Charge Dilution and PV

[Gordon61]

I think you are right but I got stuck at

MAP Manifold Absolute Pressure (kpa) = What the voltage from the "MAP" sensor says +- a bias table to cover the accuracy of the sensor.  MAP (kpa) on other tuners, apparently, is what the sensor actually sees.

Internal calculations for the effective air volume are what the ECU does, I don't see why DJ are messing with the MAP (kpa) value.  By all means create another signal but call it Effective MAP or Calculated airflow but anything but MAP, because MAP it aint!

[Gordon61]

The ecm does this because with a very short intake track and an odd fire the MAP signal goes crazy up and down.  The MAP tooth read/poll close and open tell the ecm exactly when to look at the map sensor.  This is usually based off of the cam timing events.  The MAP load normalisation table is in essence a calibration bias table to make sure the MAP sensor is on the right track.

Yea I've logged a whole pile of sensor voltage vs MAP (kpa) and I can kind of see what is going on there ...I suspect the PV MAP Voltage signal that goes into the log is not in sync with the cam timing events. But the ECU is quick enough to read the sensor at the right time so at least it knows what it is doing.

(in the logs; while the MAP voltage does wobble around all over the place there is a consistent minimum value in a trace of that log.  That typical minimum value is around the 1.6 mark at idle - so that, I think, is the maximum suck over the cycle, so should correspond to the cam timing event ...1.6v I think is around the 38kpa mark??)

[Frédéric CM]

guess we will never how to tune the cde table...

didn't a cam with a different overlap value should change the idling kpa ?

[Gordon61]

Well when I put new cams in, it did change so that has to be a yes.

Anything that affects airflow and efficiency is going to affect when and how much air the engine wants.  The MAP sensor is what is measuring how much suck there is and when so that whole MAP vs RPM table you saw is likely to be different if the characteristics of the engine are changed

...or we wouldn't be needing to re-tune, would we.  How to re-tune, properly, is the trick I don't seem to have a full grasp of.  This is not as easy as the adverts make out it is ...at least not past a stage 1 anyway.

[Gordon61]

Mind you, I've just read another thread about one of the supposed pro's not doing a good job either so if they can struggle what chance do we have 

[Sunny Jim]

Don't give up Gordon! I keep working my way through the map and all offerings of PV and target tune . Self taught with HTT support. My Intake reversion( pulsing) was more apparent when I went to a big bore free flowing 2-1 exhaust. I ended up scaling to 158 cubic in. Awsome power but still the ugly idle.  Next step for me is a cam change.
Just sayin.

[Sunny Jim]

Just for info, I was using the following CDE tables which on my bike with a 57H and Pro Pipe 2-1, and this gave a MAP at idle of about 31

Front, 153, 153, 150, 133, 114, 96, 79, 73, 67, 61, 51, 43, 35, 31, 31, 31, 31
Rear, 110, 110, 109, 105, 97, 90, 81, 72, 61, 48, 36, 33, 31, 31, 31, 31, 31

With your tune that has IVC/IVO modified by Dynojet (12D103_57H_ProPipeQuiiet) or not ?
I'll give a try to 2016 softail HO CDE table to see what happen to the idle kpa...

Just to remember, why are we targeting 35kpa at idle ?

Can you explain how this is done?

[rbabos]

guess we will never how to tune the cde table...

didn't a cam with a different overlap value should change the idling kpa ?

When all else fails and no actual reference where to adjust as in the PV, use the ve table as a guideline. Areas too high and too low for what should be a smoother transition, hit those kpa and rpm areas with appropriate CDE corrections and reset the ve tables with a few more tuning runs.
It is a trial and error process sometimes, and does take some time.
Ron

[remington007]

Right or Wrong i generally try to adjust the CDE tables around idle area to get my VE's in the 70 range. Especially on V&H power duals with cams. 
My personal 09 FL idled like crap and low speed sucked. The VE's were in the 50 to 60 range on the front cyclinder. I upped the CDE's in that area to raise the VE's. Straightened out my running issues.

[rbabos]

Right or Wrong i generally try to adjust the CDE tables around idle area to get my VE's in the 70 range. Especially on V&H power duals with cams. 
My personal 09 FL idled like crap and low speed sucked. The VE's were in the 50 to 60 range on the front cyclinder. I upped the CDE's in that area to raise the VE's. Straightened out my running issues.

I went the other way. Light load area ve's only were too high in my tune. The rest looked good. Dropped CDE tables in the light load areas, more so in the front which dropped the ve in that area for a better visual appearance. Most stable tune I've had so far. I was skeptical about the whole CDE deal early on but it does help. It's still a black art, trial and error thing with PV. Joe's reference for amount of adjustments are close to what I found as well.
Ron

[Gordon61]

remington007 / rbabos

That was kind of where I got to as well.  I had worked out what changing CDE actually did to the VE tables and was trying to get them as smooth as possible.  Just as an example, here are three Front VE tables from my maps

One uses the stock CDE tables and puts the low area of the table down to about 58 with some cell to cell steps of up to 11

One of my other configs has higher CDE numbers that raise the low area to about 72 and keep the step changes down to about 4 or 5.  And the other one generally lowers the CDE numbers past 1000rpm which drops the VE down to as low as 48 and with step changes anything up to 15 or so

I like the idea of the VE being around the 70/80 front/rear but I can't find a real answer to they should be.  A 57H is a reasonably mild cam for example so the idea that it would drop the volumetric efficiency of the pump down to 50% doesn't seem to be right in my head ...now a more radical race cam, fair enough.  The fact that the PV reports a calculation partly based on the CDE tables instead of the measured MAP also leave you wondering what that should be.

All 3 ride reasonably well with the Stock CDE probably a touch more jumpy low down than the other two.  So, 3 pictures, who thinks which is right.

[Gordon61]

^^ Sunny Jim

I'm not giving up like a lot of us I suppose, I'm just trying to learn about each bit as I go through the various tables.  My build has a new cam, ported heads and raised compression and for best/optimal/whatever tune ...I do not believe you simply run the so called "auto tune" built into these boxes, regardless of what the suppliers would have you believe.

Not sure what you were wanting explained but what I did was to edit the default CDE tables with those numbers I gave as being my example. I then re-tuned the VE tables (as you have to if you change the CDE tables).  Logging MAP value on the PV showed that the MAP at idle numbers dropped from 38-40 down to 30-32

BTW, so the PV has scaled your motor with a high flow air filter and bigger exhaust up to 158ci ...that seems awfully high, what is the actual ci [I'm also curious as to why the PV scales configs so readily yet if you look at one of the other tuners maps there is no scaling in sight?!?]

[rbabos]

^^ Sunny Jim

I'm not giving up like a lot of us I suppose, I'm just trying to learn about each bit as I go through the various tables.  My build has a new cam, ported heads and raised compression and for best/optimal/whatever tune ...I do not believe you simply run the so called "auto tune" built into these boxes, regardless of what the suppliers would have you believe.

Not sure what you were wanting explained but what I did was to edit the default CDE tables with those numbers I gave as being my example. I then re-tuned the VE tables (as you have to if you change the CDE tables).  Logging MAP value on the PV showed that the MAP at idle numbers dropped from 38-40 down to 30-32

BTW, so the PV has scaled your motor with a high flow air filter and bigger exhaust up to 158ci ...that seems awfully high, what is the actual ci [I'm also curious as to why the PV scales configs so readily yet if you look at one of the other tuners maps there is no scaling in sight?!?]

The problem with the scaling option (a flaw) is if there are cells that are 125-127, even in an area that cannot be hit it during autotuning it will keep scaling until the cows come home. I'd personally remove all base cal cells with 127 and change them to 120 before starting runs, then go out and tune. If you actually do acquire those high cells from the autotune, then scaling is in order, but only then. I don't know why this isn't made known as it bites a lot of people in the ass with ridiculously high CI ,that really isn't needed and complicates the tune process.
Ron

[Sunny Jim]

Gordon, my CI is 120.

[Sunny Jim]

I have several maps for my 120 CI. When I view them I find it remarkable the variations in these maps. The CDE on several maps  are intriguing Some maps have the CDE on both cylinders virtually equal. others have the front cylinder substantially higher in the lower rev range(idle) compared to the rear, but slightly less than the rear in the higher rev range . Now I have humbly received these calibrations from fellas clearly more informed than me, and I am sure these guys know their craft, but I find it confusing that 2,3,4 maps for the same bike can be so different.
Just sayin!

[Frédéric CM]

ssooo what's new folks ?

[Gordon61]

I've come to the conclusion there is no "definitive right" answer.  A bit like timing, lol

my vote goes with remington007 and rabbos and to see if you can get the idle/low area around 70/80 front/rear and the 1125-1750 and 0-7% TPS as smooth as reasonably possible.  The other good indicator seems to be the 50-70 kpa cells being reasonably smooth (mine for example seem to be within a couple of points of VE).

[HD/Wrench]

It really is about getting them smooth and no there is no right or wrong its based on that " build" I had a stock 110 I was tuning it it idled at 39-40 KPS I played around to get it lower , nope that where that engine wanted to be and getting the idle KPA down to me is not the biggest deal ..  Smooth from 35-65 KPA is the goal by 70 + thats a whole different area and timing started to get rolled down inthat area as well . so it becomes then playing with timing..
DOnt give up its yours and play with it.. But end of the day its still a HD engine and by design is well not the best and you can only do so much.

[Gordon61]

Thanks GMR, it's probably been said before and I think it's starting to sink in now but that is a good summary we can use

I hadn't realised about the timing affecting the higher load quite like that so good pointer as well, thanks

[joe_lyons]

Too rich or too lean at idle can have higher KPA also

[Gordon61]

Well if the PV would stick to showing us the actual sensor reading rather than some internal calculation we wouldn't be getting so confused 

A sensor IS a sensor after all 

[Onthefence]

Well if the PV would stick to showing us the actual sensor reading rather than some internal calculation we wouldn't be getting so confused 

A sensor IS a sensor after all 

Is the PV calculating the readings or the ecm?  I thought the items in the log were raw outputs from the ecm.


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[Gordon61]

Is the PV calculating the readings or the ecm?  I thought the items in the log were raw outputs from the ecm.

Good question, is it the ECU or does the PV program the ECU to do it, or there are more than one signal that does MAP (i.e. PV can log both MAP value and MAP sensor voltage) ...according to one of the other vendors their MAP value is what the sensor says it is (...which seems to make sense to me) and does not change with EGR.

but we have what we have so probably a bit academic, but it is really useful to know this stuff

[rbabos]

Is the PV calculating the readings or the ecm?  I thought the items in the log were raw outputs from the ecm.

Good question, is it the ECU or does the PV program the ECU to do it, or there are more than one signal that does MAP (i.e. PV can log both MAP value and MAP sensor voltage) ...according to one of the other vendors their MAP value is what the sensor says it is (...which seems to make sense to me) and does not change with EGR.

but we have what we have so probably a bit academic, but it is really useful to know this stuff

CDE tables directly effect afr to alter the VEs from their current state based on tables in the ECM. The altered calibration load sets this up.  I've not seen any difference in MAP readings before or after CDE table changes. Only time I see my MAP change on a daily basis is between cold oil and hot oil and it's corrisponding amount of drag per rpm.   My understanding is the calibration alters what the ECM reads in those areas for fueling once the ve is revised with further tuning runs. Smoothing the ve is also smoothing the afr as the side effect.
Ron

[Frédéric CM]

Changing the CDEs will affect MAP readings at closed thottle