SCANMASTER ELM 327 Tech Assistance
11-02-2012, 05:07 PM
#1
Newbie
Thread Starter
Join Date: Jan 2012
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Mercedes C200 Kompressor
SCANMASTER ELM 327 Tech Assistance
Hi All?
I recently purchased the Scanmaster ELM327 software.
Can i set my fuel levels and if so I please need some assistance with the setting of the fuel economy on my Mercedes m271.
I want to set the vehicle on economy in order to use less fuel.
This software works great with clearing error codes and monitoring the ecu system
I recently purchased the Scanmaster ELM327 software.
Can i set my fuel levels and if so I please need some assistance with the setting of the fuel economy on my Mercedes m271.
I want to set the vehicle on economy in order to use less fuel.
This software works great with clearing error codes and monitoring the ecu system
11-03-2012, 08:39 PM
#2
Seems to me a top down vs bottom up approaches conflicting here. Save a top line model advertising "intelligent" automated features, reflected with a high six figure price tag, ECU systems are pretty simple and not really an AI control system, they're more like electronic valves of sorts, simply responding to simple direct inputs from sensors, in a fashion set by the ECU tuning parameter.
Essentially you're talking about reprogramming the ECU parameter for leaner tuning, in order to improve fuel economy. There are so many reasons it's not the best approach. For one thing the ECU is going to work against itself as the sensors tell it what you did was bad and it tries to undo it, doing things like retarding spark under loading to compensate what you did with fuel for a net loss in economic efficiency.
Auto engines aren't like aircraft engines with economy, cruise and power fuel settings. What you're talking about, fuel mixture settings and throttle application to control economy and power, it's very old school and works in planes due to very limited operating parameters, their blowers deal with altitude compensation and otherwise aero engines have an operational engine speed band of only about 1000rpm between closed and fully open throttles (governed by the prop alpha).
Auto engines need to function across a far wider spectrum of engine speeds, in the case of Mercedes typically 1600-6500rpm...that's nearly 5000rpm of expectations in volumetric efficiency where in engineering terms squeezing more than 2000rpm of high volumetric efficiency is impressive. And in a far wider variety of meteorological conditions (aircraft can always simply climb above weather).
These have direct relevance towards the tuning requirements of the engine. Modern auto engines have fairly complicated requirements. Your Mercedes is more advanced than an aero engine basically.
With that said, the key to economy for such an engine isn't the top down approach, it's a bottom up approach. You can't just tell the mechanicals what to do with electronic instruction and expect them to respond to it. You have to change the requirements or performance of the mechanicals, and the role of the electronics is to support those in a balanced way for all driving conditions.
So first up, your kompressor: they like rich mixtures. It's because they heat induction charge and pack more oxygen in so wetter, richer fuel cools it and compensates. It's going to be fairly difficult and ill advised to even try leaning off the fuel ratio, even if you do you'd have to substitute something like a water injection system, cooler plugs and higher octane tankage to compensate. You might find yourself spending more to use less of more expensive fuel grade at a net loss.
See, complicated.
The real key to improving fuel economy is volumetric efficiency and mechanical tuning, rather than lean running like an aircraft engine. First you want your spark and mixture tuning fairly neutral (ie. smack within specification for the mechanical setup) so it's usable for all driving conditions and suits the mechanical demands of the engine under these conditions. What you can do is mechanically retune the engine to operate more efficiently at lower engine speeds and with fewer demands.
Since you have a blower you can do things like make more blower efficiency (ergo dynamic boost) at lower rpm, by upgrading the intercooler for a higher capacity aftermarket one with more cooling value. The key with that is not so much induction flow rates, you want induction cooling value, the more the better.
Next is volumetric efficiency of the engine itself, it already has variable valve timing and 4v/cylinder DOHC which is fantastic, not much to improve there but exhausting at the manifold. Some nice port sized tubular pieces fabricated for an interference excavation system bolting up to the stock exhaust system should do the trick and give a little more low speed efficiency. I found this with a quick google:
which is available from here http://www.vaeth.com/en/vehicle-refi...ompressor.html
The two biggest efficiency issues about a supercharged engine is induction temperatures and exhausting.
Well maintained/serviced filters/fluids/spark too has tremendous impact on blower engines.
Of course the thing about improving volumetric efficiency is producing the same power with less throttle, but the problem is it will use more fuel at the same throttle, so it makes the car more economical if you enforce a conservative throttle, without loss of performance. If you're a bit of an expressionist with your feet you'll use more fuel going quicker.
I realise you've got this software package and are all excited but I've seen predetonation literally blow the supercharger right off the engine before. Bad idea to take the ECU mapping outside specification unless you've got a professional using a roller dyno to do it specifically for your individual engine setup. And you can say to him, "emphasis on economy pal" but the breadth of leeway he's got to work with between max power and max economy, where mapping the ECU goes, isn't actually very much...at all. Unless he's a ****** and turns your car into a self hurting pig.
It's about throttle body airspeeds/rates and various induction harmonics controlled by the mechanical tuning of the engine. And you've already got things like DOHC and variable valve timing, some of the best bonuses in this sphere that exist.
Exhausting and more cooling effect on the intercooler are what you need. Leaning off the mixture, bad idea unless the manufacturer builds in an economy/power setting switch operated in the cabin. That would mean they've installed all the extra things to make that work without hurting the engine too.
Essentially you're talking about reprogramming the ECU parameter for leaner tuning, in order to improve fuel economy. There are so many reasons it's not the best approach. For one thing the ECU is going to work against itself as the sensors tell it what you did was bad and it tries to undo it, doing things like retarding spark under loading to compensate what you did with fuel for a net loss in economic efficiency.
Auto engines aren't like aircraft engines with economy, cruise and power fuel settings. What you're talking about, fuel mixture settings and throttle application to control economy and power, it's very old school and works in planes due to very limited operating parameters, their blowers deal with altitude compensation and otherwise aero engines have an operational engine speed band of only about 1000rpm between closed and fully open throttles (governed by the prop alpha).
Auto engines need to function across a far wider spectrum of engine speeds, in the case of Mercedes typically 1600-6500rpm...that's nearly 5000rpm of expectations in volumetric efficiency where in engineering terms squeezing more than 2000rpm of high volumetric efficiency is impressive. And in a far wider variety of meteorological conditions (aircraft can always simply climb above weather).
These have direct relevance towards the tuning requirements of the engine. Modern auto engines have fairly complicated requirements. Your Mercedes is more advanced than an aero engine basically.
With that said, the key to economy for such an engine isn't the top down approach, it's a bottom up approach. You can't just tell the mechanicals what to do with electronic instruction and expect them to respond to it. You have to change the requirements or performance of the mechanicals, and the role of the electronics is to support those in a balanced way for all driving conditions.
So first up, your kompressor: they like rich mixtures. It's because they heat induction charge and pack more oxygen in so wetter, richer fuel cools it and compensates. It's going to be fairly difficult and ill advised to even try leaning off the fuel ratio, even if you do you'd have to substitute something like a water injection system, cooler plugs and higher octane tankage to compensate. You might find yourself spending more to use less of more expensive fuel grade at a net loss.
See, complicated.
The real key to improving fuel economy is volumetric efficiency and mechanical tuning, rather than lean running like an aircraft engine. First you want your spark and mixture tuning fairly neutral (ie. smack within specification for the mechanical setup) so it's usable for all driving conditions and suits the mechanical demands of the engine under these conditions. What you can do is mechanically retune the engine to operate more efficiently at lower engine speeds and with fewer demands.
Since you have a blower you can do things like make more blower efficiency (ergo dynamic boost) at lower rpm, by upgrading the intercooler for a higher capacity aftermarket one with more cooling value. The key with that is not so much induction flow rates, you want induction cooling value, the more the better.
Next is volumetric efficiency of the engine itself, it already has variable valve timing and 4v/cylinder DOHC which is fantastic, not much to improve there but exhausting at the manifold. Some nice port sized tubular pieces fabricated for an interference excavation system bolting up to the stock exhaust system should do the trick and give a little more low speed efficiency. I found this with a quick google:
which is available from here http://www.vaeth.com/en/vehicle-refi...ompressor.html
The two biggest efficiency issues about a supercharged engine is induction temperatures and exhausting.
Well maintained/serviced filters/fluids/spark too has tremendous impact on blower engines.
Of course the thing about improving volumetric efficiency is producing the same power with less throttle, but the problem is it will use more fuel at the same throttle, so it makes the car more economical if you enforce a conservative throttle, without loss of performance. If you're a bit of an expressionist with your feet you'll use more fuel going quicker.
I realise you've got this software package and are all excited but I've seen predetonation literally blow the supercharger right off the engine before. Bad idea to take the ECU mapping outside specification unless you've got a professional using a roller dyno to do it specifically for your individual engine setup. And you can say to him, "emphasis on economy pal" but the breadth of leeway he's got to work with between max power and max economy, where mapping the ECU goes, isn't actually very much...at all. Unless he's a ****** and turns your car into a self hurting pig.
It's about throttle body airspeeds/rates and various induction harmonics controlled by the mechanical tuning of the engine. And you've already got things like DOHC and variable valve timing, some of the best bonuses in this sphere that exist.
Exhausting and more cooling effect on the intercooler are what you need. Leaning off the mixture, bad idea unless the manufacturer builds in an economy/power setting switch operated in the cabin. That would mean they've installed all the extra things to make that work without hurting the engine too.
Last edited by vanir; 11-03-2012 at 08:43 PM.
09-01-2013, 09:05 PM
#3
Newbie
Join Date: Aug 2013
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
e300
i think you can't do that. i check the feature of elm327 at http://www.diyobd2.fr/wholesale/elm3...pping-731.html, it says
Features:
The program lets you perform the following operations:
Read diagnostic trouble codes, both generic and manufacturer-specific, and display their meaning (over 3000 generic code definitions in the database).
Clear trouble codes and turn off the MIL ("Check Engine" light)
so it what it can do is read clear and check the DTCs, not setting date which feature you want. may be you can get other tool instead of it
Features:
The program lets you perform the following operations:
Read diagnostic trouble codes, both generic and manufacturer-specific, and display their meaning (over 3000 generic code definitions in the database).
Clear trouble codes and turn off the MIL ("Check Engine" light)
so it what it can do is read clear and check the DTCs, not setting date which feature you want. may be you can get other tool instead of it
