Data Log Sample - Feedback

[yamamarc]

The throttle is actually wide open the entire time. It fluctuates between 99 and 100 for some reason

@yamamarc - Why is your IAT reading so low?

It was -20*c that morning. I run the gap ram air also not sure if that makes a big difference or not?

I haven't seen any higher then 30*celcuis(300 header)

 

[snowdust]

Ahh it is in celsius. That makes more sense.

 

[yamamarc]

Ahh it is in celsius. That makes more sense.

I was just going to point that out...hahah

Between 60 - 80*f

 

[earthling]

The throttle is actually wide open the entire time. It fluctuates between 99 and 100 for some reason

@yamamarc - Why is your IAT reading so low?

A good practice when getting data samples is to make sure that you are creating 'clean' data that isn't influenced by spurious inputs. For instance at 4 seconds you pin the throttle but just prior to that you blipped the throttle (If I am reading your data correctly).

When you have closely coupled systems (throttle, timing, AFR, etc) there is always some hysteresis/latency between action (pinning the throttle) and reaction (RPM climbing, the reaction loop as the ECU samples O2 and adjusts). What you care about is the sampled data between the two most important parts of the graph, from zero throttle to WOT and back to zero. This allows you to isolate intention (what you wanted to happen) from results (what the data shows). When you do not bracket the data with clear intention (smooth application of throttle) you can inject erroneous data (not super helpful data) into the logs. When you have problems in the loop you get spikes, lagging reactions, etc.. So to ensure that you are getting clean data you should bracket (bookend) your data samples with clean intentions (hope that makes sense). Its just good data practice.

Looking closer at the graph you provided the most confusing data is at the beginning and end of your run. The second throttle blip happens during the AFR overshoot. Is one a precursor to the other, is it just lag between throttle application and the time it takes the engine to spool up or are the oscillations machine (clutch, drivetrain) or human induced. By making your intention (clean application of throttle and clean release of throttle) more specific it will be easier to figure out what is going on. All of my comments above are guessing based on the fact that I do a lot of data analysis, I am not a tuner but its clear to me that there are factors that cannot be easily explained (timing getting pulled after the run) from just looking the data alone. Eliminate all non-intentional influences (throttle blips, sudden rider weight shifts, etc) and you will get cleaner data allowing you to better understand what is happening. If you watch the guys who run dynos you will see that they are focused on just grabbing good data so their actions are very smooth.

 

[KnappAttack]

His timing being puled is more than likely noise at this point. Especially off the throttle at the end of the run. Something is rattling or clicking in the chassis.

Obviously a throttle blip or two in there as well, perhaps he just can't rid himself of the old two-stroke days and forgot he's now on a four stroke...

 

[earthling]

His timing being puled is more than likely noise at this point. Especially off the throttle at the end of the run. Something is rattling or clicking in the chassis.

Obviously a throttle blip or two in there as well, perhaps he just can't rid himself of the old two-stroke days and forgot he's now on a four stroke...

Do you mean that the sensor itself is subject to noise? I have no idea what kind of data one would expect to find on wideband sensor or do you think its something else? Do the wideband sensors generate voltages, resistance, an actual value?

 

[74Nitro]

Do you mean that the sensor itself is subject to noise? I have no idea what kind of data one would expect to find on wideband sensor or do you think its something else? Do the wideband sensors generate voltages, resistance, an actual value?

The knock sensor.

 

[earthling]

The knock sensor.

Ahh, makes sense. It would be hyper-sensitive by design. I do find this relationship interesting though. Engine is running lean, boost has dropped, right after where they cross timing gets pulled again. could be noise. There must be a way to raise the noise floor for the data that comes from the knock sensor but then I guess you give up sensitivity. Anyhow fascinating stuff.

 

[sideshowBob]

This has all been very interesting and has become a bit of a Gap Data Logging tutorial.

 

[Todd Beenen]

Exactly what was needed, a little schooling

 

[DooZ]

This thread may be a good candidate to be pinned to the top of the forum. Just a thought

 

[snowdust]

His timing being puled is more than likely noise at this point. Especially off the throttle at the end of the run. Something is rattling or clicking in the chassis.

Obviously a throttle blip or two in there as well, perhaps he just can't rid himself of the old two-stroke days and forgot he's now on a four stroke...

You nailed in Mike. I still hit the throttle at the end of the run sometimes and forget I don't need to. Weird that is such a habit from many years ago

@earthling At the beginning of the run I did let off a bit due to lack of traction. I was trying to get a decent 1000' time since I was using the dragy so I didn't ease into it as much as usual. I appreciate all the insight from a data perspective. It's all super interesting.

Side note... For anyone using Dragy and the Gap flasher.... You can connect both to bluetooth at the same time. Dragy has audio, but gap does not so it works. If Gap had audio it would not have worked. Just FYI.

 

[Fast]

It was -20*c that morning. I run the gap ram air also not sure if that makes a big difference or not?

I haven't seen any higher then 30*celcuis(300 header)

Just currious how many knock lights you get on an average ride

 

[snowdust]

Did another run today as we got about 3" of fluffy snow. I made some changes before this run...

Changed
- From 22/41 gears to 24/50
- 1/2 tank of fuel instead of full
- Stock 35 helix instead of 37/35 Dalton
- 20 degrees and sunny instead of 15 and cloudy
- 2-3" snow covered vs. very little snow hard packed
- Transfer on raceworks block changed from ground down side for more than max transfer stock to least amount of transfer which is less than lowest stock

Stayed the same:
- B/O still at 90 and daltons at 79g
- 1oz boostane per gallon
- Running a gravel railbed

So what I really was testing was running thundercat gears. Turns out the snow today really slowed me down. It was hard to get traction and it just seemed to labor the entire way. I was fine with that, but after looking at the logs it is really running rich. Rpm's climb over the run, but it's interesting how much it seemed to labor to get there. I did a video this time so you could see the entire run. Might be cool for those without data logging as well. Thoughts on why it was so rich? I actually called to get the closed loop yesterday but am waiting a callback to purchase. I'm kinda glad I didn't have it yet as this data is interesting. I didn't think to change the transfer block to see if that had anything to do with the drag but maybe it was just the snow.

Side note - The lower gears do seem to make a difference in the snappiness of it like jumping off bumps. That's in line with what everyone reported, but I wanted to try it for myself. I plan to go back to 22/41 as I think getting traction will be too tough with the lower gears.

Video of log:

Dragy run:

 

[snowdust]

Looking at this more the Dragy data is interesting. In 330 the runs are almost exactly the same. From there on out you can see the run with the taller gears is much faster. Also interesting the difference is about 10mph which is about the difference in gearing as well. Not at all the same conditions between days so apples to oranges, but interesting. I thought the 330 would have been slower for sure with the snow and difficulty with traction yesterday.