Jeff20B

iTrader: (13)

One problem with the MSD is the spark is extrememly short duration. The rotary's combustion chamber is very long and the air/fuel mixture moves past the plug at a very high velocity. Above a certain RPM, which I don't recall at this time, the MSD goes down to only one CD spark. The result is excellent fuel ignition down low but less at higher RPM.

FBII, there are lots of boosted rotaries running a so called wasted spark setup. It sounds like your light show is from way too much fuel.

mwatson184

I think it's probably a coil wiring problem causing the leading plugs to cut in and out. Let us know exactly how you wired it up zac.

Marques

FB II

ok sweet, i figured this SHOULD work, but we'll see. it's definately an ignition problem because everything was running beautifully thru the distributor, but i wanted a bit more spark. all i did was hook up this coilpack and rock out. didn't change any thing else. it cranks up great, cruises great, even boosts good at half throttle.. usually only gets to around 6 - 8 psi. but when it gets over 5,000 rpms or so and full throttle it just gets stupid. and my air fuels are in the low 11's. im not leaning it out, that wouldn't be safe. i'll get some pics here in a few. i dont see how it could be wired up wrong, i mean.. everything else is working great. boost shouldn't change how it's firing. the dizzy is locked at 10 degrees advanced, just how it's always been ahhhhh

Jeff20B

iTrader: (13)

Well that's a head scratcher. The only boosted rotary with a 'wasted spark' ignition I have access to (limited access) is a supercharged S5 T2 13B in a '77 REPU with DLIDFIS. The boost is either 6 or 8 pounds (I can't remember) but the engine is a recent rebuild and can't be pushed hard yet. It only has about 40 miles on it. We'll know more as it breaks in. It's running quite well already though, and it's hard to keep out of boost.

Anyway, it sounds like the spark is weak or otherwise not jumping the gap. I've always had good luck with BUR7EQ in the leading holes. The only other bosted rotary I have access to has B8EV in all four holes, stock FB ignition, early 13B rotor housings with 12A side plates, street porting, and a 5" supercharger and Edelbrock carb. It out-accelerated the Iotus car on a freeway when Iotus was experiencing boost leak from an FMIC hose that kept slipping off. It blew tons of flames out the tail pipe too (Iotus), yet it had a stock FB ignition system as well. Interestingly, the stock FB ignition system works far better than the MSD setup that the previous had on there.

There is probably a problem with your coil wiring or something because the 2nd gen guys can run fair amounts of boost on their stock coils with no problems, and 2GCDFISw/TT is essentially the same spark quality as if it were triggered by an ECU. Good luck getting it sorted out, and don't blow an engine on my account.

Hyper4mance2k

iTrader: (40)

and if you use the msd directfire it's still going to be wasted spark...
to the guy asking about the accel dual tower coil. those will need to be triggereed by an ignition source like an MSD or any other ignition box. you'd have to have the same set-up i have. The accell coil is the same as the msd one i'm using. And as far as how big a spark you get with my ignition. I had a coil wire fall off of the car once and the spark was jumping over 3 inches to a ground. it was a cool light show!

Kentetsu

FB II- After installing the transistor trick, you need to check the timing. For whatever reason it becomes retarded with the TT (mine was about 8* retarded).

Hyper4mance2k

iTrader: (40)

Yea what he said is true, make sure to recheck the timing.

And you don't have to do that with a MSD... lol

FB II

ok check this....... i figured it out. something did happen with the timing, but mainly the TRAILING. weird i know. maybe because now the trailing wires are on the old leading spots on the distirbutor? i dunno. i had to back the trailing diaphram out alllll the way. i guess i didn't have enough split. either way i did that and backed the whole timing out a couple degrees and now it's pulling pretty ****** hard. and that's with stock TII trailing plugs all around. i used to have to run the b9es's gapped to .014 so it wouldn't blow the spark out. i do not have this "transistor" mod, it seems noone will be getting it for a while i take it? i dunno, haven't kept up with that thread. but if this coil pack is working well on it's own, i imagine an msd box might bump things up a notch

either way, i'm happy to say it did make a difference on my turbo 12a running 16psi on a boost prepped nikki carb. hahahaha, i still want msd tho

Directfreak

iTrader: (2)

Get the MSD (or 2) and run them right thru the distributor, just like stock.

680RWHP12A

well said alex
that seup is , basic and bulletproof

FB II

i will i should have the box tomorrow i hope WOOOOOOOOOT!

wecycle

So would a GM HEI wired to the reluctor pickup do the job instead of the j109 or a MSD 6A ?
The idea is to get wasted spark DFIS in a "crude but effective" way.
(read - low bucks)
My 1985 electronic distributor should get here this week. Compared to the 1979 points system what is the magnitude of improvement from 1985 electronic, DLIDFIS, 2GCDFIS, 2GCDFIS+TT?
Kind of a ranking order IE +50%, + 80%, + 120%, + 150% respectively? Where would other schemes fit in this ranking?

Hyper4mance2k

iTrader: (40)

MSD-DIS 2143123% better than anyhting comming...

FB II

get an msd box and go punish the streets

racintang

I've got three boxes of which two I don't use. Old but work. I had one box running the two main direct fire coils and one MSD box running the distributor for the trailing. In all I had two boxes and three coils. I would pop the hood and people couldn't understand it. I've got the MSD one and two box setup if anyone needs to look at it.
Email me to see. Don't want to violate any copyrights.
zfrederick@***.net

Hyper4mance2k

iTrader: (40)

there aren't any copyright violations here it's a knowlege base. it's only a copyriht violation if you call someone elses copyrighted idea your own...

skizzle84

Bringing up this old topic...

I own a 1984 12a completely stock, and I first want to mod the ignition.
I'm leaning towards the msd box setup from what I've read, just because it seems more simple and efficient. If anyone disagrees please tell me why. I'd appreciate it.

I'd like to ask everything I would have to purchase for the msd setup, because I'm totally stock. thanks!

APEXL8T

I used the two 6A on the ITA car after two years of not having...awsome.Dont care what others say . I kept ionizing the rotor cap it was so hot a spark.(drill vent holes and have spares for after a couple of enduros).

CalG

Does anyone know about the Mallory HyFire 6852M. The specs read like the MSD 6, and the price is competative. I've seen $119 for a new one.

I really like the idea of the prolonged spark at low engine speeds. Like a continuous trailing spark.

Comments?

CalG

bad 83

iTrader: (3)

OK, my brain itches at this piont. I only have one question for everyone. What does it matter? I know I am going to get a lot of crap for saying that, but most of us are going to use what will work for each persons unique setup. I mean, come on, I haven't done a igition upgrade on my '83 yet, but I will probably go for the 2nd gen deal because of the cost factor. My RX isn't my only project right now. I have a '89 VW Cabrio, a 98 Z-71, and a 2000 Harley that gets just as much attention as the RX7. I think it mainly comes down to what my Pop used to say, " Speed cost. How fast do you want to go?"

wecycle

The elimination of secondary voltage through the distributor cap and rotor would be desireable.
I have worked out a way to accomplish this but I will need a second reluctor and a second trailing pickup coil to finish it up. The Leading will be fired through the Accel gm type HEI module to fire an Accel dual outlet HEI type coil in a wasted spark system. The trailing will be fired through the original two J109's to the two original coils (one per each trailing plug)
The setup will be mounted to the drivers side strut tower to result in plug wires less than a foot long.
The gm type HEI module has current limiting built in so I can run with no ballast resistor on the Accel coil. The two trailing coils should be OK without a ballast resistor as well due to the reduced duty cycle of running only one rotor each.
Anyone have a reluctor and trailing pickup coil I need for the project?
Free or cheap?