Who here has had issues with ignition breakdown with big power? I've head a few rumours but nothing really solid about people losing spark at X power level or X boost. What have people done to overcome these issues? -A
My coppers gapped @ 0.9mm started loosing it around 4500rpm and wasn't able to boost past 20psi. Changed to heat 7 iridiums @ 0.5mm and it boosted hard to redline and up to 23psi. Didn't push it much harder than that but I recommend iridiums...oh yeah, they also idle great.
ive had breakdown with bkr6es plugs over 18psi that was running 0.7 gap if you gap them less you can run more boost. have run heat range 7 plugs before they were a pain in the ass for cold starts tho
It's not to do with power but cylinder pressure (which yeah will make more power). Basically the more boost you run, the higher the cylinder pressures, the more power needed for the spark to jump the gap. On a big boosting motor you can either increase the energy via CDI system or similar, or make the gap smaller. The first time Mark tuned my car it was breaking down on high boost. With a new set of plugs and .6mm gap it hasn't been a problem since.
I think a lot of these spark issues seem strange as I know 2 400rwkw+ zeds @22-24psi that are on stock coils no problems. Give me to October and I can tell you a bit more if their is evidence to this
Contact Minivan, he is developing a new CDI system to deal with this issue. I think he has about 620hp AND BOOSTING IN THE HIGH 20'S.
I talk to Andrew a lot and yes he does have a new system as blow out at 30psi presented. However his coilpacks were struggling at 24 needing reduced gap. I still believe new coilpacks would have worked fine
I have been talking to Andrew too. He's sold me on chucking a new set of Mercury Marine coils in the car. They're apparently compatible with the stock PTU, but if I still have issues after that I can replace it with a capacitor discharge ignition unit for some real bang. Strong, modern, not too dear, expandable. What else can you ask for.
stock coils with HKS DLI Amplifier works great. no probs at 28-25psi . didn't gap the plugs until after 24psi.. (only because we forgot to because it ran so smooth ) will probably be pushing to 30 psi next. .
CDI - eliminates discharge and timing issues by design I tend to think coil packs should be fine as well. :agree: Tune/ Fuel Type/ Fuel map's / compression ratio's etc. etc. all effect the discharge and gap required, so it can be a very fine art getting both the tune and balance just right where everything is happy to spark perfectly especially given any one factor can throw it out completely. Based on that HKS amplifiers would work better in most cases - for sure. CDI however is superior technology and eliminates any discharge capacitive issues by superior technology and design - its why motorbikes with engines screaming at 18,000 rpm use them! So it's a no brainer having a perfect spark with CDI - but cost of buying CDI system is the issue, as its dependant on the conditions your motor is under (aggressive timing / boost/ fuel map perhaps ? ) Not implying that its not needed under harsh setups at all, just think the stock design system was slightly overbuilt in the first place and if its serviceable, it should have no overt problems in giving good spark even under larger boost conditions at high RPM etc. JC :zlove:
You're definitely right, stock seems to happy support more than double the factory output even at age so it's definitely good stuff. Depends how bonkers you want to push the motor
