here's the background. 2013 Ultra Limited. Rush true dual headpipes, rush 2 inch baffles. SE breather.

Local HD just replaced the ECM. They never told me they had replaced it and when I asked what they had done, the service writer said "I'm not sure". That whole part is another story for a later time though.

So once I found out they had replaced the ECM, I got with DynoJet and had my Power Vision remarried to the new ECM. I downloaded a map for a 103 with 2.5 inch baffles and programmed the ECM with that. I then did an autotune for about 100 miles and had a good solid block of red from the datalogging. I converted that to a new map and had to run down to Laredo, Tx.

I have never gotten more than 40 MPG and could only get that under 70 MPH. With this new autotuned map I was getting 42.5 MPG at 75 and 80 MPH.

When I compared the maps, before and after autotuning, the autotune took out as much as .15 on some of the cells in the VE table.

With that map, I can stay at 80 MPH and still get over 41MPG consistently. When I went back to the original map, I got 35 MPG while going 75 and 80.

My question is could the autotuned map be too lean? I later downloaded a map from DJ for true duals with 2 inch baffles (exactly what I have) and I consistently get 41 or 42 MPG with it even running fast.

I'm thinking about autotunning that map and see what it does.

Anybody have any thoughts on it?

I love the extra MPG, and it didn't ping or anything. I could feel the extra heat though.

 

Sounds like you got it going
your way , I never got better than 35 on my SG with a PV ,Dragos dual's and mufflers .I tried several maps and autotunes.

 

I guess I'm just overthinking this. I guess I'll run the autotuned map until I see something I don't like about it like pinging.

It's always been a strong motor and still accelerates pretty strong from 75MPH with the good milage map.

 

Your VE's only determine the optimal mix of air with fuel, Your AFR set lambda table determines how rich/lean your tune runs. Check out the PV stickys last couple hundred pages for a good read and all you'll need to know. Oh and of course RTM

 

The way I understand it, the AFR table will determine the richness if the VE table is right.

If the VE table is not right, the AFR could be anything.

 

Not exactly right. AFR's determine how rich your bike will run. VE's = Volumetric Efficiency and determine how efficient the bike is running. There will be a slight increase/decrease in overall AFR's based on your VE's.

The 0.15 change on some of your VE's will amount to small changes to your AFR's, but I would not be too concerned. It's obviously running more efficiently if your mileage has increased.

 

Volumetric efficiency....What is that other than the amount of air the engine can pump? So if the map adds the correct amount of fuel to get the right AFR, but the Volumetric efficiency is not right, the AFR will be affected.


So how can you say "Not exactly right"?


It's like you know how to make good Kool-Aid in a gallon container, but you try to make Kool-Aid in a 3 quart pitcher and you know that 2 cups of sugar will make perfect Kool-Aid and you're surprised that the Kool-Aid is too sweet.

 

I think we're both saying the same thing.

Bottom like is that once you get your VE's right, AFR determines the fuel mix. You should always optimize VE's as the first step in the tuning process.

If you are only getting 35 MPG there's something wrong with your tune.
I get about 42 MPG with my stage-2 FLHRC, and so do many others, and I haven't optimized the tune for mileage.

These large engines do generate heat. If it runs well and doesn't ping, I don't think that you are too lean.