Fuel Economy Tuning Ideas

[blucreek]

I will be getting a good MPG run this Sat. as I will be traveling from Chas. WV to Tulsa, OK. Up to this point the best I have got is around 22-23MPG but, all of those 300-500mi. test were taken in mostely "very hilly interstate" conditions while in WV(=70mph speed limit) I would see about 1/2MPG loss. Most test were taken in CC @ the speed limit.
I have since calibrated my LM1 w/ HPT so they are reading the same. I plan to go to SD OL and touch up the VE and MAF tables this week, with the o2 R/L voltages to their stock values. After completing Spark and WOT tuning I then want to lower O2 #'s but in the correct Airflow mode. My ? is how far is too far to lower o2 volts and at what Airflow mode?
Anyone have a method for achieving this?
I will be posting .hpt and .hpl files this week for opinion's and suggestions with results coming in on Sun.



93 Oct.
180* thermostat
elec. fans
no cats
K&N in stock box



Chris

[Pro Street]

Keep us posted! How many miles is that trip?
I have changed mine yesterday to 350 6-12 airflow on my 2004 GMC daily driver.
I will see if that does anything.

I will be getting a good MPG run this Sat. as I will be traveling from Chas. WV to Tulsa, OK. Up to this point the best I have got is around 22-23MPG but, all of those 300-500mi. test were taken in mostely "very hilly interstate" conditions while in WV(=70mph speed limit) I would see about 1/2MPG loss. Most test were taken in CC @ the speed limit.
I have since calibrated my LM1 w/ HPT so they are reading the same. I plan to go to SD OL and touch up the VE and MAF tables this week, with the o2 R/L voltages to their stock values. After completing Spark and WOT tuning I then want to lower O2 #'s but in the correct Airflow mode. My ? is how far is too far to lower o2 volts and at what Airflow mode?
Anyone have a method for achieving this?
I will be posting .hpt and .hpl files this week for opinion's and suggestions with results coming in on Sun.



93 Oct.
180* thermostat
elec. fans
no cats
K&N in stock box



Chris

[manxam]

I'd really like to use this formula to calculate my MPG but on my vehicle (Colorado I5) there is no injector flow rate PID. Can we calculate this value using other pids?

Thanks!

[blucreek]

Looks like about 850mi. I would like to squeeze 500mi. to the tank out if I can. On average mostly local driving I get about 400 to the tank.
Although to day after adjusting the VE as per LM1 error %, my STLT's started to increase????

chris

[alanderson1978]

I was looking around the spark tables and saw a Spark dwell multiplier vs. MAP. It looks like if RPM is "steady state" as defined by another parameter, the dwell table is multiplied by this factor. It's turned off by default on my truck, do any vehicles have it on by default, and could this have an effect on economy? And what is considered steady state RPM?

Just thinkin out loud...but with typing...and probably not thinkin enough

I'm dialing in my spark table right now, so I'm not going to mess with this till I get done with that step.

[blucreek]

Tank 1 (BP 93) =18.7mpg
For the first 200mi I was finishing the SD tune, I left the truck in OL and turned the MAF back on and made adj. by WB% err., I got all cells within .2 of 0. I enabled CL, DFCO and LTFT's. The tune went immediately (WB) rich, but the LTFT were high (3 to 9) and STFT's were neg. (1-3). So I kept adjusting the MAF as those values were also -1's, but the LTFT kept increasing.

Tank 2 (Exxon 93) = 21.4mpg
So as the fuel light came on, I got frustrated and went back to SD OL using the VCM control to turn "Off" the Fuel trim learn, CL and reset the fuel trims on a fresh tank of Exxon 93.
So as I started out I noticed my WB% error were a tad bit lean .5 to 1.5. So I made adjustments and and the % were all within .3%. The LM1 showed 14.7 constantly.
So without time to read, I left the truck in OL SD and when I arrived in OK @ 5am I had 265mi on the trip with more than 1/2 tank showing.


BTW which SD VE WB tuning guide is the best to use for Gen III's. As I would like to go through and ask a few simple ?'s I have.


Chris

[VYSSWagon]

What are everyones ideas on improving fuel economy?

What is the best strategy for timing and afrs?? particularly in cruise cells such as
1600 35-40-45map
2000 35-40-45 map
2400 35-40 -45 map

I am aiming for more timing and lean afrs of 15.3-15.5

Also have optimized DFCO settings and dropped idle in park as slow as possible.

Because we are in Oz and can use "lean cruise", it's a bit easier for us.

I'll start at the beginning (This is how I set mine up)

1) The lean cruise cells are setup on a DynCylAir vs RPM table.
2) You do not want to be in lean cruise at WOT. That's about 50-60g/cyl for me(50 at 1200RPM to about 65 at 2400RPM). You need to log yours and establish that. I finish my lean cruise 2 cells below that value, to give time for PE mode to kick in.
3) RPM range: I run my lean cruise from 1200 up to about 2800-3200RPM (for a manual, I can cruise at 80 in 6th). Auto maybe start a bit higher say 1600?
4) AFRs: I tried 15.5:1, but found better economy at 16.3:1
5) Gradually add spark to the AFR Spark Adjust Table (0.5* at a time). Small amounts of timing go a long way. I only run an extra 2*.

If you are interested PM me and I'll send you my exact settings.

[Rob]

Because we are in Oz and can use "lean cruise", it's a bit easier for us.

I'll start at the beginning (This is how I set mine up)

1) The lean cruise cells are setup on a DynCylAir vs RPM table.
2) You do not want to be in lean cruise at WOT. That's about 50-60g/cyl for me(50 at 1200RPM to about 65 at 2400RPM). You need to log yours and establish that. I finish my lean cruise 2 cells below that value, to give time for PE mode to kick in.
3) RPM range: I run my lean cruise from 1200 up to about 2800-3200RPM (for a manual, I can cruise at 80 in 6th). Auto maybe start a bit higher say 1600?
4) AFRs: I tried 15.5:1, but found better economy at 16.3:1
5) Gradually add spark to the AFR Spark Adjust Table (0.5* at a time). Small amounts of timing go a long way. I only run an extra 2*.

If you are interested PM me and I'll send you my exact settings.

Since I have an '04 GTO and can use lean cruise, can you send my your settings? With the stock cam, I had it set up to run around 16.7:1 and it ran fine. With the new cam, I can only run 15.1-.3:1 or I'll get bucking from being too lean. No knock or any other adverse things going on. Just curious as to what your settings are.

[VYSSWagon]

Since I have an '04 GTO and can use lean cruise, can you send my your settings? With the stock cam, I had it set up to run around 16.7:1 and it ran fine. With the new cam, I can only run 15.1-.3:1 or I'll get bucking from being too lean. No knock or any other adverse things going on. Just curious as to what your settings are.

Not on my laptop at the moment, so I'll get you the settings shortly.

You can really run as lean as you want. I have run my AFR out to 18.5:1 in lean cruise. The issue is that you still need to produce some power to make the car go.

DFCO cuts fuel when the engine is under no load, so that is already taken care of.

You want lean cruise to reduce fuel consumption under light engine loads. If you lean out too far you just need more throttle to achieve the power demand.
More throttle% = higher MAP = more air = more fuel (even at 16.7:1) There is a limit to how far you can go, you can not produce power from burning air alone.

[CptPalmer]

What kind of numbers are you guys seeing with EC Tune's numbers?

[Justin@VMP]

now the major manufacturers all are moving to a technology that allows the vehicles to "cut out" cylinders allowing a V8 to act like a V4

This is not true, Ford is not cutting cylinders, they are reducing pumping losses through other methods.

[VYSSWagon]

This is not true, Ford is not cutting cylinders, they are reducing pumping losses through other methods.

Their valves leak so badly they don't get any pumping losses...

[Bills96TA]

Just got an 04 GTO for my wife (she drives around 90 miles day to work) could I get these specs from you also for lean cruise.

Thanks

Not on my laptop at the moment, so I'll get you the settings shortly.

You can really run as lean as you want. I have run my AFR out to 18.5:1 in lean cruise. The issue is that you still need to produce some power to make the car go.

DFCO cuts fuel when the engine is under no load, so that is already taken care of.

You want lean cruise to reduce fuel consumption under light engine loads. If you lean out too far you just need more throttle to achieve the power demand.
More throttle% = higher MAP = more air = more fuel (even at 16.7:1) There is a limit to how far you can go, you can not produce power from burning air alone.

[chrisd]

Ok I am confused. How do I get something from 'configure user definition parameters' to 'table display'?

Scott:

Tried your new equation and works like a champ I actually average 27.7mpg on the way to work.

[Super73]

Ok I am confused. How do I get something from 'configure user definition parameters' to 'table display'?

I am trying to figure this out right now.. Anyone?

Shaun

[S2H]

these anothr thread about adding it..
ther should also be a demo file created by me..

http://www.hptuners.com/help/demos/c...stom%20PID.swf

[Bob Wiley]

^ Great demo file

[LazMan]

I see some new things on HPTuners for the LS2 (GTO):

O2 Sensor B1 and B2 R/L vs. Airflow Mode &
Closed Loop Mode vs. Airflow

But, the numbers across the top are different...

0 8 16 24 32 40 48 56 64
V:450 450 450 450 450 450 450 450 450

Same with the Mode/Airflow table. ... what cells above are the ones I would set to 350-ish in order to do what you guys are doing with LS1s? (Or will the PCM ignore my changes?)

[EC_Tune]

The mode numbers have just changed. The function is the same as the LS1's.

[onecamaro1]

How about this thought. Run 2 WB o2, then set the overall AFR to 16.0:1, and set PE to about 30% throttle to activate it and adjust the PE table accordingly to something like.....3000-4000=14.7:1, 4000-5000=12.9:1, 5000-6500=13.3:1. Any ideas on this?