Interview with dynojet – in detail on power commanders


So as you may have seen the last few videos have been focussing on fuel mapping with the Power Commander.

Till now the videos have been focussed on the Power Commander V (PCV) since it’s the one I have, but it seems like the Power Commander FC (PCFC) and Power Commander 3 USB (PC3USB) are more widespread, perhaps due to their lower cost.

In the last video we went through the process of how I build a map for my bike using the PCV + the attached autotune box which links to a wideband O2 sensor to adjust the fuel map on the fly.

But as far as I could tell there was no way of doing that with the PCFC or PC3USB. They don’t have the onboard CAN bus (a messaging protocol which car devices use to talk to each other) so there’s no way to link them to a wideband, and if that’s not how you tune.. how *are* you meant to tune them?

Lots of people talk about “chuck a power commander on it and get a bit more power” (aka “Common Knowledge”) but I never found anyone willing to go into more detail on how to go about doing that in a slightly more scientific way, or why you should have one box over another. Or at least I couldn’t find anyone *who knew what they were talking about* who would do so.

Mechanics are often better at doing than explaining which doesn’t help feed this “pool of common knowledge”, and they arguably also have a financial incentive to not tell you how to DIY since that potentially deprives them of future business. That’s just capitalism though, and also not necessarily how my brain works, so here we are.

Risk and accuracy

With my bike I did my research as best I could, used my own judgement, consulted friends etc and bought the components I evaluated to be best suited for what I wanted, and which matched my mechanical skill level at the time. I had the PCV professionally installed and then had the bike dyno tuned. Whilst nowadays I’d absolutely do it all myself, at the time I’d only had the bike 6 months and wasn’t confident I could map it properly, for the same reasons as we go into here.

Thing is when it’s my bike it’s only my risk. But I start making videos showing how to do stuff and once people start emailing and saying “hey which power commander should I get” suddenly it’s not just “my” risk/consequences anymore.

If I publish a video with bad info, or tell someone to buy the wrong thing or set it up wrong they could damage their bike – e.g. melt their cylinder while riding and get into an accident, and get seriously injured or even die. Obviously that’ not what I want and whether I’m legally liable or not is somewhat beside the point. This is why in my videos I generally stick to saying “heres how *I* did it” (and here’s what went well/badly as a result) rather than “here’s how YOU should do it”.

In general: DYOR (Do Your Own Research) and “Don’t trust, verify” 🙂

But this video/series is a bit different for me. I’m sorta responding to a “demand” (in the form of email enquiries) and investigating a subject rather than just documenting my random tinkering like i normally do.

I don’t have a PCFC or a spare bike to install it on so I can’t speak directly from experience, but I do think I might be able to help and I’d like to address the questions I get sent. So I guess that means I need to make extra sure that the info is correct.

I go round and round on stuff like this and my brain won’t let go so unfortunately this question kept bugging me..”if you can’t connect to a wideband how the hell are you *supposed* to tune a PCFC or PC3? What am I missing?”

After prodding a few biker/tuner friends for thoughts and opinions the general consensus was that you can map by “Trial + Error” aka “A/B testing” (which I start to cover HERE)…or…er.. idk.. maybe talk to dynojet? but they seemed to be The Options Available.

Well as it turns out, they weren’t bad suggestions. I mean – Dynojet. They literally make the Power commanders, so if anyone’s gonna know it’s got to be them, right?

So I sent a little email to Dynojet HQ in the UK. Honestly I wasn’t really expecting much of a response. I didn’t email their technical department since , although they’re known for being very good and helpful, I was looking for a bit more of an overview. It was a bit of a long shot.

Well, somehow my email ended up in the right inbox and I was able to talk to “someone in the know at DynoJet” who seems like they were involved in the design and build process of the Power Commanders we know and love, which means there really isn’t anyone better qualified to give us the answers I was looking for.

The conversation that followed got quite a bit more in-depth than I’d been expecting and DynoJet made some really good points, and clarified a bunch of other things I hadn’t even thought to ask.

So, where initially I was just looking for some short-ish answers to a few key questions, we ended up covering all sorts of stuff do to with Power Commanders and related tuning.

Honestly there was so much good info that it seemed a shame to just crop what I needed from it for the video (as had been the plan). Instead I suggested perhaps we turn it into a sort of interview and publish the whole thing as a long-form piece…which is basically what’s below.

I’m very grateful to DynoJet for taking the time out to talk to me at such length (over holidays, whilst in lockdown). I learnt a *lot* from this conversation, and it also confirmed a bunch of things I suspected were the case but wasn’t 100% sure of. Stuff which we’re going to build on in future videos too. Hopefully you find it interesting and informative as I did 🙂 Enjoy!

Not that kind of tuner, Dave

Interview with DynoJet re Power Commanders:


So as per my initial email, whilst I was quite careful about doing my bike upgrades in the right order so that I wouldn’t end up in a situation where I couldn’t tune it myself (or get it tuned), there’s a number of people who haven’t taken that approach. I’m trying to put together a video (or more likely) series of videos to try and help them.

I’d love to go from the start and say this is how to do it right, but that’s a bit like saying “I wouldn’t start from here” when someone asks for directions, and is not the situation these folks find themselves in. Instead they’ve put a bigger cylinder on and got hold of some variation of power commander and magically expect it all to work, and are then understandably frustrated when it doesn’t. Then they go digging on the internet and find me…but there’s not really any step-by-step type thing I can send them to.

So that’s sorta my starting premise for the series…if you’re in that situation, what are your options for building a suitable map for your bike? – autotune is $$, needs a PCV and an O2 sensor hole (tig welding, beyond most people), free-standing wideband also needs O2 sensor, plug chops ..not so easy on the R125 due to extremely long spark plug thread and really awkward location and also very limited/slow/laborious. Dyno tuning might not be an option either.. so what are they to do?

I don’t need to tell you though, that different models of PC can do different things so on one you might be able to do adjustments in the field with the mobile app, but the other not so much but maybe that one has trim screws. But how do the trim screws translate into maps? is it a blanket adjustment (over all maps) or just one specific “live tuning” map position which they affect. I actually rather like the way the PCFC has 10 map slots. It looks like it’s set up to do A/B/C tuning… so you could set up a baseline+5%, baseline+10% etc and switch them easily to test in the field. All of that nice detail is what I’d want to get into with these videos.

Also – the power commanders all seem to be very well thought out, I’m still not at the limits of my PCV yet, and I really *like* clever little boxes with depth like that so I’d be curious to know a bit more about why they’re designed that way and what other cool things they can do which people don’t generally know about or implement. Maybe how you got from one design to the other too. What you’ve packed into those little boxes is mind-blowing (to me), and that, along with the support, is also one of the main differences (imho) between the Dynojet stuff and the malossi, tuneboss etc.


Unfortunately, there is no simple solution to creating a map that will accommodate the modifications done to specific bikes. Creating a fuel map requires accurate monitoring and logging of air/fuel ratio (AFR) data. You would need to do this by either; using a dyno with real time AFR measuring and logging, or an Autotune (with PCV, O2 sensor etc.) fitted to the exhaust.

Without having any AFR monitoring it is extremely difficult to create a fuel map because you have no data to base your fuel trims on. You would have to guess at what fuel trims to make, which would be an difficult and time consuming task without the AFR data. This is without even considering the potential damage to the engine this could cause.

[ NC: i’ve highlighted these paraghraphs becasue they’re so important. If you read nothing else but that, then this visit was hopefully already worthwhile 🙂 ]

However if you were attempting to do this, my advice would always be to start rich (adding fuel) as this is safer on the engine, rather than not enough fuel (which can cause excessive heat build up and lead to engine damage, most likely through detonation). It is then possible to make improvements through ‘blanket’ changes [NC: this is more or less what I describe as A/B testing] by selecting a number of cells in the PCV map, e.g. the entire rev range at 60, 80 and 100% throttle and adding a certain % of fuel e.g. 10 in that area and seeing if the bike improves. If it feels better, but only at a certain RPM range, then we can make the next blanket change smaller, for example 100% throttle 5000 -8000 RPM and so on.

This would be very much like having a carburetted bike and setting the needle and jetting from the ‘seat of your pants’. If you consider each fuel cell in the Power Commander map as a jet, and the number a jet size, you will understand that fuel injection mapping is a lot more accurate and detailed than simply changing the jet in a carb. Setting a bike up like this can be very time consuming, and you will never achieve the results as a dyno set up, or building your map off AFR data. That doesn’t mean it cant be interesting and fun!


right so again this (tuning by “blanket changes”) is another thing where people look at me blankly when I start talking about it, but you’ve just described perfectly. I refined the map I got from the dyno this way using the a/b switch on the PCV and this was how I’d figured one would likely best tune a PCFC /PC3USB. It is however, as you say, laborious and kinda imprecise which is also why I was curious whether I was missing something and there was a better way.

So if I understand that correctly, if you’re getting a PCFC or PC3USB, you really need to budget for a dyno session too if you’re going to want anything more dramatic than carb-style tuning/accuracy (which is fine, but then, why have you got an EFI bike?). And if you happen to be in that situation like having done a cylinder upgrade and have obtained such a device, tune as you’ve suggested but don’t expect the same sort of results as the same bike running a PCV+Autotune, or one that’s been properly dynoed.

More than one of the people who’ve contacted me have been trying to run big bore kits with no fuelling adjustment whatsoever so I’ve really had to take it from the top with them about what that could be doing to their engine. I’m amazed that their bikes haven’t melted yet, so whilst this might still seem basic info by your standards, I think it’s already going to be useful info for a number of the people I chat to.

I think part of it is that if I can say to them this is “The Way To Do It” and that has essentially come from “on high” in PC terms, then they can evaluate the time/cost investment for either route. Till now I was able to suggest the split-testing method but I wasn’t sure if it was ‘the right way’ was just how I break stuff down with some of my work so I defaulted to doing it with the bike too (before autotune) and it sorta worked out for me. But I didn’t want to be telling people to do it that way if there’s a better way that I’m missing…which it seems I’m not.


It is possible to create a fuel map using the button adjustment features on either the PC3 or PCFC, however this is not ideal. This takes same ‘blanket’ change approach as above, but falls down when you want to narrow down the blanket area for a better tune. The button adjustments will only make changes to the existing fuel map in the unit by increasing or decreasing the amount in the corresponding “low”, “mid” and “high” sections of the map. The size of these areas can not be altered. On the PC3, each light indicates a 2% change in the given section of the map. This is up to a 10% change either way to the existing fuel map in the unit. The PCFC works in a very similar way, however the buttons have been changed to screws. Each notch again makes a 2% change to given section of the map. The PCFC also has the added feature of the 10 map slots; so you could make changes to the map and swap between them to see if they make a difference. Doing this would still require a base map added to each slot for you to make changes to though.


right this was what I rather liked about the PCFC – that if you were going to tune using split testing, you could set up a better range of options and be able to switch in the field without needing the laptop and perhaps test 2 things to + or – 2 degrees, but again I didn’t know if that’s why it was designed that way. Split testing on the PCV was quite slow and frustrating (though doable), but then once the autotune was in play the penny dropped for me.


Another thing to consider would be the ease of use and openness of the Power Commander, whereby I, or somebody else (who you trust!), could email you a map for similar modifications and you could easily load in the PCV. Obviously in our case this would rely on us having seen the same, or similar modifications on the bike before. This is usually the best starting point to build a map. We receive map requests for various modifications on different bikes on a daily basis. If we do not have the exact map, in most cases we can provide a decent starting point (through our years of experience). We build a map database for stock bikes and bikes with common modifications such as a slip-on or full exhaust system. It would be impossible to stretch the database beyond that but it’s always worth asking if we have ever mapped a bike with x, y and z done to it, because you never know.


Being able to trade maps has already been very useful, especially now that I can translate them to and from any Power Commander device. Whilst my motor has some querks, that portability has meant on a couple of occasions I’ve at least been able to send people something vaguely in the right ballpark to get them started.


The PCV was introduced in 2009 to take over from the PC3. The PCV does basically the same job as the PC3 fuelling wise, just with slightly more definition in the map. However, the PCV has more features and is in a smaller, more user friendly package. As the PCV can be powered up through USB without the need for an external power source (e.g 9V adapter or running bike) when connecting to a computer, this makes it easier to make adjustments to the mapping. Because of this and also the lack of precision with the buttons, they were no longer needed.

Compared to the PC3, the PCV gives the user more defined fuel tables allowing for even more precision with the fuel mapping. Also, with the addition of a gear input, this will allow you to adjust the map per gear. In addition, the built-in ignition control (bike dependent) in the PCV gives you the option to change the bikes ignition timing, much in the same way you would change the fuelling but by retarding or advancing the ignition to improve performance.

The accessories that are available for the PCV will also be more beneficial to any ‘seat of your pants’ tuning you do compared to a PC3. For example, using the map switch you will able to upload two different maps to your PCV. One with a starting map and then the other with a change to the fuelling. Then, while out riding you will be able to switch between them and see if there is any difference. Also, as you have already mentioned, using an Autotune or Wideband 2 with a POD-300 display will enable you to have live AFR data. There is also the added bonus of being able to connect a quickshifter straight to the PCV (PC3 has this function, but not PCFC) and being able to control it using the software, compared to wiring in a stand-alone quickshifter unit.


That really seems to be the main difference to me. If you’re having it dyno’d and set up properly and then you’re just going to ride it, or you just feel she’s lacking a little at the top end/mid/whatever a bit (carb-style tuning) and are fine with that.. then PCFC, PC3USB could be the way to go and save some money. But if you’re a tinkerer and actually want every last drop of performance and every last Turismo option, and your setup changes every week because you’re forever buying shiny new bits, then it’s got to be PCV, since you can still get it dyno’d, or split test tune it, or autotune it or a mishmash of all of the above.

The last person to email me about this was running with no fuel adjustment at all and asked me which device to get and again I hesitated because I couldn’t be sure I was giving them solid advice [they since got a PCV btw!] .  In Power commander terms what you’ve said is more or less the Word Of God and means I can actually relay this info with a degree of confidence, so thank you 🙂

So I’m thinking the final overview of what I should be telling folks might look a little like this:

1) before you do anything, email dynojet and see if they’ve got a map to get you going with

2) failing that, start with as best a map as we can get, start rich, tune in segments as discussed, perhaps fit a temp gauge (or one of those spark plug temp gauges like on 2-strokes) to keep an eye on temps.
and for people looking to buy one or the other device:

3) if going for a PCFC/PC3 USB – cheaper device, but must allow budget to get it dyno’d or looked at by someone who knows what they’re doing (or a reliable source of maps.. e.g. friend with exact same bike + mods which works great), otherwise only expect at best seat-of-the-pants/carb-style tuning/accuracy (in which case why EFI?), and expect segment tuning to be sloooooow and laborious.

4) if tinkerer and tuning nut, definitely go for the PCV, lots of room to grow: map switching, autotune, per-gear maps, quickshifters, pod-displays, literally all the turismo toys but without having to build a wiring loom yourself like with speeduino etc. Just make sure you’ve won enough races to pay for it all  😉


One important question when getting the bike professionally set up on a dyno would be “is the bike is going to get modified further?” I.e. if you change something once the bike has been mapped, it will need mapping again. This then becomes expensive.

You have lots of options, perhaps a good route would be to start with a base map, do all your tinkering until you are happy, then sometime in the future get the map checked on a dyno and see if it can be improved.


So how do they measure the AFR on the dyno then – is there a probe the stick in the exhaust like the MOT man has, and they adjust manually at various rpm (a bit like I was trying to do with my wideband before I got the autotune, but in a much more controllable environment). Or can they interface with the PCFC/PC3USB/PVC and write the map directly somehow (or the dyno makes a map which can be dropped into whichever device). You make the dynos too don’t you so I guess it all fits together somehow?


You are correct, we do manufacture the dynos as well as the fuelling products for bikes. Our dynos have numerous different add-ons depending on the application they are being used for.

In this application (mapping bikes) we use a dyno with an AFR module and an “eddy current brake”. The AFR module, as mentioned in the previous email, allows us to get a live AFR reading while the bike is on the dyno.

To retrieve this live reading, we use one of three methods: a probe down the exhaust (like an MOT tester), an O2 sensor fitted into the exhaust boss (if the exhaust has a free 18mm boss), or we produce a kit called ‘Stealth Extraction’ that entails drilling the exhaust and installing a riv-nut. Using an adaptor, the O2 sensor is then screwed into the riv-nut and we get an accurate AFR reading from that.

Once we are done, a bolt with a copper washer is screwed into the riv-nut to plug the hole. (Please note this is not recommended for use on the road as the adapter used for the O2 sensor has a small thread and it would not withstand the bumps from road riding).


Ah, right, that makes sense. I didn’t know about the stealth extractor thing, that’s neat, but I see how it wouldn’t withstand road use either. That’s one of the sticking points which sorta got me digging around the subject as adding an O2 bung to that little tinfoil aftermarket pipe of mine was very challenging welding indeed. I’d wanted to recommend the PCV to the folks who email me (so that they could use the autotune) but unless you happen to have a tig welder (or a friend with one) fitting the O2 sensor is where it all falls apart and as far as I’m aware most of the aftermarket pipes don’t have an O2 sensor. I think the later bikes (2014>) have an O2 sensor but I suspect it’s a smaller type and afaik they’re not as easy to tune anyway. There’s clamp-on bungs for cars which I guess isn’t ideal but would work in a pinch… but nothing similar that I could find for bikes…at least not such small cc ones. That’s kinda how I got to “well how did the dyno place tune mine then, what am I missing?”.


Essentially, all the Dynojet products, including the dyno, sync together to allow mapping to take place in one software. This is beneficial for any tuning as you can see live RPM, Throttle Position and AFR, plus any other relevant channels. You can instantly measure these channels in a dyno run to see the results. Everything is measured so there is no guess work and before/after dyno graphs will prove your work.

For accurate tuning we use the eddy current brake to allows us to set loads to the bike so we can hold it at specific RPM to allow for accurate tuning. This is critical at low RPM and small throttle openings as the exhaust gas speed is low at this point so it removes and time delay, and error in the AFR reading. This is a major benefit over Autotune.


Wow that’s a very cool setup. So then I guess once the map is created on the dyno you can export it to the power commander on the bike and job done. Given that context I can see better how the PCFC/PC3USB fit into that whole hardware “ecosystem”.

Out of curiosity, do you happen to know how come there’s no ignition timing option on the R125? Is there a hardware reason that didn’t work or was it just not deemed necessary because it’s an entry level-bike? Personally I’m interested re forced induction, which would need a bit or timing adjustment, and whilst it looks like the PCV could handle all the rest plus there’s the additional analogue input (e.g. for boost input or a rising rate regulator or whatever), but then not being able to adjust the timing means I’ve had to look into alternative setups like speeduino and powerspark for that bike. But they exist so timing adjustment must be possible, hence curious how-come the PCV can do timing on some bikes but not others. Is manufacturer co-operation a factor there?


When the PCV was initially developed for the R125 back in 2008 the PCV didn’t have the capability to adjust the ignition.  As there hasn’t been much of a demand for ignition timing on that bike, I guess it wasn’t deemed necessary to invest time into developing this further. Generally, bikes with 2 or less injectors will have an option for ignition timing. With over 2 injectors, there is usually a separate Ignition Module available. Sometimes adjusting the timing can give great results, other times it’s really not worth it. It depends on the application.


Once again, thank you very for much for your time. This has been way more helpful and interesting than I had ever hoped it would be. I know people probably won’t read it all and will still email me the same questions but at least then I can send them to this page and know that they’re actually getting good info 🙂

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