How many rpms would the stock ignition be capable of providing on a modified '93 Mark VIII?
Oh Jeez...
What kinda "modified" are we talking about now?
I've run to 7,600 on my '98 Cobra, which is essentially the same system.
How many rpms would the stock ignition be capable of providing on a modified '93 Mark VIII?
Lets keep this apples to apples and not tossing any orange cobras into the equation.
your limited by the factory edis on the car that only has enough to control spark up to a certain point. if you are really worried about it get a distributor and put it in the valve cover with a regular coil. the stock system will only handle so much. the 97 and 98 cars are coil on plug and are not the same ignition system.
Yep, Scott L. here in Atlanta has that SHM dohc 4.6 motor in his gen 1, and has hit that wall too with the stock gen 1 electronics. He tried a FAST set up too, without much luck. He is converting to a COP gen 2 set up because he could never get the gen 1 or FAST to work correctly in his car. The SHM motor needs to spin 8k+ to be in the power band from what he told me.
How much HP is that motor putting out?
I have heard from others and have researched enough to suspect limitations with the ignition when spinning higher rpms.
The question then becomes what is the limit and what can be done to overcome it?
I know some who have went with aftermarket ignition setups with varying degrees of success and failures.
Gen2s seem to be more tolerant of higher revs and I have heard of converting to coil on plug. This only makes sense to me if it is a coil issue or plug wire limit.
Seems to me different issues would require different solutions. I suspect from the tuning trials after the head swap that the car was having problems at higher rpms (well above 6000). I hope to soon have a dyno tune and be able to determine the new power curve and see if the car would even benefit from higher rpms. It may all be a moot point at this time to rev it higher if the power curve is falling off. I know before it was peaking at 5400-5500 and the seat of the pants dyno tells me it is still pulling hard several hundred rpms above that.
So if anyone has some insight, please feel free to discuss.
I would think that engine balancing and valvetrain are the limiting factors.
Ignition Control Module
The ignition control module (ICM) is a custom microprocessor-based thick film electronic module. The ignition control module receives engine position and speed information from the crankshaft position sensor, and desired spark advance information from the powertrain control module supplied spark output (SPOUT) signal. The ignition control module uses this information to direct which coil to fire, and controls the turn on and turn off of that coil to achieve the correct dwell and spark advance. The ignition control module also provides a synthesized Profile Ignition Pickup (PIP) signal. The PIP signal is used by the powertrain control module for engine speed information and fuel injector timing. The ignition diagnosis monitor (IDM) signal sends electronic ignition system failure information to the powertrain control module, where it is stored for use during diagnostic test mode. The IDM also provides the signal to drive the tachometer.
I'm fairly certain it is the ignition breaking up in my case. I would have to datalog it somehow to be certain. What would I look for?
I'm fairly certain it is the ignition breaking up in my case. I would have to datalog it somehow to be certain. What would I look for?