I Just finished turboing my Rx8 and dealing with VT and running the stock ECU... Had same issue with the MAF so moved it to run across the intercooler and works sweet now. been a long few weeks of learning VT but I am running 7psi and so much better now. All DIY manifold and exhaust but did buy a Aeroflow turbo as they arent very expensive and work well. I 3d printed a MAF straightener in PETG to help with back surging and etc also, helps alot
@@RADPotentialif you run it post blow off valve it always has a proper reading cause air isn’t leaving post maf sensor and blow offs open in mid range throttle a lot
Tuned dozens and dozens of RX8s with stock ecu. Good Maf setup is absolutely crucial to getting a good tune. Probably wasting my breath but here goes : 1/maf can't be too close to turbo due to the swirl effect 2/Maf needs approx. 2D before and 1D after it of dead straight pipe at the correct diamater. (3.5" for RX8) .3/ You must always maintain the same alignment of pre maf pipes IE if they are disassembled you must reassemble in exact same alignment. 4/Ideally you'll fit a honeycomb air straightener about 1D pre sensor. Get that part right and that's 50% of your tuning issues solved.
@@tardbucket yeah, makes sense. Just saw the RX-7 in the original commenters profile picture. Checks out, lol. Haltech has adapters for almost every single RX-7, and adapters for miatas, but diddly squat for the 8, sadly.
If you ever want to go the standalone route, I'm running a Haltech nexus R3. Not turbo but runs well NA, there's still a bit of mapping to do, but I can send you my wiring diagrams and map files to get you going. I work in Shadow Rotary here in Ireland so modding rotarys is our bread and butter. Hit me up if you go this route 👍
maybe put the MAF in front of the bumper bulkhead. A long tube crossing the bumper face interior then MAF, bend into the engine bay (like a standard cold intake setup), then across and into the Turbo inlet. This might stabilize the airflow and mitigate compressor turbulence felt by the MAF.
Every factory ECU I've dealt with that has a MAF sensor and is VE based (newer cars like 2015+ use a completely different approach and don't have direct VE table anymore) will also have alpha-n tables in the tune (and a lot of time the tuners will not show them or not have them decoded properly), and when the computer doesn't like the readings it sees from the MAF it will revert to the alpha-n tables AKA limp tables to those tuners that don't understand how they are used. You need to tune these tables as you tune the car. If these tables are way off what your main tables are it will throw the ECU for a loop as it always does a checkback, and no it won't throw codes for this or tell you when it does it. When you said you changed the scaling and it didn't result in immediate changes, that tells me the ECU is ignoring the MAF to begin with and running off the alpha-n tables anyways at those times. I'm betting if you unplug the MAF and disable the codes for it that it will run identically because it's not even using it for closed loop to open loop transitions. It was big back in the day in BMWs to just unplug the MAF, eliminate it, and tune solely using alpha-n which is TPS and RPM based tuning on race cars. It's like speed-density without using temp and pressure sensors. It's a PITA to tune for changing conditions but it's now it was done when EFI first came out.
The maf is going to make the biggest change, but if im remembering the RX-8 ecu correctly im pretty sure under wide open throttle the ecu goes into open loop. it seems like most of your issues are occurring in closed loop or the transition between the two. so you may have a few more drives with the laptop in your lap sorting out the finer details. good shit tho thoroughly enjoying the channel so far
TBH. A few ECUs (EMU Black, MaxxECU, even an elite 2000 in the used market, Link Fury) can be used and installed for well under that price point. I mention those ECUs as they can control the RX8s CAN Bus and also utilize the cars factory DBW system. Can essentially be done with slight modifications of the factory engine harness and a few wires to communicate with the body.
@ Electric Power Steering, Working RPM, Working Coolant, etc. You can retain all OEM features pretty much and the ABS unit somewhat acts independently but will see these things through the CAN data stream from the elite most likely and act accordingly (rpm, wheel speed, etc)
Curious why the maf is jot placed post turbo (right before the intake). It would make sense that it would be the most accurate reading of the air entering the motor, with the benefit of the flow being more laminar
Cant you move your blow off valve lower and put the MAF after the Blow off valve to give the computer a more accurate measure of air that is actually going into the engine? This would then allow you to keep your 90 degree elbow for the turbo intake...
I don’t know how much overlap there is on a renesis but once you go into boost, you could just be blowing all your fuel out the exhaust port if there’s overlap on top of the maf issue
Haven’t watched the whole video and looked at your setup, but where is the maf located and also where do you have your blow off valve mounted? Is it recirculated? Maf cars really want the bov to be recirculated back into the air stream post maf.
After watching further into the video you did speak on what I said. One thing about the blow off valve is that at partial throttle, anything under 0 vacuum, there is a possibility that the valve is opening on the bov while cruising letting in unmetered air.
I would not run a blowoff valve on a rx-8 with a mass flow sensor since they tend to go super rich off and on throttle randomly because it can't see the air being ejected during boost. Same thing happens on my 626 gt. All those flames and pops is just the maf trying to over correct the air fuel ratio.
i had my MAF in front of the turbo to start i left the screen in there and when i had it running good i took it off change the values and it was beautiful....ofcourse running big injector
We can buy a nice laptop computer with all the bells and whistles for under a grand. Why the F are stand alone ecu's the cost of a used car when these ECUs are basically external hard drives lol?
No. In short, that wouldn't change the fact that an "NA" ecu will essentially always be compensating for boost. It's all just trickery when there isn't a way to do things properly. The cheapest route in this sense is the most difficult.
I Just finished turboing my Rx8 and dealing with VT and running the stock ECU... Had same issue with the MAF so moved it to run across the intercooler and works sweet now. been a long few weeks of learning VT but I am running 7psi and so much better now. All DIY manifold and exhaust but did buy a Aeroflow turbo as they arent very expensive and work well. I 3d printed a MAF straightener in PETG to help with back surging and etc also, helps alot
What's VT how do you run your maf across the intercooler? I'm confused. Sounds like a cool build our you using mazda edit or versatune
I was honestly thinking of running the maf sensor along the throttle body
So you're running the MAF on the boost side of the turbo vs the inlet side? Interesting.
@@RADPotentialif you run it post blow off valve it always has a proper reading cause air isn’t leaving post maf sensor and blow offs open in mid range throttle a lot
@@jo-qp7mz versatuner
Tuned dozens and dozens of RX8s with stock ecu. Good Maf setup is absolutely crucial to getting a good tune. Probably wasting my breath but here goes : 1/maf can't be too close to turbo due to the swirl effect 2/Maf needs approx. 2D before and 1D after it of dead straight pipe at the correct diamater. (3.5" for RX8) .3/ You must always maintain the same alignment of pre maf pipes IE if they are disassembled you must reassemble in exact same alignment. 4/Ideally you'll fit a honeycomb air straightener about 1D pre sensor. Get that part right and that's 50% of your tuning issues solved.
@21:22 not a waste. It was RND, kinda what makes cars fun when they make us work it lol
for 1500$ you can get a elite 1500 with the adapter to stock harness and the elite 1500 has a internal map sensor and you can delete the maf sensor
what adapter are you mentioning that is a direct plug and play to the factory rx-8 wiring harness?
@@Ayane13bthere isnt one ive been down this path for years, you make it
@@tardbucket yeah, makes sense. Just saw the RX-7 in the original commenters profile picture. Checks out, lol. Haltech has adapters for almost every single RX-7, and adapters for miatas, but diddly squat for the 8, sadly.
@ i just looked trough the Haltech website and they don’t make it for the RX8 lol only for na nb mx5 and fc and fd rx7
If you ever want to go the standalone route, I'm running a Haltech nexus R3. Not turbo but runs well NA, there's still a bit of mapping to do, but I can send you my wiring diagrams and map files to get you going. I work in Shadow Rotary here in Ireland so modding rotarys is our bread and butter. Hit me up if you go this route 👍
I hope you find a way to share this info to the general internet. It is hard to find Haltech RX8 info.
So pumped to see buzz on the road! Great job explaining the MAF! Look forward to the next one where she is properly ripping and shooting flames! 🔥
5:35 agreed, all we ever needed in life
maybe put the MAF in front of the bumper bulkhead. A long tube crossing the bumper face interior then MAF, bend into the engine bay (like a standard cold intake setup), then across and into the Turbo inlet. This might stabilize the airflow and mitigate compressor turbulence felt by the MAF.
9.30am in Australia 🌏
Not even the Drop Bear's are awake! 🐨 Brap Brap Brap
Every factory ECU I've dealt with that has a MAF sensor and is VE based (newer cars like 2015+ use a completely different approach and don't have direct VE table anymore) will also have alpha-n tables in the tune (and a lot of time the tuners will not show them or not have them decoded properly), and when the computer doesn't like the readings it sees from the MAF it will revert to the alpha-n tables AKA limp tables to those tuners that don't understand how they are used. You need to tune these tables as you tune the car. If these tables are way off what your main tables are it will throw the ECU for a loop as it always does a checkback, and no it won't throw codes for this or tell you when it does it. When you said you changed the scaling and it didn't result in immediate changes, that tells me the ECU is ignoring the MAF to begin with and running off the alpha-n tables anyways at those times. I'm betting if you unplug the MAF and disable the codes for it that it will run identically because it's not even using it for closed loop to open loop transitions. It was big back in the day in BMWs to just unplug the MAF, eliminate it, and tune solely using alpha-n which is TPS and RPM based tuning on race cars. It's like speed-density without using temp and pressure sensors. It's a PITA to tune for changing conditions but it's now it was done when EFI first came out.
The maf is going to make the biggest change, but if im remembering the RX-8 ecu correctly im pretty sure under wide open throttle the ecu goes into open loop. it seems like most of your issues are occurring in closed loop or the transition between the two. so you may have a few more drives with the laptop in your lap sorting out the finer details. good shit tho thoroughly enjoying the channel so far
TBH. A few ECUs (EMU Black, MaxxECU, even an elite 2000 in the used market, Link Fury) can be used and installed for well under that price point. I mention those ECUs as they can control the RX8s CAN Bus and also utilize the cars factory DBW system. Can essentially be done with slight modifications of the factory engine harness and a few wires to communicate with the body.
Does the elite also keep the ABS and other CAN dependent features?
@ Electric Power Steering, Working RPM, Working Coolant, etc. You can retain all OEM features pretty much and the ABS unit somewhat acts independently but will see these things through the CAN data stream from the elite most likely and act accordingly (rpm, wheel speed, etc)
@@thepcmrtim That's awesome. I would love to know the details.
5:01 when you're struggling, you're learning
Curious why the maf is jot placed post turbo (right before the intake). It would make sense that it would be the most accurate reading of the air entering the motor, with the benefit of the flow being more laminar
Cant you move your blow off valve lower and put the MAF after the Blow off valve to give the computer a more accurate measure of air that is actually going into the engine? This would then allow you to keep your 90 degree elbow for the turbo intake...
I don’t know how much overlap there is on a renesis but once you go into boost, you could just be blowing all your fuel out the exhaust port if there’s overlap on top of the maf issue
Basically no overlap in a renesis. It's gotta be MAF stuff foshizzlr
No overlap
Haven’t watched the whole video and looked at your setup, but where is the maf located and also where do you have your blow off valve mounted? Is it recirculated? Maf cars really want the bov to be recirculated back into the air stream post maf.
After watching further into the video you did speak on what I said. One thing about the blow off valve is that at partial throttle, anything under 0 vacuum, there is a possibility that the valve is opening on the bov while cruising letting in unmetered air.
I would not run a blowoff valve on a rx-8 with a mass flow sensor since they tend to go super rich off and on throttle randomly because it can't see the air being ejected during boost. Same thing happens on my 626 gt. All those flames and pops is just the maf trying to over correct the air fuel ratio.
Thats why you recirculate the blown off air.
Remove the blowoff valve or make it recirculate that’s 90% of your issue
Timing go 12 on boost is safe whith good a/f
Put the MAF between the compressor and the throttle body. If intercooled, between intercooler and throttle body.
Use your hydraulics brain and put the MAF in place after the turbo, the calculations will be done for you. 80s and 90s tech for the win
i had my MAF in front of the turbo to start i left the screen in there and when i had it running good i took it off change the values and it was beautiful....ofcourse running big injector
You need too clamp the maf then go map and rpm
We can buy a nice laptop computer with all the bells and whistles for under a grand. Why the F are stand alone ecu's the cost of a used car when these ECUs are basically external hard drives lol?
Speeduino is $420....
More computers are sold in a given state than standalones are sold nationwide...hell, even worldwide.
Safe timing like I say go 12 degrees from there play the a/f
The maf is not going to read because of the turbo
Maf sensor near the tb is the best to run oem ecu
Well done patreon lads.
DNA Motorsports in Australia may be of assistance... They used to sell a ProCharger kit with ECU for the RX8
RX-8 turbo!
I really hate the stock wiring in the rx8, ive been thinking about relocating EVERYTHING to the trunk but its so much work 😂
Would it better to run a holley sniper with the turbo to bypass the rx8 cpu?😊
Yes I have been waiting for this one!
Speak to the Wizard...Roland Varga in Australia...
When will you try a high power hybrid
Yall just be chill. Things are moving on a lot of fronts haha
What is a "high power hybrid?"
Asking because I have no idea. Couldn't you just put the MAF after the BOV?
No. In short, that wouldn't change the fact that an "NA" ecu will essentially always be compensating for boost. It's all just trickery when there isn't a way to do things properly. The cheapest route in this sense is the most difficult.
Try too not use the maf use map for everything
They read na voltage not turbo
Have you tried putting mesh in front of the mase air flow sensor to clean up the air.
First to comment before the guy is always asking about the Rx8 chimes in. I know he will be happy.
Is going too rich the engine because is more air going from the turbo
turn off automatic autio trachs, sounds like scam ai voice trying to reach you for your cars extended Eichelkäse
Awesome