JonGP4

ok, well the reason for this is to increase my gas milage because i might be moving out of town.. and it will take me 30 to 45 minutes to get just about anywhere. and the road i will be using to get in town will be about 30 minutes of stretch doing 70 MPH.. i'm running the hack right now.. soon to be 450DSM blue tops.. and i'm woundering how bad it will be to run the car alittle lean while crusing?? i wouldn't be in boost and even if i did hit boost the FMU would bump up the fuel pressure.. and once i down shift and hit over 4k RPM the fuel curve goes rich. How many of u turbo guys od alot of highway driving?? and do u think it would be really bad driving it lean on the highway?.. i'm talking like stock lean not anything less then that

BlueSi2k

Your not really gonna damage anything leaning it out on the highway under very little load. I run around 15:1 a/f during cruise and you could probably even go further. It would be a good idea to have a wideband though.

nsxmatt

You shouldn't need the FMU with the hack and the blue tops.

p0gi

as long as your car is in closed loop mode the car will run its target a/f ratio which it reads off the 02 sensor. Even if you try to change it, it will fight its way back.

baphomet

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by p0gi &raquo;</TD></TR><TR><TD CLASS="quote">as long as your car is in closed loop mode the car will run its target a/f ratio which it reads off the 02 sensor. Even if you try to change it, it will fight its way back. </TD></TR></TABLE>
But if you send a narrow band signal from a WB controller and alter the voltage so the ecu THINKS it is at IT'S target, then you could and should do it

I love my LM1.

JonGP4

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by p0gi &raquo;</TD></TR><TR><TD CLASS="quote">as long as your car is in closed loop mode the car will run its target a/f ratio which it reads off the 02 sensor. Even if you try to change it, it will fight its way back. </TD></TR></TABLE>

thats a good point i never considered that.. but, i mean if a richin up the fuel curve, won't it base that off signals off the map sensor.. when it goes to get the amount of fuel according to the Load and RPM won't it be higher since its changing the reading the ECU sees?

b16ahybrid

do you really think that you will save that much gas if you run a 15:1 afr vs 14:1 afr at cruising speed?
If you not on the gas driving fast,, you won't be using much gas at all. IMO it's not worth trying to lean it out to gain .001 more mpg..

BTW I used to drive my car 33 miles each way to work, I would average 26mpg and I have a heavy foot..I love boost ...(stop and go traffic) so figure 30% highway cruising the rest is city...

since your not in boost or under heavy load you shouldn't be runing rich, I say leave it how it is.

But thats just my oppinion

tegasaurus

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16ahybrid &raquo;</TD></TR><TR><TD CLASS="quote">do you really think that you will save that much gas if you run a 15:1 afr vs 14:1 afr at cruising speed?
If you not on the gas driving fast,, you won't be using much gas at all. IMO it's not worth trying to lean it out to gain .001 more mpg..

BTW I used to drive my car 33 miles each way to work, I would average 26mpg and I have a heavy foot..I love boost ...(stop and go traffic) so figure 30% highway cruising the rest is city...

since your not in boost or under heavy load you shouldn't be runing rich, I say leave it how it is.

But thats just my oppinion</TD></TR></TABLE>

it would be the difference between accelerating at 12:1 on a boosted car vs 14:1 on a N/A car... Yes it probably would allow him to get an extra 15-35 or so miles to a tank.

b16ahybrid

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tegasaurus &raquo;</TD></TR><TR><TD CLASS="quote">

it would be the difference between accelerating at 12:1 on a boosted car vs 14:1 on a N/A car... Yes it probably would allow him to get an extra 15-35 or so miles to a tank.</TD></TR></TABLE>

If your afr is 12:1 out of boost then you have some tuning problems. With little or no load on the engine (i.e cruising) you should be runing close to stock afr's. Unless im boosting, my car runs exactly like it did with it was stock ..including the afr.
No load you should be close to stoich (From what i understand honda runs around 15:1 afr cruising) but that all changes when you step on the gas.
Your fuel demands don't increase beyond stock until your in boost.

tegasaurus

maybe i wasn't too clear when i posted... what i meant was the difference when cruising at 15:1 and 14:1 would the be the same difference as your fuel consumption of a FI motor at 12.8:1 and an N/A motor at 13.8:1... the FI motor will suck down considerably larger amounts of fuel

atleast when i was turbocharged it sucked down a butt load of fuel when i accelerated (it was still lean at 13:1) then when i went back to NA i could get 300-320miles on a tank vs the 200-215 boosted.

-Ryan

nevin

so what would happen if you cruise leaner than stoich say high 15s? Not that I do hehe, just wondering.

JonGP4

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nevin &raquo;</TD></TR><TR><TD CLASS="quote">so what would happen if you cruise leaner than stoich say high 15s? Not that I do hehe, just wondering.</TD></TR></TABLE>

thats what i'm woundering.. what would the affects be.. i mean there is no boost crusing and its not under a load?? so what would happen? other then the occaisional miss fire

baphomet

Better gas mileage. You will not have any issues under light/zero load. Klaus from Innovative brought this up, though it seems all of you have ignored my post above. A simple search and some reading would enlighten you.

Of course I don't care to discuss this in terms of the afc hack, do it with a wide-band feeding the ecu a NB signal, recalibrate the voltage as desired.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JonGP4 &raquo;</TD></TR><TR><TD CLASS="quote">

thats what i'm woundering.. what would the affects be.. i mean there is no boost crusing and its not under a load?? so what would happen? other then the occaisional miss fire</TD></TR></TABLE>

trbob16a

You could be driving around part throttle at 12:1 and not even know it. I run in open loop all the time and at first I was around 12:1 just cruising around in vacuum. You never notice it though b/c you are just at part throttle. Anyway I have a hondata and fjo wideband so I've been tuning it over the last few months when I get the time.

When my setup first rolled off the dyno I was going about 150 miles / tank. This was ALL a result of the vacuum side of my maps as the boost were tuned on the dyno. That was with 10.5-12.5 a/f depending on what part of vacuum. Now I'm up to 12.5-14.5 depending on where in the vacuum. I still need to do some tuning to lean sections out some. Now I'm getting 250-260 miles / tank though and I'm not even done yet! This is on a 10 gallon cx tank.

Start 15mpg, midway 25mpg, I should be able to get 35mpg out of it no problem. It is definitely worth it to tune all areas of the map and not just boost. Of course, I have 800cc injectors so I was dumping a tremendous amount of fuel to begin..

nevin

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slashDEVslashNULL &raquo;</TD></TR><TR><TD CLASS="quote">Better gas mileage. You will not have any issues under light/zero load. Klaus from Innovative brought this up, though it seems all of you have ignored my post above. A simple search and some reading would enlighten you.

Of course I don't care to discuss this in terms of the afc hack, do it with a wide-band feeding the ecu a NB signal, recalibrate the voltage as desired.
</TD></TR></TABLE>

So why dosent honda do this?

baphomet

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nevin &raquo;</TD></TR><TR><TD CLASS="quote">

So why dosent honda do this?</TD></TR></TABLE>
Why don't you ask honda?

I would guess there are probably lots of reasons, with these toping my list: emissions and power.
Have you ever heard of a lean burn engine?

A lean burn engine is designed to operate with a very lean air-fuel ratio during light load conditions. Most modern gasoline engines are controlled to run at a chemically correct (stoichiometric) air fuel ratio (about 14.7:1) to make the three-way catalyst operate at high efficiency, reducing tail-pipe emissions. Lean burn engines mix more air with the fuel when full power is not needed, resulting in better fuel economy. Air/fuel ratio in lean burn engines can be as high as 22:1. When full power is needed, such as during acceleration or hill climbing, a lean burn engine reverts to a stoichiometric (14.7:1) ratio or richer.

baphomet

Here is how you do it.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by klatinn &raquo;</TD></TR><TR><TD CLASS="quote">
DISCLAIMER: To be used only on vehicles that are never run on
a highway.
DISCLAIMER2: Experiment on your own risk. And this trick does
not apply to lean-burn, stratified charge engines.

According to research done by NACA back in the 40's on
aircraft engines (and still applicable to car engines), the maximum
efficiency of a typical engine is at 15.2 to 15.3 AFR. In closed loop
mode at cruise and idle all cat equipped EFI systems use the stock O2
sensor to keep the AFR at stoich (14.7). This AFR keeps the cat happy
and minimizes emissions. Leaner will create more NOX emissions
(but less CO). At max. efficiency the engine burns the least amount of
fuel per hp produced, which is what you want at cruise or idle.
You can program the LM-1 to save fuel when you use one analog
output as NBO2 input to your ECU.

The LM-1 comes stock with the Output 1 set to 1.099V for AFR
14.08 and 0.103V for AFR of 15.02.

Modifying that to 1.099V for AFR 14.58 and 0.103V for 15.52
simulates a NBO2 sensor whose switchpoint is at 15.2 AFR instead of
14.7. Any ECU with a NBO2 sensor assumes the sensor outputs 0.45V at
14.7 AFR. By 'fooling' the ECU as described you can force it to run
at the max. efficiency point of the engine when in closed loop. This
will of course maximize your EGT's at that run point. That's actually
how you set an aircraft engine mixture for cruise, by watching EGT and
regulating mixture to max EGT.

Regards,
Klaus </TD></TR></TABLE>