1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

MSD box install

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Old 08-15-03 | 10:25 AM
  #51  
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Originally posted by racintang
I'm sorry but I am new to alot of this rotary stuff. I did not pick up alot of the pictures for some reason or another. The dizzy is the distributor correct. I will wire the MSD box directly to the distributor wires, correct. The black boxes in the distributor are the mag pick ups correct. I just don't want to screw this up.
Yes dizzy= distributor.

on an 81-85 dizzy, the igniters are the 2 boxes mounted on the outside. On an 80, the igniters are a seperate module on the left fenderwell.

on an 80-85 dizzy, the mag pickups are under the distributor cap. see pic. you see the red and green wires? Those are what you hook the green and purple MSD trigger wires to. BTW, the forward pickup is the leading.

Old 08-15-03 | 05:34 PM
  #52  
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Carl, could use the same setup on trailing. Two coils and an MSD box. I ask because I have an extra MSD 6 box so all I would have to do is buy another coil.
Old 08-15-03 | 07:59 PM
  #53  
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Does this look right? I can always change it.
Old 08-15-03 | 09:42 PM
  #54  
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Heres a pic of the 2 box setup correct me if I am wrong. I don't want to post any wronf information.
Old 08-15-03 | 09:50 PM
  #55  
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Ignore the 2 box setup, I wa reading Paw and they said not to use it on the trailing. I don't see why since you would still be firing the plugs at the same time as before.
Old 08-16-03 | 07:27 AM
  #56  
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Originally posted by racintang
Carl, could use the same setup on trailing. Two coils and an MSD box. I ask because I have an extra MSD 6 box so all I would have to do is buy another coil.

NOOOOOOOOOOO. You CANT direct fire the trailing, youll grenade the motor. The wasted spark trailing will be a really advanced spark on the incomming charge. The first diagram looks ok, the second is a disaster waiting to happen. If you want to use the second MSD, just use it in place of the igniter.

Another pic of my setup.


Last edited by Rx7carl; 08-16-03 at 07:30 AM.
Old 08-16-03 | 02:17 PM
  #57  
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Ignore.

Last edited by racintang; 08-16-03 at 02:22 PM.
Old 08-16-03 | 05:04 PM
  #58  
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What part number did you use for the MSD wires. I don't want to buy the wrong ones.
Old 08-16-03 | 09:32 PM
  #59  
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I use Moroso Blue Max spiral wound 8mm wires. Universal set that I cut and crimp myself.
Old 08-17-03 | 04:00 PM
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Ok, I got all the leading wires hooked up but I am confused now. I have a blue and yellow wire coming from the ignitor, I'm guessing that it goes to the on the negative post of the trailing coil. Now the car had some extra wires I guess from the previous owner. I have a wire that is coming from the fire wall, solid black, It reads 12 volts when I cut the car on so I will be placing that into the ignition wire for the MSD box and onto the positive coil for the trailing. I have four black w/ white stripe wires. Two of which show 2 volts when the car is cut on. The others show nothing. I also have a yellow with blue stripe wire that comes out of the harness. I belive that it went to the leading coil.

My question I guess is which wires will go onto the trailing coil?
Old 08-17-03 | 06:06 PM
  #61  
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Well I finally found the corrolating wiring diagrphm for my car. It was under the UK model setup. Well I looked it over and it showed that all the black and white stripe wires hooked together in one way or another. Well, Thats what I did and I cranked here over. She did not start except for a little putter and then what do ya know, a big puff of smoke coming from the black and white wire which leads into the ignitor box. Well the wire is melted in some spots so I need some advice on what to do. I have three coils now and an MSD box. I'm thinking of just hooking it back to stock on Tuesday.
Old 08-17-03 | 06:14 PM
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I disconnected the trailing coil and started her up. If I give her gas she revs right up with no problems but if I try to let it idel it cuts off. I'm guessing thats from the trailing not running. So what should I do, anybody?
Old 08-17-03 | 07:10 PM
  #63  
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Where can I buy the J109 Ignitors, I could not find them on ebay.
Old 08-18-03 | 10:15 AM
  #64  
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I followed the tutorial on Paul Yaws site and had no problems, except for my tach is dead. If I were you I would print out the info (which I did) and follow it word for word. Hope it helps, smoke from wires dont sound good?
Old 08-18-03 | 03:28 PM
  #65  
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Burned something inside of the ignitor box box upon closer inspection. I am going to switch over to direct fire ignition and put the MSD on my 1966 Mustang.
Old 08-19-03 | 07:05 AM
  #66  
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I dont understand? Direct Fire Uses the MSD 6a box. You would be better off using the msd box than trying to buy a igniter, when I had one of my igniters die, I looked at prices and the dealership wanted $300 and the cheapest I could find them was over $100 on the internet.
Old 08-19-03 | 07:30 AM
  #67  
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Is this what you did? If not, this is the way it should be set up. If you have the 1980 dist, get a newer dist from an 81 or newer, up to an 85, from a junk yard.

The ignition system on a rotary, or any other engine for that matter, cannot be ignored when performing horsepower mods. If you are still using a distributor, you are losing horsepower. Period! If you have a second or third generation RX-7, you already have an excellent ignition system. These systems are direct fire, with a "wasted spark" setup on the leading Ignition. Direct fire ignition systems deliver a hotter spark, and the timing is much more stable. As an added benefit, you don't have to change your cap and rotor every other week to keep you car running well.
These direct fire systems are very good, but still leave room for improvement. The biggest problem is that the bean counters at Mazda, and all other auto manufacturers have more to do with the finished product than the engineers do. In other words, make it as cheap as possible. These distributorless systems are known as an inductive discharge ignition. Inductive discharge ignitions suffer from poor spark at high rpm, and this is aggravated by the wasted spark arrangement on the leading ignition which fires twice per revolution. Without going into a lot of detail, the simplest explanation is that the coils do not have enough time to build a strong magnetic field at high rpm, and so the spark continues to weaken as the engine speed increases. The bean counters don't give a ****, because this system works great at low speed, and gives good mileage and driveability. This is the number one priority, even in a sports car.

Buy an MSD 6A

Luckily, this is easy to fix. Buy an MSD. In case you didn't hear me the first time, Buy an MSD! Every vehicle on the planet should have one, even your grandmothers grocery getter. The MSD is a capacitive discharge system, which does not loose spark intensity at high rpm. Capacitive discharge systems deliver a very strong, but short duration spark. To overcome this, the MSD delivers multiple sparks over twenty degrees of eccentric shaft duration. This amounts to as many as six sparks at idle, and as little as two at high rpm, but no matter how many times it fires, the spark always lasts for a full twenty degrees. This is the best of both worlds, a high intensity, long duration spark. Just about every racecar on the planet has one, and you should too.
I have installed many MSD's, and the results were always more power, better driveability, and better gas mileage. A second or third gen. will require three boxes for the entire ignition system. This is quite expensive. You can make a large improvement by simply buying one box for the leading, and the results will be even better if you replace the stock dual coil with two MSD Blaster coils. Simply run both coils from the same MSD box. The ultimate setup is of course three MSD 6A's, and four blaster coils, but this will set you back about $700, and you probably will not fit all of this under the hood.
Well, that's about it for the second and third gen RX's. I am currently testing spark plugs, and I will post the results in the future. There is more power here than I thought, especially after I got away from the conventional NGK's. As soon as I have some dyno results, they will be on the page.

Distributors Suck

Now for the first generation. Distributors suck! Distributors require that the charge jump a .075" gap from the rotor to the cap before it can even fire the .055" gap of the spark plug. The gap in the distributor cap is easier to fire than the spark plug gap, because there is much less pressure, but it is still a really shitty way to make fire. Luckily it is relatively easy to convert the leading ignition to direct fire. I finally got around to doing this on my 13B, and then I was mad at myself for not doing it sooner.
Before the conversion, I was using an MSD 6A, with an Accele super coil. This is a lot of juice, so I was really surprised at the improvement after converting to direct fire. I called MSD to be sure that their box would fire two coils, and their tech guy said "Hell, it would probably fire a whole row of coils." I set it up with two stock coils for the leading ignition and was stunned at the results. The engine made more power everywhere in the powerband, and the driveabilty improved dramatically. I will never again run an MSD through the distributor.
Here's how it works. All you need is an MSD 6A, and an extra coil. Two for the leading, and one for the trailing. Trigger the MSD with the magnetic trigger inside of the distributor.Do not try to trigger the MSD with the ignitor! The ignitor output is very "dirty", and does not give the MSD a clean signal to work with. Simply cut the green, and red wires that go from the leading magnetic trigger to the ignitor. The leading ignitor is the one facing the front of the vehicle. Connect the green wire from the trigger, to the purple wire of the MSD, and connect the red wire from the trigger, to the green wire of the MSD. Wire power, ground, and ignition as per MSD's instructions. The orange, and black 16ga. wires from the MSD go to the coil. In this case, make two jumpers and connect both coils to these wires. Make sure that the polarity is correct. The stock coils are labeled positive and negative. The orange wire goes to positive, the black wire goes to negative. Do not screw this up! The same goes for the magnetic trigger in the distributor. If you wire the trigger backwards, the timing will be advanced by approximately thirty degrees. Now simply run a plug wire from each coil to a leading spark plug. It doesn't matter which one, because they will both fire at the same time. Leave the trailing ignition just as it is.
This is referred to as a "wasted spark" system because eack rotor recieves an additional spark during the exhaust phase. On a rotary, this extra spark is actually beneficial, because it fires at the trailing end of the chamber which is where most of the unburned fuel is concentrated. Igniting this fuel will not make more power, but it will clean up the emissions slightly. DO NOT try this setup on the trailing ignition. Because of the different spark plug location you will ignite the incoming mixture from the next stroke. At best, you will lose power, at worst, you will break apex seals. If you have any questions about this, feel free to send a message. This is a simple wiring job, and the results are amazing. This is cheap power, and the improvement in gas mileage will probably pay for the MSD in a years time. I have not tried this with upgraded coils, but when I do, I will let you know if there is further improvement. I am only sorry that I didn't try this on the dyno so that I could measure the improvement in horsepower. Next time I have a 12A on the dyno, I might do a comparison, and post the results.
Old 08-19-03 | 04:50 PM
  #68  
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From whta I understnaf through one of the sites. I can do a direct fire setup using 3 ignitors, 3 coils, and some shileded wire. minus the MSD box. I can the J109 ignitors for 20 a piece.
Old 08-20-03 | 07:59 AM
  #69  
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Yeah, it is possible to use all stock items, but why would you want to use a shitty igniter when you have a MSD box? Did you read over the part of Yaws site that said the stock igniters give less spark the higher your rpms go? I converted to the MSD dierect fire set up in an afternoon, it is quite simple. Seems like you are complicating things?
Old 08-20-03 | 08:43 AM
  #70  
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I'm good for doing that. So just use Paul Yaws site to do it.

Lead - Hook the dis. pickup to the MSD box. Msd to both lead coils.

Trail - Dis pickp to ignitor and to the coil

*My ignitor took a sit and burned up somehow, Black with white strip wires are on the same line correct
Old 08-20-03 | 10:06 AM
  #71  
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YES, Then coils directly to plugs. 1. "Lead - Hook the dis. pickup to the MSD box. Msd to both lead
coils."

YES 2. "Trail - Dis pickp to ignitor and to the coil"

Not sure about this question?
3. "*My ignitor took a sit and burned up somehow, Black with white strip wires are on the same
line correct"
Old 08-21-03 | 02:37 PM
  #72  
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I hoked it all bakc up and it runs. yeah. But, However, boo, It idels like crap. No vaccum lines are off or cracked. The only thing not connected is the old condenser which ran from the distributor down to the old ignition box.

Could this have something to do with the terrible idel?

Also, If the condenser is still used where should I hook it up to?

What does a condenser do?
Old 08-21-03 | 03:41 PM
  #73  
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I only have experience with 82 and up. I dont know what a condensor is? Maybe play with the timing?
Old 08-21-03 | 07:00 PM
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I got my car running with one msd box and 3 coils. Oh and of course i burned up one box too . Well, hopefully it should be alright though because i called up msd tech-support and they told me i could have it repaired for free since it's still under warranty. Still not exactly sure why it burned up...i had everything hooked up correctly except that i forgot to hook up the plug at the box itself but i don't see how that could have burned my negative cable to the coil.
Old 08-22-03 | 12:41 AM
  #75  
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I'm going to put an 81 distributor on in 2 weeks and see how that works out. I'm going to recheck everything tomorrow. Timing looked OK on the trailing but I could not get a reading on the leading. Could that be do to the MSD box being used now. Do both rotors sit in the same position.


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