Desperate for some Help With Microsquirt, Beyond Frustrated Options

[Mblizzard]

Ok so I have a better understanding.

As I said I have the EFI Quadspark and Tower 4 coil coming and it shows a configuration like what is shown below.



I think the SPK C and D requires a cam position sensor to use.

But I should be able to use just SPK A and B to fire each side of the coil

But because the firing order on this is 1, 4, 3, 2 I am not sure how to configure the wires?

Looks like I would have to fire 1&3 together. 1 would be at firing position and 3 would be the wasted spark on the exhaust, and next 2&4 together?

[JamesM]

Was just looking through a couple of options for coils and saw this using a VW coil.



Seems to be too simple? Would fire in essentially 2 banks?

Any thoughts? The coil is only $18!

I recommend this coil, same one we just used on the 2270 build. Super easy with the built in igniters. Only thing to be aware of is the firing order difference between the inline 4 VW motors this comes off of and and type 4 firing order. You will need to swap the cylinder 3 and 4 plug wires from how they are labeled on the coil in order to get the banking correct. Wasted spark on a 4 cylinder only needs two spark outputs. No need for the quad spark or external igniters if you are using a logic level coil.


As far as your head temp situation, given you are running a stock cam with a large displacement engine and a stock distributor for timing control, I would expect your head temps to be over 350 most of the time and probably pushing 400 on the freeway and hill climbs. Also retarding the timing may actually be making the temperature situation worse. Best situation you could probably hope for with your current setup is to set the distributor timing to spec or maybe even advanced beyond that a degree or two and make sure you are not running leaner than 13.5:1 anywhere in the map. You could try to richen it up a bit in the areas you are running hot (possibly all the way to 12.5:1) but without programmable timing control that is about your only option at the moment.

Also, I would bet money that you have some holes in your cooling tin that are missing their proper plugs. If you see any opening in your tin at all there is something that is supposed to be sealing it. Not going to make a huge difference but every little bit helps. Most common ones I find to be missing are the seal around the oil pressure switch, the seal around the head temp sensor opening, and the ones that always seem to be missing, the ~1/4in holes for the spark plug wire clips. If you dont have all the proper hardware for your heat exchangers you should plug those lower holes in the fan housing too. Even with everything in proper order though 350+ with that displacement, cam, and distributor shouldn't shock you.

[Mblizzard]

Was just looking through a couple of options for coils and saw this using a VW coil.



Seems to be too simple? Would fire in essentially 2 banks?

Any thoughts? The coil is only $18!

I recommend this coil, same one we just used on the 2270 build. Super easy with the built in igniters. Only thing to be aware of is the firing order difference between the inline 4 VW motors this comes off of and and type 4 firing order. You will need to swap the cylinder 3 and 4 plug wires from how they are labeled on the coil in order to get the banking correct. Wasted spark on a 4 cylinder only needs two spark outputs. No need for the quad spark or external igniters if you are using a logic level coil.


As far as your head temp situation, given you are running a stock cam with a large displacement engine and a stock distributor for timing control, I would expect your head temps to be over 350 most of the time and probably pushing 400 on the freeway and hill climbs. Also retarding the timing may actually be making the temperature situation worse. Best situation you could probably hope for with your current setup is to set the distributor timing to spec or maybe even advanced beyond that a degree or two and make sure you are not running leaner than 13.5:1 anywhere in the map. You could try to richen it up a bit in the areas you are running hot (possibly all the way to 12.5:1) but without programmable timing control that is about your only option at the moment.

Also, I would bet money that you have some holes in your cooling tin that are missing their proper plugs. If you see any opening in your tin at all there is something that is supposed to be sealing it. Not going to make a huge difference but every little bit helps. Most common ones I find to be missing are the seal around the oil pressure switch, the seal around the head temp sensor opening, and the ones that always seem to be missing, the ~1/4in holes for the spark plug wire clips. If you dont have all the proper hardware for your heat exchangers you should plug those lower holes in the fan housing too. Even with everything in proper order though 350+ with that displacement, cam, and distributor shouldn't shock you.

There are a number of cooling tin issues. First it was modified for AC so there are some leaks! But sound advice.

Been able to run in the 12.5 range and have seen some dramatic drops in temp. On highway at 70 - mpg 340 and never above 385 on hill climbs.

Should start putting in the new coil next weekend!

But I was thinking that my O2 sensor could be in the wrong place. It is currently located at the end of the exhaust pipe after the muffler. I am wondering if this is potentially giving me bad readings?

[JamesM]

There are a number of cooling tin issues. First it was modified for AC so there are some leaks! But sound advice.

Been able to run in the 12.5 range and have seen some dramatic drops in temp. On highway at 70 - mpg 340 and never above 385 on hill climbs.

Should start putting in the new coil next weekend!

But I was thinking that my O2 sensor could be in the wrong place. It is currently located at the end of the exhaust pipe after the muffler. I am wondering if this is potentially giving me bad readings?

Those temps are looking good for your current setup.

Having the O2 sensor after the muffler in the tailpipe is not the ideal location. Depending on your exhaust there is a chance it could be reading slightly leaner than it should at lower RPMs. If anything it may be adding some delay to the sensor response. I like to put mine as near as you can to the collector, as close as possible to the heads but after all 4 pipes are tied together. I wouldn't delay any other progress on moving that sensor though. Its been working this far, consider moving it as a future improvement.

You are going to love the wasted spark once you dial it in!

[Montreal914]

I like the simplicity of the cost effective option shown on post #98 (VW coil). Do we know if this coil will accept the regular 914 ignition cables or it will require 99-01 Golf/Jetta ones? I recently bought a nice set of Magnecor cables and would like to keep it if I were to do a MS upgrade.

I am also running a 2056 (DJet) and getting these type of head temp mentioned.

I know the usual route for MS upgrade is induction, then ignition but could one begin with ignition while keeping the D-Jet for induction, then upgrade to full control?

Like your MS build thread, I have been enjoying this one as much and looking forward to your ignition one. Great achievement! (IMG:style_emoticons/default/beerchug.gif)

[Mblizzard]

I like the simplicity of the cost effective option shown on post #98 (VW coil). Do we know if this coil will accept the regular 914 ignition cables or it will require 99-01 Golf/Jetta ones? I recently bought a nice set of Magnecor cables and would like to keep it if I were to do a MS upgrade.

I am also running a 2056 (DJet) and getting these type of head temp mentioned.

I know the usual route for MS upgrade is induction, then ignition but could one begin with ignition while keeping the D-Jet for induction, then upgrade to full control?

Like your MS build thread, I have been enjoying this one as much and looking forward to your ignition one. Great achievement
! (IMG:style_emoticons/default/beerchug.gif)

My understanding is it will work with stock wires. I will verify when it gets here and post.

With the 2056 and D-jet you have to add more fuel than you think. I know there are all of these "ideal" values. But you have to control the head temps. Timing is a good place to start but don't be afraid to run richer than you think is necessary. You can always back it out but too lean = hot running engine regardless of what the number on the AFR is.

I started with fuel only first because i thought it would be easy enough to trigger off coil. Bottom line is that approach is not the best and if you are going to add a tigger wheel I highly recommend McMarks set up. Absolutely flawless on the install and operation.

I found the coil on Amazon for $18. I also have the DIY Auto Tune high power coil coining as a back up. But I am going to try the low cost approach first. Simple install and low cost is very appealing.

I have learned a lot during this process and had the input and assistance of some really great people. I hope this does help some others that are heading down this road.

As i have said, i have my D-jet and will keep it intact. But for me at least, the D-jet is just very difficult to adjust for any engine modification. After running hard at Okteenerfest and many drives after I know for a fact that the engine feels like it is running stronger and while I have no way to measure that, not having any problems with the system and having it just work under all conditions is enough to justify the conversion even if the perceived performance increase is just in my mind.

I will work with McMark and some other vendors to come up with a price list for the conversion so that people can see the actual costs. I got a little beyond my orginal intent to do this for less than $1,000. But I and confident that both fuel and timing can be done for this price or less.

[Mblizzard]

A few preliminary things done. Coil and test wiring ready. Stock plug wires won't work with this coil. Will have to buy some VW ones and adapt.

[Montreal914]

(IMG:style_emoticons/default/popcorn[1].gif)

A lot of the cables offered for the 99-01 VW 2.0 have metal sleeve at the spark plug. I did see some blue ones with rubber sleeves where it might be possible to slide over the rubber washer to seal the shroud.

I saw on ebay some pigtail to connect to the coil. This is an example, I'm sure there are cheaper ones.

[McMark]

I don't understand what the QuadSpark unit is doing for you. The MicroSquirt can directly drive a coil with built in igniter. So why add the QS unit? Am I missing something?

[Mblizzard]

I don't understand what the QuadSpark unit is doing for you. The MicroSquirt can directly drive a coil with built in igniter. So why add the QS unit? Am I missing something?

The other coil from DIY is a high energy unit with out igniters. So the Quadspark is needed with it. I am using the $18 coil with built in igniters to test everything first and will switch to the high energy coil at some point.

[Mblizzard]

(IMG:style_emoticons/default/popcorn[1].gif)

A lot of the cables offered for the 99-01 VW 2.0 have metal sleeve at the spark plug. I did see some blue ones with rubber sleeves where it might be possible to slide over the rubber washer to seal the shroud.

I saw on ebay some pigtail to connect to the coil. This is an example, I'm sure there are cheaper ones.

I order a couple sets of cheap ones and will hopefully modify those to work. The DIY Autotune coil that I will switch to after proving everything out should work with the stock wires.

Depending on how this coil works I may add the pigtail if I run it long.

[McMark]

Ignition power is only relevant if the spark plug is failing to ignite the mixture. If the 'cheap' coil doesn't give you any performance issues, then increasing the spark power won't add anything.

The job of the coil, wires, and spark plugs is simply to ignite the air-fuel mixture. Starting a campfire with a match isn't better or worse than using a jet-flame lighter. The in some cases the lighter is 'better', but it doesn't increase the 'performance' of the campfire. Now that I think about it, that's a great analogy. If the match is blowing out (and this CAN happen to a spark plug) then you need the jet-flame lighter to overcome the issue. But if there is no issue, the lighter doesn't add anything and it's potential is wasted.

In case you're still looking at a low-budget build, or want to avoid possible complexity/issues from more components.

[VaccaRabite]

Ignition power is only relevant if the spark plug is failing to ignite the mixture. If the 'cheap' coil doesn't give you any performance issues, then increasing the spark power won't add anything.

The job of the coil, wires, and spark plugs is simply to ignite the air-fuel mixture. Starting a campfire with a match isn't better or worse than using a jet-flame lighter. The in some cases the lighter is 'better', but it doesn't increase the 'performance' of the campfire. Now that I think about it, that's a great analogy. If the match is blowing out (and this CAN happen to a spark plug) then you need the jet-flame lighter to overcome the issue. But if there is no issue, the lighter doesn't add anything and it's potential is wasted.

In case you're still looking at a low-budget build, or want to avoid possible complexity/issues from more components.

I could very well be wrong on this, but that's somewhat contrary to what I've always been told.

I thought that more power through the coil allowed the use of a larger plug gap. Larger plug gap gives a larger flame front at the point of ignition, and also gives faster ignition to the air fuel mix, which gives the fuel more time to burn, which allows more of the fuel to burn, which is your efficiency increase. Same theory as using twin plugs (which are even more efficient as they start 2 flame fronts, instead of just one bigger one.)

To use your example, using a match will get your campfire lit, but I bring a MAPP torch becasue it lights the fire a hell of a lot faster, and is more tolerant of damp wood, wind, rain and other things that will slow down ignition.

Zach

[McMark]

more power through the coil allowed the use of a larger plug gap

Absolutely true.

Larger plug gap gives a larger flame front at the point of ignition

It gives a larger spark length, but not necessarily a larger flame front. Flame propagates much like a balloon or bubble, with the spark at the center. Increasing the size of the origin of the flame kernel won't make the kernel bigger. Instead I would say it gives more opportunity for ignition in turbulent conditions.

gives faster ignition to the air fuel mix

I'm pretty confident that's wrong. I'm pretty sure flame propagation speed is fixed based on things like RPM, compression, overlap, swirl. I don't know of anything you can do to the ignition system that will increase the flame propagation speed (aside from twin plugs, which isn't even increasing flame speed either, it's just starting two fires at the same time and letting them expand toward each other).

Same theory as using twin plugs

Not the same theory. Two flame fronts is WAY different than one.

Maybe a better example is if you had a 1 acre field of dry grass. (no wind, or other outside forces) If you were to ignite the field in two places, 2 or 3 or 4 or 10 feet apart, the field would burn at roughly the same rate. But if you ignite the field from opposite sides, then you can clearly see that the total burn time would be far less.

My understanding is that there are two common issues that ignition systems encounter:
1. Low RPM instability: At low rpm the air-fuel mixture is moving fairly slowly. There is less swirl in the combustion chamber, there is less efficiency at low RPM so you're not getting reliable exhaust expulsion nor intake suction. The fuel has more time to fall out of suspension and form droplets.
2. High Compression instability: At high compression ratios it's harder for the spark to jump the gap because of the density of the air (maybe you could say there's more air molecules that the spark has to push past). Also, on turbo applications (maybe high compression motors as well) there is a possibility for the higher charge swirl (turbulence) to literally blow out the spark like a candle.

Low RPM instability can cause misfires if the spark event happens at an inopportune time, when the swirl effect has just happened to pull the fuel particles out of reach of the spark. Especially at low RPM the air-fuel mixture is NOT homogeneous. There are areas of greater and lesser AFR. If the spark plug fires when there's no fuel around, it misfires (no ignition). Adding length to the spark would mildly improve the chances of avoiding that situation. Multiple sparks on one plug greatly increase the chances of avoiding that situation by trying multiple times, one of which is likely to catch. Twin plug will also greatly increase the chances for ignition. Simply increasing spark voltage will do nothing to increase the chances of ignition. Remember there is no such things as a 'hotter' spark.

High compression instability is clearly a case for increasing spark voltage. If the spark plugs are failing to fire because of charge density, increasing voltage will absolutely increase the reliability of the spark jumping the gap. If the spark is being blown out, a higher voltage will add stability to the arc in those turbulent conditions.

The KEY to all I'm saying is that if a basic coil is igniting reliably, increasing anything in the ignition setup won't do anything (aside from multiple spark).



Okay, the campfire example isn't perfect. But "damp wood, wind, rain and other things" would be examples of factors that make igniting unreliable and would therefore be example of when my assertion recommends upgrading ignition components.

[McMark]

gives faster ignition to the air fuel mix

Actually, more thoughts on this if you needed more convincing that the flame propagation speed is fixed. Consider that the entire reason that we have to increase spark timing (advance) as RPM increases is because we need to ignite the mixture earlier to give enough time for complete combustion to happen.

If we could increase the flame speed by increasing the voltage from the coil, we would have engines with fixed distributor timing, and variable coil voltage. Because controlling coil voltage is a HELL OF A LOT EASIER than designing a centrifugal advance distributor.

[Keyser Sose]

Use the analogy of a bucket of gasoline. It doesn't matter if you throw a small match into it or a large match, once there's ignition it's ignited. Or maybe better if you poke a small needle or a big nail into a balloon, the bang's going to be exactly the same. Only time you'll have an advantage from a lager spark is in extremes like very high RPM's, or extreme swirl from forced induction, those kinds of things.

[Mblizzard]

While all of this is true, the one true benefit of a high engery coil is that it actually does have the ability to overcome resistance that is inherent to the system. As the engine and electrical system gets hot the resistance the flow of electricity increases. Higher energy coils do limit the degregation of the spark due to resistance.

[McMark]

I have objections, but I suspect I'm annoying at this point so I'll bow out. (IMG:style_emoticons/default/wink.gif)

You're certainly not going to hurt anything by throwing more voltage at it.

[Mblizzard]

I have objections, but I suspect I'm annoying at this point so I'll bow out. (IMG:style_emoticons/default/wink.gif)

You're certainly not going to hurt anything by throwing more voltage at it.

You have no idea just how much information you provide to others in these discussions. No need to bow out.

You are spot on most of the time and discussion is what moves the understanding of those of us that don't do this every day forward. Thank you for that.

High engery coil turn the 914 into a 10 second car? Certainly not. But it has its application as long as your expectations are in line with reality.

[McMark]

Okay, I wrote a few different replies and deleted them all. I'm going to step out of the theoretical and just talk about your setup.

The VW coil you got 'temporarily' will give you everything you need.
The QuadSpark setup will allow you to run a larger spark plug gap, and that will improve your idle, but everything off idle will stay the same.