ignition/spark problem

[disturbed1]

hey everyone

i own a 7mgte which is pretty heavily modified but running stock coils.

im running an ems 8860 ecu with ems 3 channel ignitor.

when the car was tuned last, i seem to be having some boost dependant spark or ignition problem which ressults in the car "hitting an early rev limit" as such.

as u can see from the following dyno runs, the more boost i run the earlier it dies in the ass yet i dont have any hicups/missfires during the power runs - only at peak revs


*please note* rpm scale on dyno sheet is slightly off - the pink runs roughly corresponds to 6800-6900rpm (soft limiter is 6800, hard is 7k).. and yes i know its laggy

anyone had any experience with these symptoms?

is it time to purchase some aftermarket coils or there are some basic things i can check first (bad earth etc etc)

was thinking of going ls1 coils with built in ignitor orelse bosch or M&W coils. would ideally like to keep the setup simple and cost effective as i dont plan to ever run more then 500 rwhp (assuming if i reved out to 7k atm id make roughly 430 hp (on 20 psi so another 2 psi and slighlty more agressive tuning on race fuel will see me there)

any help/suggestions or ideas are appreciated

im running champion race series plugs from usa, they are a number 8 im pretty sure with 0.7mm gap. and msd 8.5mm leads. dwell on coils currently set to 3m/s which the tuner didnt get around to playing with if cranking that up to 4.5ish would make any diff other then burning them out quicker

cheers

 

[figgie]

M&W Coils?

Not happening. You would fry every single ignition setup out there short of the M&W CDI, MoTeC CDI and Autronic CDI which means a $1.5k investment on your part at the very least, to run those coils.

The 7m coils are more than capable. The first question to you would be have you replaced the wires?

You are using Champion spark plugs? Get some NGK or even Autolite coppers and gap them down from the OEM gap.

Dwell of 3ms? To much for the 7m coils. 2.3 ms to start and go from there. To much dwell will fry the coils.

 

[disturbed1]

m&w sell non cdi coils - they actually look like bosch ones to tell u the truth

have i replaced the wires??? what do u mean the leads (if so they relatively new msd 8.5mm) im running a brand new loom also which was wired up by myself. only part i reused was the little coil harness.

will replace plugs out with ngks and go from there (what heat range would u recomend)?