Anybody that has an MSD 6AL on their 350 TPI... what do you gap your spark plugs at??! I know that having an MSD 6AL requires a larger gap, but how much larger?? Any help would be appreciated!

 

I would start @ .055 and work your way up in .005 increments. I would do it at the track until you notice it slow down, then go back smaller .005

Also, high voltage take the path of the least resistance. I would make sure you have at least a 8mm plug wire (preferably a MSD 9mm) and good wire looms to keep them away from heat, metal, etc.

Also make sure you have a cap and rotor with brass contacts.



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Mike L.
It ain't pretty.......

1987 IROC Z TPI 350 A4 3.27 Borg-Warner.

Mods: 2300-2500 Stall Converter, Shift Kit(GM parts), TPI Specialties Stage 3 PROM, Modified Airbox w/ K&N's, homemade cold air, Relocated MAT sensor, Gutted MAF, 160* thermostat, Accel 8mm Wires, bypassed TB coolant, Flowmaster 3 chamber single 3" in/out muffler, 3" MAC mandrel intermediate, custom dual !cat Y-pipe. airfoil, ported plenum. !smog

http://www.MichaelLasiuta.home.att.net

**BOYCOTT LAPEER DRAGWAY**

 

Thanks for the suggestions! I'm not sure about doing this at the track though.... right now (with manifolds) it takes me about 30-45 minutes just to change the plugs.... maybe with headers (which are going in soon), it won't be too hard to pull them out and change the gap at the track!

As far as plug wires, I've already got the MSD 8.5mm Super conductor wires so I'm alright there! I'm also using a Hypertech cap (brass terminals), rotor, and 53,000 volt coil!!

 

MSD told me .050 or a little higher in an e-mail. I think you'd have to do dyno time to find the difference between .050 and .055 or 060. The track has too many variations.

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Rob P
89RSconvtZZ4TPI Edelbrock Intake
SLP Dual Cold Air Intake 1 5/8" Headers Semi-Siamesed Runners, IROC
suspension, alum shaft. Numerous mods.
92Z28convt5spd (stock)
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

I was going to go with .045. Is that to low or should I go with the .050 you mentioned? I have the 6A which to my knowledge is the same as the 6AL w/o the rev limiter and bosch platium plugs & MSD 8.8 wires.

 

I just spoke with my best friend who has an MSD 6AL and he said he has his plugs gaped at .050! He said any more it runs like crap and any less it runs like crap! I'm sure that .050 is a good place to start but I'm sure all cars are different!

 

I have no proof but have been told that MSD provides too hot a spark for platinum plugs. Starts to melt the platinum. MSD recommended good old AC Delco.

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Rob P
89RSconvtZZ4TPI Edelbrock Intake
SLP Dual Cold Air Intake 1 5/8" Headers Semi-Siamesed Runners, IROC
suspension, alum shaft. Numerous mods.
92Z28convt5spd (stock)
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

A little tooling around with Gaps, timing and fuel pressure showed that I got the most out of the car, from SOP Dyno anyways, from 46 PIS fuel pressure, 8* base advance, and .060" gap. Ofcourse I had a Hypertech coil and 8.8mm MSD superconductor(extreemly Low resistance) wires to aid my spark delivery.

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89 Trans Am Turbo 3.8L All stock 43,000 miles #1053 of 1555

Past Thirdgen:
86 Trans Am w/ built 355TPI with SLP goodies and too much other stuff to List. One sweet *** car, wish I would have had a good enough Job to pay insurance on three cars so I could keep it, but for a 89 Turbo Trans Am w/ Low miles, I think I made the right choice!

 

Well since I'm using the Hypertech Coil and MSD superconductor wires I may just try .060 gap, 46 psi fuel pressure (which is where mine is stock anyhow), and 8* advance!



[This message has been edited by 86TpiTransAm (edited July 17, 2001).]

 

Yes but I was running a 355 and ended up being a little lean, but I think that helped because of the Hypertech chip being so rich when you went to WOT and not touching anything at part throttle. See I had no Knock retard at WOT, but the plugs showed lean. Go figure.

 

melting point of pure platinum: 3214.9 °F
melting point of pure copper: 1984.32 °F

Platinum is much stronger than copper, why do you think the plugs are so much more expensive?