Lwerewolf

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About Lwerewolf

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  • First Name
    Alexander
  • Lexus Model
    gs450h
  • Year of Lexus
    2008
  • UK/Ireland Location
    Other/NonUK

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  1. https://lexus-europe.epc-data.com/gs450h/gws191r/5066/chassis/4802/ Where to buy - from what I've read, there are quite a few Lexus dealers in the UK that are reasonable, plus the site sponsors... https://www.lexusownersclub.co.uk/forum/forum/99-traders/ 🙂
  2. These are quite famous in the 2nd gen IS community - and the 3rd gen GS happens to be much the same underneath. A common upgrade is to install the RC-F/GS-F bushings, or to completely swap them out for polyurethane ones - whether it's due to front tire wear (softer bushings = more dynamic toe) or for steering precision/feel. I went with GS-F on my own.
  3. Theoretically, you can buy, say, two yaris hybrid battery packs (20 modules each) and scavenge their modules. Salvaging a relatively new crashed vehicle is also an option - if it's a ni-mh pack and it isn't an RX or an LS, then the modules should be the same - do your research in either case, of course. I'm not aware of batteries or inverters being coded to specific vehicles. I wouldn't get a pack out of China without doing a lot of research.
  4. You cannot strip out individual cells. You also must clamp the cells while charging/discharging - there's a reason why they're compressed together in the car's battery pack. As for figuring out if one of the individual cells is worse than the others but not failed... I don't think there's a way, other than monitoring the voltage drop for "untimely drop".
  5. You can trickle overcharge the cells to balance them out. Usually this is combined with deep cycling a couple of times, measuring the capacity improvements while doing so. The resting module or individual cell voltage doesn't say much - if it's 1.2v off then you have a shorted cell, that's about it. My suggestion - if you want to do it yourself, read up and be aware that it'll take time. Again, plenty of threads and ideas over at priuschat - including rehydrating cells.
  6. Thanks for the kind words 🙂 Also keep in mind that I'm very inexperienced in this field, but then again - what's better than a learning experience 😄 The high voltage capacitors in all Toyota inverters are SH film caps - don't know which kind exactly, but the ORNL articles have graphs of capacitance, ESR & dissipation factor over different frequencies and temperatures, and the different film caps (PP/PET/PEN/whatever the film material happens to be) appear, at least to me, to be easily differentiated by those responses - so we can find out. Otherwise, there's the main DC link capacitor bank (750v/2855uf, ORNL x-rays show 20+ capacitors in parallel, potted in black, opaque epoxy or something), the DC link snubber capacitor (750v/0.9uf, very low dissipation factor) and the boost converter capacitor (500v/378uf). I've seen basically no deviations in capacitance, ESR, dissipation factor & phase shift compared to what was listed over at ORNL - keep in mind that I'm limited to 100/120hz for most measurements on the big caps (2855uf&378uf), but ESR isn't limited. I don't have access to a bench LCR meter, so this will have to suffice. At any rate - there are no thermal probes in the capacitor banks, and they are not liquid cooled either. Their location varies - in the 3rd gen 450h all banks are separate modules, whereas the ls600h combines the 750v caps (main bank & snubber cap) into one potted assembly. There are various teardown videos & articles, you can see for yourself. The 1st gen prius' inverter is the most obvious - the DC link bank caps are screw-terminal cylindrical panasonics, exposed for your eyes to see 🙂 Re: solder - there are other ways to get around it: https://www.semikron.com/innovation-technology/packaging-technology/skin-technology.html There are still bond wires used in the prius gen3 inverter ipm, and all new IPMs seem to be of the double-sided cooling variety, so I guess Toyota hasn't used such packaging in any of their production units - I'm quite sure that they've experimented internally, though... Conservative products don't mean a lack of innovation 😄 Again - the temperatures on the IGBTs (I assume the "inverter 1" and "inverter 2" temperatures are taken directly from the temperature sense probes, which are present for all IGBTs) spike when they're driving a motor under low RPM conditions - under high RPMs there are no spikes whatsoever. Above 100kph I can keep it floored for as long as I'd like and the reported IGBT junction temperatures (again, assuming "inv1" and "inv2" are those) stay very close to the inverter coolant temperatures, which is (as far as I know) measured at the coolant inlet - might as well be "inverter case/cold plate temperature", I guess. Still, looking at hybridassistant clips (mostly of 3rd gen prius & derivatives, a few rav4 hybrids as well) and comparing them to what I have - my inverter temperatures "jump around" a lot more, whereas the others stay relatively flat. There are a couple of clips with a 2010 camry (which incidentally shares an almost identical inverter with the GS) and the temperatures spike a lot more there as well - my best guess is still age-related solder fatigue leading to very high thermal resistance and resp. heat buildup. It's listed as the most common failure mode of IGBTs, along with bond wire lift-off - mostly due to the same reasons. Double-side cooled packages & sintered packages tend to not have these problems, hence the ls600h idea 🙂 EDIT: Links to ORNL articles - posted earlier, but anyways: https://www.osti.gov/biblio/928684-evaluation-toyota-camry-hybrid-synergy-drive-system - the GS inverter is almost the same, different wire harness + bigger DC-link cap + more power devices for MG1 and that's it https://www.osti.gov/biblio/947393-evaluation-lexus-ls-hybrid-synergy-drive-system - The LS transmission is essentially the same, barring the transfer case. The 10,230RPM limit on MG2 is false, unless the transfer case has a reduction ratio that Toyota haven't told anybody about - MG2 max RPM should be 14k, just like the GS. Incidentally, MG1 max RPM is 10,230 off the top of my head, I'll go rev it outside now to confirm 😄
  7. So far - not the thermal grease, not the capacitor bank (at least according to what I've managed to measure via the DE5000 LCR meter that I got - all HV caps look fine). At this point I have to assume that it's the IGBTs - thermal fatigue (cracks) in the solder layer, or something else. The plan going forward is to attempt to replace the inverter with one from an ls600h - reading this thread should give you a clue as to why I think it's quite possible with the stock ECU: https://www.diyelectriccar.com/threads/reverse-engineering-the-lexus-gs450h-inverter-converter.200883/ This is the precursor thread: https://www.diyelectriccar.com/threads/bmw-330ci-conversion.142946/ And here is where I embarrass myself publicly: https://openinverter.org/forum/viewtopic.php?f=14&t=776 🤣 As for the "why an ls600h inverter" questions: -I haven't found a single reference to a Toyota inverter with double-side-cooling IGBTs failing. These include the ls600h (first application), rx450h (found it listed as such in toyota australia marketing materials), 4th gen gs450h & is/gs/rc300h (visibly so in Damien Maguire's is300h inverter teardowns), 4th gen Prius (weber state university teardown, toyota media material, so on). On the other hand, plenty of stories about failed inverters of Prius 2/3 (and their derivatives - auris/priusV/so on), rx400h, gs450h (camry with double the MG1 IGBTs/diodes by the looks of it) - basically anything with the classic IGBT packaging. Not a Toyota-exclusive problem by any stretch, would've been nice if they'd sell only the IPM (the power module - basically the IGBTs) for, say, 1-2k euros (I know, overpriced but that's most OEM parts for you) instead of the whole inverter only (and for 4k+)... Actually, they do sell the IPM for the rx400h due to the service campaign, but the prices that I've gotten are downright bonkers - a new inverter costs about the same. -The 3rd gen gs450h and ls600h are very similar. The transmissions are the same (well, apart from one having a transfer case at the end), the electrical wiring diagram to the inverter looks pretty much the same, the communication protocols are supposedly the same (according to what I've read in the above-mentioned threads), the wiring harness connectors are the same (shuffled pin numbers).
  8. It's a very convenient grid charger/discharger. They still haven't combined the charger & discharger, which is very unfortunate. As for whether it works - it does what it says, but don't expect miracles. A full charge/discharge (3 cycles, each with increasing discharge depths) according to their instructions takes over 3 days, and is not automated - you need to swap between the charger & discharger. You can get an idea of how well deep cycling works by browsing priuschat, endlesssphere, insightcentral and other places where people have dealt with NiMH cells.
  9. https://lexus-europe.epc-data.com/rx400h/mhu38l/5162/engine/1701/?full
  10. Well, either that wasn't the problem, or I messed something up (IGBT torque as per rx400h tsb might not be enough, bad thermal paste layer, etc). Waiting for some tools to make life easier when removing/installing the inverter, then I'll take a look again. Have some other thoughts in the meantime, still reading.
  11. So.. the grease has turned mostly translucent, and pretty much all the thermally conductive filler material (if it's shin-etsu g747 like in the rx400h, it should be zinc oxide) has been pushed out of the hot zones. I maaaay have found my problem 😄
  12. Well, change of plans. I tore down the inverter that I blew up two years ago - not too difficult to do, at least on the IPM (IGBTs) side. Boost converter is trickier, but unnecessary. You can separate the coolant flow plates if you want to - you need to remove the IGBT board first, as the boost converter case is bolted to the IGBT case by hex bolts under the IGBT board. Before you do that - let me tell you straight away, I simply don't see how these passages can get clogged. Here's the rx400h TSB for the IPM replacement: https://static.nhtsa.gov/odi/rcl/2013/RCRIT-13V396-9944.pdf Key points - thermal grease. My car was from Italy, manufactured in August 2008 and had approx. 245000km at the time of the inverter failure. Long time + decent mileage + a relatively hot region + usage of thermal grease... You can probably guess what I'm ordering 🙂 LHD and RHD inverters appear to use the same IGBT & control boards. I'm guessing the main reason for most failures is people actually connecting MG1 in the MG2 slot & vice-versa. Just a thought for anybody in need of a LHD inverter, since they are extremely rare nowadays... and RHD inverters are cheap and plentiful. At any rate, if this turns out to be the primary reason for inverters blowing up (thermal grease degradation + rapid heat buildup = blown IGBTs, given enough degradation and heat), I'd just recommend that people reapply the grease every few years. I'll let you know how the TIM replacement (thermal interface material - thermal paste - thermal grease - etc) goes - I'm quite hopeful... so far this makes the most sense - spiking inverter mg1/mg2(IGBTs) temperatures, no apparent problems in inverter coolant temperature/flow/condition. EDIT: If anybody's tinkering with his electronics, the grease part should have been pretty obvious. Otherwise (well, still a good read): https://www.nrel.gov/transportation/assets/pdfs/42972.pdf I wonder if the primary reason for not seeing inverter failures in the ls600h, 4th gen gs450h and so on is the new cooling method for the IGBTs (and them being of the SiC variety) - look up the ls600h oak ridge national laboratory article for a teardown of its inverter. The gs450h one is pretty much the same as the 1st gen camry hybrid, alphard hybrid, nissan altima hybrid and a few others - key point is, shares IGBT cooling design with earlier hybrids incl. the rx400h.
  13. The UZ-series V8s are simply more reliable than the GR-series V6s, especially when comparing the 3UZ (4.3 v8) to the 3GR (3l v6) - the 3GR is direct injection only. Whether the valves will need blasting... who knows - the IS250 (4GR - smaller 3GR, basically) very rarely exhibits the problem, but it's still in the nature of the engine. In the GS models - since the EU doesn't get the GS350: GS300 - direct-injected V6, but conventional (vacuum-assisted) braking system GS430 - basically bombproof port-injected V8, but fully brake-by-wire - like the 450h and 460. The ABS block, electric pump and nitrogen brake pressure accumulator are a single unit, so if one fails (usually the pump), it'll be expensive: https://lexus-europe.epc-data.com/gs300_430_460/uzs190r/5064/chassis/4708/44510/ Funnily enough, that part number is supposedly replaced by the one used in the IS/RC/GS300h (and resp. the 4th gen 450h), so other than the more complicated brake service procedure and the potential need to acquire a 2nd hand ABS module... I'd take the 430. The LS430 should be the most reliable of the bunch - unless you decide to go for air struts. Drive the cars and decide for yourself. The 3GS is not the best "driver's chassis" in stock form, if you're after that. Transmission - zero clue.
  14. Well, it's this season again... Over here temperatures are quite high, 35 celsius today. Inverter IGBT temperatures were approaching 80 degrees while cruising, the rest is mostly still the same - replaced the oil pump's bearings and the upshifts/downshifts are noticeably faster. 3.769 diff from Japan (nengun, yahoo auctions) soon-ish. Steam cleaned radiators, no change. The inverter coolant temperature is consistently 20-25 celsius over ambient, and doesn't seem to be affected - doesn't matter if you're doing 60-140-60-140 10 times in a row or you're just cruising along. Prime suspects - IGBT cold plate solder deterioration (pretty much means new inverter), inverter cooling channels blockage, insufficient pump flow/pressure, air lock, "car is performing to spec".