Lean Cruise...legal in the USA? Possible!

[gman4dx266]

As an avid internet surfer, i end up on the oddest things sometimes...and i just happend to find a Lean Burn article on Wikipedia. If you scroll down, it says that honda uses it in thier cars. So...that said, how come we cant enable it to work in our detroit metal?

Everyone says 'yeah its illegal' and leaves it at that...but...they do it from the factory.

Heres the article/entry:

http://en.wikipedia.org/wiki/Lean-burn

[MeentSS02]

I'm pretty sure the EPA has mandated that it not be done here in the US...manufacturers can do it, they just can't sell the cars here in the states from my understanding.

[Alvin]

GM used to do this in the older TPI cars. That is probally the same time honda was doing it in the states.

[slow6]

This is gonna make me look n00b, here goes:

What about adding another EGR (dual EGRs ) on the other exhaust manifold?
Have it tuned so that when you are cruising the highway, it comes on (the most) in which it gives 2x more Carbon Dioxide (which doesnt burn). Effectively lowering displacement/cubes. Kind of like a DOD.
Does this sound like a bad idea? Discuss

[gman4dx266]

You're right steve, it could be for the hondas not made for the US, but check out the years that honda has it on...02-06 civic and 00-06 insight.

But at the same time, its active on honda marine engines. From the hondanews.com website:

"the Lean Burn Feedback Control that utilizes a Linear Air-Fuel Sensor, along with the ecm, to automatically adjust the air-fuel mix according to speed and load while maximizing power throughout the acceleration range and providing enhanced fuel economy; in the "lean" cruise mode, this engine saves 30 percent on fuel consumption"

So i can go out and stick one on my boat, but not in my car?

Oh and with that dual EGR idea, you'd probably have some problems with that...like modifying spark...and itd probably throw off the VE and whatnot becuase of the cylinder airmass being different. Atleast, thats just my first inclination.

[slow6]

Oh and with that dual EGR idea, you'd probably have some problems with that...like modifying spark...and itd probably throw off the VE and whatnot becuase of the cylinder airmass being different. Atleast, thats just my first inclination.

That goes without saying that it would throw off the VE / Fuel trims / AFR. It would make it rich.
I love modifying my VE now

[Alvin]

This is gonna make me look n00b, here goes:

What about adding another EGR (dual EGRs ) on the other exhaust manifold?
Have it tuned so that when you are cruising the highway, it comes on (the most) in which it gives 2x more Carbon Dioxide (which doesnt burn). Effectively lowering displacement/cubes. Kind of like a DOD.
Does this sound like a bad idea? Discuss

That is one of the applications for EGR now. It usually negatively affects combustion effiecency. It also negatively affects flame temp as the spent gas soaks up heat as it passes thru the combustion process. What I'm saying is theres no free lunch and they are balancing that with other things.

We will see the greatest increase in effiecency when/if electromechancial valves come on the scene. Imagine cruising down the highway with a intake manifold pressure around atmospheric so pumping losses are minimal, VE is high and more residual gas goes where it belongs.

[Alvin]

That goes without saying that it would throw off the VE / Fuel trims / AFR. It would make it rich.
I love modifying my VE now

The VE strategy like used for the E67 would perfect for such a senerio

[gman4dx266]

I love modifying my VE now

wtf is wrong with you? Are you feeling Okay?

[slow6]

v6 buddy, I only have 1 VE. So I roll around in SD mode with the maf happily unplugged (for now)

The VE strategy like used for the E67 would perfect for such a senerio

could you elaborate? Never heard of its VE, I will search

What I'm saying is theres no free lunch and they are balancing that with other things.

I knew someone would say this, as GM are scientists and know what they're doing.

Imagine cruising down the highway with a intake manifold pressure around atmospheric so pumping losses are minimal, VE is high and more residual gas goes where it belongs.

I dont know how VE is for you, but for my application a higher VE = more fuel.
Is it the same for you all?
Thanks for just being able to discuss without flameage

[EC_Tune]

That is one of the applications for EGR now. It usually negatively affects combustion effiecency. It also negatively affects flame temp as the spent gas soaks up heat as it passes thru the combustion process. What I'm saying is theres no free lunch and they are balancing that with other things.

We will see the greatest increase in effiecency when/if electromechancial valves come on the scene. Imagine cruising down the highway with a intake manifold pressure around atmospheric so pumping losses are minimal, VE is high and more residual gas goes where it belongs.

^^ One of the reasons you see EGR on Diesels now. Cools the combustion temp so NOx is reduced. In fact some diesels use a cooled EGR system to further reduce NOx. EGR works pretty much the same on gas motors.

Introducing CO (exhaust gas in general) into the intake takes up "space" and reduces pumping losses at low and mid throttle. EGR is not bad, just misunderstood. In fact in some applications (right amount @ the right time) it can actually increase mileage. Something most "hot rodders" don't care about but gas is still 2.55/gal for the cheap stuff here in CA.

EC

[gman4dx266]

wow...2.55. Im really gonna savor our $1.95 now :-p

that makes six litres hurts less and less in my commute.

[jimmyblue]

I think it comes down to, the platform had to be EPA
accepted as-is for emissions. If you can meet emissions
with lean cruise, fine. But without a really great catalyst
to bust down the NOx, any big displacement motor will
likely not pass (without a catalyst brick a yard long).
Little bitty 1.3 liter Honda motor with a full size newest-
chemistry brick, or a hybrid that only runs at some well
tweaked setpoints, maybe. Outboard motors subject to
a whole different tier of emissions requirements, maybe.
Buncha liters, broad range of load and speed? Fat
chance, and less chance for the "done deal" motors in
the field to meet with lean cruise cobbled on top.

Not to say a well tuned setup -couldn't- but nobody
wants to enable a bunch of hack job emissions failures.
Home hobbyists don't have the tools to see gas output
(wideband does not cut it) under varying load-points
so no telling whether you got it entirely right, or only
what you were looking at.

You find an EPA statement that allows lean cruise retrofit
and then perhaps there's daylight. But the EPA is not
about options.

[EC_Tune]

And we here in CA have the Air Resources Board....

[shimp]

So what happens if we turn on lean cruise mode? The EPA immeadiatly comes after you?

[Bill@HPTuners]

EPA can come after hptuners and any other tuning software package on the market crippling the industry.

[shimp]

So don't turn it on? I remember reading about enabling lean burn on the old GM TBI caprices. Someone on the Yahoo Group GM_TBI had a dad who worked for GM or something and knew how to turn it on in the old TBI cars. I saw the option for it and was wondering if it was the same kind of deal.

[EC_Tune]

As long as this discussion focuses on the merits / detriments of Lean Cruise and no specific requests / tips are given this thread will remain.

If not, it will disappear to protect HP Tuners.

[shimp]

Okay, so lean cruise mode, it's merit is good fuel economy. It's detriments are bad tailpipe gasses? Would the savings in fuel economy make up for the difference in pollution vs the vehicle without the bad tailpipe gasses, but with out lean cruise mode? How much bad gasses are spewed when in lean burn?

[jimmyblue]

It doesn't matter, logic is futile, you're talking about
the guv'mint.