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Discussion Starter #1
What caused spark blow out? Weak coil, cool plug, to wide of gap? I'm at low boost and getting what I believe is spark blow out. Under 10psi
 

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Its deff not gap then. I thought my gap was tight, jesus. lol
Id start with looking at the coil and coil wire first and work out. You can measure resistance to help narrow down issues. What coil are you running? A good condition OEM one should be more than sufficient

I cannot answer on the plug as I cannot find a cross reference to see what heat range step that is
 

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Discussion Starter #6
Just competing side by side, the MSD coil im using is rated at 42,000volts. The stock replacement tfi Accel coil I have is rated at 48,000volts. Not saying it could be that, but it's interesting.
 

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Personally I would not use either MSD or Accel coils. Do you have a stock coil to test?
BTW, I run a stock original 160K mile coil from when my car was built. Never had the slightest issue with spark and Ive bounced this thing off 20PSI a few times on my S trim.
 

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I would open the gap to at least .028 - .030 . you may have a weak, fouled or cracked plug. I would change them out and re-gap them.
 

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I run an MSD 6AL2 and a HVC2 coil and have no problem running .028 gap at 20+ psi and 8K + rpm. It is more likely bad/improper wiring job to the coil/ignition, bad plug wires or something in that area.
 

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Spark blowout is usually caused by a bad or poor ignition. People whine about it, but a healthy TFI ignition will handle way more than 20 pounds of boost at normal gaps.

If you double cylinder pressure, which would be 14.5 pounds of boost, the plug only needs 20% more voltage.



I ran 25 psi up to 7000 RPM or so with the Ford OEM TFI and a MSD TFI coil. I used normal gaps. I could run plugs for months.

Up in the 7000 range the TFI starts to roll off for energy. When I started running close to 8K and 30 psi I added a CD ignition. I still use normal gaps. I did this because of the RPM more than the boost.

If I was "blowing out spark" I'd fix my ignition or mixture.
 

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A little something to think about. When MSD or any other ignition or aftermarket electronic supplier request you to tie their ground wire directly to the battery...DO NOT do it. Use a solid clean chassis ground point. Do not use the battery. The ONLY ground tied to my battery is the Neg battery cable. On my race car, the Fast XFI engine management system, Duel Aeromotive Eliminator fuel pumps, Rule 1000 I/C water pump, Electric engine water pump, electric cooling fan for radiator, electric water pump for S/C, electric boost controller, Line lock, Trans brake, MSD ignition system, electrics for the lights, tach and power windows ALL go to chassis ground and all work flawlessly.
 

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You'd be amazed how far you can push a stock coil. I made 1283rwhp with a 6AL and a stock coil, gap at .020 ngk -9 plug.

Also, a little info, with less boost, MSD 7530T and HVC2 coil it made 1051 hp. 20 minutes later with a 6AL and Stock coil made 1048. Interesting day....
 

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It is quite interesting indeed how great the OEM ignition system is.
Everybody seems to be "Upgrading" to MSD and equivilent systems for no obvious reason. I understand the spark control the 6AL gives you, but other than that...
Seeing pictures of these "high quality" MSD distributors how they rust from the inside when they're only 1 year old and then I take a look at my 30 year old OEM distributor and it looks brand new inside...
That says a lot about the quality.
The sad part is how they advertise them. It looks like a scam...

I go with that spark is OEM only. If Ford OEM isn't enough then GM COP.
 
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