RotaryMachineRx

iTrader: (1)

I've been running this setup for 8 years now without issue. Hold your throttle so your boost stays steady at 0psi for a few seconds then let completely off your throttle. Back fire and flames on demand if your exhaust is good and hot, good for getting those tailgater's off your ***! The more load on the car while you hold it at 0psi the bigger the backfire, I find it works best in 3rd

Other than that situation I've had no reason to change my SSQV to recirc either.

JimmyBlack

Road tuning of the car is going well. The wastegate has a 6psi spring installed, and I've configured the boost controller to get 11psi using Duty Cycle. I'm hitting about 7psi around 3800rpm in 3rd gear, and hitting 11psi around 4100rpm. Boost tapers down from 11psi to 6-7psi as rpm increase, due to the exhaust pressure pushing the wastegate open. I should be able to address the boost drop off by adjusting boost controller Sensitivity setting.

Will post a virtual dyno once I get boost level consistent after a few more road tuning sessions.

Car issue I'm aware of is that there's a slow oil drip. When I'm sorting that out I'll check everything over and see how it's holding up to the heat.

Brettus

iTrader: (2)

I doubt that will do it ... I'd go to an 8psi spring . Mine doesn't do that ...wondering if it's the larger balance tubes you used .

JimmyBlack

When I was running wastegate pressure with no controller settings, the boost was very consistent. You're right about the controller sensitivity not being able to tune out the boost drop - when I set it to max, peak boost of 12.5psi dropped to 9psi by redline. The tune is good now, so I'll see about replacing the spring with a stronger one. Lol there goes the boost controller's Wife setting.

JimmyBlack

My wastegate came with 2x 7psi springs. Initially I had one of them installed, showing a consistent 6psi of boost at upper intake manifold (with no boost controller settings). I've now installed the 2nd spring alongside the first spring, so upper intake manifold boost pressure is now reading 12psi. I haven't revved it out yet to see whether it holds constant pressure to redline.

I have a slow oil leak dripping off the oil pan to the floor. I got under the car and tightened a few worm clamps on the oil drain piping, but the leak is still there, so suspect it's from a break in the sealant between pan and block, caused when I trimmed the edge of the oil pan to fit the new motor mount. I'll need to drain the oil and re-seal the pan to stop the leak.

While re-inspecting the turbo install under the car I noticed some black soot around the outside of the turbo beanie that looks to be coming from the jet air fuel mix nipple. The nipple is a sleeve that is pressed into the block. During install, I bent the nipple upwards slightly to clear the oil feed line into the turbo core. This left the jet air nipple sleeve slightly loose, though the attached hose keeps it secured in place. The soot around the turbo beanie indicates there's some sooty gas coming out of the block around the edges of the jet air sleeve, probably being released after each combustion cycle as the intake port opens. This would also indicate there may be a small boost leak in the same area, which will require fixing. I can't find much info on the function of the jet air fuel mixing line, other than a rough description that it helps atomize fuel at low engine speeds, presumably for emissions or fuel efficiency.

I'm considering pulling the jet air sleeve out of the block permanently, and blocking the hole with an epoxy, e.g. JB Weld. Before proceeding with this, I'll run the car for a few days with the jet air hose blocked to see if I notice any side effects.

JimmyBlack

Just found this PDF detailing benefits of jet air fuel mixing.
http://www.rotarydevelopment.net/Rot...790_Rotary.pdf

Summary:
- Decreases hydro carbon emissions at idle by 30%.
- Decreases fuel consumption at idle by 7%.

Interesting read - contains some interesting comparisons with other rotary engine models.

FazdaRX_8

iTrader: (1)

I have found I really dislike boost controllers, they are a pain to setup, and if they fail then you will boost to the moon. I have found my syncronic wastegate with the adjustable port configs to change boost much more simple and reliable. the boost never drops off and it kicks right in. no worries about failures.
but thats just my two sense

good progress!!

Brettus

iTrader: (2)

I'm really liking the syncronic DV I recently fitted too . How much boost variation can you get without changing the spring ?

JimmyBlack

14psi wastegate springs fitted, now showing 11-12psi in the upper intake manifold.

Two slow oil leaks have now been sorted. I removed the oil pan and replaced/improved the turbo oil train line, including new hose push lock fitting and re-welding the bung on the pan. Gave the pan a fresh coat of flat black paint and re-installed it. Looks a lot nicer now.

Fitted new spark plugs: NGK R7420-9 Leading. NGK R7420-105 Trailing with added washer from previous trailing plug. Old plugs were OEM. They were very dirty having done about 20,000 km. I don't notice any performance difference but it's good to know I should have reliable spark for the next little while.

High temp RTV silicone sealant added around the jet air nipple on the block. It's running a little leaner now, so I think there was a small boost leak there previously. Tune not looking too bad, but needs a bit of a tweak. My open fuel tables are all at 11.3 AFR, so once tuning is done I'll set it back to a smoother table with higher AFRs at lower loads, which will make driving a little nicer.

rotarenvy

is the RTV sealant to hold the hose on or is it sealing around where it enters the manifold?

Brettus

iTrader: (2)

How do your virtual dyno logs look now ?

JimmyBlack

Car is going well, running at 13psi, and it's the fastest it's been. Spool is not quite as good as the t25 turbine housing, probably increased by around 200-300rpm. I've set the RPM Limiter to 8250, and top end doesn't taper off like it did with the t25.

NPD gas stations now offer 100 Octane here in New Zealand, so I've been using this for the last 2 months. It's Unleaded, non-ethanol based with ratings of 101.5 RON and 89 MON, equivalent to US 95 octane (average of RON and MON). According to my quick read through the Octane Rating article on Wiki, E85 has a similar US Octane rating of 95-96. I'm getting no additional fuel consumption from the higher octane - still the same lousy mileage. I sometimes drive the Leaf to work to keep my conscience clear.

I've been changing back and forth between 11.5psi (WG spring) and 13psi (elec. boost controller), and that extra 1.5psi seems to give a bigger step up in performance than I would have expected. Probably because the turbo compressor is coming into it's efficiency zone without being held back by excessive exhaust back pressure from the restrictive t25.

One minor item that requires a bit of attention is a bit of knocking/vibration sometimes at idle. It'll most likely be the exhaust pipe hitting a cross brace, or a slight sag in the engine mount causing the manifold/turbo to touch the subframe. This is quite likely as there was minimal clearance during install. I'm expecting an additional spacer on the mount should resolve this permanently.

JimmyBlack

Spacers added under rubber engine mount. Seems to have done the job - no more of the vibrations at idle that I noticed previously.

JimmyBlack

Turbo inlet pipe got a bit of attention this last weekend. The left side of the pip already existed, finishing in the straight middle section. I added a 45 degree onto the right side of the straight pipe in the photo above. This replaces a 45 degree silicon joiner. Also added a BOV inlet.


The vent to atmosphere BOV was creating a lot of loud backfires. Was getting a bit too raucous for pretty much everyone except me. My son refused to ride in the car, and more than once a pedestrian jumped off the sidewalk when I eased off the gas at just the right time. It made me laugh a lot, but not that safe or pleasant for others.


Car is a lot more pleasant to drive now - no backfires or rich running after revving it out. Son also approves.

jcbrx8

Jimmy, Good work, man!

Brettus

iTrader: (2)

Nice work ! My only suggestion (based on zoom zoom-boom experience) is to limit rpm to under 8000 at that boost level . For extra safety - have a look at your g/s logs and set rev cut at the point where g/s level off .

FWIW : I set my boost cut at around 7400 and rev cut to around 8300 . I hardly notice the dropoff after 7400 .. i think it's worth it to have a setup that can do that.

JimmyBlack

Thanks. Feels like it pulls harder as it gets closer to rev limit but I'll check g/s all the same. I don't have a fancy boost cut by RPM feature, so I'll just have to wing it

Brettus

iTrader: (2)

VFAD wires and a relay

slash128

Glad to see you are still having fun!

JimmyBlack

What a sneaky guy.


What boost level would you gauge as "not too dangerous" after the boost cut is triggered (I.e. recommended WG spring pressure)? I may have to trim down my WG springs to calibrate this as the LIM is showing around 10.5psi at 8krpm currently.

Brettus

iTrader: (2)

ah ... that should be fine . I thought you were holding 13 all way to 8k.............

Brettus

iTrader: (2)

So Jimmy the deserter sold this car to a guy that lives near me.He brought it to me yesterday to fix some issues he was having so I got to take it for drive . Have to say , it goes great ! Such an awesome car Jimmy ...great job getting it to this level !

TeamRX8

iTrader: (25)

I didn’t realize he had bailed. Sorry to hear that he left, but at least the RX8 lives for another day and fortunate to be close to someone like you who can provide good support.

JimmyBlack

I'm still loitering - I love seeing the incremental progress with the renesis. I was sad to see my 8 go, but feel it's in good hands with the new owner.

The final tally to date is:

• 5 years since undertaking the NA to turbo conversion
• 3 different turbo wheel and housing combinations
• 0 blown motors

Brett, after all your contributions I'm happy you had a chance to experience the car in it's final state.