ero-jiji

seeing as how msd tech is closed on weekends, i figured id ask here, i finnaly recieved my second ignition for the trailing, but am at a loss on how to hook it up and still have the factory tach work, i know that this wire splices and runs to it..

any ideas? im not shure if i can use the standard tach output on the box without frying something

few other pics to get an idea of my layout..




edit:
fergot to mention im running the box in the 8 cyl config..

Jeff20B

iTrader: (13)

You're not going to like my post.

I'm sorry to tell you this, but an MSD on trailing won't make any difference in power. It's also not that great of an idea to run an MSD through the distributor cap on the leading ignition. You get more power and a better running engine with direct fire. You wasted your money.

The MSD's capacitive discharge is too short fot the long combustion chamber of a rotary. The only type of rotary a CD ignition benefits is a heavily boosted one pushing 400 or more HP. The guys on this forum pushing that kind of power would tend to agree. On your NA (naturally aspirated), you won't notice a difference; especially on trailing.

Just a quick story for you. I got an MSD 6AL around late '00 or early '01. Its performance was not impressive. I removed it after a few months and it has sat unused for years. If I ever use it on a rotary again, it'll be with an MSD (red) or Accel brand (yellow) DIS coil. Others here have gotten good results with that combination. I was going to connect my 2nd gen leading coil to my MSD, but its far better with its stock ignitor (it produced very impressive long dwell duty cycle sparks, even at high RPM).

Yes many others here have used MSDs for years and have been happy with them. Even more have tried various other ignition upgrades and have been happy with them. For the MSD users, only a minority still run them through the cap. Since you already spent the money, you might as well maximize your enjoyment of those bulky red boxes.

I told you you wouldn't like my post.

Edit: if the boxes are in the 8 cyl config (no wire loops cut) then the rev limiter will require different RPM 'pills' than what are included.

ero-jiji

i already knew it wasnt going to help the power on this stock 12a, im soon planning a swap to a s4, havent decided on the turbo yet, and as for the rev limiter, im running a 3400rpm pill which cuts me off a hair past 7k, for now tho i just want my stock tach to work so i dont keep bouncing the revlimiter and scaring the **** out of everyone behind me with the flames =3

edit:
i was also running without trailing completely, that was the only way i could get the rev limiter to work ><, and those are accell hi-perf coils already, tho i plan on totaly revamping the ignition to direct fire once i do the swap, for now , i figured it would be pointless seeing as the motor has almost 300k (yikes) and smokes a bit =3

Jeff20B

iTrader: (13)

For my rev limiting, I was just going to wire up a switch to kill trailing whenever I knew I was going to do any spirited driving. Of course it's less effective for those spur of the moment times.

Good luck with your turbo project.

ero-jiji

thanks, so i guess my best bet is to just wait on installing the second box till i do the swap and go DFI from there, but how do you keep your tack working when you switch off the trailing? if i unplug the coil, tach stops too , im assumeing it would do the same with a switch?

edit : nevermind, i finnaly found it in the archives, looks like i can just swap my tach whire to the leading box's tach out w/o frying anything.. i must say tho, the topics search tends to come up with are waaaay off kilter haha

Jeff20B

iTrader: (13)

My solution for a dead tach would be to know I was bouncing off the rev limiter, and the sound of the engine. Of course I'd also try the tach output on the MSD, too. I'd just go with whichever worked the best. Of course if the trailing ignitor ever died with the tach hooked to the leading circuit, I'd never miss it since it doesn't make a notiecable difference in engine power. Infact, I'd probably forget to switch trailing back on if the tach wasn't connected to it.