| Go back to previous topic | | Forum name | Turbo/Nitrous Tech | | Topic subject | msd and spark plug gap for turbo? | | Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=70664 |
70664, msd and spark plug gap for turbo?
Posted by lickscissors, May-09-04 08:55 AM
i have an msd dis 2 and iridium plugs...i currently have them gapped to .05...should i still take them down to .032? i havent had a lot of time to tune the car, but i was wondering if the ignition makes up for anything....thanks
doug
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70697, RE: msd and spark plug gap for turbo?
Posted by mcgyvr, May-10-04 05:04 AM
.035 should be fine
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70701, RE: msd and spark plug gap for turbo?
Posted by ner947, May-10-04 06:38 AM
30-35 mills is good for stock ignition...
I tried the factory 45 mill gap for NGK's, which works for pump gas. However, throw in some 117 leaded and you will get misfiring with the MSD and a 45 mill gap. This happened to me on the 1320 pass that I have in my sig. If it wasn't misfiring, I bet I would have had another 1 or 2 MPH's.
Recently, I changed the plugs again and I have a gap of about 38-40 mills. Works well.
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70772, RE: msd and spark plug gap for turbo?
Posted by lickscissors, May-10-04 05:30 PM
ner947, do you have a msd? i just got the ngk bkr7e's today...just wondering where to gap them to....is there a benifit to have them gapped larger with the msd? thanks
doug
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70773, RE: msd and spark plug gap for turbo?
Posted by ner947, May-10-04 05:47 PM
One of the perks of using an aftermarket ignition amplifier is that you can run get away with a slightly larger gap. Exactly how much can you run? It's easy to find out, keep increasing the gap until you get some misfiring, then narrow it a bit. As long as the ignition system can support it, a larger gap will effectively produce more power.
Here's an example... In the Piper Archer I rent, it's a 360 cubic inch 4 cylinder with 2 spark plugs per cylinder. Yeah, the thing produces about 160 BHP at 2500 RPM's, which calculates to about 330 foot pounds of torque :D During the run up check, one of the things to test is the two independent magnetos, which are mainly there for redundancy. Typically, the engine is runs on both magnetos, but during the run up, the engine is brought up to X RPM's, at which the magnetos are cycled. A typical drop between both and 1 magneto is about 50-75 RPM's. When the redline is around 2500 RPM's, 50-75 RPM's is a lot.
What does this mean? With more spark and the same throttle position, relatively, the engine will make more power.
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70774, RE: msd and spark plug gap for turbo?
Posted by lickscissors, May-10-04 06:25 PM
alright...well right now i have denso iridium (stock heat range)...i just bought the ngks, i guess ill start around .038-.040...thanks for the help
doug
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