I have heard that if you have higher compression(11:1), spin the motor past 7000rpm, spray N2O or have forced induction you NEED an aftermarket ignition box. Well, I have 10.5:1 compression and I take it to 6500rpm at the track, will I benifit from a MSD box? I currently have the large HEI and an Accell Super Coil right now.

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86 Camaro Sport
383 Speed-O-Motive Crate Engine, Raptor 700R4 Tranmission, Trick Flow Twisted Wedge G2's, 58mm Accel TB, 3.73 Auburn Pro, SLP Cold Air Induction and Headers, Hooker Cat-back, Serpentine Belt Setup, Dual IROC Fans, Jamex springs, 16" IROC Rims, 36mm/24mm Sway Bars, Global West Steering Brace. Hotchkis Rear LCA's,Panhard Bar and SFC's.
My Camaro Project

 

There will be some gain at the very least, especially at a higher RPM. The reason these high compression, turboed motors require a better spark is because the cylinder pressure makes the spark harder to cross the gap (higher resistance) and 'blows out' the spark. Of course better plug wires (spiral) and standard delco plugs are recommended as is a fresh cap and rotor. One thing I dislike about these high output ignitions is that for how well they work, they decrease the life of the cap and rotor. Not nessesarily, but my holley pro strip anihillator system with the race coil (c-core) puts out 135mj of energy with 535v on the primary stepping up into 40,000v@2Amps of power. Thats enough to burn the terminals (cut them right off) inside my MSD cap after about 8,000 miles. There are tamer coils out there, and I might have been better off stepping down a notch, but it never misses, even if there's sparks flying out of the plug boots there's so much power... and thats another reason I recommend the Summit brand wires. They are cheap and seal good and last (even from header heat) but I haven't found a cap and rotor that doesn't get cooked. I got a cheapie that melted the plastic around the carbon spring gizmo in the center, MSD lasted the longest in this area from the abuse, but the plug wires only got 3,000 miles to their life, not because of the ignition, but the heat turned the boots to bubble gum. They'd look fine, but when you rub them they just disentegrated into powder.

MSD sent me fresh hi temp boots that I have yet to try out, but the summits already outlasted the standard boots for $20 less (although you have to crimp the ends on, they supply a real crimper with them to do it)

 

Plus, you get a rev limiter in the process. I always felt my motor was worth the cost of a 6al, even if it were stock. One mis-shift or u-joint break and you may have to get the broom out!

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1992 Pontiac Firebird 350/Six Speed
1987 Toyota Pickup 383/500+ HP

 

The 6AL cost is justified, too... with it, not only do you get the rev-limiter, but they give you the $20 anti-vibration mounts. Since there's a $40 difference between the 6A and 6AL thru Summit Racing, you're getting the rev-limiter for $20.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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