[ab987]

Originally Posted by mistawall

Love to hear it, was there any reason u went with lamik over htg? I’ve been researching and I’m finding a lot of unhappy htg campers

Exactly as you said it, I've heard horror stories of bugs causing the cars to shift into reverse randomly and doing other things that have broken axles, diffs, even subframes. Not to mention the lamik integrates better with E9X cars and Dawid was somehow more responsive.

As for my swap, things have really turned for the worse. Absolute nightmare today. I cut down the 2 drivers' side bolts, all was good. Went to remove the passenger side bolts and 2/3 managed to get incredibly stuck to the point where I think they have corkscrewed their way into the threads. There was no meaningful weight on them and everything was square. Even with an impact they don't budge tighter or looser. Spent 5 hours doing various things to try and remove them with no luck. Tomorrow I'll be lowering the motor to drill them out and witness the damage to the threads in the block. I don't have helicoils ready, so this is about to be quite interesting.

Moral of the story: use the right bolts! Please, save yourself a weekend.

[mistawall]

Originally Posted by ab987

Exactly as you said it, I've heard horror stories of bugs causing the cars to shift into reverse randomly and doing other things that have broken axles, diffs, even subframes. Not to mention the lamik integrates better with E9X cars and Dawid was somehow more responsive.

As for my swap, things have really turned for the worse. Absolute nightmare today. I cut down the 2 drivers' side bolts, all was good. Went to remove the passenger side bolts and 2/3 managed to get incredibly stuck to the point where I think they have corkscrewed their way into the threads. There was no meaningful weight on them and everything was square. Even with an impact they don't budge tighter or looser. Spent 5 hours doing various things to try and remove them with no luck. Tomorrow I'll be lowering the motor to drill them out and witness the damage to the threads in the block. I don't have helicoils ready, so this is about to be quite interesting.

Moral of the story: use the right bolts! Please, save yourself a weekend.

F*** dam always something.

im going to order auto bell housing bolts. im wondering what fly wheel i can use i have an auto flywheel from 6hp that is 8 bolt. are you 6 or 8 bolt?

im hoping the 8hp45 convertor will just bolt up to the 6hp 8bolt flywheel.

[ab987]

Mine is 8 bolt, I got an 8-bolt N54 flexplate and it bolted right up to the F10 N55 converter.

Figured out what happened to the bell-housing bolts. All it really took was a quarter turn once it started bottoming out to permanently balloon the end of the bolts, causing them to get stuck in the block.

The middle E18 ended up breaking and needs to be drilled out, I got creative with the top one and cut some washers so it could provide adequate clamping force. Don't like leaving the middle E18 out but it'll have to do for now.

The gearbox is fully in-place and everything is torqued up. Mounts line up perfectly, torque converter has perfect clearance. This is exactly why I wanted to try this gearbox.

[feuer]

Originally Posted by ab987

Mine is 8 bolt, I got an 8-bolt N54 flexplate and it bolted right up to the F10 N55 converter.

Figured out what happened to the bell-housing bolts. All it really took was a quarter turn once it started bottoming out to permanently balloon the end of the bolts, causing them to get stuck in the block.

The middle E18 ended up breaking and needs to be drilled out, I got creative with the top one and cut some washers so it could provide adequate clamping force. Don't like leaving the middle E18 out but it'll have to do for now.

The gearbox is fully in-place and everything is torqued up. Mounts line up perfectly, torque converter has perfect clearance. This is exactly why I wanted to try this gearbox.

Well you don't whether someone was there previously and cross threaded the bolts. Usually people mess up the bolts that hold the bracket for the down/pipes. Or some of the bottom bolts from transmission hanging during dismount. Also, if power tools are used, bolts are aluminum and very soft, super easy to damage them.

[ab987]

Originally Posted by feuer

Well you don't whether someone was there previously and cross threaded the bolts. Usually people mess up the bolts that hold the bracket for the down/pipes. Or some of the bottom bolts from transmission hanging during dismount. Also, if power tools are used, bolts are aluminum and very soft, super easy to damage them.

The threads seemed very nice, I was able to go finger tight all the way onto the washers, but realized it was not clamping hard on the washers after the damage had been done. I think the block threads should be good as long as I carefully drill out the swelled bolts. Just a combination of not expecting the bolts to be different lengths, soft bolts, and rookie mistakes.

[mistawall]

Just got my domiworks cooling adapter for the transmission I don’t have yet

Hope you get some time this weekend to dig in!

[mistawall]

Originally Posted by ab987

The threads seemed very nice, I was able to go finger tight all the way onto the washers, but realized it was not clamping hard on the washers after the damage had been done. I think the block threads should be good as long as I carefully drill out the swelled bolts. Just a combination of not expecting the bolts to be different lengths, soft bolts, and rookie mistakes.

any progression?

[whyzee125]

This project is so over my head that I literally didn't even know what the purpose was or what I was reading til I was halfway through the thread but that didn't stop me from reading every word intently!

Super weird and cool project, I'm genuinely excited to see how this turns out.

[DamnDatsun]

Following!

[JonOhh]

We have plenty of updates: the car is driving now. Just give us a little bit of time and he or I will be sure to update the thread.

We ran into some seriously infuriating issues with the hybrid box specifically but came up with a decent solution to them

[JonOhh]

https://photos.app.goo.gl/moHxzkWy74vp6WXa6

[mistawall]

Originally Posted by JonOhh

We have plenty of updates: the car is driving now. Just give us a little bit of time and he or I will be sure to update the thread.

We ran into some seriously infuriating issues with the hybrid box specifically but came up with a decent solution to them

I have been waiting for this! Curious what the issues were.

[ab987]

Tons of updates. Firstly, the install was far from smooth. I didn't pot the TCU the first time around and was running into intermittent shorts. POT THE TCU! I had to pull everything out and do it again.

Second, the hybrid box actually is different from every other 8HP on the planet. We started the car and immediately noticed we had error 17 (turbine speed sensor value missing), and we'd be in limp mode, meaning we only had the "safe mode gear" which is 6 by default. We figured out that by lowering the voltage threshold below the resting voltage of the turbine speed sensor (~0.72V) we had gears 1-3, and no reverse. The shifts were properly brutal as was engagement. After some more experimentation we noticed that in limp mode we had turbine speed that matched engine speed 1:1, but by then we hadn't tried any other gear besides 1 and 2, which had no turbine speed and would throw us into limp.

On the E90 side, coding the car was interesting and still an ongoing process. We added $205 to VO and coded every relevant module - CAS, DSC, FRM, and a bunch more. We had constant CAN errors and could never get a gear displaying on the cluster. This alone could throw it into limp. It would also make any K-CAN extremely unstable, which caused a failed flash scare and made diagnostics impossible. After hours of debugging, we learned that pin 5 and 6 on X14271 (PT-CAN, JBE) did not have continuity with the primary PT-CAN pins 1 and 2 (PT-CAN, CAN). We switched over to pins 1 and 2, and we finally had a gear display! Only problem is because we don't have a gear selector, so the car tells us to put the car in park and doesn't let us shut it off (which is not possible with paddles). That one's still ongoing.

After potting the TCU to get rid of these shorts, we wanted to check that we actually had 8 gears. Right away, it would go into reverse, and we could try every gear via safe mode. Great! But then we noticed something very ominous that left us scratching our heads. Gears 3-8 all had turbine speed, but the turbine speed was equal to output speed in 4-8 and slightly lower in 3rd, no turbine speed in 1-2 and reverse. That's not supposed to happen. If you are unfamiliar with the turbine speed, it should be exactly tied to input shaft/torque converter output, so in neutral it should be engine speed, and when the torque converter is locked while driving, it should be engine speed +/- a tiny bit when the converter's springs dampen some of the shock. I've previously heard from the only other person in the world who tried this gearbox that the input shaft wasn't spinning. I was quick to dismiss this, but now it seems that there's actually something mechanically different. Whatever, we knew it had gears and noticed that it didn't complain as long as it had SOME "turbine speed". By setting our start and end gears to 3rd, we would be able to avoid limp mode and drive the car.

We drove the car 250 miles like this headed to another state, and got to experience how truly awful a gearbox that thinks it's slipping 50%+ shifts. Every shift apart from 6-7 and 6-5 (where turbine speed is correct because it's a 1:1 gear and output speed is 1:1 with whatever we are measuring) absolutely slammed, even getting into gear was a nightmare. The converter had a feedback loop where it would lock super hard thinking there's lots of slip, forcing the RPM back below the threshold. It was impossible to drive. I've never felt a worse gearbox in my life. After looking through some power flow diagrams of the ZF8, I noticed a pattern - there's 1 thing that only spins in 3-8 - the P4 annulus drum. Which happens to be the thing that normally the turbine sensor measures through to get to the magnetic reluctor ring on the input shaft. When we tore apart the gearbox to re-do the TCU, we tested its material and it was aluminum, and we felt some teeth on the other side of it. Now it's apparent that those teeth may not be connected to the input shaft, or the turbine sensor on the hybrid box is just flat out in the wrong spot due to the fact that they don't need it when they have an external input shaft sensor on the electric motor. We don't know the exact differences, nor do we know if the gearbox has the reluctor on the Nm put shaft, but I have somebody opening theirs to see. So this gearbox is different and won't work nicely at all out of the box. In fact, it's terrible.

JonOhh had a really interesting idea - notice what I said about what the input shaft is supposed to do most of the time. In neutral it's equal to engine speed (affecting initial gear engagement) and when the converter is locked it's also roughly equal to engine speed. And when the converter isn't locked but we're in gear, the input shaft is rigidly tied to output shaft/vehicle speed. Do you see where I'm going with this? I wrote up some code on the ESP32, I have one core reading CANBUS (message 0xAA, Torque3) and sending the other core our calculated input shaft speed, and the other core generating a square wave of that frequency by just toggling an output pin super fast because the PWM timers don't reset quickly enough. 90 teeth per revolution and the ESP32 is at roughly 1% of its capacity at redline (40 million teeth per minute while flat out it'll do 4 billion+). We threw in a resistor so that the car knows it's not an open circuit while we output to get rid of error 20, and voila! We have a rough turbine speed showing up on the dash. We reset adaptations and threw it in gear, and the engagement was butter smooth. The first shifts were not great but no longer slamming. It was flaring the hell out of some shifts but quickly learned the clutch handoff. We did some adaptation driving and fully disabled lockup past 1100rpm, and the result was nothing short of beautiful after all that we've been through. It still has some more learning to do, but after a half hour of driving and letting it adapt, these 8HPs really are something special.

To conclude, I actually don't really recommend the AH3 gearbox quite yet. It's still not as good as it would be with an N57 box, we need to find this reluctor ring and figure out if there's a better way to mount a sensor internally or externally. While it's 90% there, our solution won't be able to detect converter slip (and will report it as clutch slip) and needs some tweaking to really get converter engagement down. Because the engine RPM only updates roughly 40 times per second, it's also not as precise as a reluctor ring and the TCU will see some tiny "slip" sometimes under acceleration. Another option here is to install an active hall effect sensor on the flywheel, or use crank position sensor (which might not be perfect either due to the 2 missing teeth). Ideally we install one on the input shaft itself - but at least the car is smooth for now.

https://youtube.com/shorts/mCDwLuTL_uw?feature=shares

[JonOhh]

And for anyone wondering: we are absolutely not planning to keep the shifts slushy like the above video. While that may be a good comfort mode map, our end goal is the crispiest of crispy shifts- at a bare minimum we're chasing 335is DCT speeds. We'll see how much of a limitation the first gen ZF8 valve body becomes.

[mistawall]

Thank you for the update! shit i had high hopes but all is not lost. just need time. guess ill be keeping my 6MT when i throw my engine back together. 8hp is now a 2024 project haha. ill be following for updates. keep fighting the good fight.

[ab987]

The car has been alright, the take-up has been questionable because it doesn't have an accurate turbine speed when in-gear and the converter is unlocked. It also sees false slip because of the lack of resolution causing it to do strange things like extend the hand-off phase between clutches (which wears them further and prevents us from quick shifts) and shift inconsistently. It's great in slushy modes but when you want quick, it won't cut it.

We've been investigating why the turbine sensor input is missing and we found it on a Taiwanese shop's FB group - if you are interested you can search for #zf8p70h and #zf8p70h_023. The P2 planet carrier is different on the AH3, it doesn't have a magnetic reluctor ring like every other 8HP70 on the planet. It's just the carrier. Weird optimization on ZF's side.

I am not going down without a fight, so I bought a used P2 planet carrier and a genuine ZF 8HP70 overhaul kit so I can safely open the gearbox up and replace the P2 carrier. From pictures it seems like nothing else is different and this carrier should slide right on the input shaft in place of the old one. I'll take pictures to clearly show the differences and what is involved to get one of these working 100%. It makes it make less sense than an n57 box or otherwise, but if you are going for high power and tearing down the gearbox to do clutches anyways, this is only a few more minutes to swap out and bolts right up.

We also looked into using the electric machine's HCC and I am amazed at how tiny the HCC is - it makes sense why there are so many clutch plates. Here are a few stages of disassembly:






As you can see, the HCC isn't simply coming apart from the coils - everything is glued in place and the magnetic forces are immense. Even if it did, it does not drive the oil pump without the clutches being engaged so we'd need to power the electric pump which may or may not confuse the Lamik, and won't be easily possible to use the reluctor ring without permanent modification to the unit. Looks like we're going to stick with the 8HP45 converter on this one.

This weekend I should be tearing into the gearbox - and drilling out the 2 broken bell housing bolts.

[langsbr]

Love your effort and documentation! Hope all the bugs get worked out, and very excited to see the H pattern shifting when you get that implemented.

I think an "e-manual" will be the next option in factory vehicles. We see Konigsegg is doing it, and with all the control over clutches, I don't see why OEMs aren't offering it. I really expected the C8 to have a pop up shifter and pop-down 3rd pedal to simulate a manual.

Are you going to modify an OEM shifter with electrical contacts to determine gear selection?

[whyzee125]

Wow this is terrifyingly complicated. I'm pretty mechanically inclined and have replaced multiple engines, clutches, an auto trans, etc. and I have zero idea what I'm reading but bravo for even having the balls to pursue something like this. I still have no idea why you'd even want to but I don't mean that in a bad way at all, it's super badass. I just would've pulled my hair out by now haha. Definitely looking forward to seeing the end result!

[ab987]

Originally Posted by langsbr

Love your effort and documentation! Hope all the bugs get worked out, and very excited to see the H pattern shifting when you get that implemented.

I think an "e-manual" will be the next option in factory vehicles. We see Konigsegg is doing it, and with all the control over clutches, I don't see why OEMs aren't offering it. I really expected the C8 to have a pop up shifter and pop-down 3rd pedal to simulate a manual.

Are you going to modify an OEM shifter with electrical contacts to determine gear selection?

Yep, that's the plan. Though I am far out from even considering that with all of the ActiveHybrid things going on haha

[ab987]

Originally Posted by whyzee125

Wow this is terrifyingly complicated. I'm pretty mechanically inclined and have replaced multiple engines, clutches, an auto trans, etc. and I have zero idea what I'm reading but bravo for even having the balls to pursue something like this. I still have no idea why you'd even want to but I don't mean that in a bad way at all, it's super badass. I just would've pulled my hair out by now haha. Definitely looking forward to seeing the end result!

I appreciate the interest! Hopefully this will allow others to fearlessly take on a project like this without any unknowns.

Anyways, we disassembled the ZF8 last night, and found exactly what was causing this weird behavior. It's actually an easy gearbox to disassemble, except for trying to undo the P4 annulus snap ring. There aren't even many seals to replace.

Just as a refresher, remember the behavior we were seeing - we had perfect "turbine" speed in 6th, and otherwise different speeds in 3-8 but none in 1-2, N, or R. I noticed the P4 annulus only turns in 3-8 from some ZF8 training docs. We even noticed clutch material collecting in a reluctor pattern, here's a picture from 2 weeks ago:



Just as we thought, we saw a P2 planet carrier with no reluctor ring.



Now I'll remind you what it looks like in literally every other type of gen-1 ZF8 on the planet, notice the reluctor ring filled with magnets:



Here comes the weird part - that explains the behavior we were seeing but makes absolutely zero sense:



That was just relaxing in there between the P1/P2 ring gear and P4 annulus. That's a reluctor ring splined to the P4 annulus. Which confirms what we thought before, we were reading P4 annulus speed the whole time! Looking back at the FB shop's pictures again, it's staring us in the face.

Why ZF would do this makes zero sense. It's redundant in 4-8, some intermediate speed in 3, and 0 everywhere else. If anybody has any clue why they would do this, please feel free to educate.

Waiting on the seals which were lost by DHL and won't be shipped until Monday, hope to see them mid next week and finish the first phase of the project.

[iqraceworks]

After reading through this.....I think when my ZFHP21 dies, I'm going to just swap in an HP26. Adapter plate, maybe a little coding with ProTools, and it bolts right up....

Everything needing done to get this 8P70H to work looks like a major pain in the butt...not to mention the time and money associated with the project.

Cool project to follow though....keep it up

[Tambohamilton]

Great work, OPs!