would buying a new coil and module for the hei distributor be just as good as getting the msd 6al ignition? or would they work better all together?

 

No. The MSD will amplify the spark, and at low rpms it will multi fire. I have actually been able to run more fuel with an MSD. More fuel as in more power. I was also able to widen the gap on the plugs.

 

If I run anything it will be the MSD,

 

Interesting points. I understand the multi-fire aspect allows for more complete combustion of the fuel. If all else is left in tact (including stock .035" plug gap), is the MSD 6AL still an acceptable modification?

8388, in what way did you affect fuel? Did you add it to the chip, or simply higher fuel pressure at the FPR for better atomization?

 

those are good questions, i would like to know that too

 

Me and MSD go back a long ways. Back in the days when all my toys had carburators. Even then I was able to jet up, run more fuel and make more power. It was all part of the fine tunning, I found lots of hidden power to be made. The car that has it today is my super charged car. On this application it helps to keep the spark from being blown out.

 

from what i understand the 6al is an easy installation too, just to wires, right? if so where to you connect them?

 

For a stock configuration, the MSD is claimed to be money down the drain. Where it really helps out is with higher compression, or boosted/nitrous applications. I will say that I have gained a couple of mpg in cruise mode though. As for the fuel, I am going to try boosting my rail pressure and see what happens. I lowered mine a bit but want to run it higher.

 

MSD has been around for a long time and the old MSD6 and MSD6AL are tried and true ignition systems. However there are others that offer even better performance with better electronics. The Mallory HyFire line and the Crane HI-6 series are equally as good and also offers better electronics than the old MSD6. Both the Mallory and the Crane line up are digital electronics equalling that of the much higher priced MSD Digital 6 ignition.

Adding one of these systems to a stock engine wouldn't offer much gains if any at all. Now if you have a high compression high rpm engine, a supercharger or planning on NOS, then yes these have their places. Also you have to know that these boxes all do about the same thing and they all perform at about the same level. All offer multiple spark discharge hence the name MSD but you have to also know that most of these systems CANNOT fire the spark more than ONE time after about 3000 RPM. That is because there just isn't enough time duration at the firing point to fire it more than once.

But to answer that problem Pertronix who is known for the points to electronic ignition conversion has their version of a multi-spark box. Their claim to fame is that they can fire at least twice throughout the RPM range. I haven't used one of their boxes as of today so I can't really comment on how well or not that it works. I spoke with one of their engineers or maybe he was a very well versed sales guy. Their explanation was thay they used high speed IGBT transistors to do the work in their boxes. In my old job working as an EE I worked a lot with large horsepower AC Drives in paper mills so I am very familiar with these devices. And if they do use them then it is very possible that they have figured out a way to give you more than one spark thoughout the RPM range.

As for coils, I am not sure what engine you have. But the stock GM LT1 and LT4 coil are excellent coils. I am running stock LT4 coils in my blown 396 LT4 using a Crane Hi-6TR without any ignition issues whatsover. Using a box with a stock coil well often be more than enough power for 99% of any streetable combo. The box fires the coil at a higher than stock voltage at the primary side, more voltage in equals more voltage out.

 

Your going to find the conversion very simple, with the toughest step being the location of the "box". For my 86 L98, I bought the 6a box, 8.5mm wires, the MSD drop in coil, the low resistance button for the rotor and the wiring kit to wire the box to the distributor. OK I could have saved 20 bucks and not bought the wire kit. Sure made working in that tight spot around the distributor much easier.

Did I feel a difference? Nope. But she idles much smoother and has stopped pinging under WOT pressure.

 

Its more than 2 wires, but it's an extremely easy project. The hardest part is finding a location not too far from the dist.

 

Tom, thanks for the outstanding commentary. Do you - or anyone knowledgable as well - see anything worthwhile...vs. investment $$... in a setup like mine? (modded with 1,000 usuable rpms over stock L98, but not nitroused or supercharged)? Its y understanding that the stock HEI starts falling off hard in the upper 4,000 rom range. Thanks again for such a great reply This info might for useful for others in the same boat

 

right now my compression is running about 10.0:1 and i have a good deal of mods. it idles pretty ruff right now so i hope maybe this will calm it down a bit. the power also seems to greatly drop of at the higher rpms (although the engine is mostly set up for low end torque) i think this might help me in my higher rpms a bit.