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Old March 6th, 2017, 11:14 PM   #1
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Adventures in Hypermotard Tuning...

Background
As many of us know, the Hyper is not the smoothest bike around town. While it doesn't affect everyone, there are a large number of riders that complain of "lean surging", "stumbling", "sputtering", and other issues, particularly at slow speeds and through traffic. This is an issue that plagues many modern motorcycles as manufacturers try to make them pass emissions regulations by giving less and less fuel. It's not uncommon for a new bike to have complaints of being hard to maintain a steady speed, and having a very sensitive throttle at very small throttle openings.

I hope this is not too basic, but I would like to explain the whole story for those not totally familiar. The acronym "AFR" means Air-Fuel-Ratio, and describes the ratio of air to fuel (duh) in the cylinder during combustion. There are particular ratios that work best with certain engine configurations, but basic chemistry also plays a role.

Here's an informative graph:


Based on lots of research, I've found that an AFR somewhere in the 13:0-14:0 range is a good balance between fuel economy, engine smoothness, power, and longevity. In order to achieve this, you have a couple options.
-Modify the fuel map in the ECU
-Add a piggyback fuel module to change fuel injector durations

In its most basic form, a fuel map is a grid of fuel injector "on" durations with columns representing the throttle body position and rows representing an RPM. So, for every engine operating condition, the computer knows how much fuel to dump in. There are many other parameters that affect the duration, including air temperature, manifold pressure, engine temperature, etc.

Of course, in order to know how the fuel map should be changed, you need to know how the engine is working! Thus, we use an O2 sensor, which tells us the AFR directly. Our bikes are equipped with what they call a "narrowband" O2 sensor, which is simply an on/off switch used for determining whether the engine is at 14.7 AFR or not (for emissions). But that's all they're good for. So we must use a "wideband" O2 sensor, which can accurately tell us the AFR all the way from 9 to 21 (21 being pure air with no fuel, since air is about 20.9% oxygen at sea level).

So, you have two main ways of collecting this AFR data from the engine...
-On a dyno
-On the street/track

The dyno is a very controlled, steady state machine. This is very good for most things. However, dyno sessions cost $, and you must go to a special shop to get your bike tuned.


And now, the point of this thread.

The second option is to use a Data Logger to collect AFR data while you ride on the street or track. This way, you get all the real-world engine behavior with all the air-cooling and dynamic effects you see while riding! It also gives you a lot of insight into how you ride too. It's pretty eye-opening, to me at least.

I installed a Zeitronix ZT-2 data logger on my Hyper last year and only recently logged some data from a couple rides. I am logging the following basic parameters:
-AFR
-RPM
-Throttle Body Position (TPS)
-Throttle Grip Position

Here's my setup:
Front cylinder with O2 sensor


Rear cylinder O2 sensor port



The next step was crunching the data. After about an hour of riding, I had over 150,000 rows of data So with the power of Excel and some thorough data filtering, I was able to look exclusively at the useful parts of the ride - steady state and acceleration.

The goal here was to create a correction "map", which tells me where to add or subtract fuel duration percentage. Quite simple really. Here's what I found!

Just looking at the front cylinder log...


This graph shows me where I spend the most time riding. As you can see, MOST of the riding takes place at 2 and 5 percent throttle, between 2800 and 4800RPM. I was blown away by how little throttle opening it takes to get most places. The throttle is rarely open 100% - in fact it only opens to 100% by about 7500RPM, even if you open the throttle all the way.
*Note, the 2% TPS column includes all data from 2 to 5%. The 5% column includes all data from 5 to 10%, etc.



Next, the measured AFR can be seen in this chart. Notice something interesting...? Those same areas that I spend most of the time riding, are also some of the most lean. Huh.


Finally, when factoring in the data sample quantity and all the filters, I arrive at the correction map.


and for the rear cylinder.



My conclusions....
1. Many people focus on high RPM, high throttle opening riding conditions. The truth is that during street riding, you spend a LOT of time at low throttle openings, and just going from one place to another. This ride wasn't exactly lazy, so I was surprised to see this.

2. The front and rear cylinders behave very differently. The rear cylinder runs richer than the front, both to provide extra cooling for the cylinder, but also because it runs hotter as it's not exposed directly to the cool rushing air.

3. The factory RapidBike map my bike was supplied with, as well as the "auto tune" corrections, were going in the wrong direction, often removing up to 10% or more fuel at the high RPM. I am not sure why this is. Every motorcycle is different. Every environment is different. There's just so much that goes into it. Here is the included RB map, for comparison: http://i.imgur.com/91SseLE.jpg

*Notice also how the map is fully populated for example, in the 95% TPS column, from 2500 to 7300RPM. How can that be, when the throttle body physically does not open to 95%+ until 7500RPM? Again, they must have their reasons, but I don't know them. The Power Commander map is also populated from 5750 to 7500RPM. Any ideas?

4. Another thing about the RB map. The starting correction TPS is 5. But as you can see from my log, a huge percentage of the riding occurs between 2 and <5 TPS. I believe the reason they do this is to account for different TPS voltage ranges on different bikes, and to avoid adding fuel at closed throttle conditions. With proper calibration, and a 2% TPS starting column, it should really change the way the bike rides.


Phew... I hope this was interesting, and informative! I have always wanted to learn how to do this, and the hyper seemed like a perfect candidate. It turned into a good learning experience. An entirely different, and powerful aspect of engine tuning is ignition timing. Unfortunately I don't yet have the knowledge to start changing this, so it's an entire subject I didn't touch on. Feel free to ask questions or provide input.

Oh, I still have yet to actually ride it with the new map. I will get to that this weekend. I know my data is good, but it's possible my Excel filters could use work.

Last edited by kuksul08; March 6th, 2017 at 11:17 PM.
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Old March 7th, 2017, 02:12 AM   #2
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This sir, is great stuff. Although i vaguely understood most part of what you posted, it is very enlightening. Just goes to show how messed up factory tuning is. Thanks for this contribution. I will surely watch this thread and reserve my questions later until i've fully understood your graphs.

All the while i thought you were just some guy with a fancy job and a fancy hobby and very fancy tools in the garage. Now i'm beginning to suspect you're a rocket scientist as well. I'm a fan. Awesome

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Old March 7th, 2017, 06:54 AM   #3
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Quote:
Originally Posted by kuksul08 View Post
2. The front and rear cylinders behave very differently. The rear cylinder runs richer than the front, both to provide extra cooling for the cylinder, but also because it runs hotter as it's not exposed directly to the cool rushing air.
This is interesting as I've always wondered how each cylinder is treated by the ecu given that each are subjected to diff stress levels while operating. Not only does the front cylinder run cooler, it also experiences wider temp changes like when the bike runs over puddles or when riding thru rain while the rear's temp remain relatively constant. I didn't know that the 2 cylinders do not have identical fuel maps. No wonder i saw different spark plug conditions after 15k kms, the rear plug showed it burned richer, darker. The dealership took note
and apparently they didn't know it was normal so they "adjusted" accordingly. The bike didn't run any better (at low speeds) after that.

Given the assymetric operating conditions for each, does it also mean that one delivers more power (which one?) and/or will wear out significantly faster than the other?

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Old March 7th, 2017, 09:09 AM   #4
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Quote:
Originally Posted by Monstard View Post
This sir, is great stuff. Although i vaguely understood most part of what you posted, it is very enlightening. Just goes to show how messed up factory tuning is. Thanks for this contribution. I will surely watch this thread and reserve my questions later until i've fully understood your graphs.

All the while i thought you were just some guy with a fancy job and a fancy hobby and very fancy tools in the garage. Now i'm beginning to suspect you're a rocket scientist as well. I'm a fan. Awesome

Sent from my SM-G935F using Tapatalk


Quote:
Originally Posted by Monstard View Post
This is interesting as I've always wondered how each cylinder is treated by the ecu given that each are subjected to diff stress levels while operating. Not only does the front cylinder run cooler, it also experiences wider temp changes like when the bike runs over puddles or when riding thru rain while the rear's temp remain relatively constant. I didn't know that the 2 cylinders do not have identical fuel maps. No wonder i saw different spark plug conditions after 15k kms, the rear plug showed it burned richer, darker. The dealership took note
and apparently they didn't know it was normal so they "adjusted" accordingly. The bike didn't run any better (at low speeds) after that.

Given the assymetric operating conditions for each, does it also mean that one delivers more power (which one?) and/or will wear out significantly faster than the other?

Sent from my SM-G935F using Tapatalk
To be fair, the factory tuning isn't THAT bad. As you can see, all the values are within a reasonable range, and is never dangerously rich or lean. Of course, the numbers can be improved for rideability. If you get way too lean, cylinder temperatures will increase and could overheat certain parts of the engine. If you get way too rich, you can foul the plugs, or rinse the oil off the cylinder walls. The can lead to premature wear, catalytic convertor damage, and of course excess fuel usage and emissions.

I'm not a rocket scientist... Haha, but thank you This whole project is merely scratching the surface of engine tuning. If I really knew what I was doing, I would have gone into the ECU directly and started modifying the parameters. No fuel modules, no signal tapping. At the same time, you can do a lot of damage this way... like bricking the ECU, or causing engine damage, so this is a good starting point.




*One thing I forgot to mention earlier about how most riding takes place at 2-5% throttle. This is referring to the actual throttle body opening. When riding around town, it is normal to put 10-15% throttle at the twist-grip. Due to the ride-by-wire mapping, it's only just cracking the throttle body plate. All these tests were performed in "Sport" mode on my hyper SP, which is equivalent to "Touring" mode on the 'strada. I'm going to post up a Throttle Grip vs Throttle Body relationship chart at some point, to shed some light on the throttle mode mapping.
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Old March 7th, 2017, 09:21 AM   #5
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Kuk,
Just tell me how to alter my RB map, as I mostly commute in a mixed environment. I'm kinda pissed that below 7500, I'm not getting true WOT at full whack. Probably something more academic to this, but damnit! When I say full throttle, I mean FULL throttle!

Keep it up. Unless you really are a rocket scientist, in which case, pay attention to you day job, too.
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Old March 7th, 2017, 09:35 AM   #6
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Originally Posted by gatdammit View Post
Kuk,
Just tell me how to alter my RB map, as I mostly commute in a mixed environment. I'm kinda pissed that below 7500, I'm not getting true WOT at full whack. Probably something more academic to this, but damnit! When I say full throttle, I mean FULL throttle!

Keep it up. Unless you really are a rocket scientist, in which case, pay attention to you day job, too.

Sadly every bike will be different. The only way to get a perfect map for your bike would be to create a custom tune for your bike. Variances in the stock map, fuel type, environment, and manufacturing tolerances will all play a role. That said, they would probably be similar... maybe? I don't know enough to really say. However if you wanted to try one of my maps, it probably wouldn't hurt, as my corrections are pretty gradual.

The part-throttle until 7500RPM actually makes sense. By reducing the intake area, the intake air velocity is increased, improving how well the air can fly into the cylinder and push the exhaust gasses out. It's along the same lines of exhaust header diameter - our engines have huge exhaust headers, showing that the engine is designed for high end power rather than low end torque.

This is effectively the same as a CV carb, or some mechanical EFI systems, that have a secondary slide or butterfly valve that only lets a certain amount of air into the cylinder, regardless of what you ask for at the grip

I will have to run a test in "Race" mode and "Rain" mode to see if the throttle body opens any sooner or later in these.
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Old March 7th, 2017, 12:32 PM   #7
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You've definitely got a way of going about things. I think I'm more of a passive person - the bike doesn't like being below 3-3500rpm - I keep the revs above that. Short shift in the city and use the clutch. As long as I feel the machine is meeting me half way, I'm happy to make the changes in my approach. It's all good.
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Old March 7th, 2017, 01:13 PM   #8
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You've definitely got a way of going about things. I think I'm more of a passive person - the bike doesn't like being below 3-3500rpm - I keep the revs above that. Short shift in the city and use the clutch. As long as I feel the machine is meeting me half way, I'm happy to make the changes in my approach. It's all good.
Yeah... I could be medically diagnosed with OCD, I'm sure of it. Being an engineer doesn't help either. I've ridden 13,500 miles with the mostly stock setup. Definitely possible to ride around it. Maybe it'll have that last 10% now.
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Old March 7th, 2017, 04:19 PM   #9
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tuning

Great work kuksul08 - really. I look forward to seeing what you come up with. I'm seriously considering a PCV with Autotune and call it a day. Since I live at 6400 ft and will get down to sea level, Autotune might be my friend.

On the part throttle below 7500 RPM, I think you make an excellent point. Ducati seemed to seek out a balance in the engine - namely, some good torque for an 800 with revability. The stroke is just shy of the 1200 engine but the heads are designed to flow (HP). This is where the ECU limiting throttle opening makes big sense. If you could ask for all of it at once, you're looking at a big bog and that below 5300 RPM problem would be much worse. If you want more low end grunt, you need a crank more in the 70mm+ range, which doesn't rev as well (high piston speed, more crank flex, etc, etc.). In the end, I think they struck a good balance.

Look forward to reading your follow-up posts on this...
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Old March 11th, 2017, 08:15 PM   #10
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Follow up:

I loaded my new fuel maps into the bike. I still need to calibrate the RB throttle voltages, but it's pretty close now.

Wow, huge difference. The bike is just so much smoother all over. It also has a healthy mid-range power bump, and the hesitation/stumble at 6000RPM is completely gone. The power is super smooth, easy to control. Never feels insane or too aggressive, making maintaining throttle in a corner much easier. It pulls linearly to redline.

I am going to do a follow-up/check log for each cylinder to verify the changes are on target, then call it good.
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