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Hi all, new to the group owned my RX8 for 2 years now with no MAJOR problems as of now! Just curious if anyone has done or tried the LS1,2 or 3 ignition coil swap? Looking for thoughts or input thanks in advance -Ryan
What is the root cause of ignition coils failing on these cars. I dove a little into it and see rx8performance offers a bracket that has cut outs. it looks like the ignition coils rest against a backing plate of the OEM bracket. the bracket can retain water, heat, and the ignition coils can gap to the bracket through the coil itself over time as the insulation resistance wears out.
Rx8performance has a bracket with cut outs that holds the ignition coils so no water or heat can be retained between the two and will also cool the coils helping with heat evacuation.
the bracket is $79, kind of steep for what it is but much cheaper than any other option, this seems to me like the best course of action to prolong ignition coil life and not needing to move to a BHR kit or what not.
Part of it is heat. Looking into things, and looking at design I could see death by shitty cooling. Here's the thought - The lower panel is integral in design for shunting cool air while moving to the engine. Even when stopped, the fans still move air albeit not as much as when moving. Rotaries are great at producing noise and heat. More so heat than anything else. So, that being said I could see someone who's replaced the intake with an aftermarket system that also removes the tertiary box underneath the airbox leading to an earlier death. Beyond that, those coils are jammed right in a tight corner and without much airflow they like to melt and become worthless. Take note that most, if not all of the aftermarket kits have some flavor of heat sink or separation built into them to keep them spaced and allow for airflow.
Also... Cheap, Efficient, Reliable. Pick 1.5. 2, if you've got good compression.
A) ***
Becaue of the doubts of PeteH and the observations of RenesisRaceBuggy (thanks)........(the latter caused some doubts with me about my own previous testing) today I did a new temperature testing with my Rex and measured engine-, coil mounting plate support-, mounting plate- without Isolation (I lifted partly the heat isolation and blackened at the measuring spot for correct results).....note: the difference between a galvanised/partly-light corroded bracket and matt blackened measuring spot is over 5 degr. C.) and of course I measured each individual coil.
The results were different as my previous indications and you will find them beyond.
I drove the car hot with sump oil temp. 95 degr. C........stopped and started measuring a couple of times, each time after running the engine at 4.000 rpm idle for 1 minute at least.
This is wat I measured (the engine block temp raised during the testperiod of 1/2 hr from 95 to 105 degr. C.
The galvanised bracket strud measuring halfway between engine and bracket plate had an approx. 5 degr. C. lower temp. as the engine temp.
The temp of the blackened spot on top of the mounting plate was approx. 10 degr. C. lower as the engine temp.
The 3 "front coils" were more or less the same in temp, with more or less similar results measuring at 1)..the coil body close to the terminal connector 2)..the coil body just beyond the "tower"on which the ignition leads are connected) ..1 and 2...did not differ significantly.
These 3 coils were more or less similar in temp. ...between 75 and 85 degr. C......which is approx. 10 degr. lower as the mounting plate.
Coil nr. 4 (closest to the firewall) was generally 5-10 degr. C. higher in temp as the other ones.......for this coil there is a "gain" by ceramic isolation of the mounting plate of only 5 degr. C. to zero.
The increase of heat at all the measured elements were more or less parallel curves.
The results means for me for the time being (or forever) maintaining of the isolation between coil and mounting plate however for the future if I could find an easy solution for lengthening of the threaded tapends some additional air space between coils and the isolation.
Especially coil nr. 4 needs it.......
B) ***
With reference to my in yesterday's post mentioned wish/need for some free air space gap/isolation beyond the coils today I made a additional heat isolation improvement.
I removed /inspected the 4 coils with total 27.000 mls since new.........they made a good impression / as "new".....car runs fine so for this moment no reason for renewal.
To achieve a free space under the coils for better cooling at the bottom I made an 1,5 mm aluminium sheet that is placed on 1 double layer of 3mm ceramic heat insulation tape that was already installed by myself.
The coils now are not placed direct on the ceramic tape any more but have approx. 6 mm free space.
Previously I had 2x a double layer with a total of 6 mm ceramic tape.......I removed 1 layer because I needed sufficient length of the screwthreaded stud to fasten the coils.
On the pictures you can see the set-up consisting of ........1) the mounting plate.....2) one 3mm layer ceramic tape.....3) one layer 1,5 mm aluminium sheet metal....4) 6 mm free space for air ciculation.....5) finally the coil on top of that.
Furthermore I "spreaded" the 4 coils like the spreaded fingers of a hand to enable extra free space for some coolin of the coil.
Stainless steel (SS) is actually a poor conductor of heat (compared to its carbon steel cousin). SS is good at shielding heat but also once it is hot doesn't cool off very fast. Use that to your best advantage when designing modifications. Aluminum is the best at heat transfer rate.
I checked a couple of local parts stores and it looks like all ignition coils are made from the same place. All were made in Poland and all came with lifetime warranties.
^ We have known that for a long time. It is even in the New Owner's sticky in the discussion about coils.
You have a number of options for coils:
- The Cheapest option: BWD/Intermotor coils from auto parts stores like Advance Auto. These ARE OEM coils, just being sold to auto parts stores directly from the original manufacturer. This is common for virtually every OEM part for any car older than about 5 years old. 4 coils, 4 plugs, and 4 wires can be had for around $190-220 total based on whatever promotion is running at the time, shipped to your door for free. They are considered to be the first coil revision and you should expect to need to replace them around 20,000 miles, 30,000 miles max. They often come with a "lifetime warranty" by the auto parts store, which could potentially be leveraged for perpetually new coils.
- The Best Upgrade: The BHR ignition coil upgrade can be had for around $500, which eliminates the need to continue replacing coils periodically, as well as deliverying a significantly stronger spark for minor mileage and power gains. It is a proven kit with top notch customer service supporting it. It includes the wires, you still need to add plugs ($80)
- The For-Sure OEM: Mazmart sells all 4 coils of the latest OEM coil revision (C) for around $250, (just the coils, you still need to add plugs and wires) Supported by top notch customer service. They will likely last longer than 30,000 miles, but we don't have much solid data on how long the latest coil revision will last. If you are having trouble getting other coil options where you live, or are wary about purchasing coils from other sources, then this is your cheapest option for coils straight out of the Mazda dealer parts network.
- The Most Expensive option: Buying from a dealer will run you around $300+ for the coils, $500+ for coils, wires and plugs, and if you have them do the install, expect to get a bill for anywhere from $700 to $1,800. You may not get the latest coil revision, and it is unlikely that the dealer or techs will be able to tell you what coil revision you have. Yes, you are getting shafted if you take this option, so bring lube.
- The Highest Risk option: Ebay coils continue to pop up as counterfeit, mislabeled, dead on arrival, and have zero post-purchase support largely. They are the "cheapest" listed price, but when you add that $92 or whatever to the price of anything in the list above from having to do it over again, you can see that they are no longer the cheapest option. Do it right the first time. "Motor King" coils are popping up at an attractive price on Ebay, but are being proven as ineffective, to the point of being unable to get the engine fired. "Mazda" branded coils on ebay are almost always counterfeit. Check the seller's name though, since some of our vendors sell legitimate coils there. The price will be $200+ though. Anything sold as "Mazda OEM" under ~$26 per coil should really be considered as suspect and probably counterfeit.