MSD 6AL in my 951
08-04-2002, 06:28 PM
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MSD 6AL in my 951
I have seen a few topics discussing this piece of hardware, but today a friend of mine is giving me one to borrow indefinitely (a girl wrecked his firebird and it was totaled by the insurance company, so he took the good bits out of it and bought a jeep grand cherokee). I have heard mixed opinions on ignition system upgrades, but I recently replaced my tired stock coil with a blaster 2 coil, and figured since this is more or less a free upgrade, why not?
One thing that I have heard that makes sense is that in a forced induction motor, the additional pressure introduced into the cylinders by the turbo has a tendancy to extinguish the spark at high RPMs, and by boosting and multiplying (multiple spark discharge) the spark, you end up with fuller and cleaner burning of the air/fuel mixture, resulting in better power. Is this true, or is it marketing hype passed down to the end consumer regurgitated to me? What if any gains should I expect from such an upgrade? Is it worth the 3 pound weight penalty? I know skip seemed ecstatic about the gains on his 2.7 n/a...will similar gains be available to me?
Also, with the 6AL, you can adjust your rev limit...it is possible (not that I would want to) to adjust it past the limit of your ECU? How is adjusting the rev limit up and down acheived? I seriously doubt that he still has the documentation that came with the box, and I can't find anything on MSD's web site.
Thanks guys.
One thing that I have heard that makes sense is that in a forced induction motor, the additional pressure introduced into the cylinders by the turbo has a tendancy to extinguish the spark at high RPMs, and by boosting and multiplying (multiple spark discharge) the spark, you end up with fuller and cleaner burning of the air/fuel mixture, resulting in better power. Is this true, or is it marketing hype passed down to the end consumer regurgitated to me? What if any gains should I expect from such an upgrade? Is it worth the 3 pound weight penalty? I know skip seemed ecstatic about the gains on his 2.7 n/a...will similar gains be available to me?
Also, with the 6AL, you can adjust your rev limit...it is possible (not that I would want to) to adjust it past the limit of your ECU? How is adjusting the rev limit up and down acheived? I seriously doubt that he still has the documentation that came with the box, and I can't find anything on MSD's web site.
Thanks guys.
08-04-2002, 07:07 PM
#3
I think the big gain is idle to about 3,000 rpm,then the unit is just giving one strong spark,not multible sparks.If you end up not useing the unit,I would be interested in the unit for my 1987-944S.Thanks <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
08-04-2002, 07:08 PM
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Yes,
and the MSD can't change the ecu's rev limit, so whichever one is lower is going to hit first.....
[quote]Originally posted by BRB944:
<strong>Doesn't the multiple spark shut off above 3,000 rpm? That would kill the help at high revs under high boost.</strong><hr></blockquote>
and the MSD can't change the ecu's rev limit, so whichever one is lower is going to hit first.....
[quote]Originally posted by BRB944:
<strong>Doesn't the multiple spark shut off above 3,000 rpm? That would kill the help at high revs under high boost.</strong><hr></blockquote>
08-04-2002, 07:39 PM
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I just got done looking through some of the previous posts on this unit. I believe I need to get some sort of module to plug in to adjust rev limit...I am fine with the APE stage II rev limit, so the rev limiting feature will be a moot point. An improvement in off-boost performance (multiple spark under 3K RPM's) would be a very welcome change. I saw some confusion whether or not the tach will still work with this unit...I finally read one post where there were no issues, so I am glad about that. Does this unit boost overall spark energy over the blaster2 coil I already have installed? It seemed to make a slight but noticable difference in high end power by itself.
Also, regarding the vacuum canister next to the battery...I am not sure if I want to loose cruise control (all though it doesn't seem to work since I pulled my car apart and put it back together)...is there any other reasonable place I can mount this canister besides in place of the cruise control unit? Thanks,
-ribs
Also, regarding the vacuum canister next to the battery...I am not sure if I want to loose cruise control (all though it doesn't seem to work since I pulled my car apart and put it back together)...is there any other reasonable place I can mount this canister besides in place of the cruise control unit? Thanks,
-ribs
08-05-2002, 06:35 PM
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The only change you can make to the rev limit using an RPM pill for the 6AL is to lower further than what is on the chip now. Some chips have no limit, so this is useful - others simply raise the level by ~500.
After multi-spark is shutoff ~3k, it still provides higher discharge, and longer duration spark (20o).
The MSD blaster coil provides significantly uprated power to the plugs, while the MSD unit provides power to the coil - the multi-spark and long duration signal controls the amount and type of firing time, while the output of the MSD unit and consistency keep the coil firing away properly. They work together to produce the desired effect.
The vacuum canister can fit on top of the MSD unit next to the battery, but there's no good plae to tie it down. I've received replies from many folks who have fabricated brackets from aluminum to properly fit it all in there - no pics from them yet, sorry. Another option is to mount the MSD unit inside the glovebox - seen it doen, seems to work fine.
Good Luck!
After multi-spark is shutoff ~3k, it still provides higher discharge, and longer duration spark (20o).
The MSD blaster coil provides significantly uprated power to the plugs, while the MSD unit provides power to the coil - the multi-spark and long duration signal controls the amount and type of firing time, while the output of the MSD unit and consistency keep the coil firing away properly. They work together to produce the desired effect.
The vacuum canister can fit on top of the MSD unit next to the battery, but there's no good plae to tie it down. I've received replies from many folks who have fabricated brackets from aluminum to properly fit it all in there - no pics from them yet, sorry. Another option is to mount the MSD unit inside the glovebox - seen it doen, seems to work fine.
Good Luck!
