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personally, i've run a blaster 2 for years with no issues to the hep circuit or heps. i swapped out the msd coil so i could run a magnacore coil wire (not stock style msd coil) and used a stock coil and then switched to an accel after the car ran way worse then it ever did, even with the accel, it isnt what it was with the blaster 2.
 

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Ok, if you are running an aftermarket coil that is not within the 1.2 to 1.6 Ohms with out the (0.7 ohms) ballast resistor, you are on borrowed time on your ECM. The HEP has nothing to do with firing the coil itself, the ECM is what switches the ground on and off to charge and fire the coil. The coil driver in the ECM is not made to handle the low resistance/high amparage draw and will burn out at the most awkward time. Just buy a 0.7 ohm resistor and be sure. Its yours, do as it pleases ya.

The only exception is if you are running a Mallory or MSD 6AL multy-spark unit. You do not run anything to the coils lugs but the Orange and Black wires from the MSD unit. I ran a MSD on my 84 Shelby using the negitive coil wire to the MSD's white wire (points trigger) and the positive coil wire to the MSD's smaller red wire. CBMDennis's (RIP) post above fits this application. He was running a MSD 6AL with a Blaster Coil. No resistor was needed.
 

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Ok, if you are running an aftermarket coil that is not within the 1.2 to 1.6 Ohms with out the (0.7 ohms) ballast resistor, you are on borrowed time on your ECM. The HEP has nothing to do with firing the coil itself, the ECM is what switches the ground on and off to charge and fire the coil. The coil driver in the ECM is not made to handle the low resistance/high amparage draw and will burn out at the most awkward time. Just buy a 0.7 ohm resistor and be sure.

The only exception is if you are running a Mallory or MSD 6AL multy-spark unit. You do not run anything to the coils lugs but the Orange and Black wires from the MSD unit. I ran a MSD on my 84 Shelby using the negitive coil wire to the MSD's white wire (points trigger) and the positive coil wire to the MSD's smaller red wire. CBMDennis's post above fits this application. He is running a MSD 6AL with a Blaster Coil. No resistor needed.
that coil was on my car since 1995, thats a hell of a lot of borrowed time.
 

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Without knowing the actual specifications of the device used to drive the coil I don't think anyone can really say whether it is for sure safe to run any coil with lower resistance than the stock one. Failure of the coil driver circuit could occur in this case due to the(a) component(s) overheating with the extra amperage that a coil of lower resistance will draw(as stated above the HEP is just the sensor the actual power handling is done by the PM/SMEC/SBEC). Some may have different results than others based on the fact that people have different setups and operate the vehicle in different climates.

Based on my experience with the SMEC in particular. It is difficult to burn out the driver circuits. In every case I've encountered there is a current detecting scheme in place that shuts down a certain driver circuit when it becomes overloaded(injector drivers etc..). I have never overloaded the coil circuit so I can't say with certainty that there is the same type of protection present there. My guess would be that there is. I would think that if the coil was drawing too much power the coil driver would automatically shut down to prevent damage to the driver circuit.

The safe way would be to use the ballast resistor like NAJ said. You won't put any extra stress on the components and you can be sure the ECU is safe. You will not get the full power output from the coil however. Use a coil of the correct resistance and it will perform as it was intended to.

What does all this mean? If you ask me, you shouldn't try to use a coil with less resistance if you are worried about the ECU. There is a reason the stock coil was used. If you DO use one of lower resistance and you make it across town you are probably safe because if that coil driver is going to fry it's going to happen fast not over an extended period of time(minutes to hours not months to years).
Your results may vary.

:two cents:
 

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The switching transistor for the coil in Chryslers power modules, smecs and sbecs have proven to be tough. However running a coil with a higher amp draw without the required resistor will be pushing the transistor beyond its rated capacity. Its life span will probably be shortened compared to what it would do with the correct coil. Way back in the early 80's I ran an Accel supercoil on my 440 charger with nitrous. Running it with the supplied ballast resistor caused the ignition to break up with the nitrous on. Removing the resistor cured the miss. The only thing I noticed was it caused the heatsink on the Mopar performance ignition module to run hot enough to blister your finger if you touched it. It never did kill it as long as I had it but I'm sure it was not good for it. This also showed me that the coil output was higher without the resistor even if it was shortening the life of the ignition module. If only Chrysler would have made their voltage regulator switching transistor as good as the ignition one.....
 

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Guess I should have said this at the end of my above post.

Usual disclaimer:
I am an unknown entity on the internet. For all you know, I am dumber than a box of rocks. I take no responsibility for my own actions. To follow any of my advice is sheer folly on your part. Offer void in Washington. Batteries not included. If death occurs while using this product, discontinue use immediately and consult with your physician. I am not a village idiot, but I play one on TV. Some settling might occur during shipping. No user serviceable parts inside. No reproduction or rebroadcast of this message without written permission from Major League Baseball. Your mileage may vary. Do not point at face when lighting. Open slowly. Do not exceed 3600 RPMs.

WARNING! Do not look into LASER again with remaining good eye. :thumb:
 

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I had two MSD blasters go bad within 80 miles. In stock location, meaning laying down. I should have it straight up, like MSD said. Now I know why they failed. I had one in my GLHS last 1o years, but then again, it was not laying on its side.
 

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There was a Blaster 2 in my '89 Daytona when I got it (stock location, no resistor). It failed within a year of me getting the car. I pulled a rusty, beat-up, stock coil out of a junk parts bin, repainted it, and stuck it on the car. It's still working 5 years later. So, there ya go.
 

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Yes You Can Run A Blaster #2 Without a BALLAST !
I've Been Running A MSD Blaster 2 For Years On My 89 2.5 Reliant Coupe Without A Ballast, Runs Much Better With Blaster 2 Coil !

MSD Blaster Coil
PN 8200 and PN 8203
Parts Included:
1 - Blaster Coil 2 - 45° Faston Tabs 1 - 0.8 Ohm Resistor
1 - Blaster Boot/Terminal 2 - Female Fastons 1 - 18” Gray Wire
WARNING: During installation, disconnect the battery cables. When disconnecting the battery, always remove the Negative cable first and install it last.
Note: This Blaster Coil is supplied with a ballast resistor. If your application uses a :
Points Distributor the ballast must be used. " Late Model Electronic Ignitions Or An MSD Ignition DO NOT Require The Ballast.

REMOVAL
1. Label the location of the coil wires (+ and -) and remove the wires from the coil.
2. Remove the high voltage wire from the coil and remove the coil from its mount.
3. Position the Blaster Coil in the mount and tighten.
INSTALLATION
Note: The Blaster Coil will mount in most factory canister coil mounts. MSD also offers a Chrome Bracket, PN 8213. It is recommended to mount the coil in an upright position.
 

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I already have an MSD blaster 2 coil. Does anyone know the correct part number for the resistor? I am reading that the stock coil is 1.4, the resistor from s\Summit posted above was .8. Should the resistor be 1.4 or the .8? I also have the upgraded ground kit on the car as well. Thanks for the education.
 

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The resistance in the primary circuit needs to be 1.4 ohms. (1.33 - 1.55 ohms)
The MSD coil is only 0.7 ohms primary resistance.
You need to add a ballast resistor of 0.6 - 0.8 ohms to bring the primary circuit resistance into Chryslers specs.
The resistor is placed in the + coil circuit before the coil.

SPECS-Ignition Coil 1.jpg
 

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Or you can just use the proper Accel Coil and be done with it.

The Factory coil and the Accel coil both provide the same exact KV requirements @ idle/cruise and under load as the MSD Blaster coil and the Accel is a direct Mopar replacement that has the proper primary resistance.
There is nothing to gain performance wise by just replacing the coil.
Now, if your factory coil has failed replacing it with an Accel or MSD over other Aftermarket coils is an upgrade.

Unless you have major ignition system issues (which means repairs are needed) or are running Extremely High Boost the KV requirements needed for current to be able to jump the gap at the spark plug will never reach 40 KV.

IGNITION COIL SPECS
https://www.summitracing.com/parts/acc-8140

https://www.summitracing.com/parts/msd-8202
 

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Interesting thread...

On my 1990 Omni TBI, I installed an MSD6AL box, and a Blaster 2 Coil in the stock, somewhat tilted location. This was several years ago when I first bought the car. I have been running this setup for roughly 105,000 miles. I changed the HEP once but it was actually the ignition rotor that had failed at the time. I keep the old one in the glove box for a spare. I have also installed the long reach plugs about 5,000 miles ago.
I am fairly sure the coil has been fine in the stock mounting position the whole time.
 
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