yes that is what im talking about, i put 40k last year on my car, i did very hard driving every weekend on the car, and on a hot day i would cook a set of coils in weekend lol, late summer last year i spaced the coils off the plate and havent cooked them since. hope this helps others

Well there must be something in it as Mazda modified the Series II Coil Mount Bracket with a half inch wide Tunnel or air ridge under the middle of the coils, where you can sometimes see the white ARC Mark on the base of the old coils.

Why is that a stupid question?

try oreillys

http://www.oreillyauto.com/site/c/de...2767&ppt=C0334

Is the heatproblem caused:

1) by inner heating of the coils and non-sufficient posibilities to get rid of the heat by aircirculation etc. due to tight mounting on the steel mount bracket.......
(as far as I know coils are warming up during functioning but not to such an extent that the inner part gets destroyed/isolation burned, melted)
2)or is the heatradiation of the extreme hot rotorhousing towards the underside of the coil mount bracket heating up this part considerably; transferring this heat to the underside of the coil; adding additional heat to the coil in this way.......
3) or a combination of 1) and 2).........?

Has anybody some idea/knowledge?

Best regards,
Ruud

Just a hunch but I think how long and how often you spend in high revs affects its life as well. I believe i have the earliest coils failure at around 30k kilometres which is roughly 16k+ miles.

The Series II uses the same Coils so with the Modded base plate, IMO it is more to do with perhaps engine heat transfer and then arcing/shorting of the coils.

Now whether this may be because by Mazda adding a groove or tunnel under the sensitive part of the coil to isolate or insulate that part of the coil, or to provide air circulation???....I lean more to the isolation theory.

Hi ASH8,

Thanks for your post.
For myself I also have the idea that the heat radiation of the engine is the main cause and not the coil itself.
I swapped the old-type-coils on my new Rennie for the newer type and added a double layer pad (2x2 mm) of heat insulation material (lxw=200x90 mm) between base plate and coils, preventing herewith the direct contact between base plate and coil with a super-insulating material.
The material (in the USA on the market available as Cool it/Thermo Tec; withstanding 2000 degr. F) is similar as wrapped around car exhausts.
I hope that my assumption of the cause is right and that it will help to avoid unnecessary heating-up of the coils.

Best regards,
Ruud

so these have a lifetime warranty? when its time to replace just bring them back and swap for new ones?
:Wconfused

my first thought was that this thread was another one of those typical omfg my coils suck threads.... but the OP (and others( may be on to something.

I'd wager on a combination of things rather than just one problem... otherwise it would've likely been worked out in a lab prior to production circa 2001-2002

Hmm.

I like the Idea of an Extra NUT between the Coil and Mounting Bracket, I think the isolation from the base and keeping the coil off the "Hot Plate" is a good Idea...

Can only help in extending the life of the OEM Coils.

That's a good idea, indeed.........

Best regards,
Ruud

I like the idea of separating the coil from the bracket, though I would take a different approach.
I buy high temp gasket sheets from McMaster-Carr and I think that would be a better solution so the coils have an even base to rest against.

Yes, you have a point Jon, Not sure if a nut under the coil would create any other issues down the road.

Instead of a Threaded Nut you could make the clearance a little less by using a few small washers under the coil bolts and Coil Base Plate...instead of the nut?

IMO anything to get the Coils OFF Direct engine/base plate heat at the "sensitive" area of the Coil is a good idea....Mazda put that ridge in the Series II Base Plate for a Reason..:)

Couldn't you just buy the series two plate? Or is there something I'm missing here.

You can if you wish (about $25), however, I think there may be a small mod needed to one of the new plate brackets, but I think there are one or two S1 owners here who have successfully installed the S2 plate on an S1.

This thread was very helpful, i like the sound of this idea and it makes total sense if you think about it.

i never would have thought about it on my own

damn, i wish i was still working at halliburton, we had an IR heat sensor and i woulda used that to measure which is hotter, the coils themselves or the plate. This will tell us which way the heat is flowing. I do think that the plate is working as a heatsink though, i believe the usage of a thermal paste may help our current problem.

Ray.................is last one rhetorical?

I would imagine that the heat generated is taking out the secondary winding. Actually, it's probably burning off the lamination on the secondary winding and eventually.....it goes poof! That's just a semi-educated guess.

More than likely this is also the case Charles, however IMO sitting on a "Hot Plate" can not help, but would add to the cooking of the coil.

It would be interesting to see (if one can do it) the factory A and B Coil dissected to view what has changed internally....maybe very little, it could also be the material "properties" of the coil housing that may have changed...(Black Plastic).

I have a "little" faith that Mazda did the small Mods (Coils and Base Plate) for a reason which their engineers researched and tested???

In my car I guess time and mileage will tell...;)

I think that both heat generated in coils and heat from engine (stored in bracket) contribute to coil degradation.

The bracket heats up close to the temperature of a engine block and does not allow for any heat dissipation when coil heats up from its operation.
I think spacing coils out with a nut --- or phenolic material and adding a heat sink will defenetly prolong coils life, especially for those to drive car hard.

wtf? i didnt even need to and i just replaced my coils for the first time EVER 45k still the original coil packs i just upgraded coils to see what it would do.

Well... I tried to hack one of my coils with a band saw to see if the white spot was larger on the outside or inside.
This way we could tell which side the heat was generated from.
The coil doesn't have a simple housing design that you could just break apart and easily reveal the internals.
Almost like they were made through injection molding with the internals already in place.
I was hoping that by me sacrificing a coil we could stop this assumption, but all I succeeded in doing was ruining a good coil.
Oh well... I still have three more...

I think you are right . I also think that a lot of the heat generated is due to poor connections from the stock leads to the coils and plugs .

I have been running stock coils with very good quality leads on a 300+whp fi'd renesis for over 20000 miles and they are holding up well :dunno:

My leads are Autoexe and the connections appear to be excellent.