I posted this in "Jag Series III megasquirt" thread yesterday, but now I think this deserves a separate thread.
We're in the process of planning a K-jet to EFI conversion for friend's Ford V6 (Cologne, 2.8). Spectre's thread has a lot of info, but there are a few things I can't figure out yet.
What we have already: EFI intake with two throttle bodies (left/right bank), 6 hi-z injectors, common rail with FPR, idle control valve, wideband O2 with a controller, TPS. No ignition parts yet and no air flow metering.
1. Batch-fired or sequential or semi-sequential injection?
I understand most older EFI systems are batch-fired. Without a cam sensor the injectors can also be fired in pairs (semi-sequential), kinda like wasted spark. Is batch-firing "outdated" now? The general idea seems to be that sequential gives better idle, and at high RPM it doesn't matter. How much of an issue is this? Without a cam sensor full sequential isn't possible, but crank-timed semi-sequential is. The problem is that Megasquirt II has only 2 channels, so for 6-cyl we can only fire all 6 at once (3+3 makes no sense I think). For semi-sequential (2+2+2) a much more expensive MSIIIX is needed. Also, how are injectors timed in a batch-fired system? Once per revolution or several small squirts?
2. Air flow metering
From the beginning I was planning on MAF as he most "advanced" method, and really thought it's a no-brainer these days. But Spectre mentioned in his thread that MAFs are difficult to get working on MSII. And I find a lot of discussions online how great the megasquirt is because it allows you to remove factory MAF :? Technically all MS versions seem to support it. To get the MAF working we need to combine two TB inputs into one hose and put some aftermarket MAF there (any suggestions which one will be the easiest for MS?). And if not, how to calibrate the system for metering with MAP, is there a fixed table to make temperature correction, or is this going to be engine-specific?
3. Ignition
EDIS6 and a coilpack seems an obvious choice. Are there any benefits from driving the coilpack (or individual coils) by MS directly? EDIS needs a crank sensor, can this sensor be used for both EDIS and MS? Or can MS operate fine with just a PIP signal from EDIS and is able to synchronize the injection correctly?
4. Microsquirt/MSII/MSIII?
We're quite tempted by the Microsquirt, which is basically MSII in a small sealed package, without in-built MAP. Also cheaper.The car in question is an offroader, so having the box watertight is a bonus (good idle and low-torque is important for the same reason). Microsquirt also can't control 6 individual coils, but with EDIS6 this is no issue. Basically, I just want a confirmation that Microsquirt is enough for this application, and we're not missing something important by not getting full MSII or MSIII
5. Tuning
How hard will this be to get running decently without a dyno? Can we use a generic map and then use the wideband lambda reading for some basic adjustment? Not looking for a peak power now (and right now the engine runs just awfully with this old, worn, badly set-up k-jet anyway).
We're in the process of planning a K-jet to EFI conversion for friend's Ford V6 (Cologne, 2.8). Spectre's thread has a lot of info, but there are a few things I can't figure out yet.
What we have already: EFI intake with two throttle bodies (left/right bank), 6 hi-z injectors, common rail with FPR, idle control valve, wideband O2 with a controller, TPS. No ignition parts yet and no air flow metering.
1. Batch-fired or sequential or semi-sequential injection?
I understand most older EFI systems are batch-fired. Without a cam sensor the injectors can also be fired in pairs (semi-sequential), kinda like wasted spark. Is batch-firing "outdated" now? The general idea seems to be that sequential gives better idle, and at high RPM it doesn't matter. How much of an issue is this? Without a cam sensor full sequential isn't possible, but crank-timed semi-sequential is. The problem is that Megasquirt II has only 2 channels, so for 6-cyl we can only fire all 6 at once (3+3 makes no sense I think). For semi-sequential (2+2+2) a much more expensive MSIIIX is needed. Also, how are injectors timed in a batch-fired system? Once per revolution or several small squirts?
2. Air flow metering
From the beginning I was planning on MAF as he most "advanced" method, and really thought it's a no-brainer these days. But Spectre mentioned in his thread that MAFs are difficult to get working on MSII. And I find a lot of discussions online how great the megasquirt is because it allows you to remove factory MAF :? Technically all MS versions seem to support it. To get the MAF working we need to combine two TB inputs into one hose and put some aftermarket MAF there (any suggestions which one will be the easiest for MS?). And if not, how to calibrate the system for metering with MAP, is there a fixed table to make temperature correction, or is this going to be engine-specific?
3. Ignition
EDIS6 and a coilpack seems an obvious choice. Are there any benefits from driving the coilpack (or individual coils) by MS directly? EDIS needs a crank sensor, can this sensor be used for both EDIS and MS? Or can MS operate fine with just a PIP signal from EDIS and is able to synchronize the injection correctly?
4. Microsquirt/MSII/MSIII?
We're quite tempted by the Microsquirt, which is basically MSII in a small sealed package, without in-built MAP. Also cheaper.The car in question is an offroader, so having the box watertight is a bonus (good idle and low-torque is important for the same reason). Microsquirt also can't control 6 individual coils, but with EDIS6 this is no issue. Basically, I just want a confirmation that Microsquirt is enough for this application, and we're not missing something important by not getting full MSII or MSIII
5. Tuning
How hard will this be to get running decently without a dyno? Can we use a generic map and then use the wideband lambda reading for some basic adjustment? Not looking for a peak power now (and right now the engine runs just awfully with this old, worn, badly set-up k-jet anyway).
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