Power Commanders

[The Stranger:Me]

So why does it take authorised and 'experienced' guys to tune it? If all it is is just changing some figures at a laptop, shouldn't anyone with half a clue be able to sort it?

Changing the figures is the easy part. What you change them to is a little more involved.

[Pussy]

It's done on a rolling road/brake dyno, in conjunction with an exhaust gas analyser. As previously mentioned, the end result is adjustments in fuelling for every 250 rpm, and ten throttle positions for each of those 250 rpm. It takes a few hours. Best results obtained by bike specific custom mapping. In my opinion, it's worth it (and, Kiwifruit, I've already done my suspension ).
You end up with a VERY chrisp fuel efficient engine

[dipshit]

So why does it take authorised and 'experienced' guys to tune it? If all it is is just changing some figures at a laptop, shouldn't anyone with half a clue be able to sort it?

So hows you going to know what to change the numbers to..?

[breakaway]

Change it and see if it runs like shit or not? Or is it not quite that simple?

[imdying]

So why does it take authorised and 'experienced' guys to tune it? If all it is is just changing some figures at a laptop, shouldn't anyone with half a clue be able to sort it?

Ahhh, and in there is the rub

What are you going to change those numbers to?

Even with a wide band oxygen sensor (or something more complicated like a 4 gas analyser), there's only so much you can do.... people have indicated that you're looking for an essentially flat AFR across the range... but that's not entirely true. Due to resonance and other exciting things that affect cylinder filling, some places in the map are better off a little richer or a little leaner than stoich. And that's the difference between someone who can operate a Dynojet link dyno, and a good tuner that can improve on the map that the dyno generates somewhat automatically. In fact, a good tuner doesn't even need a dynojet dyno, they can use any dyno.

But yes, anyone with a laptop can make and/or adjust their own map.

A PCIII without a tuned map is a bit of a waste of time.

[The Stranger:Me]

Change it and see if it runs like shit or not? Or is it not quite that simple?

Definately not that simple.
Though I have adjusted mine in that fashion in a few areas to achieve specific goals - for example maximum top end speed on the XT.

[imdying]

Change it and see if it runs like shit or not? Or is it not quite that simple?

Not quite, the adjustments are often more subtle than that. Here's a scenario... it feels stronger in the top end... have you improved the top end, or reduced the midrange which makes the top end feel stronger?

A lot of time with a data logger and you could do it... but it's easier and cheaper to get it done by a tuner with a dyno.

[Pussy]

Change it and see if it runs like shit or not? Or is it not quite that simple?

Stranger, dipshit, imdying and myself have tried to explain it... the answers are there

[imdying]

Read Stranger's post... if offers some good insight on some of the gotchas with using other peoples maps that aren't initially apparent.

[Gremlin]

A Powercommander plugs into your wiring between the ECU and the engine. All it does is change the commands sent by the ECU (according to the map) to the engine.

ie, if you have a look at a map, it has a series of numbers, positive or negative, so it takes input from ecu at x, adjusts by number in table, and sends output y to the engine.

There are different models for different bikes because the wiring has different plugs (and there are several cables). Plug from ecu gets plugged into PC, and there is a corresponding plug on PC that plugs in where the ecu used to.

If the PC is a usb one its easiest, as you plug any laptop in with usb, use the PC software, and you can change the map yourself. I have two custom maps for my zx10, one for baffle, one without, and I can change when I like. As others have said, you can make your own map, but you have to know how to change the numbers (where the dyno comes in).