I could see the VE tables of two tunes being compared to determine if the mod "You have changed some bits (but CI stays the same)" has increased efficiency. Something external like Air Cleaner or Exhaust.

Let's say you are experimenting to see which slip on mufflers are better for your bike. You have your tune dialed in for the current mufflers and you switch to another muffler. Then you proceed to re-tune your bike with the new mufflers, once the tune is dialed in you could compare VE from one tune to the other. If VE was increased/decreased significantly (because VE can vary with atmospheric conditions) in areas then you could make the argument that one muffler was better for you than the other. But the dyno results should have already told you that in torque and horsepower. This kind of testing has to be done in a very controlled environment to be accurate and would involve some extensive dyno time. Things most of us DIY guys do not have open access to.

If any internal changes such as cams then there could be no comparison

Short answer as stated before, not a practical comparison for determining power

 

Since the Delphi system senses barometric pressure and air inlet temp.. One would hope that those values would be included when setting VEs during the tuning process as the system is running closed loop. It's part of the process of a speed density system. I guess the delphi system's correction tables would have to be valid tho..

 

That's exactly what I was wondering about.
Short of a dyno (real or your butt's imagination) - can you see from the tuned map where your gains (or losses) may have happened.

Or, are the transients like intake temperature, atmospheric pressure, and engine temps going to be so significant and variable that VE alone is not worth looking at at all. As you say Bruce, unless you have some controlled environment, unlike street tuning with different days, different weather, probably different routes and traffic conditions.

If the rule of thumb for these autotune programs is get it to within 5% change (because it will be different if you do it again tomorrow) presumably any difference between a before and after tune in the order of 10% is pretty meaningless ...is what I was wondering about.

The example that spawned the thought was my comparing my tuned ported/57h/ProPipe with what was the stock 2014 103ci softail map ...I think I expected more than this?

 

First Off I wouldn't call "intake temperature, atmospheric pressure, and engine temp" transients.. They are more like corrections, IMO.. I really saying the opposite about closed loop than what you seem to be thinking. I'm stating that the input sensors correct issues with the environment that the motor is running in then look at closed loop changes.. Obviously they can't correct for differences in the proportion of O2 in the air caused by differences in humidity or even emissions from other cars but they can use the sensors you listed. I suspect that motor temp is used to correct AFR instead of VE tho.. Only because that is what Tmax does.. Just a guess tho.

As far as your table goes, I'm not sure what quantities you'd be looking for.. The numbers seem reasonable to me. The amount of power won't likely track VE changes directly but will be a indicator of increase or loss. When you start changing cams and compression ratios, you change the efficiencies of the motor under various operating loads.. If efficiency goes up, motor just made more power with the same amount fuel.

 

Yea, transients is the wrong word, external factors that as you say, the ECU makes corrections is a much better description.

What I was wondering was that if a stock 103 is about 66hp/85tq and a stage 3 is supposed to get you up to around 90/110 ...could you expect to see that 36% increase across your VE tables (or at least down the WOT column given that's all a dyno chart tells you)

I think what we are saying is that while the VE tables may offer an indication of airflow improvements (or losses), that's not all there is to power gains so just looking at your VE tables is not realistic


Get it tuned properly on a dyno

 

Wouldn't you have to add up the total change? Which would include figuring out how to scale it too? Cause the 2nd and all consecutive data runs after that will be based off the flash before? Maybe I'm just missing something about the software your running?

 

Whether its software or a simple spreadsheet, comparing the starting point with the finishing point gives the total change. WinPV for the Power Vision just happens to make that simple.

I didn't have to scale ...which I think is either something of a PV foible or more related to peaky cams.

 

Has anyone questioned the 3500-4000 corrections at 80-100% TP?
Does anyone feel this is a bit much?
You think garbage in garbage out applies?
Or do you think it's a tuning software issue?
Definetly SOMETHING ain't right! Right?
Bob

 

I have been looking and it doesn't always add up. Remember if you did do EGR adjustments. It will be an apples to oranges below about 65-70 kpa. Unless you want to compare those tables as well.

 

Thanks Bob, I did see that.

If you look at the stock map the VE has a nice shape to it across the rev range, almost as you would expect the torque curve to look on a sheet.

My current tune isn't what I was expecting to see, and the reason I'm still asking awkward questions and still tinkering on with it. Whether it's garbage in or the way autotune is working with the narrow bands, or my street technique (which I thought was getting better), I have no idea.

Auto tune or logging I cannot get rid of that peak at 1750, or the dip at 2250. The VE peaking at 3500/4K I sort of thought was the 57 pushing the torque a bit right, and the head porting helping even further??



The rear cylinder has a lesser peak at 1750, a horrible dip at 2500/2750, but also seems to peak at 3500/4K



It started as a general question about VE tables but if you have any thoughts I'll happily take them or start a new thread if you think it would be an interesting discussion??

cheers