Most excellent forum!

[jpgmtech]

Hey everyone. I'm a closet ecomodder, with a big diesel truck and a v8 car... But i've finally found a forum I can get excited about!

I had a 1988 chev sprint with a engine-off-coast switch rigged up and a few other little tweaks a couple of years ago. I didn't even know sites like this existed! It was rusting and I could sell it for what I got for it so I did. I regret that completely, would like to get another for more modding.

Best mileage with my diesel pickup has been 9.8 litres/100kms with custom ECM programming. That's with 7000lbs of brick-in-the wind to push around...

Awesome ideas here!

BTW, a significant portion of the gains on the coming new GM hybrids come from low-rolling resistance tires, aero mods, and other things that you guys are already doing....

[DifferentPointofView]

NIiiice, welcome to the site! how'd you retune the ECM?

[MetroMPG]

Nice to have another experienced modder join up.

I'm assuming you're either Canadian or a science type, with your L/100 km notation for your truck.

9.8 L/100 km is pretty good for such a beast (that's 24 mpg US for those of you not familiar with the superior metric fuel economy measurement ).

So, are you actively shopping for another Suzukiclone / ecomodding platform?

[DifferentPointofView]

I know I am, but I haven't found one whoever said that finding geo's is easy can kiss my rear end, because anywhere I look I can't find one. I my friend has one, but that's because his dad's had it for years and gave it to him, and he ain't selling it. You guys must have better luck than me

[jpgmtech]

Tuned with ECM tuning software/hardware. I am an experienced GM tech and a tuner. Unfortunately there is nothing much for the Nippondenso ECM's that run the Suzuki product... There are a huge number of very interesting parameters that can be tuned, from ECT vs open loop fuel ratio tables (which are pig rich from factory typically) to the huge range of spark control and compensation tables. I have seen as much as 15% gains from spark timing adjustments alone (that comes with a trade-off, usually increased NOx emissions)

My best with the electronic carbed chevy sprint was 3.9 l/100 kms. I am a canadian

And I would prefer another suzuki product (the chev/pontiac/geo variety). My main concern is parts availability. I work at a GM dealership so that gives me an inside line on parts ;

[jpgmtech]

So i guess that makes my 2005 Chev K2500 4WD tuner truck more efficient than DPOV's Jeep SUV? Note that my truck is much heavier and larger... lol.

Just wait 'til i do some trans tuning...

[cfg83]

jpgmtech -

Originally Posted by jpgmtech

Tuned with ECM tuning software/hardware. I am an experienced GM tech and a tuner. Unfortunately there is nothing much for the Nippondenso ECM's that run the Suzuki product... There are a huge number of very interesting parameters that can be tuned, from ECT vs open loop fuel ratio tables (which are pig rich from factory typically) to the huge range of spark control and compensation tables. I have seen as much as 15% gains from spark timing adjustments alone (that comes with a trade-off, usually increased NOx emissions)

My best with the electronic carbed chevy sprint was 3.9 l/100 kms. I am a canadian

And I would prefer another suzuki product (the chev/pontiac/geo variety). My main concern is parts availability. I work at a GM dealership so that gives me an inside line on parts ;

Welcome to EM! It's nice to have a GM tech on board. You are under the hood *and* inside the chip!

There is no escape!

CarloSW2

[MetroMPG]

Originally Posted by jpgmtech

...usually increased NOx emissions

I'll admit I'm often tempted by the idea of tuning for a leaner burn in particular, but I just don't think it's worth it.

Southern Ontario already had its first smog alert of the year last weekend. I was in Toronto at the time and I don't want to contribute to the brown tinted skyline I saw.

[Daox]

Originally Posted by MetroMPG

I'll admit I'm often tempted by the idea of tuning for a leaner burn in particular, but I just don't think it's worth it.

Southern Ontario already had its first smog alert of the year last weekend. I was in Toronto at the time and I don't want to contribute to the brown tinted skyline I saw.

Same here. I have a zeitronix wideband zt-2 system on the Matrix and it would take nothing to lean it out and get 40 mpg all day with the wife driving. However, with all I have learned about emissions its really not worth it.

Welcome to the site.

[jpgmtech]

Most OBDII controllers will not let a lean burn happen (unless you happen to live in Australia) the only way you could "fool" the computer into a lean burn is by modifying the pre-cat o2 sensor signals so that the computer would "see" a higher voltage and presume it is slightly rich, causing it to correct fuel trims.

The big device to keep happy is the 3-way catalytic convertor. Even is spark timing is causing a little more NOx than typical, the cat will usually take care of it. But if the mixture moves off of stoich, the cat efficiency drops dramatically and then it can't be your "savior" for a little aggressive spark tuning...

On cold-starts you would not believe how much fuel is thrown down the tailpipe and the timing retard induced just to feed the cat and get it lighting off... I usually fudge those tables a little to improve cold-start fuel economy. As long as the car doesn't idle alot the cat will light off with engine load.