[DRIVING] Project RX8 , Prius gen2, Lexus transaxle to rwd

Tell us about the project you do with the open inverter
Post Reply
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Mg1 tuning commenced today, syncof similar to mg2, was having issues with unwanted acceleration until I lowered syncadv to 6.
Mg1 performance not anywhere like as impressive as mg2 and so far I’ve not drawn more than about 30amps from an 80s pack, seems low end torque is pretty low, have driven round the block with both motors, it’s not bad but I’m not pushing the inverter very hard so hopefully there is more to come unless I’m just lacking on voltage
RetroZero
Posts: 702
Joined: Tue Oct 29, 2019 2:48 pm
Location: France
Has thanked: 311 times
Been thanked: 38 times
Contact:

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by RetroZero »

Nice one!
I'm recharging battery today, really slow charging as I don't have a bms. Looking at cookie6000 and all his drama's, I'll take it easy on the battery pack.
I haven't played with any values besides Foc tuning and recently 'udcofs' and 'throtcur'. I got unwanted regen and motor not as smooth, so first up is making sure the inverter values for 'udc',' il1' and 'il2' correspond with adapter board.
Since I'm not sure enough as to what each value does when changing from standard set parameters, I'm going by what I find in other builds after lots of wiki/google browsing.
Do post your parameters please, so I could compare (hopefully Lexus transaxle is similar in construction to prius, so values will be very similar) 👌
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

I’ll post up the parameters next week when I’m back at work, and work out how to save them! Lol I have moved syncof on mg2 to 11950 now which is no longer in the middle of the dead band when foc tuning but interesting when you are foc tuning and get no movement even at150amps you get funny noise from the motor (almost like a radio between stations) 11950 is where this noise is much quieter either side of that it gets louder, I don’t know if this method has any real merit or is just some kinda fluke,
I also think that trying to foc tune 2 motors on the same shaft that are slightly misaligned is a pain in the ass as your having to overcome the cogging of the magnets on the non driven motor
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Well with a mostly drivable tune, the wiring tided up and finally finding the right can messages to convince the abs the engine ecu is still there I’m about ready for a fresh mot and some real testing.
Attachments
19AA8808-2DA1-49DC-8619-AE83BB064037.jpeg
1D984ABE-EABB-4BAB-9E44-1C90D5129A3A.jpeg
Richerson
Posts: 17
Joined: Sat May 02, 2020 8:11 am
Location: Oxford
Has thanked: 77 times
Been thanked: 1 time
Contact:

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Richerson »

Very professional looking project, can't wait to see how much power you can get out of it.
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Thanks, I do a fair bit of custom fabrication as part of my job, it’s probably when im at my happiness,

Currently it’s drivable but lacking in power over about 2500 rpm, basically the first upgrade in the pipeline is to up battery voltage
RetroZero
Posts: 702
Joined: Tue Oct 29, 2019 2:48 pm
Location: France
Has thanked: 311 times
Been thanked: 38 times
Contact:

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by RetroZero »

Awfully clean project!! I'm going back to clean mine up before posting anything. Do you have a vacuum reservoir with your brake boost setup? You got cooling all plumbed in too?
Nice going 👍
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Nope no vacuum reservoir, I did on the previous setup that used a Saab pump and switch it needed one because of the lack of hysteresis, but the Audi pump and johu’s board works well without a reservoir,

Cooling is all plumbed into a fiat cinquecento rad behind the bumper,

And the auxiliary oil cooling pump which runs when the motor is turning has an oil cooler radiator beside the left fog light
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Well it’s been a year off the road and a complete re engineer of the drive system, almost to the point I’ve basically converted 2 cars now, but I’m back on the road Mot passed and drove home, some interesting slow speed drivability kinks to sort out so lots of software tuning to do, but I’m happy to have made this milestone
Attachments
9AB91380-BF63-4C56-8380-0F228BD5B355.jpeg
FFE985D5-E59C-4430-979F-0F39E495FB8B.jpeg
34189A37-B876-4591-8FF0-5CFB7B088B88.jpeg
02EB1E88-B276-414A-AAE9-36BF74508B70.jpeg
4ACCC503-04F0-4DA6-8F68-2879D773E25A.jpeg
B8ACA9DF-82FA-4C37-A158-5FA80DFC7BC1.jpeg
RetroZero
Posts: 702
Joined: Tue Oct 29, 2019 2:48 pm
Location: France
Has thanked: 311 times
Been thanked: 38 times
Contact:

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by RetroZero »

Congratulations!!!! Huge milestone 👍
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Thanks
User avatar
Bigpie
Posts: 1585
Joined: Wed Apr 10, 2019 8:11 pm
Location: South Yorkshire, UK
Has thanked: 74 times
Been thanked: 299 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Bigpie »

Smart job.
VW Beetle 2003
Outlander front generator
Prius Gen 3 inverter (EVBMW logic board)
Outlander charger
3x Golf GTE batteries
Chademo Charging
Outlander water heater
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Ok 1 week on the road and 40ish miles of to and from work, ( I live in 2.5 miles from work so every day is a test drive, not an efficient one either!) I have been playing with syncadv a lot slowly increasing it, I’m up to 14 now with no Ill effects, increasing it certainly helps maintain power higher into the revs,

I like others have experienced am getting strong regen when lifting off the throttle when over 4000rpm which will persist until revs lower significantly then returns to normal with a jolt, I need to test if this is the case with regen turned off or not? If so maybe some kind of regen disable above a certain rpm may help, I only run 5% off throttle regen as I prefer it this way.

Happy with the progress so far,
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

2 weeks of driving around town and even briefly on the dual carriageway upto 70mph, some more tweaking of the tune, and I’ve learned some more things, like 3rd gear is perfect around town and pulls away fast but I need to change up to 4th for over 50mph so I really need to rig a regen kill switch as turning the regen pot down and up again is too much work, I’m think button on the gear knob or maybe reinstall the clutch pedal with a switch? Not sure yet. Also 3rd gear in this box is damm noisy compared to 4th but 4th is just too sluggish at the bottom end and pull away to leave it in.

On another note I’ve started collecting things to create a budget Chademo charge system thanks to winning a brand new charge port on eBay for just £60, I plan to hack together a controller using an arduino, 2 separate can buses, and the guts of a bmw s-box I found I still have, which can spit out current and hv messages over can much like the isa shunt except this was free, I also have the matching Panasonic contactors around somewhere, I hope to patch together some code to run it all based on the old due based controller, and go from there, hopefully get it talking to my simpbms as well.
Attachments
05C2C928-2264-48C9-BCD2-191AE6C7A74D.jpeg
1B90514D-2A9F-4FA6-867E-7463CACBB6B2.jpeg
User avatar
johu
Site Admin
Posts: 5681
Joined: Thu Nov 08, 2018 10:52 pm
Location: Kassel/Germany
Has thanked: 153 times
Been thanked: 959 times
Contact:

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by johu »

Great update! In my tests I had unwanted regen not matter if I had actual regen turned on or not :( Hoping to cover more ground with the A2 conversion
Support R/D and forum on Patreon: https://patreon.com/openinverter - Subscribe on odysee: https://odysee.com/@openinverter:9
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Not much of an update as I haven’t had much time lately, no work done on the chademo although I now have an isa shunt to use, will help me use existing code, otherwise I’ve just been playing with lots of inverter software versions trying to tune things better.

One big milestone however is I have now covered more mileage with my frankenmotor than I did with my old dc conversion before I melted its brushes and leads!
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

So I guess my project thread is overdue an update, no real hardware changes but I’m hoping to get chademo installed by Christmas….. mostly I’ve been doing lots of driving, tuning, testing firmware…. I’ve done 700miles and still finding small gains or improvement In drivability, those who have been following the IPM control thread or Johu’s a2 Prius build will know how these motors love high voltages so although I’m hoping to pick up some more modules and increase the battery voltage I’m quite happy that I’ve managed to squeeze 100kw out of the pair with just an 80s pack so that’s about half the rated power of the Lexus motors at half the voltage! The torque is pretty impressive
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Ok so with the uk weather suddenly turning into 3c in only a couple of days things have changed priorities, I had started project chademo by cutting a hole in my bumper to make a flap to cover the charge port.
7551DCEA-F632-4368-B7CC-55A4E89DEA23.jpeg
D15CE3AE-5B2D-40F4-B8A7-7EF33A174FDC.jpeg
But now it’s cold and this car is my daily transport so it suddenly beacame a case of I need a heater quick to de mist my windscreen, what can I cobble together out of stuff I have laying around?
Please excuse the crudeness this is currently just wired to a 240v plug as I have been putting the car on charge for an hr before leaving in the morning to warm the batteries a bit, so I will just plug this in at the same time to dry and pre warm the cabin, mid term I will wiring the dishwasher heater into the battery, repurpose the thermoswitch to turn a contactor on and off, and maybe try and put a box around it and mount it better than zip tied to the abs pump!
D877949C-D435-46AA-9FEB-0E01E487324D.jpeg
D877949C-D435-46AA-9FEB-0E01E487324D.jpeg
01BB0E64-BE29-4D61-942A-9B3D371FDAFA.jpeg
Attachments
200F2641-72AA-43C4-8E5D-D1D30FDA398E.jpeg
User avatar
Bigpie
Posts: 1585
Joined: Wed Apr 10, 2019 8:11 pm
Location: South Yorkshire, UK
Has thanked: 74 times
Been thanked: 299 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Bigpie »

How on earth did you cut such a neat hole?
VW Beetle 2003
Outlander front generator
Prius Gen 3 inverter (EVBMW logic board)
Outlander charger
3x Golf GTE batteries
Chademo Charging
Outlander water heater
m.art.y
Posts: 550
Joined: Sat Jun 06, 2020 6:54 pm
Location: UK
Has thanked: 24 times
Been thanked: 17 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by m.art.y »

Bigpie wrote: Thu Dec 01, 2022 5:26 pm How on earth did you cut such a neat hole?
That was my first reaction too. Must be high accuracy laser cutting for sure 😊

EV8 I would like to know how you are heating your batteries? Do you have coolant circulating through them and you heat that coolant with some sort of coolant heater?
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

To cut the hole I used a fine toothed fretsaw blade, snapped the end of it off and heated it with a blow torch on the end to melt through the bumper to get started, I had masked it all up and drawn it out neatly so I had something to follow,

As for battery heat currently I have nothing other than the warmth they create giving them a charge for a bit, but the front modules are actually sat on heated seat mats in their box but these aren’t wired in yet, rear batteries are inside the boot a stay a couple of degrees warmer,
I really hadn’t counted on the weather going from 10-12c to 3-4c
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

CAD
Attachments
B0A7B8AD-7685-4853-9243-4FAD038A3B3E.jpeg
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Precharge resistor completely split open but somehow still working!
Attachments
5D61D115-8F1F-4EC7-B6E9-8F9E78D4AD6B.jpeg
Pete9008
Posts: 1801
Joined: Sun Apr 03, 2022 1:57 pm
Has thanked: 102 times
Been thanked: 347 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Pete9008 »

I'm guessing that moisture has caused that.

The porous ceramic package has soaked up a bit of moisture from humid air and then when the precharge has happened the core of the resistor has got hot enough to vaporise the water and the rapid increase in volume/pressure splits the package. Not too surprising that it is still working as that failure mode wouldn't stress the resistive element too much. You can get similar effect if electronic ICs that have been stored in humid conditions are reflowed without baking.

See you have a silica gel package in there but it is surprising how quickly they get saturated and stop doing much and with the cold weather recently it wouldn't be surprising if it was slightly damp in there.
User avatar
Ev8
Posts: 801
Joined: Sat Jan 30, 2021 11:05 am
Has thanked: 41 times
Been thanked: 149 times

Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Well I’ve just replaced with an aluminium bodied 100w 15r resistor hopefully this will be less prone to this kind of failure, I have some silica packages here that are self indicating so I’ll get them in there
Post Reply