ciprianrx8

Thank you again for the sugestion with the crashbar. I will pursue to clear the foam padding and to make the front bumper grille flow more air. Of course I want max amount of fresh air towards the climate/water radiators.
Being winter right now, this is not a priority though.

TeamRX8

iTrader: (25)

well I can send you an appropriate maf tube if you want it since I’m switching to a MAP system and also have a backup too if ever needed again.

lmk.

TeamRX8

iTrader: (25)

didn’t realize the Mazda Motorsports here imports and sells it; $190 + shipping. Wouldn’t buy it myself unless the class rules etc. specifically allowed only that part, but here it is. Since it’s imported and technically not a USDM OE part anyone with a US shipping address can order it from their website; Part No. F151-50-070D



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ciprianrx8

While the car is getting its pressure pipes made, lets talk a bit about the WMI system I plan to run. I say "plan" because it's been a pain in the back since the purchasing of it - I've lost 2 parcels so far due to this pandemic, and one of them had my wmi nozzle and solenoid. The other parcel with the pump arrived, but the pump was DOA. Fast forward a few weeks and now we are here: reordered the wmi nozzle, solenoid, hose and have manually rewound the pump motor to get it to work. Honestly AEM stuff is just overpriced GARBAGE. I still wish I had gone with something else but the money already went down the drain.

To control WMI, I've made my own multifunction controller. Long story short, it will use MAP and MAF sensor signals to give me a progressive-by-air-volume spray. I also have an EMAP sensor as a plausibility check for the mix of intake pressure and airflow, if there is no backpressure how there can intake pressure? bonus points for reporting EMAP which I find to be critical to such a setup.
Since this WMI thing will draw some amps, like 10-12A, I had made up an entire 12v ignition switched system, with a relay and fuse. I have also laid the hardware to implement an electronic boost controller, but time will tell if I'll bother with it. 7-10 psi isn't that much anyway.
I'll leave the pictures tell the rest of the story.







I've found a neat spot to mount the WMI pump without taking room in the trunk. The tank itself is a metal jerrycan, if it's good enough for gas its good enough for whatever I find to use as alcohol.

TeamRX8

iTrader: (25)

as long as it’s not a steel container, otherwise it’s likely to have a corrosion issue in the near future.

ciprianrx8

Left to do - intake and charge pipes. By mid january this thing should be done.

RotaryMachineRx

iTrader: (1)

You'd be surprised, if the EBC is already partially done and you have a plan for it out of personal experience I'd recommend sticking with it. Maybe the peak hp gains aren't crazy but being able to control what the wastegate sees allows for a noticeable spool-up difference compared to just wastegate alone.

Do I have any empirical evidence of this? No lol, but it was noticeable enough doing back to back pulls.

ciprianrx8

I have the hardware in place and the software written - but if I ever put them to use, it will be after the ecu tune and wmi is set up properly. Don't want to be juggling with 10 glass marbles at once.


Still not done, but getting there.

ciprianrx8

Allright. Car is back from fab work shop.






Left to do - a lot. No time for the car right now, so this will sit stuck for some days now. Bottom line is that it runs and drives, still NA.

ciprianrx8

Small weather update:

• turbo changed to a proper GTX3076 Gen2. Never undersize a turbo on a rotary unless you love spanners.
• changed WGT actuator to an adjustable one so as to get desired boost levels
• turned blow off valve into a protection device(besides normal purpose of venting pressure when getting off the gas)
• WMI ditched - IATs were a mere 5 degrees above ambient except for heatsoaking in bumper to bumper traffic and idling in the city.
• created a proper gauge/boost controller setup with 3 boost levels for 95/98/100 RON octane pump gas + 9 boost-killing protections
• changed MAF location to allow maintenance
• raised oil pressure to ~90psi
• placed oil temp sensor directly in the oil pan near the oil level switch
• did away with OEM oil pressure switch - placed turbo oil feed there. Dumb ECU doesn't give a damn that to it I am running with no oil. Thanks mazda.
• did away with oil sandwich plate - oil press sensor mounted in the banjo bolt that feeds the oil filter stand. Now the car can be serviced identically to a stock one.
• did away with the turbo oil return via the drain bolt. A 90 deg nipple was welded on and a hose routed much better than the botched-greddy style return I had till now. 2 layers of metal sheeting protect the hose from heat and 4500 miles ever since no problem arrised.
• still tuning with ME to get AFRs under boost somewhere between 11-11.5.
• too many to recall

Issues still standing:

• EMAP reading seems entirely wrong. 20psi at NA flow levels and 48psi during boost. Now if those numbers were true this engine would have long been toast. EGT readings do not add up either to the EMAP readings being right. Will need to fabricate a damping chamber or just never use EMAP readings again.
• Suspect intercooler to be creating a large pressure differential across it. Size-wise it is a big bigger than a greddy IC, just like the turbo is.
• Somehow my stock-ish(but recently replaced) fuel pump seems to flow enough enough fuel to maintain <11 AFR at 340g/s of flow. Can't complain but would love to know what is its flow limit. I suspect my 6AN fuel line from the tank to the secondary fuel rail might have something to do with it, helping with fuel flow.
• P2 and secondary injectors (uncapped yellows) seem to flow too much fuel for what I need, perhaps smaller injectors with better spray pattern will aid tuning. I am still so pig rich that I went through a fuel tank in 100 miles. Well, can be rich a million times, can be lean only once.
• From the exit of the intercooler to the upper intake manifold I seem to have 2-3 psi pressure differential. Now that seems excessive for my flows(300-340g/s) and pipe diameter(2,5").

Here is that pride and joy of mine, a piece of kit that I'd say does the best there can be on this car as far as NOT getting a standalone ECU and a hodge-podge of gauges:



I've given the OEM sat nav case a new purpose. Shown here is a diagnostics/tuning screen. It changes to this screen when the lower screen is tapped to show the buttons that select boost levels. The screen dims with the scroll wheel near the steering column and folds up/down just like it once did @ the factory.
Sneakily in the astray resides a smaller touch screen that doubles for the most important gauges (as a backup) or as a boost level selector. It also allows me to clear any errors in boost control that may come up.

Everything half-decent but that EMAP I was speaking about. I also seem to be running a lot of boost for the poor airflow I'm getting...



At the press of a button I can make my blow off open up once abs_eng_load gets past 60% and the wastegate to run on spring pressure. This leads to just about NA flow/power levels, safe to run on 95 RON gas.
Then I can toggle my first boost controller PWM table to get about 8 psi and 150% engine load. And if I get my hands on 100 RON(93 MON) octane gas, then boost town is here at about 170% abs engine load. And while we are on the topic of gas, how about some instant fuel economy to spoil the mood and some fuel trims. Gas stations where I'm from seem to mix some water with it so that they sell more of it for less dime.



The great view of night time driving. Notice how coolant/oil gauges tell a story too. Both screens can be folded away.


Right, the protections I've thought of are:

1. System defaults to 0 boost / poor octane rating fuel. I'd have to make a conscious move to enable boost. This I found to be needed so that I can get home if I get on a roadtrip and the only fuel I can get is 95RON, or use this setting if I ever track the car.
2. On low boost level setting, no boost past 10 psi @ lower intake manifold is allowed. If that happens, then the wastegate is set back to spring pressure and 0.5 seconds later the blow off is opened. This condition is kept until I press a confirm button on my ashtray screen. Same story for high boost, but on a 12 psi limit.
3. If the solenoid that actuates my blow off protection is faulty (it does not draw a current when turned on at boot-up) then the system is locked on wastegate spring pressure and an error pops up. For this I use a plain solenoid that you find plugged in the upper intake manifold.
4. My wastegate also uses the same kind of solenoid and it works wonders. But if it fails, it fails towards wastegate spring pressure. Result = maximum boost of 5 psi/130% engine load.
5. If any boost sensor fails its calibration at boot-up, again the system is locked on wastegate spring pressure and the BOV is set open.
6. If the CAN bus network is not getting updates... read above ^^
7. If EGTs get past 1750F.......................................^^^^^^ ^^^^
8. If AFRs get above 11.5 while boosting...............^^^^^^^^^^^
9. If the fuel tank gets low(light turns on)...............^^^^^^^^^^^
10. If the MAF reading gets past 360g/s..................^^^^^^^^^^^
11. If absolute engine load gets past 175%.............^^^^^^^^^^^
12. If the wastegate actuator itself fails(membrane pinches/boost hose comes off) then the boost sensors will pick it up. If those fail too, absolute engine load parameter from ECU is the last bastion of hope before apex seals come flying.
13. If the throttle is not wide open, the boost controller will limit the duty cycle sent to the EBC solenoid. This avoids building boost against a wall... such as part throttle accelerating.
14. If absolute engine load gets past 172%, then the EBC will also start limiting boost. I'd figure this would be the case in winter with IATs freezing and load increasing.
15. If IATs get past 40C, boost is halved. At 45C boost is forbidden entirely.

Quite the list and quite enough for a post. Hope to find more reasons to extend them both.
If anyone is interested in those gizmos, here is more detail:
https://www.rotarytronics.com/produc...-rx8-gauge-kit

Brettus

iTrader: (2)

Awesome work on the display !

jcbrx8

Ciprianrx8, Solid DIY build. I applaud your thoughtfulness, clear objectives, systemic planning, and patience throughout. Your fabricator appears to have done a quality job, which you've complimented by an efficient electronics monitoring and control setup.

ciprianrx8

Yeah, well the fabricator did a very good job but on my very, very poor choice of a turbo at that time. I regret deeply having selected a T25 flange to flow all the turbine and wastegate gases... and starting to believe that EMAP readings are correct. I shall do a virtual dyno run soon enough to confirm my fears: EMAP readings are right and there is a huge pressure fighting back at the engine. If that is true, then I am stuck with it with no reasonable fix but to scrap everything I have and start over. Not happening sadly, not at this time and age.

As if that was not enough, at that time when the fab work was done that same stubbornness of mine said no to a full 3" exhaust starting from the downpipe till the end. Now I am stuck with a 3" downpipe reducing to stock OEM exhaust diameter of 2.5". The fact that I can't weld 2 scrap bits together(and I can't find anyone decent around me to help) doesn't help in the slightest, nor does the downpipe requiring a day to take off and another day to put back on.
Currently looking at catback kits that may allieviate my EMAP problem even in the slightest, but at this point I don't expect miracles. I also love quietness more than I love power, so tough call to decide on a catback that flows much better but is not noisier than stock.

Brettus

iTrader: (2)

Decent cat back , better intercooler, larger air filter and an external WG . Do those four things and your EMAP will plummet giving you an excellent power powerband..... IMO

TeamRX8

iTrader: (25)

add an external wastegate where the manifold comes together at the turbo flange inlet and tie it together with the IWG canister lines so the controller works them both. Initially I was going to suggest wiring the IWG shut and using EWG only, but then thought they might be ok together if setup with the same spring pressure. I’ve no experience ever trying this though.

Then you could even let it dump to atmosphere initially before tying it in to the exhaust to see what the difference is. Which there are RX8 catbacks with 3” piping. What you can do is get one of these aircraft exhaust ball joints as shown below and have the inlet and outlet flared as a slip over joints to replace the factory reduced size donut issue. Then you only need to cut the pipes and clamp it on. A bit gimmicky, but get’s you around the welding issue.



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ciprianrx8

"Just put a EWG there" - well that area would give nightmares to anyone knowing how to weld:





Leaving it as a screamer pipe is out of the question as well or I'd hate even building boost. Not a fan of anything loud.
If anything, equally half-assed, I could place a EWG on the runner for the rear rotor where it is closest to the downpipe:



...and that would work with poor results, poor flow -> boost creep on its own -> need to keep the IWG in place. I am actually surprised how good the IWG works and flows. I've had to fit a very strong spring to keep it shut at higher rpms/pressures.
There is no fixing this manifold and downpipe, even taking them off the car is a nightmare in itself.

Brettus

iTrader: (2)

It works well because EMAP is so high ....

Several free flowing 3071 setups I've tuned really struggle to control boost and they have to hog out the WG massively just to get under 12psi !

jcbrx8

Argh, agreed: T25 flange w/ 2.5" exhaust = strangulation. You've come this far...pity you don't have your fabricator cut the T25 flange off, and replace it w/ the T3. Install a T3 turbo w/ full 3" DP, and exhaust. If not, I suppose implementing Brett's suggestions to optimize the existing hardware is the next best option.

If you do go the T3 flange w/ 3" DP and exhaust, consider the BHR midpipe and Borla exhaust. Together they allow good power w/ a rich deep, but relatively quiet exhaust note.

TeamRX8

iTrader: (25)

no you can just mimic the Brettus manifold in your own style; the front rotor and siamese exhaust port are piped from the front toward the rear. Just tie into those two and carry it rearward. They will be strongly biased to the wastegate. Maybe better than his even. You already demonstrated great courage, don’t let us or yourself down now




Which btw a full 3” system will support more hp than you’re going to make with a 3076.
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ciprianrx8

Haven't gotten to fitting any mech improvement... just wanted to see how much I can get with what I have:



This is still on a stock fuel pump, albeit one that was replaced very recently. While the airflow is there, it just doesn't feel like pulling hard enough for 13psi. Or I'm getty greedy.

First in line will be changing the exhaust to a full 3" - though I will have to DIY something like a Racing Beat with twin 4" mufflers while hoping it will be quiet at all times.
About upgrading the intercooler as well - will have to mount a pressure sensor on compressor outlet and measure total pressure loss from turbo to UIM. I seem to be getting 3 psi loss merely from the outlet of current IC to UIM. If the turbo is doing cartwheels pushing pressure against a wall, then a good chunk of EMAP will vanish if I can keep that flow up with less boost.

Last on my list is the hardest and possibly the biggest culprint... bypassing wastegate gasses away from that tiny T25 turbo flange. Haven't found anyone yet will to take this job, can't blame them.

One small improvement I've discovered is that the oem O2 sensor can be made to read a bit richer than stock calibration... ~11 instead of 11.15. Not much, but why not have it if its there.

Brettus

iTrader: (2)

While it's true that airflow usually translates to power ... how can you be sure your measured airflow is actual airflow? Boost is pretty much meaningless when there is as much backpressure as you have.

ciprianrx8

That's the reading from the OEM MAF, in its factory housing(cut from original intake), with factory scaling, with factory air straightener 3cm before it and 15cm of straight tubing before straightner. Never gave me any headache apart from looking ghetto. And now I see I nearly maxed it out. Don't think I'm leaking air anywhere as LTFTs stay within +3% at all times.

So if 350 g/s of air enter this engine then they surely exit it as well, problem here may be that much of the power that this airflow would allow is stolen by restrictive IC and exhaust. Until I don't do some hardware changes, I'll never know.

This is the curse of knowing, and why they say ignorance is bliss? :D

Brettus

iTrader: (2)

If you nearly maxed it out but are making sub 300whp .............. id suggest it's far from an accurate reading.

TeamRX8

iTrader: (25)

you’re overlooking the EGR effect of the excessive emap pressure





if you don’t address that soon then kiss your engine goodbye, why are you even reading it if you’re going to ignore what it’s indicating

pretty much the way of most unwise people and how they create misery in their life … immagonnakeeponhammeringonit

you have to understand that with a Renesis once it closes off the exhaust port then what remains is exhaust gas at almost 50 psi, that then is expanding into the intake cycle once the rotor rotates into it. That’s a lot of hot exhaust gas and honestly, it’s a wonder that poor engine didn’t go zoom-zoom-boom already.
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ciprianrx8

I've ordered a RB catback(comes...next year :/ ) and looking to build a complete 3" exhaust starting from turbo outlet. That, atm, is my most accesible path from a fabrication point of view.
I want a 3" resonator about here:

Anyone knows the length of that portion ?

If that alone doesn't do much then a bigger IC is next. Perhaps bigger plumbing as well. It just struck me that I'm measuring boost in 2 different diameters... 2" before thr body, and 3" after thr body - of course there will be a pressure difference.

For IC upgrade, I'm looking at this, with a 3,5" core:

Hardest for last - adding an EWG somewhere.
Not giving any more EMAP numbers... but that engine took even more and didn't blow up. What I wanted to know is that there is at least a hope in hell that the combo can do 350+ g/s.

I'd like to try one day to measure EMAP on a stock car, with a gutted cat and stock exhaust. Thinking of tapping the secondary air pump pipe and placing a sensor there.