Question About Ignition Modules
08-01-2017, 03:04 PM
#1
Question About Ignition Modules
I have a 1984 Corvette and I'm in the process of doing a complete tune-up. I'm going with a MSD cap & rotor, MSD Super Conductor wires and a high output coil. I'm looking at replacing the 7 pin ignition module with either a Davis Unified Ignition Dyna Mod module or a Pertronix Flame Thrower module. Anybody out there had any experience, good or bad, with either module? The car currently has an Accel ignition module in it that the prior owner installed. Thanks!
08-02-2017, 12:57 AM
#2
Race Director
I don't think it really matters. The stock ignition system is capable of putting out way more spark than the engine could ever use.
Unfortunately the old Sun ignition scopes have all disappeared. One of the standard tests the techs used to do was disconnect one plug wire while the engine was running. The disconnected cylinder would show 50,000 (or so) volts, while the others were in the 10,000 - 12,000 volt range. That shows how much potential voltage is there, even with a stock system.
Unfortunately the old Sun ignition scopes have all disappeared. One of the standard tests the techs used to do was disconnect one plug wire while the engine was running. The disconnected cylinder would show 50,000 (or so) volts, while the others were in the 10,000 - 12,000 volt range. That shows how much potential voltage is there, even with a stock system.
08-02-2017, 04:27 AM
#3
I'm with Cliff on the parts. At this point very likely all of the product regardless of brand is just relabeled very generic product.
If the car runs well now why the module change? I don't know that there's a very good reason for any of the expense for the products you mention in the list. A quality cap and rotor I understand but why the coil? Does the car actually need wires, cap, rotor and coil? How long/miles on the last tune-up.
If the car runs well now why the module change? I don't know that there's a very good reason for any of the expense for the products you mention in the list. A quality cap and rotor I understand but why the coil? Does the car actually need wires, cap, rotor and coil? How long/miles on the last tune-up.
08-05-2017, 01:42 PM
#4
Tech Contributor
Member Since: Jun 2004
Location: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Posts: 18,343
Received 767 Likes
on
549 Posts
I agree with Cliff and WV. Save your money. The stock GM (Delco) stuff is more than adequate for the job. I'm running the stock 7TM module and coil in my '84 turbo 355. I've made a lot of changes with this setup, but the ignition system has been the least of my worries.
The following users liked this post:
440music (10-08-2017)
10-08-2017, 07:22 AM
#5
I'm looking for more power from my 84 and changing the ignition module never crossed my mind. I'm seriously considering swapping to a LS1 or a ZR I just have to decide how much I'm willing to spend.
Tommy
Tommy
10-08-2017, 09:53 AM
#6
Melting Slicks
Quite a few have reworked the intake manifold's small ports (for intake charge velocity; more low end torque) to get impressive power from the L83, Check threads here for details.
The HEI, as remarked above, works fine up to 7000RPM or for boosted engines (I was advised).
Last edited by whalepirot; 10-08-2017 at 09:56 AM.
10-08-2017, 01:12 PM
#7
Melting Slicks
I have a 1984 Corvette and I'm in the process of doing a complete tune-up. I'm going with a MSD cap & rotor, MSD Super Conductor wires and a high output coil. I'm looking at replacing the 7 pin ignition module with either a Davis Unified Ignition Dyna Mod module or a Pertronix Flame Thrower module. Anybody out there had any experience, good or bad, with either module? The car currently has an Accel ignition module in it that the prior owner installed. Thanks!
10-09-2017, 12:05 PM
#8
Race Director
I've been using an Accel module for years. I don't know if it is any better or worse than anything else, but revs to 7K on my bracket car with no problems.
