[langsbr]

With all of the issues you've had using the activehybrid 8P, have you considered simply changing to the proven N57 8HP70? Sure it would be a bit of sunk cost, but with a pretty much guarantee to work since it's been done a number of times.

I'm a manual trans guy myself, but I will say that the e-manual would be a great compromise.

I''ve also been through hell with a GM 6L80E and if I have another issue I'll be putting an n63 8HP into my Escalade

[Tambohamilton]

Originally Posted by langsbr

With all of the issues you've had using the activehybrid 8P, have you considered simply changing to the proven N57 8HP70? Sure it would be a bit of sunk cost, but with a pretty much guarantee to work since it's been done a number of times.

I'm a manual trans guy myself, but I will say that the e-manual would be a great compromise.

I''ve also been through hell with a GM 6L80E and if I have another issue I'll be putting an n63 8HP into my Escalade

They might be better off, but we wouldn't be

[ab987]

Well guys, everything works! Got the gearbox together and it's acting a good bit better. Seems more consistent overall on shifts but I think there are a few differences hydraulically when it comes to the TCC circuit. It slams the clutches closed. We seem to have made it manageable by tweaking close time.

Otherwise, I think this wraps up the gearbox installation side of things. If you want to use a hybrid gearbox, make sure you get a regular HP70's P2 planet carrier and an overhaul kit, and it should do the trick! It'll be a while before I get to the clutch and shifter part of the project, but I'll let you all know when I do.

[mistawall]

Originally Posted by ab987

Well guys, everything works! Got the gearbox together and it's acting a good bit better. Seems more consistent overall on shifts but I think there are a few differences hydraulically when it comes to the TCC circuit. It slams the clutches closed. We seem to have made it manageable by tweaking close time.

Otherwise, I think this wraps up the gearbox installation side of things. If you want to use a hybrid gearbox, make sure you get a regular HP70's P2 planet carrier and an overhaul kit, and it should do the trick! It'll be a while before I get to the clutch and shifter part of the project, but I'll let you all know when I do.

Thanks for keeping us updated, let us know when you get some more miles on this set up. How much of a cunt was the disassemble of the trans? I’ve watched a few tare downs and read through some of the 8hp documentation. Doesn’t seem tooooo daunting if a task if u can get a few tools for the job. Bonus is u can rebuild it with upgraded clutches and have an even more solid trans.
Do u think any other issues may rear thier head on this or does swapping the p2 seem to solve it?

[langsbr]

After re-reading your initial post on the H pattern, I was curious what your thought would be on trying to retrofit tremec TR6070 7 speed shifter. It would require some fabricating of a box with 'gates' to get the feel correct, but having the 7th gear might be cool to be the "auto" position instead of using the paddles.

[ab987]

Originally Posted by mistawall

Thanks for keeping us updated, let us know when you get some more miles on this set up. How much of a cunt was the disassemble of the trans? I’ve watched a few tare downs and read through some of the 8hp documentation. Doesn’t seem tooooo daunting if a task if u can get a few tools for the job. Bonus is u can rebuild it with upgraded clutches and have an even more solid trans.
Do u think any other issues may rear thier head on this or does swapping the p2 seem to solve it?

With a proper set of snap ring pliers it's actually not too bad at all. The hard part seems to be sourcing an overhaul kit with new bolts and seals. I would do it again myself if it meant saving $1000. I'm fairly certain the trans is functionally equivalent to an 8HP70 at this point apart from some odd differences like the lack of shims on the P4 annulus drum, the plastic retainer for the B clutches instead of a wave seal, nothing that seems to matter though.

As for upgrading clutches, there seems to be slight differences with the B steel spline pattern - if you undertake it definitely reference the pictures I posted before with the B splines and make sure it's all the same.

It's been great apart from the converter tuning and usual complaints people have, haven't gotten the converter lockup quite perfect yet (partly due to a lack of info) and the 3-2 and 2-1 are pretty rough but people everywhere seem to complain about that.

[ab987]

Originally Posted by langsbr

After re-reading your initial post on the H pattern, I was curious what your thought would be on trying to retrofit tremec TR6070 7 speed shifter. It would require some fabricating of a box with 'gates' to get the feel correct, but having the 7th gear might be cool to be the "auto" position instead of using the paddles.

Yeah, a 7-speed shifter would be pretty cool. In fairness, it doesn't matter what shifter we use because we are designing the gates after all. We can give it all 8 if we really want to

I'll keep you all updated but progress is slowing down. I'm out of town for at least a month so it'll be a little while. In the meantime I'm sniffing CAN on the M3 to try and see what its torque reduction strategy is. It's quick in a straight line without reduction and quite smooth but I don't like the potential clutch wear that's going on from binding and lack of reduction.

[mistawall]

Nice video that goes into the 8p70h difference video from zf

[ab987]

Originally Posted by mistawall

Nice video that goes into the 8p70h difference video from zf

Wow, huge find there. That's really interesting, and actually explains exactly the behavior I've been seeing. The B brake has an extra clutch plate compared to an 8HP70 - it has 6 instead of 5. 1st and 2nd gear engagement has been horrible, which both use the B brake.

Problem is they had to keep the transmission the same length and took one away from the C clutch... it's still stronger than the 8HP45 by a decent margin given its bigger and extra C and E clutch but 2-3 and 4-5 might be a bit weaker than an 8HP70 which are important shifts on certain acceleration metrics...

[ab987]

Well guys, it's been a very busy few months and I haven't had much time to work on the car much less update the thread, but I'm finally picking back up the project.

Firstly, tuning with the Lamik has been a pretty bad experience. We haven't been able to get any details out of the Lamik brothers on what parameters do and so we've been trying to learn for ourselves. Not a pleasant experience, and we can't seem to get the calibration we're going for. Additionally I don't think the H pattern idea will work well enough with the Lamik as it doesn't do skip shifting (yet) and there's no target gear input.

That brings me to the exciting phase of the project - I've been ordering tons of electronics over the past few weeks and am starting development on my own controller. Firstly it'll be strictly H-pattern - the goal is to make it virtually indistinguishable (besides shifter feel, which we can mess with) from a real H pattern. Then I'll work on auto gear determination, B-brake take-up (converter on the 8P70H just sucks - something is hydraulically different on this gearbox and it is extremely harsh and drains quite a lot... an empty converter doesn't do much converting), bring the shifts closer together which will in effect mimick the E90DCT, and finally dial in some torque reduction. Then I'll likely have a lightly used Lamik for sale if anybody is interested

I have the exact same TCU box/connector that the Lamik uses on the way - meaning I can simply swap between them at will. Here's the really exciting part - this will be open-source. That means you all can contribute and change exactly what fits your needs for your use case. I'll be kicking it off in a few weeks and update the thread once I get it driving on my controller.

[Dandrews9383]

How the controller project going ? I like to help where I can ,/ see what your working on .I'm doing a BMW 8hp70 swap into a Volvo 740 with a 2jz. I've already designed and had made PCB to replace the TCU to bring the solenoids to the transmission connector , the same as the turbolamik. Also what are you using for high side drivers to drive the solenoids ?

[Motown65]

Any updates? Found this thread last night. I have a 2018 m4 dct that I’ve been trying to drag race with and a 8hp swap would really help

[JonOhh]

Originally Posted by Motown65

Any updates? Found this thread last night. I have a 2018 m4 dct that I’ve been trying to drag race with and a 8hp swap would really help

Most of the notable progress came to a halt when we had to start dealing with the TCU. There's little to no documentation that's worthwhile, lots of calculation going on in the background, not exposed in the XDF, and the control system is built in such a way that optimizing for one set of conditions obliterates it's behavior in others.


The Lamik isn't bad, but it is absolutely NOT the openly tunable TCU that it appears to be at first glance - it is also not "like OEM" as the fanboys claim, in any sense. Attempts to get more information from them so we can understand and tune it effectively has resulted in us being accused of being a competitor, by them and a few of the more... obnoxious vendors. I even wrote a page of their only source of documentation (the TCU manual) but I had to experimentally test everything I listed since they wouldn't tell us - so of course they wouldn't tell us anything else if they won't even help us help them.


Ironically, them trying to avoid this reality, by not giving us "secret information" (which is actually in no way something worth protecting and is typically as simple as "what does time value T2 represent"), has infuriated us to the point that we are now working on our own TCUs. By trying to avoid this reality, they've created it. I guess that's how it goes.


Quite a shame, but we're still working on coming up with something to make the swap worthwhile.

[JonOhh]

Originally Posted by Motown65

Any updates? Found this thread last night. I have a 2018 m4 dct that I’ve been trying to drag race with and a 8hp swap would really help

You likely wouldn't need to go through any of this headache. Your DME should (I'm not certain on this but theres a high probability) be able to natively control some generations of factory 8HP TCUs. However, that limits you to the stock TCUs feature set which may be detrimental in drag racing (no transbrake).

Is the DCT becoming a limitation for building boost at launch or something?

[CarAbuser]

Originally Posted by JonOhh

You likely wouldn't need to go through any of this headache. Your DME should (I'm not certain on this but theres a high probability) be able to natively control some generations of factory 8HP TCUs. However, that limits you to the stock TCUs feature set which may be detrimental in drag racing (no transbrake).

Is the DCT becoming a limitation for building boost at launch or something?

The MDS81 is capable of running an 8hp too. You have them paired together in the E89 Z4 which uses the same DME logic.

[rbryantaz]

How difficult would it be to merge a V8 hp70 with the active hybrid version to make it exactly the same as the V8 transmission but in the inline 6 compatible case?

The goal would be to remove the active hybrid bits and make a "hybrid" (pun intended) of the two transmissions in the active hybrid case that bolts directly to the N54/N55/S55 including having the more standard clutch configuration you mentioned, etc.

If I had 8hp70h and an 8hp70 from say an n63 car side by side what would it take to essentially remove the hybrid parts and swap in the standard parts so that I get the right case?

Would all of the parts from the N63 version swap over? Would they both have to be Xdrive or RWD versions to be compatible or are the tailshaft differences not important?

I would just run an adapter plate but the N57 RWD 8hp70 seems even more rare in the US than the active hybrid one.

[ab987]

Realized it's been a really long time since I updated this thread. Life happened and the car is in storage 2500mi from me, but hopefully I'll have it again in the next year or so to pick it back up. I ended up getting the calibration pretty decent, definitely better than another local Lamik 8HP45 M3, but still had a few complaints in the end:
- Downshifts are either way too slow or send you through the windshield. Blips are not advanced enough to cover them up.
- General lack of documentation, especially if you have a built or "non-standard" gearbox, good luck making it shift acceptably.

We did get our breadboard TCU "driving" the car in the end - it's probably documented somewhere but we had to engage the park release solenoid to get pressure to the clutches which was a bit of a hang-up. And with low clutch and line pressure the shifts were pretty harsh, so there's something we're doing wrong with the solenoids.

I'll let you all know if I pick it back up, it wasn't making the happiest noises towards the end of my 15k miles with it but was still shifting fine and felt good enough. May end up going with a directly-controlled DCT in the because of how complicated controlling these 8HPs is, but time will tell. Sorry to disappoint

[ab987]

Originally Posted by rbryantaz

How difficult would it be to merge a V8 hp70 with the active hybrid version to make it exactly the same as the V8 transmission but in the inline 6 compatible case?

The goal would be to remove the active hybrid bits and make a "hybrid" (pun intended) of the two transmissions in the active hybrid case that bolts directly to the N54/N55/S55 including having the more standard clutch configuration you mentioned, etc.

If I had 8hp70h and an 8hp70 from say an n63 car side by side what would it take to essentially remove the hybrid parts and swap in the standard parts so that I get the right case?

Would all of the parts from the N63 version swap over? Would they both have to be Xdrive or RWD versions to be compatible or are the tailshaft differences not important?

I would just run an adapter plate but the N57 RWD 8hp70 seems even more rare in the US than the active hybrid one.

Don't remember if we talked about this in DMs, but I do believe the B brake has different dimensions as it has an extra friction - it more than likely won't fit together properly. Of course you're welcome to try, the N63 boxes are cheap cheap

[rlesko]

Just wanted to say thanks for taking the plunge and sharing all your information with the community ab987 ! I recently was looking at active hybrid 3 parts catalog and noticed it had a ZF8hp70 and pondered if it would be usable for transmission swaps. I did some googling- this was the only thread that came up!

[Quick335XI]

Wow, makes me so sad to read this! I will NEVER own another sports car without 1) AWD and 2) A MANUAL transmission. I can't imagine why anyone would go thru the trouble of de-evolving down to an auto from a manual!! 6sp'd are so hard to find too. Unbelievable!

[OMEGA412]

Originally Posted by Quick335XI

Wow, makes me so sad to read this! I will NEVER own another sports car without 1) AWD and 2) A MANUAL transmission. I can't imagine why anyone would go thru the trouble of de-evolving down to an auto from a manual!! 6sp'd are so hard to find too. Unbelievable!

Manuals are undeniably fun. But autos win races. Plus the n54 manual loves eating synchros past 600 torque. The 8hp can easily handle 800 ish or can be built to handle more.

[suspect]

Originally Posted by OMEGA412

Manuals are undeniably fun. But autos win races. Plus the n54 manual loves eating synchros past 600 torque. The 8hp can easily handle 800 ish or can be built to handle more.

600Nm?