Hi To All,
I have a 2017 Fattie that has the following:
- 110 CI
- 10.2 Compression
- SE CNC Ported Heads
- SE-585 Cams
- Bassinni 2-1
It drinks nothing but 98 Octane.
The Tune is based around the
DBC600-01-A0 TTS Map
The bike runs well with the one exception, where at light throttle values and Engine RPM around 1700, typically when maneuvering in city traffic, the bike will want to surge, which then results in having to slip the clutch slightly to get through the traffic.
I use the VTune to assist in the development of the maps, but I have always noticed there is a hole on the Front VE Table (see attached).
I believe this may be the culprit causing the grief.
I have always had difficulty getting my head around the EGR Tables and what effects it has on the VE Tables.
I now wonder if I can push the hole out of the VE Table by increasing the Multiplier for the Engine RPM range (see attached).
Would I be on the right track with this?
[attach=0,msg1310724]
[attach=1,msg1310724]
The front egr table acts on the MAP. This is not the case of Rear EGR table. It's a fact and I don't know why...
However, if you increase front egr table then MAP decreases and therefore VE decreases too.
To properly adjust the EGR table, in fact it is necessary to observe the MAP curve in deceleration and smooth it in little. It is sensitive on the motor behavior.
I d'ont know how the TTS tuner acts on EGR and MAP.
Can you post the map currently in the bike, and the Data Master runs?
You should consider the possibility that the cells in question never got tuned. Blending may be in order. Data logs may be helpful in determining that.
BTW, 1750/2000 RPM @ 26 KPA is decel area.
Please find the Tune attached.
Don't have any Data files for this particular tune, but will sort that out on my days off which will be this coming Thursday.
I will provide at that point.
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Excessive spark advance can cause surge, also. Looks like you're running up to 53° in places where I normally see 40 ish.
If you're going to collect info, I'd reset the lambda table, for data runs only, to 1.0 all the way to 80 KPA, just to see what it wants.
G'Day rigid,
That is what I am hoping to do this coming weekend.
In past I have done this and tried to cover as much coverage I can on the road, but the hole never disappears.
I can manually bring the VE's up to fill the hole in but when I VTune in Closed Loop, then the hole reappears.
This is the reason why I am now looking at EGR.
The reason why I run so much timing (without ping) is that we used 98 Octane.
Get off the 98 octane
95 is good
tune for 95 and it is a small shift for ecm to adapt if 95 is not available and you run 92 or 98
the service manuals recommend 95
my 110 is at about 11:1 and it loves 95
Increased octane fights detonation, but only makes more power if you actually need it. Mean Best Torque (MBT) is found with just enough octane and spark advance to apply max pressure on the piston ~11° ATDC.
Aussie fuel and European fuel is different to US fuel
98 in OZ is around 93.5 in US
95 in OZ is around 91 in US
Harley say to use Premium unleaded which is 91 in the US or 95 in OZ
So what 98fxstc says is correct but always buy from a place that has a high turnover of fuel especially when tuning.
Well..... there ya go Scotty, I never knew that.
Like the logic 98fxstc, but are you basically saying that only use 95, to just tune to 95 but them use 98 as I would normally do?
I have started using GMR's recommendation for tuning, 1st tune the VE tables and I always use stoich setting 450 mv or 1.000 lambada do not accept any EGR changes, 2nd tune the ignition tables (Steve Cole has said on here several times that there is no need for anything over 40 in the timing tables), 3rd verify VE tables for closed loop area and accept EGR changes
I also tune with 86 octane which is regular in my area where 91 octane is premium
Quote from: Fritzables on August 13, 2019, 03:27:55 AM
Well..... there ya go Scotty, I never knew that.
Like the logic 98fxstc, but are you basically saying that only use 95, to just tune to 95 but them use 98 as I would normally do?
tune with 95
run with 95
Thanks everyone for your input.
I have played around with the EGR Table numbers and the trough has now gone.
Bit more tweaking over the weekend should finalise the tables.
Feels so much better.
I'll bring the timing back to 40 where it needs it. Will be using 95 from here on.
:up:
Quote(Steve Cole has said on here several times that there is no need for anything over 40 in the timing tables)
Hey wolf_59, just looking over the base TTS Maps (Timing) and they are showing up to 47 Degrees, so unsure why Steve would say such a thing.
I've asked myself that question several times :scratch: when I read that post
I have tried running up towards 50* in the low load areas of the map and not have any SKR events but engine and exhaust temps were pretty high
I bumped them down to 40 and made a big difference on the temps and kept adjusting from there until I couldn't feel the heat or very little coming off the pipes by the passenger floor boards which made the wife very happy
OK Last question.
I took a look at my EGR Effects plot (see below).
What do the blue dots represent - the area where I need to clean things up??
[attach=0]
the EGR didn't show up on my last vtune when it had adjusted on the 2 previous runs so I guess it was close enough at that point positioning the blue dots for the most part ended up just below or left of the red line which if I remember correctly represents the 60 Kpa point
Quote from: Fritzables on August 16, 2019, 01:07:17 AM
Thanks everyone for your input.
I have played around with the EGR Table numbers and the trough has now gone.
Bit more tweaking over the weekend should finalise the tables.
Feels so much better.
I'll bring the timing back to 40 where it needs it. Will be using 95 from here on.
so to try and answer your original question (as i've come to understand it, someone correct me if i've missed something), but the ecm needs to know how much oxygen is going into the engine to determine the correct amount of fuel to give for the commanded AFR. it knows the oxygen content because it knows the %age given the MAP and IAT. at low rpm and throttle openings due to engine characteristics (shared intake, odd firing of HD engines, can overlap, exhaust design) at some points the MAP reading is partially due to exhaust gasses. exhaust gas has less oxygen in it and displaced some of the new air charge coming in. because there is now less oxygen, some of the fuel for that cycle goes unburned. your o2 sensor reading now shows that the system is rich at that point and so tells you to lower the VE for that cell. technically, doing so will work and give right amount of fuel, but the problem is that the ecm has to fuzz the calculations for all the in-betweens. if you've got a value that's way off of surrounding cells, the calculation gets less accurate and part throttle driveability suffers. EGR allows for a smoother VE table which is the main calculator factor and EGR is applied to reduce fueling when the intake charge is contaminated.
edit: ugh, i reread this after only 2 hrs sleep last night and i'm just dead right now. i may have confused the issue by reversing increase/decrease terms, but basically the egr says how much of the intake charge is displaced and this allows you to smooth the VE table making the calculation more accurate. back to bed for me.
To complete your speech, I would say:
If you increase Front EGR, decel MAP decrease. And to get the same O2% in gasses, VE increase.
It seems to me that MAP signal represents, in fact, the partial absolute pressure of inlet air.
:scratch:
i suspect that the MAP value reported to us is what the ECM has calculated as the pressure due to the fresh air coming in. like, the EGR effect has been applied and that's how the ECM has determined that less actual o2 is being taken in?