Spark Plug Gap
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Spark Plug Gap
What should my spark plug gap be on a 200 shot using a B8EFS and also on a 300 shot B9EFS. I am currently 30 on the 8's.
What is the downside to closing the gap? Why not run a say 28 on everything.
What is the downside to closing the gap? Why not run a say 28 on everything.
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How about on 300?
I did the unthinkable and sprayed 300 on the B8's without pulling timing but with VP. Someone challenged me to a grudge match that I know runs 10.5s and on 200 I ran 11.1 so I uppted the shot to 300. It hurt me cause I ended up running 11.4 to his 11.1 but his front driveshaft broke on that run.
The B8EFS re gapped to 30, should I close it?
I did the unthinkable and sprayed 300 on the B8's without pulling timing but with VP. Someone challenged me to a grudge match that I know runs 10.5s and on 200 I ran 11.1 so I uppted the shot to 300. It hurt me cause I ended up running 11.4 to his 11.1 but his front driveshaft broke on that run.
The B8EFS re gapped to 30, should I close it?
#4
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more gap is associated with better efficiency, increased economy and more complete burning/use of fuel and air. The larger the plug gap the better the spark performance- until it "blows out" of course. I would seek to increase the power of my ignition before gapping down, unless it was too expensive or I was simply willing to give up the advantages a larger gap and more powerful ignition system might have for my application. In other words, gapping down is free, and it works. But I wouldn't do it unnecessarily or unless I had no other realistic option.
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If you are dead-set on improving ignition performance mostly for the sake of economy, I would still try to keep as much of the OEM system as possible to avoid electronics problems. That said, something simple like an MSD box (what we all used in the old days) might be what you are looking for, it will allow you keep most of the OEM hardware if not all of it, improves spark output, and lets you run a larger gap. I don't know if there is an MSD box for the LS-X (you might have to run two DIS-4's or something stupid I never tried it, although you said wires which implies a standard box would work) Anything more than that- I would copy somebody's setup exactly (find someone using the nitrous you are using), find out exactly what they are using and for how long, and make sure they are having the large plug gap you are looking for, AND have been using the setup reliably for 2-5 years at least. And even then, don't cut or move any wires that are OEM, simply move them out of the way and shrink them off if necessary, that way if you DO have problems you can always go back to the OEM ignition to diagnose them.
If I had a street car with 500~bhp I would keep the OEM system, with possibly brand new components for maintenance measure (if they have 150k+ it might be beneficial to renew them), use a high quality compatible plug (iridium if possible), and make sure you do everything in your power to ground the engine and chassis properly, protect any electronics with heat shields and blankets (minimizing heat absorption/retention in electrical systems traditionally improves their performance). Then start with the gap they come with and boost it. If it blows out, gap it down bit by bit until you hit the safe spot for your setup for consistent performance. Turn the power up just a bit extra to make sure you have headroom, and use all "special devices" such as meth/water injection while you do so. Nitrous is another story; I am not sure I would want to blow out my spark during a run with nitrous. Extra safety precautions are required for nitrous. My recommendation mostly revolve around you having access to the power full time (forced induction) and being a daily driver/ street car.
Last edited by kingtal0n; 01-16-2016 at 12:19 PM.
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#8
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Do you really think .030 to .028 is going to make a difference?
It won't. The OEM coils can fire across an .060 gap, so they have plenty of juice. Closing the gap is more about getting away from a huge long ground strap like on a projected tip and keeping the ground strap from becoming a glowing ember for detonation.
While my ignition is a single MSD it also fires 7 times more than the OEM individual coils. I had asked my engine builder (Tony Bischoff) about gap and his reply was "have a gap"... So I simply check each plug with a 0.025 feeler.
It won't. The OEM coils can fire across an .060 gap, so they have plenty of juice. Closing the gap is more about getting away from a huge long ground strap like on a projected tip and keeping the ground strap from becoming a glowing ember for detonation.
While my ignition is a single MSD it also fires 7 times more than the OEM individual coils. I had asked my engine builder (Tony Bischoff) about gap and his reply was "have a gap"... So I simply check each plug with a 0.025 feeler.
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Do you really think .030 to .028 is going to make a difference?
It won't. The OEM coils can fire across an .060 gap, so they have plenty of juice. Closing the gap is more about getting away from a huge long ground strap like on a projected tip and keeping the ground strap from becoming a glowing ember for detonation.
While my ignition is a single MSD it also fires 7 times more than the OEM individual coils. I had asked my engine builder (Tony Bischoff) about gap and his reply was "have a gap"... So I simply check each plug with a 0.025 feeler.
It won't. The OEM coils can fire across an .060 gap, so they have plenty of juice. Closing the gap is more about getting away from a huge long ground strap like on a projected tip and keeping the ground strap from becoming a glowing ember for detonation.
While my ignition is a single MSD it also fires 7 times more than the OEM individual coils. I had asked my engine builder (Tony Bischoff) about gap and his reply was "have a gap"... So I simply check each plug with a 0.025 feeler.
On B9's I will go to 26 or 28?
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stock coils, MSD wires, you would be surprised what the stock coils can fire. I have driven home on a 6:07 pass in the 8th and had two burnt plugs and the 3rd, strap was almost all gone and the car ran like it didnt have a problem till I checked the next day when i thought the idle was a little odd lol