The noise is intense despite not being anywhere near max rpm. I believe it is mostly the belt as opposed to the bearings because my initial mockup so far has ceramic bearings and the rotating assembly spins freely by hand, but when the motor is spinning it the noise level is quite threatening still. I'm curious about the effectiveness of a grooved belt instead, considering it is highly unlikely we're getting anywhere near the belt loads of a timing belt serving in a true automotive application involving camshaft rotation. I believe the belt temps would be much lower due to reduced friction.Belt is in, got to about 5000 motor rpm but then got scared of the 3D printed motor bracket vibrating apart. Working on the aluminium version now:
View attachment 875
Finishing the other side tonight, I hope.
My current 6S lipos are also starting to show their age, so getting to max rpm on 6S might not be possible with that setup. Will just need to start working on my final battery pack.
View attachment 876
I'm also afraid I will need to take apart the P2 supercharger and clearance all bearings properly... As I previously noticed it does not seem to spin freely, and getting to 5000 rpm the bearings were incredibly noisy. Probably will replace the bearings with ceramic hybrids as well, I want to hear the compressed air, not the bearings.
Mazda RX-8 P2 build
- Thread starter wkerstens
- Start date
The thing is, it’s already noisy when I spin it by hand, and while I would expect the mass of the compressor wheel to rotate for at least a few seconds, it stops within a second.
It’s also impossible to remove the back cover without using a hamer, I’m afraid it simply does not have enough clearance.
I did order hybrid ceramic bearings today though, so I guess I will find out it they’ll improve the sound
It’s also impossible to remove the back cover without using a hamer, I’m afraid it simply does not have enough clearance.
I did order hybrid ceramic bearings today though, so I guess I will find out it they’ll improve the sound
r.brown.bayliss
Member
mine is the same
Somewhat boring update but I have been working on the electronics / controls of the system in the past few weeks.
The idea is to use the ODB-II connector to sniff the ECU CAN-bus for current RPM / TPS values (to start). This is then put on the "supercharger" CAN-bus, which has the:
This is all very much overkill but it's part of the fun.
Did most of the work on the ESC controller and Main controller, this is working pretty well already. Now need to work on the OBD-II sniffer and BMS node.
Somewhat old log (with some errors in it) but this is the information I can now pul from the ESC using the BT connection
Unfortunately still waiting for the battery mounting brackets but getting the feeling that this "free gift" is actually "no gift" and I need to buy them myself somewhere else.. Or just design something and print it myself.
Also working on replacing the bearings in the compressor, disassembled most of the compressor but cannot really get the main shaft out yet. It does feel very very notchy so even more reason to replace the bearings. I only somehow thought the compressor only had 2 bearings, while it actually has 3.. Meaning I need to get another hybrid ceramic bearing
The idea is to use the ODB-II connector to sniff the ECU CAN-bus for current RPM / TPS values (to start). This is then put on the "supercharger" CAN-bus, which has the:
- Main controller
- ESP32
- Listens to vehicle parameters
- Has a 2D RPM / TPS to supercharger setpoint map with interpolation
- Checks health of CAN-Bus and the nodes connected to it
- BMS node
- ESP32
- Connects to JK BMS using RS485
- Puts battery status / health on the CAN-Bus
- Can disable battery pack when commanded to
- ESC node
- ESP32
- Connects to the Mad Max 20 ESC
- PWM to control motor
- BT to read telemetry
- This took way too long to reverse engineer but works really well!
- Listens to main controller, has a load of failsafes in place
- Errors / warnings protocol with RGB LED error / warning pattern
- [optional] Display node
- Will probably put all the telemetry stuff on a display eventually
This is all very much overkill but it's part of the fun.
Did most of the work on the ESC controller and Main controller, this is working pretty well already. Now need to work on the OBD-II sniffer and BMS node.
Somewhat old log (with some errors in it) but this is the information I can now pul from the ESC using the BT connection
Unfortunately still waiting for the battery mounting brackets but getting the feeling that this "free gift" is actually "no gift" and I need to buy them myself somewhere else.. Or just design something and print it myself.
Also working on replacing the bearings in the compressor, disassembled most of the compressor but cannot really get the main shaft out yet. It does feel very very notchy so even more reason to replace the bearings. I only somehow thought the compressor only had 2 bearings, while it actually has 3.. Meaning I need to get another hybrid ceramic bearing
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You must be very young. I remember back in the 90s while in college I purchased the equipment necessary to read and download ECM chip data. I actually downloaded the tune to my car, but didn't know how to decipher and organize the data into easily understandable tables to make tuning adjustments as simple as they ended up being not long after when someone else did. I was too busy building, working and going to school to explore it any further. I still have the hardware after all these years removed from DOS operating systems.Somewhat boring update but I have been working on the electronics / controls of the system in the past few weeks.
The idea is to use the ODB-II connector to sniff the ECU CAN-bus for current RPM / TPS values (to start). This is then put on the "supercharger" CAN-bus, which has the:
View attachment 888
- Main controller
- ESP32
- Listens to vehicle parameters
- Has a 2D RPM / TPS to supercharger setpoint map with interpolation
- Checks health of CAN-Bus and the nodes connected to it
- BMS node
- ESP32
- Connects to JK BMS using RS485
- Puts battery status / health on the CAN-Bus
- Can disable battery pack when commanded to
- ESC node
- ESP32
- Connects to the Mad Max 20 ESC
- PWM to control motor
- BT to read telemetry
- This took way too long to reverse engineer but works really well!
- Listens to main controller, has a load of failsafes in place
- Errors / warnings protocol with RGB LED error / warning pattern
- [optional] Display node
- Will probably put all the telemetry stuff on a display eventually
This is all very much overkill but it's part of the fun.
Did most of the work on the ESC controller and Main controller, this is working pretty well already. Now need to work on the OBD-II sniffer and BMS node.
View attachment 882
View attachment 884
Somewhat old log (with some errors in it) but this is the information I can now pul from the ESC using the BT connection
View attachment 885
Unfortunately still waiting for the battery mounting brackets but getting the feeling that this "free gift" is actually "no gift" and I need to buy them myself somewhere else.. Or just design something and print it myself.
Also working on replacing the bearings in the compressor, disassembled most of the compressor but cannot really get the main shaft out yet. But it feels very very notchy so even more reason to replace the bearings. I only somehow thought the compressor only had 2 bearings, while it actually has 3.. Meaning I need to get another hybrid ceramic bearing
Now I try to keep it simple and practical, I have some Basic stamp code routines I intend to use in a little controller to read two or three parameters; MAP sensor, throttle sensor and a trigger circuit to turn on water/meth injection at a desired pressure. HPTuner's scanner can log the rest to help make sure the tune is safe. I've used water/meth enough to know it is very effective insurance against hot inlet temps and engine knock.
Simple formula, at 75% pedal start reaching for desired boost, PWM control compressor speed through ESC, with a manually set blow-off valve as max boost safety. Later programming can be changed to vary boost with pedal input and a few more sophisticated functions can be added.
I purchased this little genie in a box a short while back when I started looking into the CANBUS system and module data chips to work with at some point. I've already accessed the VIN for my OE nav system to make interchange possible without programming through the car.
REVELPROG IS - Serial Device Programmer with USB interface
Professional serial memory programmer for I2C, SPI, uWire and 1-wire devices. It supports EEPROM, FLASH and FRAM with 1.8V, 2.5V, 3.3V and 5V power supply.
www.reveltronics.com
You must be very young. I remember back in the 90s while in college I purchased the equipment necessary to read and download ECM chip data. I actually downloaded the tune to my car, but didn't know how to decipher and organize the data into easily understandable tables to make tuning adjustments as simple as they ended up being not long after when someone else did. I was too busy building, working and going to school to explore it any further. I still have the hardware after all these years removed from DOS operating systems.
Now I try to keep it simple and practical, I have some Basic stamp code routines I intend to use in a little controller to read two or three parameters; MAP sensor, throttle sensor and a trigger circuit to turn on water/meth injection at a desired pressure. HPTuner's scanner can log the rest to help make sure the tune is safe. I've used water/meth enough to know it is very effective insurance against hot inlet temps and engine knock.
Simple formula, at 75% pedal start reaching for desired boost, PWM control compressor speed through ESC, with a manually set blow-off valve as max boost safety. Later programming can be changed to vary boost with pedal input and a few more sophisticated functions can be added.
I purchased this little genie in a box a short while back when I started looking into the CANBUS system and module data chips to work with at some point. I've already accessed the VIN for my OE nav system to make interchange possible without programming through the car.
REVELPROG IS - Serial Device Programmer with USB interface
Professional serial memory programmer for I2C, SPI, uWire and 1-wire devices. It supports EEPROM, FLASH and FRAM with 1.8V, 2.5V, 3.3V and 5V power supply.
It’s all relative I guess
.During my job we would go with the simple, safe approach as well, but it’s nice to go all out on a hobby project. Especially now we have the AI tools of today.
The current approach will allow me to easily tune the “boost” map, and also help me understand system health.
We actually had a few of those EEPROM programmers at my previous job, nice to see it again.
Put the assembly in the oven today, to then quickly cooled down the shaft while the assembly was still hot, managed to get the shaft out that way. One bearing is still stuck.. need to heat it up again and give it another go.
The shaft dimensions are actually really good, I’m measuring 17.005 mm for the main shaft.
Its just the back bearing that seems to be in a bad shape. Also just like the thread linked before the pulley side wall/ring is way too loose, causing noise and inbalance.
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What are the diameters of the inducer and exducer of the compressor wheel? The bearing and seat quality of these units are making me favor buying the turbo compressor housing and wheel assembly that I've spec'd for my platform and build it since I would end up tearing the P-2 down anyway to address factory sloppiness in addition to the recent price bump.It’s all relative I guess
During my job we would go with the simple, safe approach as well, but it’s nice to go all out on a hobby project. Especially now we have the AI tools of today.
The current approach will allow me to easily tune the “boost” map, and also help me understand system health.
We actually had a few of those EEPROM programmers at my previous job, nice to see it again.
Put the assembly in the oven today, to then quickly cool down the shaft while the assembly was still hot, managed to get the shaft out that way. One bearing is still stuck.. need to heat it up again and give it another go.
The shaft dimensions are actually really good, I’m measuring 17.005 mm for the main shaft.
Its just the back bearing that seems to be in a bad shape. Also just like the thread linked before the pulley side wall/ring is way too loose, causing noise and inbalance.
View attachment 889
Too bad you don't have any liquid nitrogen.
I was also wondering about the seal between the backplate and the housing:
Seems like they prepared a nice edge for an oring to be seated, but they didn’t. Shouldn't this be sealed?
I’m still happy with my P2 purchase by the way. I would take any solution apart anyways, and upgrade where I can, so might as well start with a maybe non perfect solution. The P2 is so universal with more than enough holes to mount stuff and keeps the required motor (and bearing!) rpm low due to the huge size which is a big plus.
Thanks for that post, it helps put things into perspective regarding the most reasonable compressor map to use by comparison of map compressor combos with known specs (Vortec has a list somewhere, I didn't save the link.). I past up good deal on a returned P-2 a couple of weeks back on ebay because the seller who dealt with returned items had a poor rating (80ish) and although it eventually ended up being priced down into the high $400 range, I recalled the situation with the charger Alex posted about that had the trimmed down exducer, which greatly reduced flow as well as changed the compressor map and didn't want to take a chance on such a low rated seller with a "No returns" policy. The proper compressor wheel costs almost as much as the blower.
As far as I know there should be. For convenience you can use a DIY paper gasket which is what many of the early turbos used and likely many of the smaller turbos are still using today.
Battery brackets are finally in! Well, partly. I received 18 instead of 24, so can only make a 18-cell pack right now. Also one of the cells turns out dead so it's time to find out about Hakadi their return policy.
I now need to figure out a way to reinforce the battery pack and mount the BMS, probably going with a combination of 3D printed top/bottom caps and a laser cut aluminium frame to further add some structural rigidity.