megasquirt

[squarebush]

I am looking to see if anybody has megasquirted their benz, the older the better. I am trying to get the maximum performance from my M117. I am still sort of at a loss since I do not have total wire diagrams and the d-jet system is a less complicated set up then the modern ecu.

[300EVIL]

Hi squarebush,
What's your question and I'll see if I can help.
Adam

[squarebush]

well right now I have decoded most of the d-jet input out put stuff but it is way off from what I need. I am still trying to work out the general relays and figure it out. I found some old stuff a couple of minutes ago from tomguy but looks like this is the first 280se 4.5 that is actually being done. Any clue where the fuel pump meets up with the system, there is a large red wire with a cloth braided cover, looks like it is very important, could that be it?

I have to start figuring out how to go from a positive engine computer to a grounded engine computer.
what is the deal with switching out the ignition system? I understand the injection system but I am still trying to get a grasp of the whole spark scene. what do I use for engine speed inputs? Do I have to add a tach wire if I pull the distributor a replace it with a mega squirt ignition system?

[300EVIL]

Originally Posted by squarebush

well right now I have decoded most of the d-jet input out put stuff but it is way off from what I need. I am still trying to work out the general relays and figure it out. I found some old stuff a couple of minutes ago from tomguy but looks like this is the first 280se 4.5 that is actually being done. Any clue where the fuel pump meets up with the system, there is a large red wire with a cloth braided cover, looks like it is very important, could that be it?

I have to start figuring out how to go from a positive engine computer to a grounded engine computer.
what is the deal with switching out the ignition system? I understand the injection system but I am still trying to get a grasp of the whole spark scene. what do I use for engine speed inputs? Do I have to add a tach wire if I pull the distributor a replace it with a mega squirt ignition system?

First off, what body does that M117 belong to? Are you running Megasquirt II? What input sensors/accessories have you purchased? The factory KE Jetronic offers very little in reuseable outputs except for coolant temp and VR flywheel trigger. If you don't already have one, I'd purchase the relay box for your megasquirt. It will make wiring simple and clean. The fuel pump relay is located where your original ECU is. It's a black rectangular module that cuts off when the factory redline is reached.

Red wire with braided cloth doesn't say much. I'd suggest getting the wiring diagram for your vehicle. As for the factory ignition, you can use it but you won't be able to advance the timing. The factory EZL module is preset internally and adjusts itself based on RPM and load via manifold pressure. Switching to another module is cheap, easy and will allow your megasquirt to control ignition timing. I'm guessing your dumping the CIS for EFI because you are looking to make more power. If so, you definately want to be able to adjust the ignition advance.

Give me some more info and we'll see what we can do.

[squarebush]

It is the w108 m117
I haven't purchased anything for the megasquirt yet, I have been using parts I have laying around. I've been reverse engineering the wiring and D-jet system I have now trying to get a good starting point.
My girlfriends father just finished megasquirting his car so he is also a good source.
I've got plenty of questions, I am still learning the basics, this is my first car and my first real electronics project

[300EVIL]

Ah, you do have a D Jetronic injection system. I assumed you had KE Jetronic. So you must have a 280/300SEL 4.5. With that said, you should be good to go with all the stock parts except for the MAP sensor, Megasquirt has one built in. The coolant and air temp sensors will need to be calibrated to your megasquirt, but that's easy. The ignition is vacuum advance via actuator on the distributor. You can defeat this function and fire the coil with the megasquirt. All you need now is a wiring diagram and your all set. You should however consider just making a new wiring harness. 30+ year old wires tend to cause more trouble than their worth.
Adam

[Matt L]

I remember from my SAAB days that the D-jet MAP sensor is quite expensive. What does it cost for a M-B?

[300EVIL]

Originally Posted by Matt L

I remember from my SAAB days that the D-jet MAP sensor is quite expensive. What does it cost for a M-B?

Yeah, I'm sure that part alone going bad would justify a switch to megasquirt. That's the kinda part you buy in the used market.

The map sensor in the megasquirt is about a 10th of the size, way more accurate/reliable and is only $20!

[squarebush]

Originally Posted by 300EVIL

Yeah, I'm sure that part alone going bad would justify a switch to megasquirt. That's the kinda part you buy in the used market.

The map sensor in the megasquirt is about a 10th of the size, way more accurate/reliable and is only $20!

that is half of the reason I want to switch to megasquirt, I can avoid the costly hunt for parts I can't get anymore. So the MS unit negates the use of the vacuum advance?
I am also looking into building a programmable ignition system. I want to see how far I can push it. I want my 280se 4.5 to get 20-25mpg
hopefully I can push the horsepower up.

[300EVIL]

Originally Posted by squarebush

that is half of the reason I want to switch to megasquirt, I can avoid the costly hunt for parts I can't get anymore. So the MS unit negates the use of the vacuum advance?
I am also looking into building a programmable ignition system. I want to see how far I can push it. I want my 280se 4.5 to get 20-25mpg
hopefully I can push the horsepower up.

Ignition control is built into megasquirt II. I don't like megasquirt I, but if that's what you are considering, you can add ignition to the ECU. I would suggest looking into your options carefully. You can use the factory ignition if you want, but you'll be able to tune for performance or economy substantially with the control handed over to MS.

Tuning for performance and economy are two seperate things, but you can switch tuning by just loading different maps with a laptop at a moments notice.

[squarebush]

Originally Posted by 300EVIL

Ignition control is built into megasquirt II. I don't like megasquirt I, but if that's what you are considering, you can add ignition to the ECU. I would suggest looking into your options carefully. You can use the factory ignition if you want, but you'll be able to tune for performance or economy substantially with the control handed over to MS.

Tuning for performance and economy are two seperate things, but you can switch tuning by just loading different maps with a laptop at a moments notice.

I was thinking more a toggle switch
anyways you get more power from more economy in a case like this. Think about it, D-jet was the FIRST full electronic fuel injection system.... that was 1969. . . How can we not do better?
My girlfriends father, like I said, megasquirted his car so I have been talking to him about it. He also happens to be an engine nut. I was wondering what the biggest difference between the AMG E63 and the 300sel 6.3 because they have similar engines, similar weights, similar everything but major power and speed differences. He said that the most dramatic thing they could so was update the control unit.

This is awfully exciting. Talk about a great project to learn everything.

Oh and yes I believe I will be going with version II but I am not sure about the ignition, I believe it only supports up to 4 cylinders. . . and that there is a larger ignition control in the works

[300EVIL]

Originally Posted by squarebush

I was thinking more a toggle switch
anyways you get more power from more economy in a case like this. Think about it, D-jet was the FIRST full electronic fuel injection system.... that was 1969. . . How can we not do better?
My girlfriends father, like I said, megasquirted his car so I have been talking to him about it. He also happens to be an engine nut. I was wondering what the biggest difference between the AMG E63 and the 300sel 6.3 because they have similar engines, similar weights, similar everything but major power and speed differences. He said that the most dramatic thing they could so was update the control unit.

This is awfully exciting. Talk about a great project to learn everything.

Oh and yes I believe I will be going with version II but I am not sure about the ignition, I believe it only supports up to 4 cylinders. . . and that there is a larger ignition control in the works

"6.3 liters is 6.3 liters" good try but,,,,, no... Comparing those engines based only on displacement and engine management is unfair.

The "KEY" to making more power,,,, is "AIR".

The new 6.3 liter AMG engine "breathes" way better than the old 6.3 liter. That's where it gets most of its power. It performs this with a very well designed intake, 4 valves per cylinder, well designed heads, a higher redline and higher compression ratio.
Sure the engine management is way better but adding fuel is the easy part, moving more air is the goal in making horsepower.
If all you do is change the ECU and perform tuning, good tuning, the most you'll get is maybe a 10% increase in HP and torque.

Now that we cleared that up, back to megasquirt.

Currently their is no way to change fuel and ignition maps at the flip of a switch. If you want that your going to need to buy a retail aftermarket engine management system.
I don't know where you heard the "4 cylinder only" ignition thing but that's not true, if you think about it, that wouldn't even make sense.

I'd suggest you do a little more research before jumping into this project.
Start here. http://www.megasquirt.info/

[squarebush]

Originally Posted by 300EVIL

Currently their is no way to change fuel and ignition maps at the flip of a switch. If you want that your going to need to buy a retail aftermarket engine management system.
I don't know where you heard the "4 cylinder only" ignition thing but that's not true, if you think about it, that wouldn't even make sense.

I'd suggest you do a little more research before jumping into this project.
Start here. http://www.megasquirt.info/

I know what you are trying to say, I meant replacing the distributor with an electronic ignition firing box it is actually under the megaspark project. anyways I am also not just talking about a little switch but a little software cue that feeds a different set a values. I guess what I am really going to do is borrow one of the small handhelds laying around the house and use them to talk to the system.


I understand that displacement only looks similar... but doesn't 6.3 liter mean 6.3 liters of air and fuel? Obviously a cold 6.3 liters of air will give you a much higher oxygen concentration and way more power.
I guess what I was trying to figure out was why the 1969 6.3 was so slow and lacked the power while using more fuel. Obviously too, better engine mechanics makes a difference such as more valves and lighter components.
truth is I am still learning the subtle facts about cars but I am open minded and ready to listen

[AustinsCE]

I'm pretty curious about that myself. Take a 350 chevy stock does 180, but play with it and you're over 375+. I want to see someone play with a 100 engine.

300Evil- what are your thoughts on a different 3rd party ignition unit, like MSD, or you think integrating everything in the one MSII unit is better?

[wbain5280]

Originally Posted by squarebush

I was wondering what the biggest difference between the AMG E63 and the 300sel 6.3 because they have similar engines, similar weights, similar everything but major power and speed differences. He said that the most dramatic thing they could so was update the control unit.

To add to what Mr. Evil wrote, the old 6.3 V8 is a cast iron block with aluminum heads and Bosch mechanical FI. It produced gobs of torque.

The new 6.3 is a low friction engine all aluminum engine producing lots of HP with a modern FI system.