Re: [DML] Re: Coils

[wingd2@xxxx]

Jim,

Bob is correct. Our dyno testing a couple of years ago showed that the 
different Deloreans we ran that had factory original Bosch coils in them all 
had problems with the ignition systems above 4500 to 5000 rpm. The original 
coils just could not supply the power required to keep the plugs firing in 
the upper rpm ranges. It seems the engines require a hotter spark then the 
original coils that were installed at the factory are now able to put out to 
keep everything working correctly.

The "fix" I used on my turbo car was to install an aftermarket high 
performance coil. I chose an "Accel #8140" coil. This unit is a direct 
replacement that will even fit the original mounting bracket. It is a "plug 
and play" type part and requires no additional wiring or parts. Just remove 
the original coil and replace with this unit. This coil puts out about 50% 
more voltage (about 22,000 volts) then the original unit and works well with 
the rest of the D's ignition system. Additional dyno testing last year shows 
the original ignition problems are now gone and the car will pull to 6000 
plus rpm's with no problems.

Another route I looked into was to replace the ignition system with 
something like an MSD Hi-Output unit. These type systems can make tons of 
juice (like 50 to 65,000 volts) and can fire spark plugs under almost any 
conditions. I've run these systems before on racing vehicles and they work 
very well, but the problem I have with them is the life you get out of the 
parts. These Hi-Output systems tend to destroy OEM distributor caps and 
rotors in pretty short order because of the extreme amount of voltage you run 
thru them. And unfortunately, no one makes a hi-performance distributor cap 
or rotor for our cars that can take these voltages. Plus changing the cap and 
rotor every 5000 or so miles on our cars is not something I'm interested in 
doing, so...........

Because of my concern with parts life, last fall I removed and inspected 
my OEM distributor cap and rotor and the rest of the ignition system after 
having put about 10,000 miles on my car with this new Accel 8140 coil and 
found everything to be in excellent shape. It appears the service life of the 
other parts in the ignition system should not be affected to any great extent 
thru the use of this hi-performance coil.

One other bit of info, for what it's worth. When we did our 2nd round of 
dyno testing this past fall, we also ran another D which had a stock ignition 
system but was running a NEW (20 year old) OEM Bosch replacement coil from 
DMC Houston, and this car pulled 6000 plus rpm with NO ignition problems 
either.

Marty


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