I've just purchased an Autronic R500 to run my FC, along with some 2003 Honda CBR 600 F4i coil-on-plug motorcycle coils. I'm curious to see what coils everyone else is running (e.g. Mercury Marine, MSD, Crane), and how many othe r people are using a Coil-on-Plug configuration. If you can, post part numbers as well.

The part number on the coils is: Denso 129700-3881/Honda 30700-MBW-611

 

You will need to use plugs that have removable tips on them. That just made your spark plug choice very limited. i would use a different coil.

 

Thanks for the input. I'm hoping the modification I have in mind to let the coils take a non-threaded terminal will work well. If not, I'll look at something else (maybe 300M, or just ditch the CoP idea).

What coils are you running?

 

I have used alot of coils all with good success. MSD Blaster SS coils, Mercury Marine coils, MSD HVC coils, and crane PS92 coils. All have worked very well. HVC's seemed to have the biggest spark. But the marine and blaster ss coils both worked flawlessly with meth and over 50psi boost so there's no need to spend all that money for them..

 

Update: I decided to pick up some Mercury Marine coils. The modifications to the CBR600 coils looked like they work properly, but I wanted something definite to bring the car up with.

Here's the information on the units I picked up:

Mercury Marine
339-832757A4

I bought them from OldMercs; they shipped quickly and were professional.
http://www.oldmercs.com/ignsys.html

 

You gotta use aftermarket ignitors with those coils?

 

I've seen those MSD SS Blaster e-core coils fail.
Lots of people complain about them - for <$40 each, you get what you pay for!

If I had the money, I'd go all MSD HVC's.

On a budget, I'd go with the Crane Cams PS or LX series coils.


-Ted

 

Definitely. The coils I've posted, I'm intending to use with an aftermarket CDI.

 

Ted, it's my understanding that the Mecury Marine coils I bought are recommended by MoTeC and Autronic for use with their CDI systems. They're $29 each, so maybe this is the exception to the rule.

 

I'm in the process of upgrading my ignition system so I've been getting my thoughts cluttered by the possibilities.

Two questions I pose:

1) Are the Mercury coils of extraordinarily low primary resistance?
2) If so, will driving such a low resistance coil lead to overloading/overheating most CDI units (i.e. MSD, Crane)?

 

Yes and Yes...

mercury marine coils are of very low primary resistance.
And Msd/crane cdi's are known to fail when using these coils...

 

I have used Crane LX-92 with my 500R. No problems there and I dynoed 580hp@the flywheel. My 500R has the high power mod and the coils seems to hold up well. I have 4 of the mercury's lying around too, but havnt got around to using them.

 

OK, got the four Merc Marine coils from oldmerc.com. First thing that I did was measure the primary coil resistance on two of the coils, it was .4 ohms. This is far more than I expected and more than most aftermarket coils. I have no way of measuring the secondary resistance. Perhap some in the audience know this importance coils spec, and would like to share it.

That said, I'm not sure why ANY aftermarket CDI would have any trouble firing them. Though the proof will be in the pudding when I dyno the new setup, and unexpected deployment may put those results off for about 18 months.

 

That's about typical, especially for an aftermarket coil.
I think some of the "hotter" aftermarket coils run under 0.2-ohms.


If the coil grounds through it's body, I think you measure between coil body and coil tower.


Yeah, you're right - it should not be a problem.


-Ted