Adding timing to my ITB install
 

Hi,

I have a fuel-only installation of EFI and Triumph ITBs on my 1977 911 S Targa.

This fall I am planning on adding timing control to my installation and was hoping to confirm what I need to purchase. I have confirmed my ECU has the supporting mods to control the timing.

I am planning on replacing the 3 point CDI in my car with MSD Streetfire and replacing the points in my distributor with Pertronix Ignitor. I believe I need to wire a 1 kohm resistor between the 12v supply to the ignitor and the signal wire to the Pertronix ignitor.

I currently have the stock Bosch black coil and stock plug wires with grounds, do I need to replace the coil, plug wires and new plugs?

Thoughts?

Thanks,
Kevin

Hi Kevin,

I’m not even close to an expert, but how would the ECU control advance and retard on the setup you’re proposing.

Rutager

Also not an expert but I faced the same situation: efi with fuel only and wanting to add timing.

The options were to either lock out the distributor, a procedure that isn’t difficult but isn’t easy or remove it all together. Keeping the dizzy and adding pertronix won’t achieve ECU timing as the dizzy will still be controlling timing mechanically. You’ll just be removing the points and CDI. Some say an improvement, some say otherwise.

I chose to remove it and replace it with COP.

I think your options are COP or EDIS, but again, I’m not an expert so more research is advised.


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Great questions, that is part of what I'm hoping for clarification from the Pelican brain trust.

I thought I could use the Pertronix Ignitor to replace the points on my distributor, and run the black wire from the Pertronix to Pin 24 on the ECU, in essence acting as a Crank Sensor.

I would replace the CDI with a MSD Streetfire, connecting it as follows: Orange and Black to the coil, White to Pin 36 on the ECU, Gray to the Tach, Red to switched power and the heavy black to ground and heavy red to the positive starter.

If I'm reading the setup of previous wasted-spark timing set up, that is what it looks like and I was hoping for confirmation on my plans.

Also, hoping for confirmation that the coil I have is sufficient and clarification on whether or not I should replace the spark plug wires and plugs.

I looked at both an EDIS and COP solution but I thought the MSD/Pertronix would be a bit more inexpensive and easire to wire.

I'm basing this plan on what dannichols1474 posted regarding his installation. I'm a bit confused also on how he says you should wire a 1kohm resistor between the negative and positive wires on the Pertronix.

@Julian, how was your COP solution, can you expand on it in terms of cost and complexity?

@Rutager, can you also provide more information on your EDIS solution?

Thanks,

My COP required the purchase of a new ECU- I also wanted something better than the MS2 I had so I went with the MS3ProMini- $600 or so. I’m running wasted COP; the car is a street car and single plug with stock compression and M1 cams so I felt that sequential spark wasn’t really necessary. Because of that I didn’t need lots of the features of some of the higher end ECUs and the cost delta was enough. Next engine (if…) I’d go twin plug, a bit higher compression and a full featured ECU with two AFR sensors, knock sensors, PDM, etc… all the bells and whistles. But that’s a big project and I didn’t want the car out of commission for that long so this was an incremental change.

The COP were $300 for 8 of them (I think- the Audi 1.8 coils are plentiful and pretty economical) and there there was all the wire and associated bits and baubles.

My first foray with Denso coils was not good and a bunch of them failed right before Ruchlos. Possible that they were bad coils or fakes but I haven’t had any issues with the Audi coils.

Hard to identify if the cams, the COPs, the trans rebuild or the new ECU, wiring and sensors play the biggest factor in how the car feels but it’s much quicker and powerful throughout the entire RPM range than before with stock internals and fuel only EFI. 4k-6500 it’s really noticeable and pulls quite strongly; massively different than stock.

The Audi coils also had an appreciable positive difference over the Denso coils and I could instantly feel the engine running better and stronger.

I’ve been working on dialing in the ignition map in conjunction with the fuel map and while it’s another thing to have to manage and understand, it’s been positive and I’ve been able to really control how the engine operates and where.

Given the amount of wiring you’ll have to do for COP, I think it’s worth considering a wholesale engine management change; new ECU, new wiring, new sensors, etc… it’s much harder in my opinion to piecemeal add something than to design and build a whole system from the ground up.


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Hi Kevin,

I would be pretty hesitant to go with EDIS in this day and age as it is mid ‘90s tech and harnesses and the EDIS module are getting harder and harder to source.

I’m currently fighting some sort of issue on my setup that I think could be ignition related, but not sure. I’m now heavily leaning towards going COP soon.

The interesting question might be what choices are available in ignition control. Are there more options than EDIS and COP? Clewett makes some stuff, but not sure how it or if it works off of any ECU.

It turns out Megasquirt V2 3.57 supports up to 6 coil packs so that would work but I'm not sure what else would be needed?

It looks like Pin 36 is the ignition wire but I have to assume that there would need to be another part or module that is required.

@Julian, when you hooked up your COP to MS3Pro Mini, how did you wire the COPs?

Adding timing to my ITB install
 

https://uploads.tapatalk-cdn.com/202...84192a6758.jpg

This is my schematic.