msd.........to do or not to do

[Greg72]

[ QUOTE ]
It isn't the off road ignition box is it? I'm on my 4th off road box now with MSD distributor and coil. The guys at MSD said they had a problem when they first came out and supposedly fixed it. Well now my new box is acting up after 1 summer. I'm thinking MSD HEI now.

When it was working properly it had great off idle (800rpm)response all the way to 7000rpm

[/ QUOTE ]


You know the more I think about it.....the more I recall LOTS of complaints about the so called "Offroad" Box.

They charge more for it, but I really can't see what's so "optimized" about it for 4x4 usage??? Certainly it's reliability is questionable from the posts I've seen.

For the record, I run the 6AL box (behind the dash, not in the engine compartment) and haven't had a lick of trouble with it. /forums/images/graemlins/thumb.gif

 

[Klef72K5]

I think the off road box is a 6AL too, not for sure, just has some other features to it, like water proofing the inside to prevent shorting and suppose to give better spark at idle for crawling but yet can handle higher RPM's like the 6AL.

I just know that I'm not happy with it at all!
12,000 miles = 4 off road boxes and it's missing again! When it first starts acting up I never think about it being the problem because I just fixed it a couple months ago. I tear apart my Holley and adjust the timming. Once I even adjusted my rockers because of the symptoms. Starting to be a PIA. I will look into the 6AL and relocation!

 

[Mudzer]

Im not too quick to jump on the bandwagon either. My stock HEI works fine. If you have it - save it for a drag car or something or sell it and make money to buy more useable parts. That's what I'd do. /forums/images/graemlins/thumb.gif

 

[84_Chevy_K10]

[ QUOTE ]
As I stated previously, if you aren't expecting or looking for gains, why the HELL would you install something that is just another failure point?

I bet if I did some digging on this board, some people that bad mouth injection for being potential failure points probably spout the "benefits" of the MSD box. Can't say I dislike the rev-limiting features, but I can do that with my ECM.

[/ QUOTE ]

1. Installed for rev limiting capabilities and for no other reason. I was going to buy the rev limiter by itself but it was more cost effective to simply buy the box.

2. I don't have an ECM so I'm limited in my ways to limit RPM. I either lift or use an aftermarket ignition. I chose the aftermarket ignition.

 

[Greg72]

[ QUOTE ]
... if you aren't expecting or looking for gains, why the HELL would you install something that is just another failure point?

[/ QUOTE ]



MSD has "cooler" stickers than GM......


/forums/images/graemlins/thumb.gif

 

[ntsqd]

[ QUOTE ]
[ QUOTE ]
B) In a side by each comparo MISF & I checked the dwell at various RPM's of a brand new stock Delco HEI module and one of Performance Dist's modules. The PD part had 45* of dwell at every rpm we checked at up to 4500. The Delco part had 45* at idle and it plummented to something less than 30* by 2000 rpm.

[/ QUOTE ]

Just to clarify here, we never really mentioned the modules or coils. I am a pretty firm believer that the stock ones can and have been improved on. I just don't think an additional box is the answer in most applications.

[/ QUOTE ]

Which is why I phrased my response the way I did. I was hoping to not confuse the issue further.
I'm not terribly fond of the stock module's design. They are power hogs and they require a very robust trigger pulse or they won't fire. The problem is that the MTBF of the aftermarket units does not appear to be as good as the stock module (assuming the heat sink grease is used on the stock module). The Crane unit looks the most promising to me, but I've not had the experience (time in service) with it that I've had with the MSD's.

And to clarify my thots some; There is no way I would trigger either an MSD or a Crane with the stock module. I would go directly to the magnetic trigger in the HEI dizzy for the trigger source. I may or may not leave the stock module in place for back-up. Would depend on wire clearence.

As an aside; I've considerable experience putting the HEI pick-up coil & reluctor in points dizzys. Most of the serious race intakes won't clear the HEI's large diameter and we wanted a known-to-be-good dist for use on the dyno. The first cast iron points dizzy I converted got sold to a customer. He saw it and wanted it badly enough to pay my employer's reluctant price for it. I've since built it's replacement and a couple others for cutomers. I built one that was for a Buick GS 455 engine, the Buick HEI wouldn't clear some bracket and the owner wanted it to look dead stock. He uses it to drive a carefully hidden MSD 6.