MegaSquirt EFI Conversion

Sven --

I don't use Megasquirt, but I do have a fully programmable ECU. Here are two timing tables I've been using. The first one is one I modified from a vette motor with aluminum heads. It is a little more conservative and is much smoother. It feels like it provides more torque too. This is what I'm running right now. You can probably bump up the upper values by a couple of points, but I would leave it as is and just work your fuel tables around it.

The second one is one I built up and ran for the past year. It is pretty raw and has great power and throttle response, but it is jerky at low/mid rpms. I think this table gives better power in the mid-range, but at the expense of driveability. I ran both with 91 octane and got no pinging.

Here's the first:

TimingTable1-1.jpg


Here's the second:

TimingTable2.jpg


Hope this helps.
 
Re: MS

TodB said:
Check out the mye28.com forum, specifically the turbo section. There's a fellow on that board, First Fives Dictator, who is one of the resident MS gurus who could probably cut your learning curve quite a bit.
Click to expand...

That's Peter Florence, aka the guy behind the firstfives (e12) board.
 
Re: MS

TodB said:
Check out the mye28.com forum, specifically the turbo section. There's a fellow on that board, First Fives Dictator, who is one of the resident MS gurus who could probably cut your learning curve quite a bit.
Click to expand...

That's Peter Florence, aka the guy behind the firstfives (e12) board.
 
Thanks Andy.

I see some similar trends to the table I presently have (although for the 3 liter engine). The range of my numbers is bit greater. For example, at 2,100 rpm they range from 15.4 (100%) to 32.4 (20%). Did you get your results from dyno testing or seat of the pants testing?

Sven
 
Thanks Andy.

I see some similar trends to the table I presently have (although for the 3 liter engine). The range of my numbers is bit greater. For example, at 2,100 rpm they range from 15.4 (100%) to 32.4 (20%). Did you get your results from dyno testing or seat of the pants testing?

Sven
 
I did dyno the car with the second table. I got 200 hp and 205 ft/lb of torque at the rear wheels. This is with a mildly built 3.5. I've done a lot of tuning since then, so I don't know what its currently putting out, but it is definitely more (mostly due to changes to the fuel curve). Try to be a little conservative on the timing table until you get the fuel curve set up. Then you can go back and tweak it a bit more.

Don't worry so much about the range between high and low ends of the table -- the motor will never see many of those values. You should be in the 45-50 range at idle and a higher at part throttle. Wide-open throttle under load will be close to 100 and overrun goes down toward 20.
 
I did dyno the car with the second table. I got 200 hp and 205 ft/lb of torque at the rear wheels. This is with a mildly built 3.5. I've done a lot of tuning since then, so I don't know what its currently putting out, but it is definitely more (mostly due to changes to the fuel curve). Try to be a little conservative on the timing table until you get the fuel curve set up. Then you can go back and tweak it a bit more.

Don't worry so much about the range between high and low ends of the table -- the motor will never see many of those values. You should be in the 45-50 range at idle and a higher at part throttle. Wide-open throttle under load will be close to 100 and overrun goes down toward 20.
 
By the way, Peter Florance can probably provide you with the MS tables for both timing and fuel for a 3.5. I know he's done them before and was just speaking with a guy running a turbo'd 3.5 with Megasquirt that Peter had set up for him. He had to do some more tuning, but I believe he bought the MS system from Peter.

I also went back and checked out your conversion. Very nice! It is very similar in concept to mine. I had built the MS system a few years ago, but didn't use it. Instead I run a GM ECU and tune it with TunerPro. My thought was to hide all of the non-stock injection components in plain site so the casual observer never knows the car isn't D-Jet. That meant keeping the distributor and making a few other compromises. I also wanted to be able to just go into a Kragen or NAPA and get replacement parts for the fuel injection. I have about 15k miles on it and its been great. Other than the ECU, the main differences for mine are the ignition and the air intake bypass. I used an L-Jet distributor (with advance locked out) and the VR sensor to trigger the ECU, then have an MSD handle the spark. Your's is definitely a nicer set up since you have the capability to use multiple coils - I'm anxious to hear how it works out. For the by-pass valve, I used a GM part that is mounted on the bracket for the original D-Jet by-pass valve. I know MS can control it, so it would be an option for you if you don't want to run the big Bosch valve and want it hidden. Also, on your TPS, you can keep the D-Jet throttle body and easily modify it to accept a TPS from a Ford Mustang and hide it all under the big round cover. It has the same resistance rating as a GM TPS and is fully compatible with your MS system. Just a couple of random thoughts for whatever they're worth. Keep up the good work!
 
By the way, Peter Florance can probably provide you with the MS tables for both timing and fuel for a 3.5. I know he's done them before and was just speaking with a guy running a turbo'd 3.5 with Megasquirt that Peter had set up for him. He had to do some more tuning, but I believe he bought the MS system from Peter.

I also went back and checked out your conversion. Very nice! It is very similar in concept to mine. I had built the MS system a few years ago, but didn't use it. Instead I run a GM ECU and tune it with TunerPro. My thought was to hide all of the non-stock injection components in plain site so the casual observer never knows the car isn't D-Jet. That meant keeping the distributor and making a few other compromises. I also wanted to be able to just go into a Kragen or NAPA and get replacement parts for the fuel injection. I have about 15k miles on it and its been great. Other than the ECU, the main differences for mine are the ignition and the air intake bypass. I used an L-Jet distributor (with advance locked out) and the VR sensor to trigger the ECU, then have an MSD handle the spark. Your's is definitely a nicer set up since you have the capability to use multiple coils - I'm anxious to hear how it works out. For the by-pass valve, I used a GM part that is mounted on the bracket for the original D-Jet by-pass valve. I know MS can control it, so it would be an option for you if you don't want to run the big Bosch valve and want it hidden. Also, on your TPS, you can keep the D-Jet throttle body and easily modify it to accept a TPS from a Ford Mustang and hide it all under the big round cover. It has the same resistance rating as a GM TPS and is fully compatible with your MS system. Just a couple of random thoughts for whatever they're worth. Keep up the good work!
 
The system was running fine until the blown head gasket became too troublesome. I pulled the engine and now have the car completely stripped to the shell and beyond for a full on restoration. I hope to be back in the game next summer. Are you running MS?
 
No I'm not. I'm searching for a CSi and reading all I can find about the D-jetronic and the MS looks like a potential conversion alternative should the D-Jet get to the point where it is not economically feasible to keep running due to parts prices. Good luck with your project and keep us updated.
 
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