I hope that you’re not admitting to still having OEM differential support bushings? 🤯
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Unfortunately I am...... It's not something I had really even thought of until you brought it up..... looks like a nice project for the upcoming winter though.

 

Wait what did I miss or forget about the OEM differential support bushings?

 

Apparently they are common for wearing out with age and its worthwhile to replace with some Poly bushings. Not something I can say I've really heard much of until I specifically searched it. For reference I only have 92,000kms on my chassis (57,000 miles).

For reference:

https://www.rx8club.com/series-ii-di...cement-264285/

 

As of right now, I still have the OEM 80k mile diff bushings in. I did run into issues on my other two Rx8s with those before. Seeing how the REW cx crossmember is on poly, I am going to match that in the rear when I get around to rebuilding the diff.

We welcomed Lana, our new puppy to the family. At the same time I have been fighting with my daily RX8 with its clutch system. Ended up replacing the master, slave, and softline. Probably bled it 10 times. After re-adjusting my pedal several times it is starting to feel normal again.




Otherwise I got the JDL surgetank in the car. I am soon to buy materials for the plumbing. Honestly I think if I ever take it back apart I will end up removing the surge tank and go the fuelmat route instead. There have been a few tricks in fitment to get the kit together. Like shaving down the setscrews and tube routing.







On the turbo side we are nearly complete finishing the design. After clocking the turbo it looks like I will have to make my own WG actuator mount to achieve the oil drain angle I want. One purple manifold design was trying to angle the inlet of the turbo towards the center of the car, but I think it moved the turbo too far forward while also being unequal. In the end we are going to flush out the design of this orange manifold. Ideally moving it closer to the LIM and adjusting the runners. Note I will probably relocate the solenoid.






The slight angle orients the turbine outlet towards the direction I liked. Otherwise the runners will be symmetrical. On the IWG we have alot of room around the turbine side. Remember the IWG moves the compressor forwards by 20mm due to the T4 flange placement on the turbine.

 

Awesome work so far! So these photos are with the IWG turbo or is this the EWG?

Also how did you get the turbo mounted in there? Did you drop the block into place with the turbo installed or were you able to fish the turbo in place and get it all bolted in while the block was already mounted? This kinda goes hand in had, but is the LIM able to be removed and all the bolts accessed with the turbo mounted?

Reasons I ask all these. My current setup I cannot get at all the LIM bolts with the turbo in place.... and with the LIM mounted I cannot get the turbo in and out of that area lol

 

This is with the 8474 IWG turbo. As far as I can tell I have access to all of the bolts. The only tricky ones will be on the manifold itself. I will have to stud the two top T4 holes.

Even so I am able to install the LIM and uninstall it. I can also install the turbo with the LIM in place if needed.

Are you talking about the upper bolts on the xcessive? The cx LIM is just that flange so it is really accessible. Bolts install just fine, actually I probably have room to get closer to the LIM.

 

edit: thanks for clarifying in the post below.

wrt the diff bushing's, the OE bushings were way soft for the Renesis engine output, but now you more than doubled the torque output with a turbo REW. It will likely have a lot of wheel hop trying to launch hard from a dead stop with grippy tires.
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Both of these Orange and purple manifolds have dummy runners that I have yet to adjust. We printed these quickly to just test where the flange lands the turbo. The orange one will end up with symmetrical runners both curving through the flanges. The runners will have to fatten up a bit from what you can see now.

Just ordered a ton of fragola AN goodies, and plan on starting the fuel lines soon.

 

btw, Mazda ~doubled the new REW engine keg price last week and I heard Motorsports is no longer selling them to members. You’ll be lucky to find one for under $9000. It will actually be cheaper to order all the parts separately. Assuming they don’t jack up those prices too.
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Adam was saying that prices per plate have been going up consistently by about 100$ every month.

I had paid about a year ago (oct 2022)
$2463 for the irons
$1990 for my housings
$1738 for rotors

 

Makes that spare keg I bought last year seem like I knew what I was doing lol...... but for real, that price increase is a shame, the price of used, and rebuilt/refurbished parts is going to follow that trend as well and everything is going to be much more expensive.

 

I believe with my turbo location the middle and front lower bolt on the LIM to the block is not accessible. Last year I was able to get my exhaust manifold out through the bottom while I left the turbo in place...... to be completely fair, I left my water and oil feed lines connected to the turbo and didn't really give it a good effort to see if I could remove the turbo, it certainly didn't look like it could but if you are able to then there isn't really a reason I shouldn't be able to either if I removed my exhaust manifold first.... hard to truly say for sure without actually trying it, but at the time I had some cracked welds on my exhaust manifold and that was the focus.

 

you can order rotors from Japan including shipping for less, I paid $1350/pair shipped back in April for the 8.5CR. I couldn’t touch that even through the Motorsports racer program wholesale pricing with discounted domestic shipping.

you can order two front REW rotor housings since the EGR function isn’t needed, the rear housing costs $200 - $300 more than the front one

and of course the RX8 6-port stat gears are almost $1000 less than the REW version
.

 

Small update again, waiting on several orders of fittings. Planning out the oil and fuel systems.

Fuel:
The current setup will mimic the stock setup of hardlines under the car and then softlines jumping the firewall to the engine. One idea I had was to mount all of the fuel components on the UIM and LIM. This way I could easily disconnect and unmount everything. This should also help avoid conflicts with wiring. To aid this, I modified the UIM and LIM. On the LIM I slotted the stud mounting holes and also slotted the front mounting hole. This should just ensure that I do not have to fuss with it when the turbo is in place. For the UIM I removed some parts to give extra clearance on the firewall, and also some space underneath for the Flex fuel sensor.




Here are the rough final locations of the fuel components in the engine bay. I can probably tuck the Flex fuel sensor up in there some more.



Otherwise JDL sent me out his new taller Side AC/Alt bracket. This fits much better, his original one was based on a custom engine mount that did not have the engine flat. Now I will have to find an alternator and a pulley/belt setup that works. I will have to make a bracket to hold the top part of the alternator.



Here's an extra image with the strutbrace in. I should be able to fit an intake pipe between the Alternator, ABS, and the strutbrace. You can also see I fit the Rx8 OMP, but I will not actually be running it to start off.

 

Great job, well done. Love the slotted mounting points on the lower intake manifold. If you are able to produce multiple casted turbo manifolds like that, I will be interested if my design does not pan out.

 

@Warrior777 Once the design is done I can see what places will quote for single or small batches. I plan on 3d printing it through work out of Inconel 625, but I would not be opposed to having some made if folks want me to. I can post costs once I have them.


Also, I have updated the Google sheet for the oil system. Link
Really the only question I have left is about the turbo oil feed. BW's instructions say that the EFR's have a built in restrictor so an additional restrictor should not be used. However I remember some people on the Rx7 forums discussing various restrictors. I also saw that Turbosmart has a 40psi regulator that could be put on the REW turbo feed outlet fairly easily.

 

the one thing to consider wrt to offering a turbo manifold to others is your CXRacing engine support and LIM compared to which brand they’re using. Because the manifold might not fit the same.

I also bought a Turbosmart turbo oil supply regulator. Because a modified rotary engine will typically have much higher oil pressure than a piston engine; 120+ psig with a modified engine oil pressure regulator using 40W or higher oil. The supplied orifice in the CHRA oil inlet isn’t sized properly for the higher pressure.
.

 

I've been a big proponent of this as I noticed it as well. The BW manual says no restrictor as it has its own...... then later in the manual it states that you should not feed the turbo more than 60psi...... anyways that turbo smart oil regulator will work perfectly, i've seen a few people using it now, 40 psi is plenty of pressure for the turbo. I have an adjustable regulator on mine, but when I say that it's basically a ball valve and I just closed it partially until I saw less than 60psi at the turbo on a cold start.

 

If anyone wanted a manifold, we could work something out where I ship a 3d plastic version for test fit.

Ok looks like I will order the turbosmart regulator then. Sadly my feed line has a banjo bolt end, so it might be a pain to get working with the regulator.

Edit: nvm I am dumb, the feed line is a 4an to banjo that can be removed.

 

Most hydraulic stores will build you a new -4 feed line. I recently had one made for Dondo on his turbo rene 8.

 

You can cut the line and add fittings for attaching the regulator. It should not be too close to the turbo due to the heat.

 

I'm not, not interested

When you get your final version made, are you going to be putting EGT bungs in it?

 

Yes, I did add provisions to tap for EGT thermocouples.

 

Don't consider this a rush, but when you have information I'd love to chat with you about the plastic mock up for test fitting and just getting an idea of numbers for an actual production version. I'm currently working through some issues with my build still (either fueling or ECU from what I can see right now) so that is on the forefront of my concentration...... also we just got our first snowfall for the year a day or two ago, so the car is parked now. Looks like it might warm up for a few more days yet next week so hoping I can get the car out for one last test run this season still.

But I definitely think my manifold design is far from ideal.