Mits... I have an enormous amount of experience in these issues but admit no car yet and this will be very first MB/Mitsu variant...
That said, I suggest a back to basics approach first...
warm motor...new properly gapped plugs.... full acceleration up to 3rd or 4th gear... kill motor..... coast to stop...pull each plug and see the rich or lean evidence
I suspect guys like you and I will have to experiment for a year or so before we have the true electron geeks bring the re-mapping software over here.
There is quite a bit of potential in this motor but I am somewhat intimidated with the stupid automated manual tranny... I would dearly like to divorce the motor management from the tranny management loop.
Good luck with that divorce....... and, at 2000 miles, the trans is one happy camper insofar as working with the engine, and shifting pretty much whenever the right foot tells it to do so. Soft pedal and it shifts early, tip in and it shifts late. And once you get praticed with the paddles or stick on the manual side, it's a dream. Enjoy.......
The reason I used the term "very likely" is because Thorley did NOT include the AF ratio plot in their dyno graph.
In my 1000 plus hours of dyno experience as an R&D engineer, most of the time, bolt on performance gains were a result of changes in AF ratio. As soon as you re-adjust the AF back to baseline, the performance gain is reduced.
Quote:
Originally Posted by jwight
Have to ask the two posters above:
torqueaholic, very likely leaned out the AF ratio? Best guess or based on some sort of scan results? Again, not meant as a slam but an awful lot of speculation goes on here, most of it backed up by....not much. Maybe the DTH guys can comment on their power gain vs. AF ratio at some point.
MY 1000S of R&D with a dyno and 1 to 7 liter car and motor cycle motor tuning agrees with the observations of torqueaholic
Re the divorce the manumatic thought...
the current system is designed for common user dirvability and is heavily weighted to always provide CARB emission results...
Those of us who desire a light weight, rear drive car that can have the HP to weight ratio enhanced will be severely thwarted by the on board computers decision in gear selection.... and power output....
get used to it and like it for what it is ....is one way to think about it...
I have other desires for the Lil Bugger ...as obviously do others
Easy to engineer a true manual with clutch pedal adaptation
Infinitely harder to divorce the trany sensors from the engine management and safety management side
Just a few of the more memorable adaptations in my resume
283 in a chevette
289 in a Ford Tanus 2 dr
283 in a Opal GT
440 in a Dart swinger (stock was 6 cyl)
427 in a AC cobra kit
454 in a S10
327 in a Datsun 260
327 in a Jeep
289 in a Mustang II
131 Cubic Inch V twin on a 458LB FXR Harley (156HP)
98 Cubic Inch V twin on a 424LB Harley Sportster (101HP)
No blowers, many turbos and twin turbos a lot of NOsystems
Current project is a 415 CI V10 in a 23 T bucket Kit
Lil Bugger will most likely get a NOs kit for grins when arrogant butt heads try to cut me off....
You make a good point, Dave777. The WB sensor will help to tell that tale.
I am curious if you have any opinion or comment about the 90's era Geo Metro-similar weight and drivetrain, but significantly higher (~20%) fuel efficency. I have to confess I haven't looked too deeply into this, but I am just looking to start a bit of a discussion.
i had a '98 metro, 993cc, actually, now that my smart is "broken in", the fuel economy is the same on the highway (53mpg at 55-60mph) and my daily commutes are 10% better in the smart (lower 40's mpg in stop and go). it would seem the metro was more inefficient, same basic engine (one liter, 3 cylinder) but half the number of valves, less horsepower (55 vs 70).
though the metro's engine seemed "bullet-proof", maybe due to it's being "under-powered". it'll take a few years of driving to see if the smart's engine will hold up like the metro. i like the better "pick-up" with the smart, you hit the gas and the car actually moves, merging on the highway in the metro was "punch-n-pray".
i had a '98 metro, 993cc, actually, now that my smart is "broken in", the fuel economy is the same on the highway (53mpg at 55-60mph) and my daily commutes are 10% better in the smart (lower 40's mpg in stop and go). it would seem the metro was more inefficient, same basic engine (one liter, 3 cylinder) but half the number of valves, less horsepower (55 vs 70).
though the metro's engine seemed "bullet-proof", maybe due to it's being "under-powered". it'll take a few years of driving to see if the smart's engine will hold up like the metro. i like the better "pick-up" with the smart, you hit the gas and the car actually moves, merging on the highway in the metro was "punch-n-pray".
Seems you did the break in the right-way. Can you share some tips, of things to do and things to avoid and roughly for how long? (I hate to admit it, this will be my first brand new car, I always buy 1 year leases or low milage to take advantage of depreciation so breaking the smart in will be a new experience for me and I want to do it right...)
Maybe a little anecdotal in relation to an ECU equipped car, but I have found the use of "Gunson" plugs quite handy. They are "test & tuning" sparkplugs with glass insulators and the actual combustion burn inside the cylinder is visible and a change in mixture can be monitored directly by observing the color of the burn: yellow - rich; blue - lean. The optimum is just after when "bunsen" blue replaces yellow.
In use on the 4-cylinder Ford Crossflow with two Weber double side draft carbs I would put a Gunson in #2 and #3 cylinders and balance the mixtures in #2 and #3 chokes. Then I would move the #3 plug to #1 cylinder and balance #1 choke to #2 choke on the forward Weber. Then plugs in #3 and #4, balancing #4 to #3. Again check #2 against #3, and finally, #1 against #4. I s'pose life would have been even easier if I had four Gunsons, but they are a little pricey.
Anyway, it beat tearing up the road and stopping and pulling plugs.
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(I hate to admit it, this will be my first brand new car, I always buy 1 year leases or low milage to take advantage of depreciation so breaking the smart in will be a new experience for me and I want to do it right...)
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