Haha, yes and to add to the confusion the first photo has that water hose just loosly flopped in front of the LIM like it would be the oil feed. But you are correct, that is my coolant feed to the turbo, the oil feed is a -4AN that will connect to the oil regulator/gauge coming off the top of the CHRA.

 

Just for reference, snapped this photo last night of the positional difference of the Xcessive vs stock LIM. Stock LIM held up and lined up with the bolt holes on the Xcessive, the latter moves forward approx 1/2".

 

the Excessive LIM benefits greatly from porting. use the LIM gasket to block for reference. a Dremel can easily get it done.

 

Engine is back in the chassis. Pic of the Xcessive vs stock manifold against the firewall for reference as well.

 

Is that a non-stock (or non-Mazda) Brake booster and master cylinder?

 

All factory Rx8 components.

 

Mocked up. A few minor interferences to deal with switching from stock to Xcessive LIM, but overall fitment is looking good! In the photos below, AN vent fittings off my oil fill neck are really tight to the vacuum line cluster on front of UIM, will likely get oil fill neck flange clocked a bit to spin this out of the way some more. Charge pipe from intercooler to TB needs some slight modification to hit the new TB location. Fuel regulator inlet fittings are hovering just above alternator. These may contact when I raise alternator to tension the belt, hoping I can just swing this out of the way some more but if not I'll just get a new braided line made an run it to the other side of the regulator.

 

Figure I may as well close the loop on this journey for now. Below are videos of first start and the engine idling after it's fully warmed. This is my first DIY engine build, so far I couldn't be more pleased with the result. Let's hope whatever weird apex seal wear issues I was seeing prior was some sort of mechanical anomaly and going forward I can monitor all the engine vitals and put that behind me.






Here's the link to it warm idling, Youtube turned it into one of those stupid "shorts" videos.



https://youtube.com/shorts/PJu2xKoXP_A?feature=share

 

L1 is bottom left, L2 is bottom right.


Looking for some input or read on these spark plugs. These are BUR9's that I used for first start and had them in for the first 110kms (70 miles) of city cruising up to ~5000rpm that I now have on the rebuild engine. I will be switching to some 10's but wanted to get first start and a bit of light driving in first on these cheaper plugs. I drove roughly 35miles in one session, car ran pretty good other than I think my EGT's seem to be a bit high (would love some input on that also). Then cold started the car again after a couple days and it ran pretty rough until it was fully warm after a bit of driving (the second session putting ~35miles on). I believe the rough cold start and idling was a combo of fouling plugs and just needing my tune updated for this engine. Car cold starts in about half a crank and it even hot started exceptionally well (1-2 cranks) after the total 70 miles on these pretty fouled up spark plugs.

EGT's at idle will range from 650C to 710C at 13.5 AFR but this is currently pretty high idle rpm at 1350 (as mentioned above this is my tune from previous engine and needs to be refreshed for this setup to bring this down to around 1050rpm). I'm seeing anywhere from 750-840C at cruise depending on rpm, load etc. I'm targeting and holding a pretty good 13.5AFR in cruise vacuum areas. Performed a compression test on a piping hot, 0 mile, engine before I took it off the jack stands for the initial drive and was getting 99psi on the front and 105psi on the rear. I'd say the car runs better than ever until the plugs started fouling..... but if my spark plugs are that carbon fouled in such a short time, how does the rest of the internals look?

Anyways, I ask about the spark plug fouling as my previous engine was fouling plugs just like this even after 2500kms of break in. What do the carbon deposits on these seem to indicate? I'd think just from rich conditions but I don't think my AFR's are crazy rich at all.

EGT's I'm more or less just looking for some input on if those numbers are absurdly high? I know they should come down with some tuning, especially at idle but my cruise regions seem to be already in a pretty good spot fuel wise.

Thanks in advance.

 

what fuel & premix type/ratio?
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I'm not a rotary building expert, but I started tuning the standalone ECU in my RX7 15 years ago and it has run well since then. You can run the engine pretty lean at idle and light load / low RPM, because whatever heat might be registering on the EGT sensors isn't accompanied by enough exhaust flow to transfer dangerous amount of heat to parts. Think of a faucet flowing a trickle of very hot water (low RPM, light load, low airflow) compared to a strong stream of somewhat hot water (high RPM, high load, high airflow). The flow influences the heat transfer quite a bit. If you're idling at 0.85 lambda, try 0.95 if the engine will still run smoothly. Try even leaner if it will run smoothly at 0.95 lambda. Disable idle feedback and watch engine speed as well as manifold pressure like the old carburetor guys used to do, you should find some range of air/fuel mixtures that result in strong vacuum and high RPM. Personally I would want the idle mixture to be a little on the lean side of what makes best vacuum (to avoid fouling), and then configure the ECU so it will go a little richer if the engine load increases (to avoid stalling). I should probably note that my car still has the Oil Metering Pump installed, but the feedback sensor has been showing weird readings lately so I've been premixing about 0.5 ounces per gallon of fuel.


I assume that heavy premix ratios will foul plugs more easily, and also assume that the assembly lube from a fresh rebuild will foul plugs easily too. If it were me, I would check that a second set of the BUR9 plugs will survive longer before switching to the expensive ones.

edit, link to a video that shows my car's air/fuel ratios and manifold pressure when idling and creeping forward in the staging lanes at a recent autocross. It also shows info during the brief moments of full throttle, which was not long on that course. The spark plugs had been in the engine for a few years, I don't drive the car much lately so it might have been 3000 miles.

 

Thank you for that input Scott!

 

It's 93 octane and 10ml/L of premix (~1.25oz/gal) of Idemitsu, no OMP.

 

I agree with Scotty. If you are just cruising around and fouling plugs, then it is an obvious sign you are too rich. These engines are perfectly fine running 14-14.7 AFR on pump gas for cruising and around 13.5AFR at idle. Assuming you are running with no decel fuel cut, that can also contribute as well. Think of all the poorly burnt and completely unburnt fuel running through the chambers and out the exhaust port under no throttle. That helps cool things down and lubricate, but spark plugs need heat to stay clean. I ran R7420-10s all around when I had my FD and made sure the engine was running hotter just to keep the plugs clean. When you go in to boost, your EGTs should initially drop as well.

 

edit: never mind, I was thinking those were the cheapo piston engine plugs rather than proper rotary plugs.
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Bit of an update on the spark plugs, I've come across some interesting info this weekend. The AEM IGN-1A's have 3 grounds from the coil itself. 1 is for the block/chassis, one should go to the rotor housing, and the other should go to the battery negative terminal. Tracing out my Rywire Ignition subharness I'm finding that there is no ground cable at all on the harness meant to run back to the battery terminal, there is two grounding ring terminals 1 for each housing only. I can only assume this has all 3 of the coil grounds from each coil going to these ring terminals on top of my housings. Apparently this causes a ground loop (Earth loop) when they are grounded to the same spot.

Someone who has experienced the exact same symptoms I'm seeing on multiple cars in their shop has found that not having Pin D from the AEM coils grounded directly to the battery causes this. Over the weekend I modified my sub harness and and ran wire from Pin D of each coil to a grounding cable that I ran back directly to my battery in the trunk. I just finished doing this late last night and need a larger ring terminal to fit my battery, then I can give this a test and see if this solves my woes. Having an inconsistent spark like this would really explain most of the concerns I have (above average EGT's, fouling spark plugs, faint fuel smell in my garage after the car cools down (like flooded engine), bit of an unstable idle at times).

Let's hope this solves the issue. If it does, this really makes me think about the previous failed engine and how carbon build-up from poor fuel/air combustion could have played a huge factor in the abnormal wear I saw. Don't want to count my chickens before they hatch, but I'm feeling like I've found a serious flaw in my setup that has been holding this car back from performing like it should. *fingers crossed*

 

fingers crossed for you

 

That's the thing about upgraded parts. They need to be installed properly.

 

you’ll find people on here who’ll argue against the proper ground wiring for those coils (because Haltec etc told them even though Lance Nist says otherwise), hard to believe rywire would do it that way though
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Probably worth clarification, it's 2 actual grounds and an ecu ground reference to ensure the trigger signal is clean. It's specifically designed to minimise trigger signal and earth loop issues by having them separate.

 

100% agree. In my defense the coil wiring I had done back in 2020 by somebody else and they installed it as per the Rywire instructions. Because it was the Rywire harness I never really put much thought into it or looked into it myself prior to this, thinking Rywire must have this figured out, should have learned by now that assumptions are killers. It's the same reason I decided to do the rebuild on my own this time around.



Yes agreed, I may have to reach out to Rywire and ask. I currently have 6 wires coming from my ECU to the harness; according to Rywire that would be (obviously) 1 for each coil trigger signal, one is low amp power from ignition switch, and one for ground (relay).




Would this Ground (relay ground, low amperage) be my sensor ground from the coils going back to the ECU? My understanding is that this Pin B ground is less important than C and D and could be chassis grounded or grounded to block if it's not back to the ECU (yes I'm aware the intent is to be wired to a sensor ground in the ECU). I'll have to do some more tracing/testing on this harness and see if I can confirm where this is pinned to or if it is shared grounding with pin C on each rotor housing.

 

Following. Im running the same ignition set up and rywire harness, lost compression on rear rotor during dyno tuning,

Mike

 

I've rewired my grounding for Pin D and wired them directly to negative battery terminal. So far I've only been able to put about 20kms on since which is not a good indicator. I'll say my initial impressions are that nothing has changed, but I'll report back when I'm able to run the car a few times and judge spark plug fouling.

I did do some probing on my Rywire harness, specifically to figure out what Pin B was doing. Of the six wire listed above, the Relay ground is grounded to my chassis, with the other 5 wires pined directly to my ECU. When I did a continuity test on the ring terminal for the chassis ground (no longer connected to chassis) I was getting continuity to Pin B on one of the coils. Seemed straight forward. I then did a continuity test for pin B of the same coil just grounding my multimeter to the chassis which also gave me a positive continuity result. For fun I then grounded the prove to the engine block and got continuity there as well.......... consider me confused by that.... considering my newbish experinece when dealing with electrical, does this indicate that Pin B could be grounded improperly at all?

In the meantime I am also going to test each coil individually with an HEI Spark Tester. If those all pass then the next line of sight will be on my injectors. These have all been flow tested and cleaned, so this seems unlikely as well, but nonetheless I will attempt a difference set of injectors to see if the issue lies there.

If coils seem strong, and different injectors don't solve this issue I'm going to be at a bit of a loss. We'll cross that bridge when we get there but if that was the case, could this be a result of a bad injector drivers on the Adaptronic ECU? (maybe I'm getting ahead of myself too soon here)

 

any updates?
hopefully one of us figures this out
on mine i have 3 grounds
rotor housing ground (pin c)
5v sensor ground on haltech (pin b)
and battery ground (pind d)

 

that would all be correct per the general setup diagram:


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but if there are 5 pins per coil and 4 coils per 13B engine, which some pins are common and can be shared, then the overall harness pinout would be something like this (the order can be different/as desired)


pin 1 - Switched +12V All Coils
pin 2 - Battery Ground All Coils
pin 3 - Sensor Ground All Coils
pin 4 - Trigger Rotor 1 Leading
pin 5 - Trigger Rotor 1 Trailing
pin 6 - Housing Ground Rotor 1 L & T
pin 7 - Trigger Rotor 2 Leading
pin 8 - Trigger Rotor 2 Trailing
pin 9 - Housing Ground Rotor 2 L & T

(each additional rotor requires 3 more pins)

I don’t see how you can do it per the diagram and not have a harness that matches the noted pin layout.

but again, I’ve seen plenty of different sources claiming otherwise and it’s been argued over on the forum, but the list above is how I believe Lance Nist would say it should be done.
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