[EvolutionTheory]

I've been trying to find a thread made a while ago about advancing the timing at cruising RPM to make it better on the highway. I'm good for about 24mpg @65mph but I've heard some talk about 26-27 and I'm getting a job further from home so I could use the extra MPG's. I'm not sure why I can't find it, maybe because the forum is polluted with MPG threads. Or even if you could provide a little insight about the subject that you've experienced. I'm not looking to make it "fuel efficient" because I know that can't happen. Thanks to those who don't flame. I'm always game for a good laugh though :thumbup:

 

[jyamona]

most people have 43-44 degrees in the cruise areas

 

[EvolutionTheory]

most people have 43-44 degrees in the cruise areas

Yeah thats about what I have. I wanted to see if anyone has tried even more, or had any success combining advanced timing with modified mivec, etc... I'm open to anything.

 

[chetrickerman]

44 degrees with proper fuel management gets me 30 mpg on the highway. 400 miles to a tank

 

[jyamona]

44 degrees with proper fuel management gets me 30 mpg on the highway. 400 miles to a tank

all open loop running leaner than 14.7?

 

[chetrickerman]

nope. closed loop.

 

[jyamona]

nope. closed loop.

then you have no control over fuel management?

 

[chetrickerman]

I am open loop over 60 load, not always open loop.

Sorry for the confusion

 

[Golden]

I run 43 timing, open loop, and a fairly lean afr at cruise. My car only sees closed loop at idle.

As for mivec, "advancing" your cam shaft helps shift the torque curve around. Lots of overlap doesn't seem to help much.

I don't recommend open loop cruise for the average user. But with E85, I like my mileage.

 

[EvolutionTheory]

I run 43 timing, open loop, and a fairly lean afr at cruise. My car only sees closed loop at idle.

As for mivec, "advancing" your cam shaft helps shift the torque curve around. Lots of overlap doesn't seem to help much.

I don't recommend open loop cruise for the average user. But with E85, I like my mileage.

Could you explain the open-closed loop thing in a way that I could understand? Doesn't have to be too in-depth. How lean is your afr at cruise? Thanks

 

[razorlab]

Could you explain the open-closed loop thing in a way that I could understand? Doesn't have to be too in-depth. How lean is your afr at cruise? Thanks

Set Open Loop tables at cruise RPM to zero (or less load then cruise sees), this forces the car to run Open Loop at cruise RPM's. Then tune fuel table while watching wideband until you get your desired cruise AFR.

Keep in mind the narrow band is just that, narrow, and get's exponentially less accurate the further away from stoich it goes.

 

[Clipse3GT]

Set Open Loop tables at cruise RPM to zero (or less load then cruise sees), this forces the car to run Open Loop at cruise RPM's. Then tune fuel table while watching wideband until you get your desired cruise AFR.

Keep in mind the narrow band is just that, narrow, and get's exponentially less accurate the further away from stoich it goes.

Ideal would be to to have the ECU read the WB O2 sensor and have a table to hit WB O2 target with a set table depending on condition parameters same as with a standalone. Not sure if its possible even with the Evo Ecu.

 

[razorlab]

Ideal would be to to have the ECU read the WB O2 sensor and have a table to hit WB O2 target with a set table depending on condition parameters same as with a standalone. Not sure if its possible even with the Evo Ecu.

You can do that with:

http://www.zeitronix.com/questions/NBpoint.shtml

 

[sstevojr]

Wow, that's niffty

 

[Golden]

Closed Loop is when the ECU uses the Narrow Band Oxygen sensor to dynamically change the fueling based on actual AFR values. If the car starts running a little leaner, the ECU adds fuel. If the car starts running a little rich, the ECU removes fuel.

Open Loop is blindly adding fuel based on table values and measured / calculated air flow.

 

[khaydin]

44 degrees with proper fuel management gets me 30 mpg on the highway. 400 miles to a tank

30mpg? Best I've gotten is 26mpg w/ timing and mivec adjustments. When you say fuel management what other map(s) are you changing if you're cruising in closed loop? Calibration Fuel map, cylinder fuel trim maps, injector maps?

 

[Tr6]

Get a protune, increases efficiency especially after you get a fuel pump an injector upgrade. My stage 1 Cobb got me about 24mpg up from 21 that I only ran for a week then I got a protune that gave me the same amount as I was running stock injectors/fuel pump. Now I have about 27-28mph @75 mph but not with cruise control. If you do 65-70 with cruise you can get 27-28 also keep in mind that I live in a part of Arkansas where it's surrounded by mountains so a lot of climbing. In Dallas I have gotten 29.7 mpg as its straight and the weather around mid 50s.


Sent from my Autoguide iPhone app

 

[razorlab]

Get a protune, increases efficiency especially after you get a fuel pump an injector upgrade. My stage 1 Cobb got me about 24mpg up from 21 that I only ran for a week then I got a protune that gave me the same amount as I was running stock injectors/fuel pump. Now I have about 27-28mph @75 mph but not with cruise control. If you do 65-70 with cruise you can get 27-28 also keep in mind that I live in a part of Arkansas where it's surrounded by mountains so a lot of climbing. In Dallas I have gotten 29.7 mpg as its straight and the weather around mid 50s.


Sent from my Autoguide iPhone app

Just remember that the HUD/Combo Meter will show incorrect MPG with larger injectors... so make sure you are measuring MPG the traditonal way.

For now at least.

The IPW Multiplier that gets fed into the Combo Meter has been found and it's being tested, and it works. I can make my car show 50+ or 1 MPG if I want to. So soon everyone can calibrate the HUD/Combo Meter for larger injectors.

 

[sstevojr]

more niffty-ness!

 

[nonschlont]

more niffty-ness!

I was literally just thinkin, thats niffty! then read your post... lol