RotaryMachineRx

Hi everybody, my first post to this forum, but I've been a long time member of Rx8Club where I had a boosted Renesis from 2010 - 2019.

Over the past winter I had a 13B-REW swapped into my RX8. Some Mods highlights include:

- Built Engine with Large Street Port (built by a reputable builder)
- Adaptronic Rx8 PNP ECU
- Rx8 DBW Electronic TB
- BW EFR 9174 single turbo
- FFE fuel rails with ID1000 primaries and ID2000 Secondaries (Aeromotive FPR)
- Walbro 450lph fuel pump
- AEM IGN-1A Coils with Rywire subharness and Sakebomb plug wires




The current issues I'm having are that the car is extremely difficult to get a solid idle out of and I'm burning oil at a very alarming rate. This is causing pretty much constant blue/grey/white smoke coming from the exhaust. I'm noticing the most smoke at idle and decel (revving engine in neutral creates the most smoke). It seems to be much better at cruise and worse again under acceleration. I currently have approx 800kms (500 miles) on the new engine, I am still performing my break-in miles so I haven't been hitting positive boost pressures and I have the rev limit set to 4500rpm.

Initially it was nearly impossible to get the engine to idle smoothly under 1500rpm. Thinking it was possibly an ignition problem I switched from BHR Rx8 Coils to the AEM coils with dedicated subharness. Noticed immediate improvements to ignition (especially start-up) but was still unable to get the car to idle smoothly are my targeted 1100rpm. Thinking it was possible I had a sticking injector I pulled them out and had them tested and cleaned (they checked out just fine). In that process I found a small nipple that was missing a cap causing a vacuum leak. Capping this vacuum leak I've now been able to get idle to smooth out at 1100rpm but it seems to still be fairly inconsistent (getting a good lope a lot of the time when returning to idle).

Vacuum leak:



Example of smooth idle:

In my opinion vacuum seems to be a bit low at idle (-12 - 13.5ish). AFR's are richer than what I'd prefer (12.5 on Adaptronic, 12.0 on my AEM gauge) but this is where my tuner (Tuned by Shawn) wanted to keep it for now.


Here is an example of the loping I'm getting when it doesn't seem to want to idle smoothly. You can see RPM is much less stable as well as AFR's compared to previous video:

I'm currently using BUR9EQP spark plugs in all 4 locations for break-in miles. It's quite possible these are starting to get fouled up causing the rougher idle. This is this is my 3rd set of plugs in the car in the 800kms (500 miles) I've driven it. The following set of plugs were pulled out of the car at about 320kms (250miles) of use (all miles on these plugs were with the above vacuum leak):





On to my oil consumption issue:

I noticed early on that I was consuming oil and the exhaust was smoking at an alarming rate. Burning a quart of oil every 50-100miles. During my tuning session the other night to acheive the stable 1100rpm idle, the car was idleing for aroun 1.25 hours (mostly poor idle while we sorted the tune out) and I ended up burning 1 quart of oil during that also.

Initially I had a -4an feed line directly from REW front cover to the turbo CHRA inlet. Turbo oil drain was a -8an containing a 45deg and 90 deg fitting back into the stock front oil return. Crank case venting consisted of a -6an line to a vented-to-atmosphere catch can. After discussions with a number of people I decided to get an adjustable oil feed regulator (Freelance motorsports) and swapped the turbo drain out for a 5/8" barb with vibrant silicon heater hose wrapped in DEI heat shrouding. I've opened up a second -6an port on my oil fill neck as well hoping that the combination of all 3 of these items was causing oil to blow-by the turbine seal.

After installing the feed line regulator I would have expected to see 100-120psi cold start oil pressure and around 60psi warm idle pressure into the turbo. This however is not the case; cold starts I am seeing around 50psi which eventually drops off to 0psi at warm idle!

Turbo feed oil pressure gauge:


All of my intake/charge piping off of the compressor side is clean and oil free. I haven't pulled the downpipe yet to investigate the turbine side but I can imagine it's not good. My thoughts are that the turbo seal is gone on the hot side so bad that the oil feed line is not able to build up any pressure. I unfortunately do not have an aftermarket oil pressure gauge anywhere else but my assumption would be that if the oil pressure was actually that low in the engine I would't have made it the 800kms (500miles) I already have.


Anyways, I apologize for the very long first post but this has been beyond frustrating. Looking for any advice, experience, words of wisdom, or ideas on where to look to get this engine running the way it should. Please feel free to ask me about any other details about the engine you think may help. Ideally when I get this all set up and running I'd like to see approx 450whp and around 15psi of boost.

RotaryMachineRx

Just for fun; a photo of the car how it sits today:

Turblown

iTrader: (12)

Have you done a compression check? The fact that engine idle vacuum is super low, and the car is burning oil points the finger at the engine. Also the EFR turbochargers are extremely robust, I have YET to see a bad one out of the box( literally sold 1000s of them). I've also only seen only one burn oil( ending up being a highly contaminated oil feed from a bad engine, again a " freshly rebuilt" one).

RotaryMachineRx

I did do a series on compression tests very early on (150 miles on engine). The rear rotor seemed to be pretty consistent but the front rotor was getting results all over the place. One test I even saw one face at 67psi! Here are the results from my latest compression test (with a rotarycompressiontester.com unit) at around that 150miles mark.

R1 Test 1: 87, 89, 76
R1 Test 2: 82, 88, 91
R2 Test 1: 95, 91, 96
R2 Test 2: 87, 90, 97

Definitely lower than I’d like but not terrible. Was hoping I could get the engine running properly and get a few more miles on before testing again in hopes the numbers would improve.

fendamonky

iTrader: (6)

I'd be talking with the engine builder, those numbers are low.. combined with the excessive oil loss I'd assume sloppy clearances and oil control ring/seal issues.

Can you confirm new oil rings and what the clearances were set at?

RotaryMachineRx

Absolutely, engine builder is aware. Just waiting to figure out our path forward. In the meantime wanted to hear what people thought of the conditions in the first post. Maybe someone has experienced similar.

fendamonky

iTrader: (6)

Well, I'm not a pro by any means... however I started rebuilding my own engines after being screwed over by "professional" engine builders on multiple occasions.

TeamRX8

iTrader: (2)

so it turned out the engine was built fine, but a different shop that did the installation plumbed the remote oil filter backwards. Which meant the engine was trying to pump oil the wrong way against the filter drain back valve and more or less starved the engine of oil.

but the reason for bumping this is it has an EFR9174 turbo and BW does a really crappy job when it comes to listing dimensions.

was hoping somebody might have a 9174 around to help me out with the A, E, and H dimensions indicated on the diagram below, preferably with a 1.05 turbine housing, but a 0.92 would be ok

TeamRX8

iTrader: (2)

the OP pointed out to me that the 9174 is dimensionally identical to the 8374 and also that there are some outline drawings in the BW EFR technical paper.

I was able to scale off those to determine what I was after, or close enough

A - 200mm
E - 180mm
H - 89mm


.



couldn’t help but notice that they have the 4” compressor inlet listed incorrectly. It scales out proper though

silverTRD

iTrader: (36)

I have a 9174 sitting here if you need anymore dimensions off of it. PM me as I probably won’t see this thread again soon.

That's a nice RX8 btw

RotaryMachineRx

Glad that worked out for you Team.

Thanks for the Compliments SilverTRD.