304 Ignition, ICE or MSD

[kiwi pup]

Well all, I am after info on ignition systems. I have a modded 304 inj car running a LINK ECU, currently using a modified rotary dizzy as a crank angle sensor in the standard dizzy location, through the ecu and firing 8 coils in sequential set up.
question is, all the mags i read and look at, all the top cars run MSD or ICE dizzy with single big coil and large leads.
what set up is the best for a street car?
currently eng runs 10:1 comp and pulls 7000rpm, plans for either more comp and bigger cam, or blower, possible NOS, so decent ignition is a must.

currently has a poor idle, stalls easily and fouls plugs on a regular basis.

what have people done in the past that works?

 

[Immortality]

One coil per cylinder should be better than the older style set up where one coil fires all cylinders. MSD is different in that it's a capacitive based system where as the normal ignition is inductive based system.

What coils are you using now?

 

[kiwi pup]

i am running Bosch capacitor style coils, and mitsi ignitor boxes, one box per 2 coils. i think the coils were for a mitsi of some sort but i bought them all new on the advice of the dyno tuner. car has never really run 100% since the set up was put in

 

[Circlotron]

currently has a poor idle, stalls easily and fouls plugs on a regular basis.

Sounds like a nice setup you have, but the first thing I'd do is find someone that knows what's what and get a decent tune. You may well find that after that your current ignition runs well enough.

What kind of coils are you using?
How many mS dwell are they getting?
I got myself one of these current clamps that you plug into a scope -> Hantek CC-65 AC/DC Current Clamp Meter Multimeter with BNC Connector - Blue + Black - Worldwide Free Shipping - DX For coil per plug stuff they are the ducks guts because you can see exactly how many amps the coil primary runs up to for a given amount of dwell time instead of relying on your friend's cousin's mate's mum's uncle for a recommendation that might have sorta worked for them but won't even come within a bull's roar of being right for your car anyway.

Assuming you are using LS coils, get a clamp, borrow a scope, and set the dwell until you see the coil current ramp up to say 6 amps.

Edit -> I see you are running Bosch coils. Which ones exactly?

 

[kiwi pup]

thanks for that, i guess its more confusion caused by reading magazines where all the serious holden engine cars still run a dizzy, even some of the LS conversion cars are running a dizzy. really cant be sure if my miss matched multi coil system is going to perform better than a out of the box large single coil and dizzy.
yea the first stop would be talk to the tuner and see how the ignition is running, i have heard ICE do a multi coil set up, from memory my coils are just a generic Bosch style.
ive also heard you can get a bit of timing scatter when using a dizzy, should check that too being my dizzy is a modified mazda rotary item lol.
does anyone know of a aftermarket crank angle sensor that i can buy to use the standard dizzy location?

 

[Deuce]

Encase you need a change: My mate works at the local official LINK dyno tuning agent, and recently tuned a link on his VN V8.
Hamilton.

Rough idle definitely sounds like dissy/coil/timing issue.

 

[Circlotron]

does anyone know of a aftermarket crank angle sensor that i can buy to use the standard dizzy location?

Maybe a VT 304 distributor might do the trick. They have two sensors - one 8-pulse for ignition trigger and one single-pulse for sequential injection sync but you could also use that for coil sync, especially if you had an 8-channel coil driver.

 

[kiwi pup]

never thought of using a vt dizzy, is a good point as we have also changed the vn injection to sequential instead of the group fire they run, the ecu is using 8 injector drivers as well as 8 coil drivers, so it is similar to a vt

 

[Circlotron]

the ecu is using 8 injector drivers as well as 8 coil drivers, so it is similar to a vt

and mitsi ignitor boxes, one box per 2 coils.

Do the Mitsubishi ignitors have two separate channels, like for wasted spark on a 4 cyl?

 

[kiwi pup]

have done some racking of the brain, im at work in aussie and car is in NZ, pretty sure the coils are Bosch MEC717. ignitors are of a mitsi magna, which only ran one coil so im not sure excactly how they are wired.