Eco remapping aka chiptuning

[Dust]

Originally Posted by rmay635703

No offense but if it was easy I would have retuned my 3800 98 buick to run lean on the highway,

EFI Live, Hp Tuners, AFC 2.0, to name a few. A U-bend delete should improve your power and mpg a bit. There is ALOT to be done to that vehicle. A WB02 with adjustable output ($200-up) should have gotten you somewhere with no tuning at all. That plus a $80 Alex Pepper scan-tool could have showed you all of your numbers, but not allowed you to change them.

To the OP, I think that checking your intake manifold and getting it cleaned if needed, or looking into water injection would help you out a bit. The re-flash would be good only if the company was good.

[jfitzpat]

Originally Posted by rmay635703

Not to mention most tools don't do lean.

Obviously I wasn't clear above. The reason that the tools don't 'do' lean is that, aside from situations like coast down with injectors closed, a modern gasoline vehicle is running stoich, or richer.

Stoich is measured, with excellent precision in normal combustion, by the O2 sensors. So the ECU typically adds fuel relative to that measured point.

Originally Posted by rmay635703

No offense but if it was easy...

Well, "easy" for me is a matter of experience, not access to all the goodies I have.

You could do what I describe above with readily available performance aftermarket stuff now. For example, I happen to have an aftermarket wideband setup sitting on one end of my bench now. The UEGO sensor used would screw right into the same bung your pre-cat O2 sensor is screwed into now. This particular unit has two analog outputs built in, both programmable. By default, one is a wideband output (0-5V DC for .5 to 1.5 lambda) and the other is a simulated narrow band (1V output with 450 mV at lambda 1.0), but you can reprogram either one to whatever you want.

There are some gotchas, like having to put a load resistor on the heater circuit for the removed O2 sensor so you don't throw a check engine light or drop open loop. And you generally have to either mimic the signal with an offset from a small discrete circuit (or just program the 2nd analog output) so that the ECU sees a shift on the post cat sensor in the right direction (HC's being removed). But aside from maybe having to double things up (I can't remember if the 3800 V6 used independant banks or not), pretty straight forward stuff. Since the cat will be rendered ineffictive you can use a bypass (another readily available performance market piece) and pick up a little economy that way (less back pressure in the VE/RPM curve).

You generally would want to periodically reprogram the analog outputs slightly leaner in small steps because a big jump messes up your fuel trims. But the limit is generally not your ability to shift the lambda measurement, but the limits of the fuel delivery system. As you get leaner and leaner you typically hit a point where fuel is not evenly distributed and the engine runs rough. Some engines will actually get to theoretical best economy, some won't. Sometimes swapping around or changing injectors will help.

Originally Posted by rmay635703

NoX may not be as much of a bad guy as the US government believes.

I recently did instrumentation for an ag study, specifically regarding exhaust and possible positive impacts on soil for cultivation, but I'm not really going to go there. Even at technical conferences specifically in this area discussions tend to drift from what the science tells us (which is all I'm interested in) into people's political ideology.

Originally Posted by rmay635703

Heck many Honda cars ran lean including the gen 1 insight and had EXCELLENT emissions. I don't doubt their technique would have been far superior to our pig rich and CAT approach.

The problem is in scaling it up for a larger engine and higher powers. For power generated, modern engines are typically more efficient and cleaner, but we're dragging around much heavier vehicles loaded down with built in Barca Lounges and home entertainment systems.

There are two good SAE papers on the system your talking about, including a good one from Horii on the problems of scale encountered. They are fairly technical, but worth slogging through.

[t vago]

Originally Posted by Galane

Anything out there for hacking a 1995 Buick Century V6 or 2004 Dodge Dakota 4.7L V8 to get a bit more MPG?

The Buick nudges 30 with a mix of city, highway and freeway driving. Just recently turned up 60K. Dunno what the Dakota will do yet, just bought it, needs some repair and seems to have a leaky valve on #8 so most likely the engine will need replaced. 140K miles on it.

I recommend getting a SuperChips FlashPaq for your Dakota. It's what I'm using.

[Galane]

What MPG do you get on the Dakota with the FlashPaq?

[t vago]

About 18.5-19.0 MPG, mostly highway driving.

[Galane]

A Fiat Dakota? Nahh, it's a Hudson. Hudson bought Nash, then bought Chrysler, then Mercedes, now Hudson own Fiat.

[Ernie]

I have not posted for a year or two nor have I updated my gas log. I am still running in the 50-55mpg range with my Saturn SL1. I had not heard of the UEGO but a Goggle search showed it to be reasonably priced and it sounded very capable. I tried an innovatemotorsports wide band to narrow band converter several years ago but I did not have the recommended serial port to USB adapter and messed up the calibration. It would not revert to factory settings. This trimmed my Saturn so lean it almost would not run. I barely made it back home and was afraid I had ruined the cat at first. After re-installing the original EGO sensor it took almost 50 miles for the computer to fully trim back to normal operation. I bought the right serial to USB converter but never got around to hooking the system back up. When I first bought my Saturn and added warm air intake the plugs ran white. Over the years the plugs have gradually gotten darker. I am sure the innovate system is better but I bought and installed a "digital" dual quad EFIE from FuelSaver-MPG. I am only treating the pre-CAT sensor so far. As one adjusts for a leaner mixture it takes some time for the computer to adjust the trim. The claim is that this signal modifier can go leaner with a narrow band sensor than other similar systems. I have only driven it about 800 miles so far and as anyone familiar with a Scangage can tell you it can not be trusted after changes like this until it has been recalibrated for a couple tanks. Given that caveat this simple device appears to have added back the mileage that my car has lost over the years. The current tank is at 59 mpg for 380 miles but the calibration may take some of that away. Again I would concur the the wide band sensor is the way to go but This EFIE can make the most of your narrow band sensor and the installation was quite simple. Just needs power, ground and the sensor wire. The adjustments are truly quite precise and easy. I am running a 0.40 volt shift right now with no drivability issues. My plugs are getting white again. I find this to be one cost effective approach if one is not hung up over NO emissions. Ernie

[Floppie]

Originally Posted by California98Civic

So Hondata's s100 is only $195 and allows tweaking of the air/fuel tables on an OBD2 ECU, such as on my 1998 Civic. Lots use it for street racing, of course, but it should be tunable for MPG, no? Has anyone tried it? I'm not ready for such a move yet, but if anyone has tried it or has an opinion, I'm curious.

If the s100's interface is anything like KManager (I've got Kpro for my RSX), yes. Not only did it give me a slight improvement of fuel economy (but mostly, more power) at WOT, it very significantly improved my P/T fuel economy. This was achieved by a combination of running leaner, pulling a little ignition timing out for safety when running leaner, and advancing the intake cam further (at P/T) to reduce the vacuum in the intake manifold.

All this required significant time spent tuning it though, and not just a one-time tune and forget either. Because I'm running it at the extreme limits (farther than an OEM would be willing to go) I do have to occasionally take my laptop out and make some changes, otherwise, detonation. It provides an option, though, to flash the CEL if it detects a knock - and the knock sensor is much more sensitive than the human ear. If I can actually hear it knocking there's a major problem.

I don't mind having it taken much farther than an OEM would be willing to, though, because I can always just plug in my laptop and make some changes.

For what it's worth, if the s100 is anything like Kpro, not only can you shut off closed loop (making this all possible), you do get temperature compensation tables for both fuel and spark timing. They take a tremendous amount of time to get dialed in, but they're very helpful.

Hope this all helps. If you do purchase it and need some help with tuning let me know. I'm pretty accomplished, I do all the tuning in my little group (95% power tuning, for the most part I'm the only one who's done any FE tuning, but still)

[ausias]

I think that fooling with cheaps resistors complex control systems will only improve the budget of the seller.

I think that ECU eco tuning it's Greenwashing Greenwashing - Wikipedia, the free encyclopedia most of the times.

I did several high precision data logging sessions measuring fuel consumption with a 0.05 L/100 km precision, and never got any saving.

I have a lot of data and I decidet not tu reflash a fleet because of the results.

Savings are only noticeable depending on gearing and in high slope roads or full weight capacity towing or loading.

The high precision tests needed to obtain optimal fuel consumption and minimum BSFC I think there are no chiptuner that invested time or money enough to develop a scientific research or a scintific independent assesment to ensure the consumer that it's all true.

I know it is possible to obtain little improvements if you don't matter emissions regulations of CO, HC, PM, NOx,... but I have not found any chiptuner that can explain why their new numbers in the ECU will save fuel (according to physics, engeenering, R+D assessments,...). You will get hundred of words, the more you ask the more you will not understand (or, if you have enough sci-tech knowledge in the matter, the more disappointed).

I got coherent savings results in ABA testings when I improved driving techniques, aerodynamics, tires, gearing, repaired thermostat, and sensors who where not precissely tuned or fooling the ECU.

I will appreciatte if anyone could post a BSFC map of a tuned engine. I did not find one.

[momorris]

I have chipped my 1.4 hdi. The box has 2 maps. 1 for economy and 1 for power. The box plugs in series into the fuel rail pressure signal. I know that it is simply increasing fuel pressure earlier than standard but it does work. The car used to be flat above 3000 but it continues pulling now. The economy part simply comes from the fact that I can now use 4th where I would previously have to be in 3rd. Lower speeds but higher gear without labouring the engine.