MSD 12 performance

I`am running a 375 cid blown alky big block topped with a 14-71 HH Mert retro here in Germany in comp eliminator.
From 5500 rpm up it makes over 40 lbs. of boost.
As i´am using a MSD 12 mag alot of people that come over shake theire
heads about the ignition setup used.
I never had a single ignition failure (to my knowlege)
Will i need to upgrade to a MSD 20 or even bigger?

Any help would be apreciated.

Bjoern

 

I bought a Supermag from Jeff Mould that was bumped up to 7 amps. He said when he went from that to a 44 his car didn't improve. I believe he said his blower was making 45 lbs?

 

5.64 @ 255 with a pair of 12's 10 years ago.

 

Upgrade to 20

Hi Björn ! We ran an MSD 12 in our 477 CID BBC dragster with 27 lbs boost and never had a problem. The new engine is a 397 CID and makes 47 lbs of boost, so we chose a MSD 44 mag to be safe (and allow for a programmable 8973 controller). BUT: you could look into upgrading the 12 to a 20. I think Lehay offers that at a very reasonable cost. And you can keep all the rest of your setup. Call me at +47-90122977 if you want to discuss any blown BBC matters. I speak German. MfG Craftsman Racing, Norway.

 

You can't "Be too rich, too thin, or have too much spark".

 

Just make sure you keep your spark plug gap close (015 to 018)

 

i would update to a 20 through Leahy, it's not that expensive to do and i think you need it with the boost that you are running. we run a 14 HH with around 40 pounds and MSD told me that a 20 would be fine, but when the boost goes up you will need more spark. i could probably burn a little more fuel with a 44, but for what i am doing this is working for me. a 20 is also a little easier on wires, caps, etc. my 2 cents....go with at least a 20.

 

Per MSD engineers

When I was talking to the design Engineers at MSD, their statement was that if your fuel is right on a 20 or 44 will not improve performance. If your system is sometimes too rich or not on, then the 20 and 44 will improve performance at those times.

I have a multi engine pulling tractor.
Side note, I was having a TERRIBLE time with breaking belts, read that, one or two belts every run, I was heading for 25 for the season. I was ordering 5 every week. The interesting deal was I would break them the first run, if I could replace them and come right back I would not have a problem. I changed EVERYTHING, fuel system, belt tension, timing and more.
I had made several calls to MSD discussing what could be the problem, a long with many other people and companies in the racing industry. At the end of one of our conversations I asked the engineer if brake clean would hurt the wires his response was "cleaning products will not bother the wires, BUT if wires are stored in a damp cold area then they will get pores and will hold moisture". I had purchased 8 of the 20 amp promags used. I immediatly changed wires and stopped breaking belts, since then I went to the 11 mm belts. In the 3 years since I have not broken a belt! So bring those mags inside during the winter rather than an unheated shop, replace the coil to mag wire every year as it fires 8 times more than the plug wires.

Interesting thing is I found out the previous owner had the same problem and could not figure it out.