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So replaced my L1 coil with my spare Holley EFI coil and the issue seems to be mostly resolved. Idle seems to be a bit more rough and vacuum seems to be sometimes at is typical -13.0 to -13.5 inhg and other times lower at like -12.0inhg. I'm thinking my T1 coil may also be experiencing the same problem the L1 coil was. Put a bunch of km's on the car this weekend though, and definitely some of the hardest driving I've done on this engine so far. It seems to have liked the harder/hotter driving and idle seemed to have slightly improved after the hard driving. I think I'm going to replace both the L1 and T1 coils with some new IGN-1A's so all 4 coils are matching again and then work on pulling some more fuel from my tune. One of the other factors that is likely not helping my ignition system is just how rich I still am, especially in shallow vacuum cruise areas (at some points seeing low 11's), which is worsened by the fact that I actually read 0.5AFR richer with my AEM UEGO stand-alone AFR gauge compared to the Adaptronic wideband. My AEM gauge always read the same as my front Rx8 O2 sensor on my boosted Renesis so I'm leaning towards that one being the more accurate reading. The two current sensors are about 8" apart, one on the downpipe and one in the BHR midpipe bung (I don't remember which one is in which place off the top of my head).
So replaced my L1 coil with my spare Holley EFI coil and the issue seems to be mostly resolved. ... Put a bunch of km's on the car this weekend though, and definitely some of the hardest driving I've done on this engine so far. It seems to have liked the harder/hotter driving and idle seemed to have slightly improved after the hard driving...
Glad to hear that things are moving in the right direction, and that you're beginning to enjoy the result of your labor /expense.
From your first summary of the issue I suspected coils or leads. Based on your trouble shooting approach it seemed simply a matter of time before you'd have the culprit isolated and resolved. It'd be nice if there were a tool /device to proactively monitor gradual coil degeneration so these c/b replaced in a timely manner prior to issue, making this less a guessing game.
Anyway, I look forward to hearing of continued progress .
. It'd be nice if there were a tool /device to proactively monitor gradual coil degeneration so these c/b replaced in a timely manner prior to issue, making this less a guessing game.
I use this coil test regularly : (https://www.rx8club.com/series-i-do-...ight=coil+test). If there are any coils beginning to degrade , that test will show it.
It still amazes me how many near new coils this test uncovers as weak. I generally get everyone I tune for to do it before we even start. And the few times I haven't .... I ended up regretting not insisting on it.
The funny thing is I was looking for my HEI tester from when I was tuning my Renesis with you Brett, but it got lost over the years and a couple of moves. Fortunately I already had a spare coil on hand but looks like I should be buying another tester ASAP; because as per Teams write-up that's exactly my case, the coils all bench test perfectly fine, even the bad one.
I have a HEI tester, and perhaps I should use it more frequently when all coils are "good" to establish a baseline in order to better read the tester when one is starting to degrade, I.e. still firing, but with less frequency or intensity.
I have a HEI tester, and perhaps I should use it more frequently when all coils are "good" to establish a baseline in order to better read the tester when one is starting to degrade, I.e. still firing, but with less frequency or intensity.
In the absence of having the HEI tester what I have been using is a timing light. The thing I find with this though is that it will actually start to skip/miss if your spark plugs get really fouled (ie like mine have been) so its not a good indicator of whether its a coil issue or just spark plug fouling. HEI tester is still the way to go..... for $30 on Amazon I don't know why I hadn't grabbed another one sooner.
So have a few updates; been a busy past few weeks.
The biggest of which is; FINALLY, I hit some WOT boosted pulls with this engine; and I got to say it was exhilarating! Ended up utilizing the services of Ryan Heinrich (RGHTBrain Design) for tuning. I have to say that I am SUPER impressed with his work so far. The car has never driven and run so smooth, and of course I got to go WOT for the first time!! Now over the past few weeks prior to this I had been hitting some low boost numbers but those had all been at part throttle. During this tuning session there was a few indicators that maybe something wasn't quite 100% and by the end of the session we were thinking a possible vacuum/boost leak because I was only seeing about 8-8.5psi peak boost with a 12lb spring (was expecting to see more around 10psi imap but I also think my wastegate actuator needs much more pre-load) and AFR's just seemed to be sporadic and hunting at idle (this seems to have been getting worse over the past few drive cycles). I've smoke tested this engine a couple times before and fixed all leaks; but that was before I ever pushed anything into positive boost numbers so figured maybe a new leak had risen due to the added positive pressures.
Anyways, I smoke tested things again and fortunately didn't find any vacuum leaks..... however, I did find this nice big exhaust leak which appears to be a cracked weld in my manifold right on the turbine flange. Also found my turbine to downpipe Vband was leaking so I'll try and address this when it gets re-installed with a bit of high temp RTV as well:
So something I now know that I wasn't sure was possible prior to this; the low mounted exhaust manifold CAN come out of the car from underneath and I didn't even have to remove either of the intake manifolds and I was able to keep the turbo hooked up and in place. Of course this task is nowhere near what I'd call fun, but at least it's possible.
Fortunately I have a good friend who is a welder and he was able to take care of this for me. His initial thoughts are that the wrong rod type was used on the turbine flange. It is a carbon steel flange welded to stainless tubing which leaves the welds prone to cracking if the right rod is not used. After touching up the welds at both flanges (only the turbine flange was carbon, everything else was stainless), cleaning things up, and doing a bit of port smoothing I picked the manifold back up last night. Of course while I had this out and had the opportunity I also got some EGT bungs welded in for future use that I will just plug for the short term. Of course after all this welding both flange faces were touched up with a belt sander to ensure we have perfectly flat mating surfaces.
Last night I wrapped the manifold with some new DEI Titanium heat wrap and will likely begin reinstalling everything tonight. Picked myself up all brand new gaskets (decided to go with OEM exhaust manifold gaskets this time) and some stainless steel threaded plugs for the EGT bungs. Once this is back together I'll smoke test everything again and confirm we are leak free. *Fingers Crossed*
Last edited by RotaryMachineRx; 07-04-2022 at 05:59 PM.
sorry to hear the same guy got you coming and going, must be a bit frustrating for sure, but congrats on the progress
the turbo manifold may come out from underneath, but not the turbo, lol. I couldn’t even get the much smaller EFR7163 in there from underneath.
I recently bought the same DEI Ti wrap for mine as well. Waiting on the latest DEI Gen 3 turbine housing cover to arrive tomorrow.
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Oh the turbo is definitely not coming out that way; but I do think with the coolant and oil lines disconnected it could be "maneuvered" around the LIM and frame rail out the top...... hard to say for sure without trying; which I don't intend on doing until the day it is absolutely necessary . Worse case scenario I think the compressor and CHRA could be removed from the turbine housing and it could be removed in 2 parts.
That DEI TI wrap was actually quite nice to work with and doesn't require any water wetting like their standard stuff does.
Manifold is back in and turbo mounted again. I used some Permatex copper RTV on the stock REW exhaust gaskets as well as a thin layer on my new SS turbine/manifold gasket; between that and the new welds this thing should be leak proof (knocks on wood). Tonight I will double check all my bolts for tightness; re-install the turbo oil drain, and RTV the turbine/downpipe v-band flange. Will then smoke test things again; if successful I'll be looking to continue getting the tuning dialed in and start looking to bring boost up to my target of ~15psi.
The biggest hang-up on progress I'm going to have now is the fact that my wife is due with baby #2 (boy this time) in a week!! Ultimately though this may actually allow me more flexibility since I'll be taking the remainder of the summer off of work on parental leave.
A few photos of the re-installed components:
A shot from below of how much clearance I have between my compressor housing band and the LIM:
Last edited by RotaryMachineRx; 07-06-2022 at 02:45 PM.
Smoke test was successful. At first the downpipe V Band was leaking like crazy but a bit of fine tuning and I was able to eliminate that completely. Bumper and wheels will be going back on this evening and I'll be taking it for a test drive, weather pending. Should be all ready to go for a nice 7's day meet this Saturday and then continue on with tuning in the coming weeks
Small update on the good stuff everyone actually wants to see. This is on a preliminary "basetune" that was done with Ryan prior to my exhaust leak. Still a lot to do tuning wise but this is at least giving me the ability to open the car up.
3rd Gear Pull; 10psi peak.... see that traction light doing some work up top You'll notice after shifting I experienced a safety ignition cut due to a bit of lean out; obviously this is because there's still work to do on the tune but luckily Ryan has the safety margins pretty tight.
Next are a couple videos a buddy sent me while cruising back from a 7's day meet on the weekend. The sound of this thing just has me grinning from ear to ear. Honestly I couldn't be happier with how things are finally shaping up; its funny how your passion for a project can be completely reignited with a bit of good progress!
Unfortunate update. Was doing some 16PSI 4th gear highway pulls during a tuning session and everything seemed to be going just fine. I pulled over to make a U-Turn when my idle vacuum dropped drastically and idle became quite rough (exhaust note like one rotor was not firing properly). Went straight home so I could diagnose (thinking that maybe a vacuum leak had appeared) but was not able to find anything obvious.
Performed a compression test and Rotor 2 is reading 20psi on all 3 faces (I've tested like 6 or 8 times and get 20psi on all 3 faces every single time). I've spun the motor by hand and checked all Apex seals/springs and they appear to be fine still. Unfortunate but it seems this engine needs to come out and get torn down. My initial thoughts are that this must be a housing or iron issue for all 3 faces to read exactly the same like this.
Anyways; with having a newborn (born 2 months ago) and taking some time off work the engine teardown/rebuild is something I'm going to have to put off for a couple months. I will be tearing down and rebuilding this engine myself this go around so I'm looking forward to doing that and having the chance to redo a few of the minor engine bay things that I would have done differently (some hose/wire routing, etc). Plan to try out an xcessive LIM this time to give the back of my UIM a bit more room against the firewall; but that's assuming it doesn't affect too many other components such as fuel rails and charge/intake piping.
Unfortunate update. ... Unfortunate but it seems this engine needs to come out and get torn down. ...Anyways; with having a newborn (born 2 months ago) .
Jesse -
Congratulations on the addition to your family!
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Sorry to hear this bad news about the engine...
Damn it , just when all your issues seemed to be resolved . I know that feeling only too well .... hope you can learn something from it and get her back on the road soon.
Huge congrats on the new addition to the family !
Damn it , just when all your issues seemed to be resolved . I know that feeling only too well .... hope you can learn something from it and get her back on the road soon.
Huge congrats on the new addition to the family !
Thanks! And yes, it will be a very interesting learning activity tearing this engine down and trying to see where the failure stemmed from. I also look forward to the experience of assembling one of these engines on my own, will be a good skill to have and build upon for future needs. I have absolutely no idea where the issue arose; at cruise and under boost/load it was asymptomatic and I never would have even known there was an issue. It was strictly the large drop in idle vacuum and idle exhaust note change that drew my attention to any issue. I'm hoping this means it is a minor issue and the engine can be rebuilt with minor parts replacement. Ideally anything that needs to be replaced can be borrowed from the spare engine I have in the garage and a rebuild will only essentially cost me the soft parts (seals, gaskets, etc).
It's at this time a really regret not having EGT info lol. Front rotor is still testing at 100psi on all 3 faces.
there are a few people on RX7Club that swear the RA apex seals will always warp, so even if they look ok through the exhaust port you may not be able to know until pulling it apart and placing them on a precision straight edge.
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Not dead, just some major procrastination over he past few months. Finally spent a couple hours on the car, a short update of where I'm at. Plan is to leave trans in place along with leaving the AC compressor hooked up the the AC lines. Hoping I can shove that over enough to maneuver the engine out the top with the turbo, exhaust manifold, and LIM still installed.
Down to a wastegate actuator vacuum line and the 23mm banjo oil return line off the front cover then its only transmission and motor mounts keeping the engine in place. As you can see in the 4th photo I need to shove the engine over about 1" (probably even less than that) to avoid interference between my compressor housing and the subframe. Right now the subframe sits about 1/2" in front for the compressor housing. The subframe and frame rail both hang over/in front of the compressor housing by about as much. What this means is currently I don't have enough space to pull the engine forward off the transmission, nor do I have clearance to lift it straight up. My idea is to loosen off the PPF bolts at the diff, remove the motor mount bolts and see if I can shove the engine over that ~1" while still connected to the trans. I don't see this being a problem as I was capable of moving the Renesis over while doing the Greddy turbo install even without loosening the PPF. Anyone see any flaws with that line of thinking?
If I can move it over that 1" that means with this setup I can pull the engine forward off the trans and lift it out of the engine bay easily, all with the turbo (with all water and oil lines still connected), exhaust manifold, and LIM still on the block. This will allow me to dress/undress this all outside of the car which will be SOOOO much easier. The AC compressor has plenty of slack in the lines that it can be left connected and held out of the way while the engine comes in and out.
Welp, as suspected getting the engine out was a breeze, especially with a couple extra hands and the PPF loosened off on the tail of the transmission . Currently have it on the engine stand and at the point where I'm ready to crack the rear nut. The plan is to tear this engine down sometime between Christmas and New Years. Another photo dump:
Also, intitial inspection of the housings and irons through the exhaust ports don't show any signs of damage. I know that's only 1/3rd (or less) of the surfaces but hoping that's a good sign that maybe we're just dealing with some flattened springs or some failed seals...... we'll find out next week.
06-06-2022, 11:48 AM
Now over the past few weeks prior to this I had been hitting some low boost numbers but those had all been at part throttle. During this tuning session there was a few indicators that maybe something wasn't quite 100% and by the end of the session we were thinking a possible vacuum/boost leak because I was only seeing about 8-8.5psi peak boost with a 12lb spring (was expecting to see more around 10psi imap but I also think my wastegate actuator needs much more pre-load) and AFR's just seemed to be sporadic and hunting at idle (this seems to have been getting worse over the past few drive cycles). I've smoke tested this engine a couple times before and fixed all leaks; but that was before I ever pushed anything into positive boost numbers so figured maybe a new leak had risen due to the added positive pressures.
. Worse case scenario I think the compressor and CHRA could be removed from the turbine housing and it could be removed in 2 parts.
Ultimately though this may actually allow me more flexibility since I'll be taking the remainder of the summer off of work on parental leave.
Looking forward to further progress updates.
