this in one run (about 2-5 minutes) and graphs it on paper for future reference. It is definitely faster than the way you describe, but you could do it that way.

Proper A/F is (and many have their own opinions) a subjective question.For me it is about 13:1, or 13 parts air to 1 part fuel. This is for max power. Max economy will be achieved at around 14:1, and it can be run as rich as 12.5:1, although I think power and economy will begin to be sacrificed this rich. They will run much leaner or richer, but nowhere near the most efficiently.

[DGXSER]

Just my 2.5 cents worth, So with all this talk of Dyno runs, and air/fuel ratio meters, how much improvement are you going to make on the bike in the first place?

If you tune your carbs by the plug color, your bound to be pretty dang close. IMO, unless you are out there shreddin up on the roads, you are not going to know the difference between the bike tuned on plug color and a good synch over the dyno run tuned machine. Yes, you will see those numbers on the paper. But longevity of the engine, or experience of the ride to 90% of those riding these bikes will be undetecable. JMHO

[T99Ford]

DG makes a good point also. Where I think the dyno runs come in really handy is for those that are wanting to start modding a little, but lack the experience to read plugs, or can't tell the difference between a lean or rich bog. Additionally, plugs color pretty easy, so it can be difficult to tune all ranges thoroughly just off plugs alone. Plus, you have to take the plugs out a lot, and it takes a significant amount of time to get everything dialed properly going long hand like that.
A dyno run can tell you all of this on paper in 5 minutes, and all you have to do is run the bike. There is the main advantage. To some, the cost is not worth that advantage, but I think everyone agrees it is the fastest and most accurate way to tune, but by no means the only way.