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It's just friendly discussion And we had a local with a 2010 R3 that had failed coils at like 30,000 miles. I assume those were the C coils, he never bothered to check, the dealer covered the cost at no charge to him which I thought was pretty cool. He tracks a lot. We have two R3's that are semi local and both guys track a lot and both have gone thru stock cats so apparently they didn't make any changes to the cat.
Sorry a 2010 can not have the 'C' coils they would be B's... factory line production did not start using C's until September 5th, 2011 (exact date) and only in Spirit R.
Replacement Parts supplies were well into 2012, in the US very late 2013 as they had about 5000 units in stock of the B's according to old Jason at Montgomery Mazda..
I am not saying the C coils will not wear out or fail, but every iteration (now 4) (in general) has seen a longer life span.
I did not feel or notice anything wrong with my original s2 "B" coils at 30k and a little over 3yrs, but after changing them my dyno plot looked much better. This was not a back to back test, so it could have been something else, but coils were the only thing that physically changed on the car.
The replacements were "c" even though they had "b" on the box. After almost 2yrs and 20k I did not notice anything wrong with them (including in my butt dyno and straight line speed on track). I was planning to dyno them in the next couple of months to see how they had held up, however, now that my engine is out I am replacing them. The replacements that came though a US dealer are "c" coils again even though "c" is not on the box. I'm slso doing plugs and leads at the same time (I did not do leads last time, so they were still original).
One thing I noticed - one of my plugs has a corroded top. There was also one with a corroded top the 1st time I changed them. Seems a little odd to me so hopefully new leads helps. The plugs overall look like I left them a bit long as well (~22k and 2yrs).
After all this, I'm thinking that 1yr/10k on plugs, 2yrs/20k on "C" coils and 3yrs/30k on leads is a pretty safe maintenance schedule.
I've also ordered coils for our Civic Si - it is on the original ones after 7yrs and 94k, but it seems to be knocking more than I remember now so hoping this helps.
I just finished replacing my C coils with 2yrs/20k and a bunch of track time with a new set. No noticeable issue with the old set them, but figured it was due. Couple of pics of the old ones:
I'm guessing the spot is due to heat discoloring the plastic casing. Looks like the 2nd from the front gets the most, at least on this set.
If anyone wants some used oem "C" coils for the cost of postage let me know
I replaced the leads and plugs as well. NGK plugs identical to oem. The NGK leads were not quite identical, but were an exact fit. I transferred the plastic guarding, and the colored tape off the old leads onto the new:
Bit of a pain to take the motor out just to get to them, but it is now back in and seems to be running smoothly
Just want to add, I also finished replacing the coils and plugs on our civic (2008 Si), and it does seem to have improved the knocking. So, not just RX8s that have coils wear out :-) The plugs on that were clean, but did have some noticeable wear, although still within spec. They had around 50k on them (supposed to last 100k per the service manual). The coils were the originals, so 7 years and 94k on them. Both coils and plugs had some track time on that car as well.
blu3dragon, IMO one, if not the biggest issue with any of these OEM Coils is long term exposure to heat, particularly heat soaked engine bays from 8's being stuck in traffic jams for long periods, year after years.
When I renewed my 7 year old B coils (54k) just for the fun of it, their bottoms (of each coil) were like new when cleaned off, no marks at all, I don't have a traffic issue with my 8's use and the last 2 years has been a winter car only.???
From a parts interpretation point of view Mazda Japan in EPC are saying that as new replacements the new iteration of coils are an improvement as they note NOT to install old iteration of coils into a car which has previously used the latest version(s) from factory install, new parts interchange-ability is one way ONLY , new for old, but not old part for a new install.
Conclusions can only mean there are 'some' improvements, IF there were NO improvements then the parts interchange code would be both ways, not a one way.
99% (roughly) of all OE Mazda parts updated during 'a' Series cycle in 'a' model are interchangeable both ways (new for old or old for new), it is the other 1% (like Coils, ECU's) which are parts that technically either wont physically install or should not technically be installed, only new for old.
So far I have heard of no 'C' coils fail, they are only roughly 3.5 Model Years old (Spirit R was the first model to use them).
So I tried to get the C coils from the dealer, and it just pissed me off. The part number with C on it pulls up for a Protege, and the part number with C-NU doesn't exist because NU means local source. (The parts guys pissed me off, not the process)
The may just have said screw it, why retrain the US parts staff, just don't change the box, those guys will never figure it out!
So I tried to get the C coils from the dealer, and it just pissed me off. The part number with C on it pulls up for a Protege, and the part number with C-NU doesn't exist because NU means local source. (The parts guys pissed me off, not the process)
The may just have said screw it, why retrain the US parts staff, just don't change the box, those guys will never figure it out!
Huh, I don't know where Protégé comes into it, they are not the same Coil or Part Number, RX-8 Coils (OEM) are ONLY used/supplied on/for all series RX-8's and are specific only for RX-8's.
Anyway, this is/was the story a few years back and for whatever reason Mazda NAO PARTS have not changed the PART NUMBER of these Coils on the parts BOXES, But the Part inside the Box IS the updated one, a 'C'..
MNAO chose to purchase large quantities in BULK (of many fast moving parts) and then put their 'local' printed Part Numbers Label over the Mazda one (adding #9U).
This is the Part Number to order latest OEM RX-8 Coils..
N3H1-18-100B9U
Here is 'a' Mazda Dealer (as an example) in US, and THE correct Part Number for US ordering is.
As has been said before the OLD Part Number B is still used and shown, but the physical COIL inside is a C Coil and is stamped 'C' on the side of the Coil Body to ID the coil.
blu3dragon, IMO one, if not the biggest issue with any of these OEM Coils is long term exposure to heat, particularly heat soaked engine bays from 8's being stuck in traffic jams for long periods, year after years.
When I renewed my 7 year old B coils (54k) just for the fun of it, their bottoms (of each coil) were like new when cleaned off, no marks at all, I don't have a traffic issue with my 8's use and the last 2 years has been a winter car only.???
This may explain why my coils appear to be fine after more than 6 years and about 47,000 miles (garaged in the winter). I even paid the dealer $90 to perform their tests on the coils, and they said they're fine. I don't spend much time in truly congested traffic and I live in Michigan (where we only have really hot weather for a short time in the middle of summer). Most of the miles I've put on my RX-8 are from driving my 170-mile round-trip commute to and from work, plus occasional drives on the country roads outside of town. My first track day a few weeks ago probably wasn't great for them, I suppose.
So after changing my B coils at 42k miles here is what I found...
The number 2 coil (front trailing) had the most noticeable white spot, and the coil was going bad. Wire was very tight on the plug. The plug itself had the copper turning blue despite the wire being tight. The end of the plug had oil and carbon deposits on it.
1 and 3 had white spots, but not as bad. (leading)
4 was not as bad as #2, but same thing with the plug being discolored and dirty.
A couple posts up you see Bludragons's #2 doing the same thing.
The trailing housing is not open like the leading housing in the rotor chamber. I am wondering if this is effecting the spark jumping around.
I had my car running one month, then it started adding 9% LFTF, then 12, then 15, then 7, then 15 again, then misfires everywhere. It ran best at that seven when dry, hot, and Sunny. With massive humidity in Houston, I wonder if that is also making a case for something.
I decided to try something new and get the RaceRoots LS2 set, and extend the harness to fit where the battery box is. that will keep the heat out, and provide some elements protection. The battery was replaced with a capacitor for now for time purposes, and the battery may stay and be relocated.
I wonder about that "condenser" as well because it essentially a capacitor,and I wonder if it just can't handle Mazda's clever ignition timing and demands of 25 to 40 amps. (IG pulls from battery side of 120A fuse)
White spots don't mean anything except older coils are more likely to have them. Coils can be dead and not have them, coils can be failing and not have them, and good coils can have them. Only way to tell for sure is to test them with a timing light or a spark tester.
Agreed on the white spots, a white spot does not imply a failure or otherwise, but they do appear to be a result of heating in the coil and so there is likely some correlation between coil wear and the existence of a white spot.
I would assume that heat is accelerating deterioration, but I don't think under hood temps are really the cause. Most modern cars have the coils mounted directly on top of the plugs, in what I would expect is a hotter location than where they are mounted in the RX-8. So, I'm not convinced sitting in traffic is really the cause of coil failure, although extended idling, without some higher speed runs, could lead to plug fouling earlier, and more stress on the coils.
My theory is that it is the required current, and frequency of firing that causes faster wear in the RX-8 than typical piston engines.
I expect any car that is driven on track will wear the coils (and cat) out faster than if it was just street driven.
This may explain why my coils appear to be fine after more than 6 years and about 47,000 miles (garaged in the winter). I even paid the dealer $90 to perform their tests on the coils, and they said they're fine. I don't spend much time in truly congested traffic and I live in Michigan (where we only have really hot weather for a short time in the middle of summer). Most of the miles I've put on my RX-8 are from driving my 170-mile round-trip commute to and from work, plus occasional drives on the country roads outside of town. My first track day a few weeks ago probably wasn't great for them, I suppose.
For a 2009, you will have the "B" coils. I would recommend changing them (and plugs), particularly if you plan to do another track day and if you are tracking the car with the cat in place.
To summarize my own experience with a 2010 RX-8 with B coils
2013 at ~30k miles, replaced plugs, original "B" coils dyno showed power dropping unexpectedly at higher revs. No noticeable problems driving.
Replaced with "C" coils, subsequent dyno showed expected power at higher revs. I did track the car in between dyno runs as well, so it is possible that "cleaned" something out, but the new coils seem the most likely reason for the "fixed" power.
2015 ~20k miles and ~20 track days on the "C" coils and the plugs, no noticeable power drop or other driving issue. Replaced coils, plugs and original leads. Pics of coils above. Sorry, no pic of the plugs, but they were visibly fouled with mostly brown deposits, and the top was corroded on one (which seems weird).
2008 Civic Si:
Replaced (original) coils and plugs. Coils were 7yrs old and 91k miles, plugs had ~50k on them. Both had some track time. Plugs were clean, but had some visible wear. Noticeable improvement in knock. Honda service interval on the plugs is 100k. Coils are not listed as a service item.
Last edited by blu3dragon; 06-26-2015 at 12:20 PM.
White spots don't mean anything except older coils are more likely to have them. Coils can be dead and not have them, coils can be failing and not have them, and good coils can have them. Only way to tell for sure is to test them with a timing light or a spark tester.
This TSB calls it "corona discharge effect," which is accurate. By gas law it is allowing high voltage discharge through it supposed insulation and shorting to engine ground via the bottom of the coil. That is a failure of the concept of the ignition coil by allowing the air to conduct instead of the wire. (the wire could also be a fault because of high resistance)
So the air has less resistance than the wire, so the wire doesn't take the whole spark because the air is a path of lesser resistance to engine ground. Now here is where it gets tricky, electricity has been recorded in the past as positive to negative, but the whole book got thrown out when people have said negative to positive in the last 25-50 years with semi conductors.
How many times it happens will more than likely determine how quickly it fails. On some coils once and on some coils maybe years. Air density, temperature, and humidity levels will determine that.
With the Series II "improved" bracket and it clearly still happened on all 4 coils. All 4 coils passed the test in the FSM, and resistance levels are normal, but clearly they are failing somehow. These are series II B coils, not A.
An un-grounded electrical discharge is a bad thing, and it is exactly why there is all that black insulator there in the first place.
So here is my conclusion....It is bad....period. Now here is the thing, will it effect everyone or even be a problem for everyone, NO. I do think we as a community can find the answer and improve the solution with some simple science and get better life from our coils and have a better car out of it.
The white spots are going to vary by every known variable of gas laws.
-Humidity
-Air Temperature
-Air Composition
-Elevation
-Duration of airflow
My theory is that the more humid the air, and the more "****" you have in the air, the more this will be a problem for you. Salt, Water, and low elevation means air can charge easier.
I will take the science and speculation to another thread, but I do want to point out that in the TSB they defined what it was called to the techs, which in itself means they know what caused it. It not effect performance sounds like the same story. Some fail, some don't, apply factor X.
All these Coils have a hard life, at the second hottest position/location possible.
I wanted to know some more about temperatures around the coile so today I did a new testing with my Rex and measured engine-, coil mounting plate support-, mounting plate- without Isolation (I lifted partly the heat isolation and blackened it 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./41 F) and of course I measured each individual coil.
When my new purchased Rex had 6.000 mls on the odo I mounted four layers of ceramic heat insulation material (the same like used for wrapping exhaust pipes etc.) with total thickness 6 mm between coils and mounting plate to prevent more additional heat exposure from the mounting plate to the bottom of the coil.
At that time I assumed that coil temperatures would not exceed approx. 70 degr. C./158 F
The results were different from my previous expectations and you will find them beyond.
I drove the car hot with sump oil temp. 95 degr. C/203 F........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 95/203 F to 105/221 F degr. C.
The galvanised bracket strud measuring halfway between engine and bracket plate had an approx. 5 degr. C./41 F lower temp. as the engine temp.
The temp of the blackened spot on top of the mounting plate was approx. 10 degr. C./50 F lower as the engine temp.
However the temp. of the coils was measured with a layer of 6mm ceramic heat insulation tape between mounting plate and coils.
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 75/167 F and 85 degr. C/185 F......which is approx. 10 degr./50 F lower as the mounting plate.
Coil nr. 4 (closest to the firewall) was generally 5/41 F-10 degr. C./50 F 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./41 F 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.......
With reference to my in previous 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 (B type) 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.
With 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.
Ancient thread, I know, but here is a little idea I am experimenting.
From some quick research, the corona effect is obviously something we don't want. It means some of the electrical energy being sent to the spark plug would be lost.
So here is a little idea of mine: Painting the bracket with some kind of dielectric coating. I used some Permatex liquid electrical tape and painted the bracket with it. I applied 3 coats of it to make sure there aren't any bare spots. Let it sit overnight so it can cure before I reinstalled my coils.
The black coating is the liquid electrical tape.
Here are two of my coils. Strangely, both leading coils show the white spots while both trailing coils have very clean bottoms.
I switched them around and I will see if there are any new white spots when I change my tires in the spring. If there are, I might buy some corona dope and try that. It is supposedly even more dielectric than the liquid electrical tape, but a tad more annoying to apply(you have to cure it at 80C for an hour).
Ancient thread, I know, but here is a little idea I am experimenting.
From some quick research, the corona effect is obviously something we don't want. It means some of the electrical energy being sent to the spark plug would be lost.
So here is a little idea of mine: Painting the bracket with some kind of dielectric coating. I used some Permatex liquid electrical tape and painted the bracket with it. I applied 3 coats of it to make sure there aren't any bare spots. Let it sit overnight so it can cure before I reinstalled my coils.
The black coating is the liquid electrical tape.
Here are two of my coils. Strangely, both leading coils show the white spots while both trailing coils have very clean bottoms.
I switched them around and I will see if there are any new white spots when I change my tires in the spring. If there are, I might buy some corona dope and try that. It is supposedly even more dielectric than the liquid electrical tape, but a tad more annoying to apply(you have to cure it at 80C for an hour).
There are multiple problems with the stress on the ignition system. Here are some prototype theorys I did myself and proved, at least for my car, that they not only work as replacements, but there is an improvement in times between services and overal love for you car via knowledge and upgrades self seeking.
The Bracket. You are thinking man, that is me too, but not everyone gets how deep these things can go or even cares. They should, but their brain is just to busy with something else.
Ok look into these things to perfect your theory, but more importantly watch for the insulating materials to build up a even higher voltage when they cannot discharge like OEM because it could be a pretty cool tesla coil or you turn into a fireball and we never know if this worked....
Abother flaw is the gounding system on all OEM coils. The bracket is designed to be conductive so it self distructs not the red and blue fuel linr just 6 inchs to the driver side and back.
Here is what I did and what I learned from doing it (and what the vendor didnt make clear)
Relocated Group 35 AGM Flat Plate virgin lead battery to trunk. (dealer had a group 26 disaster walking around with no trim/mounts/covers.....
That is either a local front battery like a 51R and a bigger rear battery with a OFC 4AWG or better yet Higher Voltage Battery (AGM and FP = 14.8Max over 13.5/13.75/14.0/14.25) and they settle at higher voltages not the typical 12.7-13.2, so the starter and coils DO NOT have to fight the EPS and Airpump to work or strain damage the coil from low voltage.
I used that Supercap and its resistance was so low the coils wouldnt even get hot. I mounted them in the battery bay with the OEM freshair duct intact just in case.
2 Breakers on the Positive (1 SJB/Batt lug to rear positive ofc cable)(prefirewall....)
(The other Pre battery/Post 10ft run so that if you short it in the middle, everything and everyone is safe.
SB175 Anderson Plugs for quick connects.
EPS and Positive Battery lug emulated via M6-Post / NO OEM Wiring changes.....just additional runs. Take that dealer..... OH you dont know how it is ran, check the glovebox, OEM wiring diagrams with added runs, engineered measurements, test data, and buissness inprovement cass. Suck it!
LS2 Coil Kit w/ Bracket (Mounts in Stock location OR other places.....)
Had to extend the wires provided by vendor, the Signal and Pwr wires not High Voltage Leads.
Sleeved each wire with heat and fire-proof sleeving with Coil # Front to Back, R1L/R1T/R2L/R2T
Added Stainless Steel zip tires......
I ******* DARE YOU TO USE THOSE!
Cut through 4 pairs of gloves and there was blood on everything and I had to go into work suddenly, everyone was like What the ****.
Used Rubber-Silicon 600V 20AWG Wire
-RED -Black1/Black2 -White Signal
LS2 Coils have 2 GNDS, so I took the 2nd set and fed them right to my 58Farad Supercapacitor.
Car started on the first crank, Compression Test Score INCREASED!, and the car loved the higher 14.4v the Supercaps can hang with, but just go look up the resistance of onr of those things. Maxwell BCAP0350E270
My plugs arent wearing, the Signal Wires are Protected, The HV Leads are in Heavy Duty Fireproof sleeving and the rubber will not crack from age. Ill Change them both anyway at the 60K Interval, but just burning money to hope it keep the engine fresh.
So TLDR.......
16.2V 58Farad Supercap
SB175 Anderson Plugs
Battery to Trunk
LS2 Coil Kit
Mount in Stock battery box
Add Circuit Breakers
Sleeve wires
MPG HW around 30 on a trip/ Higher Volatge under load/ after settling when per off / Less Resistance - Happy Starter and CoilPacks / LS2 Coils fix many problems by changing the design and work well on RX8 Series 2.
Keep thinking man, either way
Do science, Make Lemons, and Burn your house down with the Lemons.
So basically, you are running 2 batteries? That's a lot of work. I prefer to keep my system close to stock, but I am sure there are people who would attempt it. Who is the vendor you are mentioning?
As for the coil building up voltage... I am no electrical engineer, but the layer is to prevent the corona from happening in the first place. I would think the supposed discharge route(which to the wire-spark plug-ground) is by far the least resistive path. I don't think arcing would be a concern here, let alone an arc that can jump an 6-inch gap onto rubber.
06-12-2015, 10:08 AM
And we had a local with a 2010 R3 that had failed coils at like 30,000 miles. I assume those were the C coils, he never bothered to check, the dealer covered the cost at no charge to him which I thought was pretty cool. He tracks a lot. We have two R3's that are semi local and both guys track a lot and both have gone thru stock cats so apparently they didn't make any changes to the cat.
wat
