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Old 10-25-2008, 12:49 AM   #1
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Default Spark over 12psi

I have an older BEGI / FM turbo system with manual wastegate control, and I'm a little too lazy to adjust the spring every time the temperature changes by 20 degrees, and I'm a little too power hungry to live with 12psi in the winter and 8psi in the summer - so, I'm set at about 11psi in the heat of the summer, and during cooler weather I might peak around 15psi.

My problem is that somewhere past 12psi, I start to have ignition problems - you might be familiar with the feeling, power is just starting to peak at a nice sweet level, then puuuuh.... I suffered under the delusion that it was a fueling problem for awhile, but it deteriorated and started happening at lower and lower boost levels. When I pulled the plugs, #2&4 had major carbon tracking on the insulators, wiping off the carbon resets the boost-ability back up around 12psi, but it deteriorates quickly (like over the course of 100 miles or so) as the carbon builds back up.

So, my question is: is there a simple drop-in replacement for the 1.6 coil packs, or something similar, which gives a more energetic spark? I don't need much more, but to get to 15psi, I definitely need more ignition oomph than I've got with the stock system (computer is replaced with a Link ECU, but the rest of the ignition is standard + magnacore 8mm wires and the FM recommended long reach plugs.)

Thanks.

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Old 10-25-2008, 02:26 AM   #2
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Old 10-25-2008, 04:42 AM   #3
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I won't flame you too bad since you seem to know at least enough to identify the problem you're having (ignition related). Check the "Useful Posts" section for the Toyota COP conversion. Four Toyota Corolla/Matrix/Celica coilpacks, a little wiring, and one adjustment to the Link for dwell reduction and you'll be back in business.

As a stopgap, though, gap your plugs to .024 across the board. I was able to do 13psi on stock ignition with .024 gaps. With the Toyota coils, there are several guys doing .045 gaps at 15psi+.
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Old 10-25-2008, 11:08 AM   #4
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Definitely go through your stock parts- wires, plugs and coils. I've run 16psi (and as much as 19psi) on the stock 1.6 ign w/o misfire with .030 gap and ngk blue wires. Unfortunately the Link has no adjustable dwell, but it does have a good dwell curve.

FWIW the Link has great closed loop boost control once you get it adjusted for the setup. Just the cost of adding the solenoid valve... which is cheap.
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Old 10-25-2008, 05:09 PM   #5
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Definitely go through your stock parts- wires, plugs and coils. I've run 16psi (and as much as 19psi) on the stock 1.6 ign w/o misfire with .030 gap and ngk blue wires. Unfortunately the Link has no adjustable dwell, but it does have a good dwell curve.

FWIW the Link has great closed loop boost control once you get it adjusted for the setup. Just the cost of adding the solenoid valve... which is cheap.
I've had varied results with the near-stock parts, I have run 15psi without misfire, but it seems like I eventually get carbon buildup in the plug wire boots which causes arcing in there when the plug-gap has higher resistance, such as during high boost.

Yep, the Link has improved a lot since it first appeared here, I got #1 off of Bill Cardell's test mule, they eventually upgraded the PCB for me - but I'm still a bit behind the latest release. If I get into tuning mode again, I'll definitely look into boost control.

@ Savington - thanks for the pointer to useful posts - I really am new here, not just acting that way - and the COP conversion looks like fun, if I didn't have a storage shed to build, fallen trees to chain-saw, two sons aged 5 & 7 to play with, coolant pipe to replace, honey can you furniture to build, etc. etc. etc.

@ naarleven - that looks EXACTLY like what I've been looking for - question now is, has anybody tried it and gotten the desired results?
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Old 10-25-2008, 05:19 PM   #6
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What gap are you running on the plugs? What heat range? I run had a high RPM miss fire running nitrous above 5K on the new stock ignition system with 2 heat range colder NGK BKR7E plugs. Gapped them down to .030 and moved the problem to after 6K. Gapped to .020 and problem is gone. And so far no adverse effects from running less gap.
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Old 10-25-2008, 05:21 PM   #7
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Also: I would highly advise against running low ohm sparkplug wires. Don't do it. Run regular wires. Low resistance does nothing good and only causes noise in the electrical system.
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Old 10-25-2008, 05:24 PM   #8
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COPs solved my misfire problems, FWIW. I didn't have the time to build them myself so I bought them pre-made from a forum member here, but I think he's stopped making them.

BTW - this thread doesn't really fit in the susp, brakes, drivetrain section.
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Old 10-25-2008, 09:38 PM   #9
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What gap are you running on the plugs? What heat range? I run had a high RPM miss fire running nitrous above 5K on the new stock ignition system with 2 heat range colder NGK BKR7E plugs. Gapped them down to .030 and moved the problem to after 6K. Gapped to .020 and problem is gone. And so far no adverse effects from running less gap.
After some brief experimentation with platinums, splitfires and others I can't remember, I've settled on these:

Flyin' Miata : Engine/Drivetrain : Fuel and Ignition : NGK extended reach spark plugs

I run around 0.024, which seems to help compared to the NGK factory gapping, but it's not the total solution.

@kotomile - if going COP could be easily reversed, I'd probably try it - I'm surprised the aftermarket hasn't picked up and made a commercial COP solution. A couple of things give me queasies about the Good-Win product - mostly that they bundle zero ohm wires with the coil pack - also, just because they make 45KV doesn't mean the spark is any more energetic, though the higher voltage should deal better with boost-insulation, even if it has the same or lower total energy.

Oh, and I guess that Dealer Alternative has trained me to think that the ignition system is part of the Drivetrain - I always thought it was a wierd place to categorize it.
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Old 10-25-2008, 11:03 PM   #10
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Quote:
Originally Posted by Mangocats View Post
After some brief experimentation with platinums, splitfires and others I can't remember, I've settled on these:

Flyin' Miata : Engine/Drivetrain : Fuel and Ignition : NGK extended reach spark plugs

I run around 0.024, which seems to help compared to the NGK factory gapping, but it's not the total solution.

@kotomile - if going COP could be easily reversed, I'd probably try it - I'm surprised the aftermarket hasn't picked up and made a commercial COP solution. A couple of things give me queasies about the Good-Win product - mostly that they bundle zero ohm wires with the coil pack - also, just because they make 45KV doesn't mean the spark is any more energetic, though the higher voltage should deal better with boost-insulation, even if it has the same or lower total energy.

Oh, and I guess that Dealer Alternative has trained me to think that the ignition system is part of the Drivetrain - I always thought it was a wierd place to categorize it.
Just saying less gap may fix the problem. Like I said on a 100 shot I would get a missfire even at .030 after 6K. That was with a "new" ignition system too. All less than 6 months old. New plugs at .020" and it pulled to 7500 with no spark blowout.

If you're interested in COPs, type that in the search menu and do a title search. Look for a thread with over 1K post. Read that one and you'll be up to speed.
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Old 10-25-2008, 11:08 PM   #11
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FWIW - COPs are reversible if you do them right.
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Old 10-25-2008, 11:21 PM   #12
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I haven't had any blowout with a a gap of .020" and 14psi. Still going to COPs for better idle/mileage/ smoother AFRs, etc.
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Old 10-25-2008, 11:58 PM   #13
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I get spark blowout anywhere past 9psi on my 94. That is with the stock ignition coils. I have cops ready to go in as soon as I make a bracket to hold them down.
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Old 10-26-2008, 11:42 AM   #14
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I don't there's any aftermarket solutions because of cost related to the Miata's wasted spark ign. Most available cop coils aren't designed to fire double duty as in a wasted spark environment. Granted nobody has seen the toyota coils fail, but they're essentially running them to 14,000 rpm duty cycle firing them as wasted spark. So it would need to be a sequential ign or guarantee on the coil to sell them. If anything, running a cop in a wasted environment says loads about OE quality. My MSD DIS2 lasted about a year and half. Fortunately I wired it up so I could plug in a jumper to return to the OE ign.
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Old 10-26-2008, 02:01 PM   #15
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Mike, put your location in your profile.
In addition to the link to your homepage (which needs some SERIOUS updating), put a short synopsis of your car in your signature.

Questions:
How old is your fuel filter?
Are you familiar with Seafoam?
Have you carefully checked all your vaccum lines for integrity?

So, now on to COPs. Brains writeup is awesome, here's what I did:
https://www.miataturbo.net/forum/t18937/

You'll see my setup (like most people do it) is 100% reversible in about 5minutes... in fact, it's easier to do it that way. You can buy a spare ignitor to gut and solder your leads to... or just (WAY EASIER) solder some wire-ends onto your leads and plug then into the ignitor harness. My thread explains this in detail. It's an easy DIY project that you can do in an afternoon.

15+psi with a .045 gap and never misses a beat.
It's the only way to go.

It's a perfect time to teach your 7yr old some soldering/electrical skills. Turn the whole thing into a family project. The fabrication of the hold-down bracket and some sanding/cleaning/painting of the valve-cover and bracket is something they will eat up and give your under-hood area a nice personal touch and a talking point whenever you open the hood for a buddy.
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Old 10-27-2008, 11:38 AM   #16
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FWIW, the fuel filter has maybe 40Kmi on it - worth a change, but the problem isn't really consistent with a dirty filter (e.g. wipe carbon off plug insulators, then able to boost 4-5psi more without problem...)

I'll do a search on Seafoam...

And, the vacuum lines seem good.

This COP does look like my next car project - not sure when that will fit into the time/$$$ budgets, my 7 year old is better at giving instructions than following them (and he really doesn't understand why we don't do everything he says.....)
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Old 10-27-2008, 11:41 AM   #17
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Quote:
Originally Posted by Mangocats View Post
FWIW, the fuel filter has maybe 40Kmi on it - worth a change, but the problem isn't really consistent with a dirty filter (e.g. wipe carbon off plug insulators, then able to boost 4-5psi more without problem...)

I'll do a search on Seafoam...

And, the vacuum lines seem good.

This COP does look like my next car project - not sure when that will fit into the time/$$$ budgets, my 7 year old is better at giving instructions than following them (and he really doesn't understand why we don't do everything he says.....)
Looking at time/budget, gapping plugs to .020" would take 10 minutes and cost nothing. And could very well 100% solve the problem...
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Old 10-27-2008, 01:39 PM   #18
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I agree- simple quick first. Then see what happens.
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Old 10-30-2008, 12:27 AM   #19
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I put in new wires and plugs tonight - gapped to .025, high boost stumble is gone now (and it was 44 degrees over dark cold pavement on the test run, boost was peaking near 16psi).

Just a single misfire happening now around 4000 RPM as it spools up, not even at full boost yet.

Old plugs were gapped at .037ish, I seem to remember dialing them in to .035 when I installed them. At the time, that worked well too. Will have to see how idle is with .025, I was hearing a miss every 15 seconds or so after it warmed up tonight - that might be just a little worse than the old plugs / gap were doing, but not much.

Has anybody every tried to collect on a Magnacore plug wire lifetime warranty? The wires are fine, but the plug boots weren't fitting tightly on #2 & 4, allowing arcing that actually cut grooves into the plug insulators.
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