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Discussion Starter · #1 ·
Looking for some tuning help with my 2012 XCT. I can not seem to get a reasonable air fuel ratio (AFR) between Idle and cruise. The bike has factory stage 1, pipes and air cleaner. I have added timing wheel set at 6+, vfc III, o2 sensors are unplugged.

I added a wide-band o2 gauge and have found the bike was running major lean due to vacuum leaks at the throttle body IAC hoses. Fixed the vacuum leaks and now I can not get a AFR at idle and cruise that makes any sense.

So here are some examples of my AFR:
G = 1.5 Setting
Idle 13.5 - 14.5 / Cruise 16.5 - 17.0

G = 2.0 Setting
Idle 12.3 - 13.2 / Cruise 15.5 - 16.0

G = 2.5 Setting
Idle 11.0 - 12.0 / Cruise 14.0 - 15.5

My choose is either super rich at idle (stinks bad) or super lean at cruise. The only thing I have not done is replace the exhaust gaskets. My testing says they are not leaking but for $25 bucks I'll give it a try. I have spends many hours reading all the forums and I'm just not seeing the same result as others. I get every bike is different but it seems my bike wants two different fuel settings one for idle and one for cruse. Any thoughts would be greatly appreciated.
 

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If I understand you correctly; you change the AFR settings using the VFCIII but they don't change to what you expect?

First thing I'd do is change your timing wheel setting to +4. Most X-bikes do well at this setting with a few exceptions.

This is what a fuel table looks like using a PC-V. Obviously yours would look different. Also; do you have a dyno-tuner in your area you can have take a look at this?


Do you think you might have a bad VFCIII or possibly something isn't connected right or maybe switched backwards?
 

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Looking for some tuning help with my 2012 XCT. I can not seem to get a reasonable air fuel ratio (AFR) between Idle and cruise. The bike has factory stage 1, pipes and air cleaner. I have added timing wheel set at 6+, vfc III, o2 sensors are unplugged.

I added a wide-band o2 gauge and have found the bike was running major lean due to vacuum leaks at the throttle body IAC hoses. Fixed the vacuum leaks and now I can not get a AFR at idle and cruise that makes any sense.

So here are some examples of my AFR:
G = 1.5 Setting
Idle 13.5 - 14.5 / Cruise 16.5 - 17.0

G = 2.0 Setting
Idle 12.3 - 13.2 / Cruise 15.5 - 16.0

G = 2.5 Setting
Idle 11.0 - 12.0 / Cruise 14.0 - 15.5

My choose is either super rich at idle (stinks bad) or super lean at cruise. The only thing I have not done is replace the exhaust gaskets. My testing says they are not leaking but for $25 bucks I'll give it a try. I have spends many hours reading all the forums and I'm just not seeing the same result as others. I get every bike is different but it seems my bike wants two different fuel settings one for idle and one for cruse. Any thoughts would be greatly appreciated.
Which air cleaner are you using? The VIC cleaner is relatively restrictive and could very well be causing your rich condition at cruise where it's not blanketing so much from less demand at idle.
 

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With the VFC it will always be rich on initial hit under acceleration. The A/F curve will always look like this.

View attachment 469313

There are too few setting/parameters to get it perfect. It will not take out fueling only add fueling. All you get is zero, no going negative.

Other tuners can go -/+ and have many cells to adjust the fueling in (every 250 rpm at 9 throttle positions).
 

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If I understand you correctly; you change the AFR settings using the VFCIII but they don't change to what you expect?

First thing I'd do is change your timing wheel setting to +4. Most X-bikes do well at this setting with a few exceptions.

This is what a fuel table looks like using a PC-V. Obviously yours would look different. Also; do you have a dyno-tuner in your area you can have take a look at this?


Do you think you might have a bad VFCIII or possibly something isn't connected right or maybe switched backwards?
There is no fuel table in a VFC-III. You get idle/small throttle opening, acceleration, and full throttle... then you can adjust where in the rpm range the transitions are. Not nearly as sophisticated as a PC or ECU tuning device. What you posted is a target AFR table for auto-tune, not the actual fuel table.
 

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There is no fuel table in a VFC-III. You get idle/small throttle opening, acceleration, and full throttle... then you can adjust where in the rpm range the transitions are. Not nearly as sophisticated as a PC or ECU tuning device. What you posted is a target AFR table for auto-tune, not the actual fuel table.
It was meant only as a sample of what a fuel table could look like but I do get your meaning. Of course I know the VFCIII, being a Dobeck device, only has settings on the device.

I'm not sure how a dyno tuner would see the fuel table though with a VFCIII or other Dobeck tuner. Do they have software that looks similar to a PC-V fuel table to adjust the different settings at different rpm's and throttle positions?
 

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Discussion Starter · #7 ·
Just to clarify the AFR readings I posted are from my AFT meter I have installed on the bike.

Air filter is the PERFORMANCE AIR FILTER BY VICTORY 2878041. Its not the paper style filter

So as a test I set all tuner setting to 0, all lights flashing fast. So the bike tuning should be back to stock tune and a rich open loop as the o2 Sensors are unplugged.

Idle AFR 13.7-14.3 OK not bad
Cruise AFR 16.5 - 17.0 Really!!!!

BBob - pulling back on the timing crossed my mind and I think I will give that a try this weekend. I also pick up a set of exhaust gaskets.

I'm surprised after reading all the forums that so many people have had really good luck with their tuner, but its becoming very apparent to me I may need a smarter one.
 

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I had to dig back for this:

http://www.thevog.net/threads/vfc-iii-or-pcv.73257/#post-1272329

I had the Wiseco tuner, which despite what anybody tells you is exactly the same as your VFCIII.

My humble opinion? Set the wheel back to +4, throw away the Vic filter and get a Lloydz, set the VFCIII to 2.5 on the first and the rest zeroes, and take off that AFR meter 'cause it's fukking with your head; just go out and ride it and see how it feels.
 
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I'm surprised after reading all the forums that so many people have had really good luck with their tuner, but its becoming very apparent to me I may need a smarter one.
Not with your mods and needs. The VFCIII should be just fine. In fact you may need to dumb down a little. The AFR gauge, as someone said, may be messing with your head a little. If it's running lean at cruise; it's because it's designed that way to maximize MPG and satisfy emission standards.

The real test is your thighs. If they get too hot or you see the exhaust pipe at the heads getting red hot then you know you have a problem that could either be too lean or too rich and the gas is burning in the pipe.

Of these two settings you posted; the 2.0 setting looks fine to me if your butt dyno and thighs tell you it's good. Like mentioned; if you get the Lloydz air filter at some point then the 2.5 setting may be better.

G = 2.0 Setting
Idle 12.3 - 13.2 / Cruise 15.5 - 16.0

G = 2.5 Setting
Idle 11.0 - 12.0 / Cruise 14.0 - 15.5

Out of curiosity; what does the AFR gauge read under load?
 

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I'm not sure how a dyno tuner would see the fuel table though with a VFCIII or other Dobeck tuner. Do they have software that looks similar to a PC-V fuel table to adjust the different settings at different rpm's and throttle positions?
Again, there is no fuel table to view. Very limited device. You CAN'T see it.

The Power Commander table you showed is a/f targets for the auto tune (like 13.2:1) not a fuel table. A fuel table has percentages, not target ratios.

View attachment 469577

2750 rpm at 20% throttle opening = 8% more fuel added to the stock map.

If you look at 2250 rpm and 60% throttle opening = 13% less fuel than the stock map. This is what you can't do with a VFC III... go leaner than zero... if the bike is too rich set at zero, that's just too bad. You cannot tune the cylinders individually, you cannot change the rev limit, and there will be places where the tune 'is what it is'.

My Power Commander fuel table ranges from -25 to +70... try tuning that with a VFC-III.
 

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Just to clarify the AFR readings I posted are from my AFT meter I have installed on the bike.

Air filter is the PERFORMANCE AIR FILTER BY VICTORY 2878041. Its not the paper style filter

So as a test I set all tuner setting to 0, all lights flashing fast. So the bike tuning should be back to stock tune and a rich open loop as the o2 Sensors are unplugged.

Idle AFR 13.7-14.3 OK not bad
Cruise AFR 16.5 - 17.0 Really!!!!

BBob - pulling back on the timing crossed my mind and I think I will give that a try this weekend. I also pick up a set of exhaust gaskets.

I'm surprised after reading all the forums that so many people have had really good luck with their tuner, but its becoming very apparent to me I may need a smarter one.
Get a Lloydz air filter and it will be a lot leaner you can actually use the VFC then.
 

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Discussion Starter · #12 ·
Thanks everyone for all the info and suggestions.

OK did a quick test when I got home.

Reset timing to 4+ and removed the air filter until I can pickup a Lloydz.

Set G to 1.5 left everything else off, rapid flashing.

idle AFR 13.2 to 13.8
Cruise AFR 14.9 - 16.0
Hard roll AFR 12.5 - 13.0

Defiantly feels better in the seat, a hole lot smoother.

Tried G at 2.0 but that put the idle AFR at less than I would like but need to ride it more to see if the rich stink is there or not at stop lights.

Was able to find the exhaust gaskets on the way home today and will try to get those changed out just to eliminate that possible issue.
 

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I tuned my Dobeck via Inova AF digital meter and have similar readings to your final readings. My idle is a little richer @
11.8 - 12 and cruise a little richer from mid 13's to mid 14's with uphill load sometimes into low 15's which is all fine and well. WFO I am 12.5. My bike runs great. Reasonable mileage 36 - 43. The Polaris knock off K&N air filter works about as well as stock - it is just reusable. I tested both air filters with the AF meter. No difference in readings. Lloyds should give you more air but not having experience with it I cannot talk to that. Plugging in the Ox sensors will lean out the mixture also if you want to experiment that way also.
 

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Here's a thought. If you install Lloyd's adjustable idle air valve would that allow you to set the green at 2.5 for cruise and use the IAV to lean out the idle?
 

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idle AFR 13.2 to 13.8
Cruise AFR 14.9 - 16.0
Hard roll AFR 12.5 - 13.0
This is what I meant. The whole thing is a big compromise. If you get the idle where you want it, it's too lean at cruise (yes, 16:1 is way too lean). You have it zero'd and it's still rich on acceleration.

What is the point of installing a tuner and not being able to get the tune where you want it?
 

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Again, there is no fuel table to view. Very limited device. You CAN'T see it.

The Power Commander table you showed is a/f targets for the auto tune (like 13.2:1) not a fuel table. A fuel table has percentages, not target ratios.

View attachment 469577
I think I may not be asking the question correctly. I know the dyno tuner inserts sensors in the pipe(s) to take reading which he can then see on his display to show him where the AFR is at during each pull. They may install the sensors in the bung holes where the onboard O2 sensors normally go. I'm not sure which method is normally used.

On a Dobeck style tuner he would know to make adjustments with one of the 3 adjustment points whether they were digital or manual pots.

He would then run the bike through another pull to see where the readings were at. He would do this over and over until he reached an optimum tune with that particular tuner; correct?

I think everyone is in agreement the smarter the tuning device, say a PC-V or Maximus, the more finite tuning that can take place. What you said about the Dobeck tuners only allowing fuel to be added is quite relevant as well as other adjustments not available on those.
 

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I had the AFR+ (lots more tuning options) and it still sucked butt! I couldn't get the bike to ride clean at all. Popped, spit, coughed, chugged, tumbled, piss poor mileage and poss poor performance...less power than my stock Vegas 100 and I have plenty of performance upgrades (lloydz VM1 cams, lloydz air filter, Vance and Hines H/O pipes and at the time, I had a timing wheel too).

Everyone I takes to about the tuner told me the tuner was the problem and was going to end poorly if I kept trying to use it. I tried quite a few times to set it up with other people's numbers, even called Dobeck, but it always ran like crap!

I jumped on the Maximus bandwagon and it IMMEDIATELY scared the heck out of me. I pulled the front end of my XC off the ground shifting from 1st to 2nd the very first log ride with the initial "canned tune".

I refuse to fight with something that will not yield even mediocre results. These bikes cost too much and the are too valuable to be cheap. We put too much time, money and pride in our bikes to settle for lackluster performance and inferior reliability. That was the realism I was faced with when I looked my wife in the eyes and she told me she didn't trust the bike to ride with me......

Unfortunately, you need a better tuner and a professional to set it up.

If you fight for your limitations, you get to keep them.
 
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