So here is the thing. I ran all last year with pump gas and dynoed 506 RWHP. E6X and LS2 coils. Figured i would try E85 and a couple more psi this year, so i went and bought a Autronic 500R, with Mercury coils. I was told i were not to use precious metal spark plugs with E85, so i tried some regular BUR9EQ (wich i dynoed 500 RWHP with before). I split the signal from the ECU to the 500R on the leading plugs, and it fired right up... So far so good..

Went for a little run on the dyno, and it barely made 450 RWHP.. Had a lot of trouble just getting the engine over 5000 rpms, and was in a hurry for a track event, so i went ahead and replaced the Autronic with the old LS2 coils again, and sure enough; idle was much smoother, and it revved 7K without problems..

What am i doing wrong? Is it the plugs? Have i wired it incorrectly?(split signal leading, and separate trailing) Or could it be the spark plug wires (wich were no problem used with the LS2 coils)
Faulty Autronic? Im all out of answers, anybody got any ideas?

 

I just switched from LS2 coils which made 504whp to M&W CDI w/mercury coils and having the same issues.

Where does everyone else have their CDI boxes?

I have a dedicated ground and twisted the wires as per instructions.
I've moved the trigger wires FAR away from anything that has do with the ignition outputs and alternator.

It seems to not want to go above 5,000rpms as well.
It free revs just fine all the way to 8,000rpms, but revving with a load is a whole-nother story.
My tach goes crazy as soon as it acts up too, so I keep chasing my tail.


Forgot to mention, mine is an E8.

 

tach going crazy would indicate interference.

 

Makes sense...that's what C.ludwig said too.
I'll move it tomorrow and see what happens.

 

It sounds like we are having the same issues.. Ill try other plugs, and moving it to then..

 

What trigger edge are you guys using with the M&W?

 

Falling edge.

 

I know it's a PITA, but I'd like to see you move the whole M&W box to the driver side of the car. Get the whole bit of kit away from the ECU. That and keeping the main power leads to the M&W isolated from anything ECU related.

 

Also, use shielded wires to the coils.

 

It hauls *** again!!!
Of course due to my stupidity.
I was using the stock plugs (9s) all around.
I just threw in my set of 6725 racing plugs (10.5s), and it fixed it all.
I went back to the manual and it suggests running non-resistor type plugs, but both plugs I used were resistor types and one worked and the other simply didn't.
I'm guessing that cdi works better with platinum or has a deep hatred for copper and his mother?
I'll probably try some EGVs later and see how it goes too.

Thanks again for all the help fellas!!

 

Sweet! You had me worried. What did the gap look like on the stock plugs? Might have something to do with the multiple grounds too????

 

Mates drag car just uses SD10's with CDI (on methanol).

 

have been using crane and dynatek cdi with haltech with an ignitor box inbetween and works great. Without the ignitor box get timing drifting up to 5 degrees.

 

The stock plugs looked horrible.
Lean and a bunch of metal speckles.