No Device: Possibly the most basic tuning question
You have changed some bits (but CI stays the same) and re-tuned your EFI...
Does the reduction/increase in VE between new and stock maps equate to a reduction/increase in torque(power) of the tuned engine?
And ...would you expect the difference between the two cylinders to be kind of similar?
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
Last edited by Fat11Lo; Feb 1, 2017 at 02:14 PM.
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?
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?
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.
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
I didn't have to scale ...which I think is either something of a PV foible or more related to peaky cams.
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
The Best of Harley-Davidson for Lifelong Riders
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
Last edited by Gordon61; Feb 8, 2017 at 02:51 PM.








