Brief Encounter

iTrader: (6)

Hello,

On my 98 Camaro I am trying to save a little gas on the highway and around town, so I am trying to figure out the leanest I can safely go below 2,500Rpm's.

Right now my mods are:
5.3 Ported Heads
TR220 W/ 114LSA
LS6 intake w/ ported TB
No Emissions
3,000 stall
3.73 gear.

Right now im at about 10.5:1 CR.

I was thinking something along the lines of 15.5:1 or 15.6:1 AFR.

I have HP tuners, and AM buying a LC-1 soon.

What would you guys recommend for a good "gas mileage" AFR?

Thanks

mr2guru

iTrader: (16)

I set my lean cruise to 16.4 when I had it enabled in my GTO. It netted about 6 more mpg on a bolt on ls1.

Brief Encounter

iTrader: (6)

I am using HP tuners version 1.23, and I cannot find the DCFO settings,
I think this might get me some more mileage.

Any old school HP tuner guys out there?

macca_779

DFCO doesn't save anywhere near as much fuel as a good cruising AFR does. I'm running 16.13 between 1200 and 2000 below 55kpa. This is using a custom OS in EFI Live. I'm unfamiliar with HPTuners and its ability to control fuel.

2002_Z28_Six_Speed

iTrader: (19)

Well, you have an Aussie car anyways.

You have to alter the ASM code to get it to work on a Camaro.

macca_779

I wasn't aware that it couldn't be done with a Custom OS. I knew you guys didn't get lean cruise though. I just figured B3647 was fully functional.
Learn something every day.
If you wanted to be rough you could cheat and lower VE to get a higher AFR below 55kpa and between 1200-2000

2002_Z28_Six_Speed

iTrader: (19)

I know the mods at EFILive made a big fit about people asking if it could be done for American cars too.

There are work arounds I understand.

Maybe their custom OS does it.

ringram

Custom OS allows you to command any afr at any load point. Lean cruise on the other hand is triggered and is rpm x g/cyl rather than rpm x kpa in the custom os.
The triggers are engine on time, min and max speed plus I think a couple of others.
15.4:1 is a good idea for a nice flexible fuel level while retaining good power. 16.x:1 will get you more economy but power will be sad. So log your motorway travel and try to just single out the area where you know 70mph sits and lean that out. Leave the other load points around 15.4:1 and enrichen for full power as per normal.
I doubt many will note much difference running 15.4:1 at low load especially stock.

Steel Chicken

iTrader: (3)

I noticed in my testing as it approached 16.5 the power would drop off enough you were no longer saving gas but burning more. id also say don't go over 16.

just make sure you are only using lean during those very low flow rates.

2002_Z28_Six_Speed

iTrader: (19)

Thank you!