Auto Vs Human Tuner

Bazzaz Z-AFM user/tuner here. To be clear, I am no "real" tuner. I'm an IT guy

The Z-AFM will not do *all* the work. It will get you pretty close in my opinion, but you will likely still need to fiddle with the map to get it just right. I set my target AFR at all throttle positions under 5,000RPM to 12.8:1, and 13.2:1 above that. I'm experimenting with running even an even lower 12.5:1 under 4,000RPM to help with that ugly 3,000-5,000RPM range we all know and hate. I've never ridden on or with another properly tuned SF, so I cannot speak to how good mine is, BUT, It is at least 90% better than what it was.

The Z-AFM does not modify under 5% throttle openings (idk why) automatically, so I had to basically manually plug in % values which is mostly what fixed the 0-5% steady pace surging.

Also, i'm of the opinion that while yes, one can definitely tune this on a dyno, I fail to see how it would be better than tuning your bike at speed, say on a track for instance. On the dyno there is no way for you effectively get the intake air velocity with blowers. In fact, just about ALL of the conditions will be different and in my opinion less ideal than tuning when and where the bike will be run. Just my 2c.

EDIT: This is how she's running:

From nationally recognized tuner/mechanic Doug Lofgren on this subject:

I use auto-tune systems whenever they are available, and they all work well.

The problem I see is that;
1) you can't auto-tune over a wide enough range without using a dyno
A) yes, you tune in the normal riding range until the odd case where you go outside that range
B) WOT auto-tuning can be dangerous
2) one mustn't leave the system in auto-tune (that is all too common)(if a little is good, a lot is better) because reversion and sensor failure will tune you into the ditch
A) by the way, sensor placement is critical
3) a trained tuner with a dyno can watch over the results and pick out problem areas, like decel
4) there can be a big difference between static and dynamic fuelling requirements

Doug Lofgren
[email protected]
http://www.visi.com/~moperfserv


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defrang said:

I think he means autotune works well if you are an expert tuner.


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Click to expand...

Lets assume one doesn't have access to a proper tuner/dyno. Having that auto tuner and using it per the instructions, ideally on a race track or even doing "dangerous" (and illegal) freeway pulls is far better than purchasing a device you can only manually tune (if you have the pre-requisite knowledge and experience) or have to rely on a tune that was created on/for a different bike in a different environment (elevation/air density, temperature, humidity, mods, miles, engine health, etc).

There are many options one may take, but personally I think having the Bazzaz (et. al.) with the Auto tuner effectively simplifies and brings home this capability for us weekend warriors and garage tinkerers. It's not perfect, but its damn good and builds you a solid tune.

EDIT: I was able to build pretty solid tunes where the auto tuner "learned" an adjustment for 95% of its observable TPS and RPM range simply by doing a few WOT 2nd,3rd,4th gear pulls on the freeway and some canyon riding. After the auto-tuner worked its magic, I then manually filled in the 0% throttle range across the 2,000-6,000 RPM range and then "smoothed" that with the 5 and 10% fields. I had great results!

The 'dangerous' comment refers to doing WOT runs on the street.
With my DynaPro dyno (same as the unit that Bazzaz is selling) I can add load and slow down the WOT runs to get more data.

<I use it went its available.
It could be dangerous.
Need to replace the sensor regularly.
Tuner will do a better job.>

I said 'sensor placement is critical' (not replacement) but you do need to monitor the function of your sensors.

When someone drops a bike off with an auto-tune system installed I need to confirm that their sensor is actually working right, if not I have to install my own, which I replace often.

Finally, a comment on the earliest posts in this thread;
AFR targets richer than 13.5 at light loads are really bad for sooting the plugs and plugging the sensor. Your engine doesn't make enough heat at light loads to burn the soot.

Doug

I can't think of any reason that a bike would run significantly, noticably better richer than 13:1 vs 13.6:1.
In the long run 13:1 will mess up your plugs and your wide-band sensor.
That is where I would start questioning the output or location of the sensors.
Before every dyno tuning session I 'free air' calibrate the sensors, which means I have to warm them up out of the exhaust and then power down and install them in the pipes.
I have sensor adapter manifolds that I can install in the pipe when I think that the location of the existing sensor bungs or inspection bungs (the 1/8 BSP bungs that are OE on Ducatis) are wrong for calibration purposes.
I have spent way too much time trying to find the source of high RPM ultra-leanness when the cause was a sensor location too close to the pipe cyl-to-cyl junction. And I mean more than 10" from the junction.
You don't know the magnitude of these variables until you have the ability to put the same sensor in the same pipe at a different location. It's an eye opener.
Having two sensors on a Ducati also opens ones eyes to the huge variation in idle AFR. Fixing that, using the idle air bypass screws, has a big positive effect on idle quality.
Don't assume that I'm ignoring idle vacuum synch. Even after synchronizing the idle vacuum, the AFR difference can be huge. Small changes in the air bypass screws will support large changes in AFR. (think about it; high vacuum gets rather large airflow changes, relative to the amount of air at idle, with small bypass adjustments)

Doug