bawfuls

Yes the coupler is meant to mimic the stock engine output shaft. It was machined professionally by a company who makes these specially for EV conversions. I have previously used a dial gauge to check the flywheel runout (0.005” variance) and checked the coupler at that time as well. It came in even better, <0.002” variance. I’d be surprised if the coupler is what’s imbalanced. It’s possible the six flywheel bolt holes on it aren’t concentric, but again that would be quite a surprise. The coupler presses perfectly into the back of the flywheel, and the bolt holes line up with the flywheel easily, so for them to be eccentric would require their eccentricity to match the eccentricity of the outer rim of the coupler as well. I did not attempt to measure their eccentricity when I received the coupler initially. If I pull everything apart again this week I can check. Here’s what the naked coupler looks like on the motor: https://imgur.com/6U8VVsJ and here’s the coupler with the bell housing adapter installed on the motor as well: https://imgur.com/5ZaaylP

Yes, it still vibrates when I hold the clutch in, though not as much initially (ie at low rpm). Yes there is a fresh pilot bushing in the coupler on the motor side (takes place of the crank shaft).

Background: Bought a '77 280Z unmodified with original 5-speed transmission, got the L28 limping along briefly (3 cylinders were missfiring), then pulled all combustion components and converted the car to fully electric drive. Now there is significant vibration at higher RPM (starts by 3000), which I assumed meant flywheel was not balanced well (I had the flywheel alone lightened slightly and balanced earlier). So I took the full flywheel and pressure plate assembly back to the local shop to re-balance. Got my flywheel-pressure plate assembly back from the shop this week. They said it was very imbalanced, 12g off. So much so, there wasn't enough material to remove from one side of the pressure plate, they had to weld on a bit to the other side. Here's what that looked like: They also marked pressure plate and flywheel with paint to make sure I reasemble it in the proper orientation. Here's the one picture I took at that step of the process (from the 'gram): You can see the orange paint tick in the bottom right. Problem is, the thing still vibrates just as much at higher RPM as before! There is also an audible click/tick or something at low RPM. Here are two videos showing what it sounds like with the transmission attached, revving up to 5000+. Camera is pointed at the shifter to see it bounce around because the tach isn't working presently. First, with the transmission in neutral: Same thing but holding the clutch pedal in all the way: Separated motor from transmission, left flywheel assembly attached. Clicking is gone, and I did not get any of the vibration from before, I think. It is difficult to judge, it’s certainly still makes (some different) noise at high RPM but when exposed like this the assembly moves a lot of air too. Here is a low-speed video: And one from ~3000-5000 RPM: This suggests the issue is in my transmission right? I am trying to remember the behavior when I first got the car running (poorly) on the original engine. I don't remember the loud vibration, but it's possible it was simply drowned out by the engine before. I do remember it felt like a lot of heat coming up from the transmission through the shifter hole in the body, but I wasn't sure if this was a transmission issue or just excess engine/exhaust heat seeping in b/c of a lack of insulation. I realize diagnosing by sound over youtube is tough, and that this motor-transmission sounds weird because there's no combustion engine over top of everything, but the motor itself should be a LOT quieter than this, it's mostly that high pitched whine you can hear at some points in the videos. I’m not sure how to diagnose from here. Any suggestions of further testing to isolate the issue?

I did not yet, unfortunately. I've been prioritizing other things on the car since the headlights reliably work (with the old bulbs) in the high beam position, though they aren't high beam bright. I finally got the car running this past weekend and there's a lot of other bits I'm focused on at the moment. Your help has been invaluable though and I will revisit this thread once I've got other things dialed in (suspension, flywheel re-balance, etc).

Motor is rated for 120 hp 179 ft.lbs peak. I should get somewhat better acceleration around town than the stock L28 (particularly since I get peak torque now from 0-3500 RPM), but with a reduced top speed. Continuous power output is only ~40hp, so based on that and gearing/drag calcs I've found online puts top speed around 90-100 mph (this car has the 5-speed transmission), which IMO is plenty fast for a 40 year old tin-can of a car. I expect around 90-100 miles of range out of this once everything is dialed in (suspension leveled out, front aero cleaned up, etc).

BTW this car runs as of today. Still need to address the suspension and a couple other issues, but at least it's moving now. motor spin for the first time: https://imgur.com/a/jb5W8An test drive: https://imgur.com/a/51VIz4Y

If the GC sleeves give more adjustability and are of higher quality, I don't mind paying a bit more. With my very unusual weight distribution, it is probably a good idea to lean towards more height adjustment. I am also weary of reports the Cosmos are quite stiff, while the GC kit will let me pick from a range of spring rates that may be more suitable to daily driving on our decaying San Diego streets. Particularly if the GC sleeves give me a bit of "future proofing" in case I add power/bigger tires/etc down the road. $500 for all 4 corners and the piece of mind that they'll work for potential future upgrades is worth it to me. Now I just have to figure out how to pick shocks and springs. I might give GC a call and ask them some Q's. This thread has been quite helpful already, thanks!

Is this a better version of the Cosmos method? Looks like quite a lot of height adjustability. https://groundcontrolstore.com/collections/s30-coilover-conversion/products/coilover-conversion-kit-74-78-nissan-260-280z-not-zx-weld

Thanks, sorry I miss-read the subforum heading. The Cosmo kit sounds like the easiest option, could I also replace the stock shocks at the same time to address the ride harshness? It looks like the Cosmo kit is only ~$250 for all four, while the BC kit that comes up for this car is $315 for just one corner. I expect to get access to scales this weekend or next week, so I can get more details on weight distribution at that point.

As I've mentioned briefly here before, I'm nearing completion of my electric conversion on a 1977 280Z. The conversion has resulted in a significant change to the car's weight balance, and I need advice on suspension adjustments to go along with this. In lieu of the ~500 lbs L28, there is now a 120 lbs electric motor: And where the spare tire well/gas tank once was, there is ~300 lbs of batteries and battery housing: As a result, the ride height is quite high up front: The rear looks fine to me though: This car will be a daily driver around town and on freeways. I have no plans to track/autocross/etc (and would need to do a major overhaul of my battery pack to set it up for that). So I'm looking for a way to lower the front while keeping the ride comfortable for daily driving. It's been suggested that I just cut the springs up front, but others have warned that's a horrible idea. I'd rather not spend big money on a fancy setup with a ton of adjustment meant for racing that I'll never use, so is there something in between that might work better for me?

There is definitely something draining my 12V battery faster than expected when the car is off. I typically disconnect the negative terminal when I stop working on the headlight issue and leave for the day, but I left it connected Monday night I think and as noted the battery was down today to ~11.9 from the 12.4 or so it was at on Monday. It has been recharging for the last 15 minutes or so and is up to 12.15, so my recharge circuit is working as intended at least. I've no idea if this drain is related to the headlight issue or not. But I also have no idea how I'm going to chase down the leak. I guess I need one of those multimeters that has the clamps so you can check current through wires, then just start from the battery and eliminate branches one by one?

I just checked voltage again at both the round connector sub-harness and at the headlight bulb connector, and they were the same (this is with the high beams pin on the 6-pin connector at the turn signal grounded directly to chassis). voltages on these three pins: 11.4V, 0.8V, 10.9V. That's the middle pin, the fatter one, that reads low while the other two read high, all of these are measured against chassis ground. Voltage at the two headlight fuses are both 11.0 currently. I just checked the battery directly and it's reading 11.88V right now (lower than the ~12.4 I was seeing on Monday, I have the car "on" right now so the DC-DC converter should be recharging the 12V battery from the high voltage pack). Voltage at the C-4 connector is 11.98V for both headlights. This is a bit funny because when I checked the voltage directly on the battery terminals immediately after this, it read 11.88V. Verified no power at any of the sub-harness connectors for either side while the C-4 connection is open. Still feels like a grounding issue because I only get power when I directly ground the high-beam pin at the turn signal harness as you instructed in your previous post, and I get no power at the headlights when I ground the low beam pin and put the switch to low beams.

-unplugging the 6-wire connector for the turn signal switch did not remove the "extra" power from the headlight plug -grounding the red/black wire on the harness side did not enable low beams in the "on" position -grounding the red/white wire on the harness side DID enable lights in the "high beam" position, but when I unplugged a headlight to check the voltage, it's only getting 10V on the high connection. My stock lights come on with this (not super bright), but the new LED lights don't of course because they need 12V As best I can tell, this is how the lights behaved when I first got the car and had it running (limping) on the stock engine. Headlights did not come on in the low beam position, came on but weren't very bright in the high beam position. That makes me feel a little better about having not fucked things up more when I ripped the engine out. So this means... there's some issue with the ground loop connections? Not sure how to diagnose further.

Finally back in the shop with some time to look at this issue again, and it feels like I'm going in circles. I replaced the 12V battery with a fresh one and started the process again. -I've got power at the white/red stripe going into the combo switch on the column now (I checked the connection behind that white plastic harness in the passenger foot-well area as well, it didn't work at first but did after cleaning the contacts a bit) -I've got 12V at each of the two headlight fuses on the fuse box, but ONLY when combo switch is on high beams, not when it's off or set to low beams -ground connection between combo and turn signal switches is intact and reads within 1mV of chassis ground -no power at any of the 3 headlight contacts, unless the switch is on high beams, in which case i get 12V at all three

I got sick right before the holiday and then the usual obligations took my time, so I'm just getting back to this today. Unfortunately some complications from my EV conversion have now impacted the headlight issue. Long story short, I left the 12V battery connected over the long break and it drained (because I did not have the DC-DC converter powered on to keep the 12V battery topped up from the high voltage system while I was away). The 12V battery now reads ~350 mV directly across it's terminals. It seems to me that it should not be able to discharge that deeply, but I presume it is now dead and will need to be replaced. The fact that it drained so completely while I was gone also indicates that there is some kind of leak path in the 12V system which I'll need to track down once I've got a fresh battery installed. Maybe this is also the cause of the headlight issue? Not sure that I've articulated it in this thread, but I am converting this Z to fully electric drive, so I have removed extensive systems from the car. In addition to all the obvious (engine, fuel lines, fuel tank, radiator, alternator, etc) I also cut out all the EFI wiring and the ECU. I was careful to make sure that the wiring I removed was only the EFI and ECU system based on the car's wiring diagram, but still that could have introduced complications to the 12V wiring system.

-verified power at fusible links -large white/redstripe wire at the column that goes into the combination switch does NOT have power, but when I plug it in anyway, I get 10V at each of the headlight fuses if the combo switch is in the high beam setting. No power at the headlight fuses when combo switch is off or set to low beams. This... shouldn't be possible without power at the white/red, no?

Thanks for that diagram, worked like a charm! Both turn signals worked just fine with that jumper (even blinked at an appropriate speed with LEDs up front, thanks to the new flasher). Now I will look for hazard switch rebuilding guides/replacements. edit: opened up the switch, cleaned the contacts off, put it back together, and signals now work even with the hazard switch installed. Just need to get to the bottom of the headlight issue now...

Thanks, saw those flashers on Rock Auto but O'Reilly also claims to stock several that are compatible so I'll stop by there today and pick a couple up. They're so cheap that even if they don't work it's nbd. edit: replaced both stock flashers with this one from O-Reilly, no change in behavior. Hazards still work, turn signals (and headlights) still don't.

I just double checked, and that unmarked black/ground between the headlight and turn signal switches is connected. My turn signals don't work currently either, though the hazards do flash them properly (even with LEDs swapped out up front). New flasher units are cheap, should I start there? Is there a reliable aftermarket flasher unit that will play nice with LED bulbs without the need for load resistors? I also realize now that I should have disassembled and cleaned the hazard switch while the console was out of the car, is that worth doing now? I've read it can interfere with the turn signals if it's worn, even while the hazard function still works.

Nope! Been keeping busy with other things, but it’s time to come back to this now. I was considering replacing the wiring along with the turn signals/flashers/relays if I can’t figure this out. I have not yet researched how to do that though.

Resurrecting this thread as I've come back to the issue again after 6 weeks of other things. So I have verified power at fusible links, fuse box, 4B, etc. I checked power at the headlight connectors themselves, and found something weird: with the light switch on, all 3 contacts at the lights read 12V, even the one that should be ground. Tracing things back on the wiring diagram, I found 12V at the Earth connection on the combo switch. That's E on the combo switch table in the above images. When the switch is in the OFF position, this connection reads no voltage, but when on the second (high beams) position it reads the same 12V as 4B. It still reads no voltage when in the first on (low beams) position, BUT in this position the ground connector at the headlight reads 12V This.... means my combo switch is wired incorrectly or shorting something? I can't find any difference in the ground connections between my refurbished and my old combo switches. (The old one did work intermittently ~7 months ago). What other sources could be causing this ground to see 12V when the light switch is on? I am extremely confused now.

Alright so the new combo switch is here which should make testing easier. I checked without the switch connected and I've got 12V at #2 and #4 (at the steering column). I am also seeing the tail lights come on when the battery is connected but the combo switch is in the OFF position (wtf?). This is the case even with the combo switch completely disconnected. With the new switch connected and turned on, the marker lights come on but the headlights do not, same as before.

I'm not using the switch because mine is broken and the new one hasn't arrived yet. I'm jumping the pins at the connector where the switch plugs in. I have power at the fuse lead that feeds the combo switch connector, but I did not check for power at the connector itself, which seems like an obvious oversight now. Will have to check tomorrow.

bumping this thread with mo' problems In trying to repair my switch, I eventually broke it, so I bit the bullet and ordered a refurb off ebay. In the meantime, I'm trying to test new lights by just jumping the connections in place of the switch. With the ignition at Acc and nothing jumped, I am getting power at the fuse box at the "Power to Combo Switch for Park" point in the image above. If I jump #1 and #2 in the combo switch image, the side marker lights come on, along with turn signals (not flashing obvi) and the tail lights. But no headlights (this is with original headlights installed). I also see no power at the headlight connections in the fuse box (on either side of the fuses) in this condition (the orange and orange/white leads on the top left in that image). tl;dr: when using a jumper to bypass the combo switch, marker lights come on but no headlights and no power at the headlight fuses Any ideas?

I am not sure, it didn't occur to me to try swapping those push rods, in part because I gave my busted old Z booster to Oreilly for a $30 core refund when I bought the Tacoma booster. Chopping it with an angle grinder was pretty easy and quick. The main headache was fitting it into the car, realizing it needed to be chopped, removing it, etc. If I knew from the get go that it needed to be about 1" shorter that would have saved some time and hassle.