LS1 "Mobilgas economy run" - back to the future.

Officially "off road" of course, removed cats, O2 sim.

Say you wanted to maximize miles per gallon up to WOT.

Lean burn, Minimal idle, tight shifts, up and downshifts based on efficiency, not smoothness.
Mid speed (55MPH) throttle settings presumed to be between closed and 50%, 3/4 throttle still economized, but rich enough for no stumble, transitino from 3/4 to WOT as stock, WOT set for maximum power (HP/TQ).

Durability and reliability should be withing realistic limits (no melted pistons when completed) Drivability allowed to suffer at less that 75% throttle for economy.

0 to 50% throttle absolute maxed for economy, without destroying engine/systems, and without requiring excessive or permenant modifications. Should still meet MVSS accereration minimums for safety

Presumed to have free flowing intake, OEM engine/exhaust manifolds, possibly catback or custom duals, street legal sound, narrowband O2's or WBO2, but no "live" tuning - (No OBD2 port connection permitted)

Duration of run to be in weeks, and thousands of kilometers; not single 24/7 contest, but average over many runs.

Vehicles (for competitiveness) will feature OEM automatic tranny, but low resistance tyres, and external aero mods, lightened and stiffened chassis body..

Altitudes are sea level to 1000 meters, grades to be as high as 10% so engine braking WOT are needed. Handling to be low speed sharp turns, moderate speed turns - typical modern road coarse of gentle off road course - not oval or test track, nor straight line.

What would YOU do with EFILive to accomplish this??? How would you validate it
What minor mods would you perform?

Also vehicles may be returned to OEM conditions afterwards so permanent mods not permitted.

MRK

I haven't got the time to even think about it ...... :doh2:

You can lean it out by playing with the NBO2 switch points and changing which CL mode correlates to the airflow scenarios of the driving you described above. But, personally, I wouldn't think it's worth the effort. You want fuel economy, go to Home Depot, buy a brick, and wedge it between the gas pedal and the floor. ;) That'll take 5 minutes in and out.....and it'll get you better results than a full weekend of tuning. LOL

I'd tweak DFCO and learn how to drive

Yep to DFCO , works wonders for saving a little go juice .

BTW, I know how to drive, for performance and economy....

What specifically about "Lean Cruise" I never really confirmed if it's possible to enable it or has someone graphed it so it can be applied anywhere?

DFCO is on the list already, as well as shift points, and advancing timing, and in some areas even richening the mixture (theory is get up to speed with higher vacuum/richer mixture for overall less fuel usage)

Doing much research on this but finding most are carburetor type discussinos and YES, I know the correltation, but there are tools now (EFILive...) that allow a much better adjustment of the mechanics, and most of the theory and data is bsed on the "NO BAND O2" type of tuning in the past.

Either I am blazing a trail or I am missing something somewhere, but these tools can also be sued to save fuel and with the press of a mouse, gain power, too.

(Of course three's a way to have a "POWER - ECONOMY" function "switch" here, now, too)

Any other ideas or links ,or comments?

You could run OLSD and set the commanded AFR as lean as you need... and install a brick (as Jeff suggested) which has the side effect of preventing you from getting into lean-knock-under-load conditions.

I don't know about making power... power requires fuel consumption.

Yep go OLSD with OS3 or 5. We have Lean cruise available to us in AUS and I don't even use it on my SD based tunes (I do on Stock OS's ofcourse) because B3647 is that good.

Quote:

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Originally Posted by emarkay

BTW, I know how to drive, for performance and economy....

What specifically about "Lean Cruise" I never really confirmed if it's possible to enable it or has someone graphed it so it can be applied anywhere?

DFCO is on the list already, as well as shift points, and advancing timing, and in some areas even richening the mixture (theory is get up to speed with higher vacuum/richer mixture for overall less fuel usage)

Doing much research on this but finding most are carburetor type discussinos and YES, I know the correltation, but there are tools now (EFILive...) that allow a much better adjustment of the mechanics, and most of the theory and data is bsed on the "NO BAND O2" type of tuning in the past.

Either I am blazing a trail or I am missing something somewhere, but these tools can also be sued to save fuel and with the press of a mouse, gain power, too.

(Of course three's a way to have a "POWER - ECONOMY" function "switch" here, now, too)

Any other ideas or links ,or comments?

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My point earlier was somewhat sarcastic - I apologize. What I was getting at was, yes, you can work to tune your car to run a leaner AFR. However, there are other, easier & more effective ways to get the desired results (i.e. better fuel economy). I say this because in my experience, running a little leaner is fine for light throttle/cruising applications. The cooling systems on the cars are capable of handling the job. However, I don't believe leaning out the AFR a point or so will net you much more than 2~3 mpg. But, the risk you're taking can be rather significant. Say you decide to set this lean cruise up with an OL tune. You lose the safety of the NBO2's and fuel trims to keep you around that new, leaner mixture. If the operating environment changes enough, you could potentially go too lean. If you try to tackle it with a CL tune (by changing O2 switchpoints), a little part of that safety factor is built back in. But, I still have some reservations because of the theory that the NBO2's are really only accurate around stoich. You start tuning them to operate outside of their accepted range, and you run a risk. It's virtually the same reasoning behind having a WBO2 to tune WOT. The NBO2's are just not trustworthy for AFR's outside of stoich.
My suggestion of a brick under the pedal is obviously not the solution. Going easy on the gas, driving with the windows up (aerodynamics has a significant effect on mpg's - more so than a leaner AFR), keeping momentum (time your stop lights - dead stop accelerating sucks gas fast), etc....all of those types of 'economy' driving are really what your focus should be on for fuel economy. The other side of it is TCO (total cost of ownership). You don't buy a Ferrari if you can't afford the service/maintenance costs, right?