1000ft/lb with 6hp28 on N54? (maxed out 1060HP/920ft/lb with 6HP21)

Brule

Sergeant
Feb 20, 2017
378
447
0
Ride
335i 2007 6spd manual
How much timing advance are you using to get that power?
 

Scorpstan

Corporal
Feb 27, 2017
111
130
0
Ride
335i
its interesting because Diesel cars have max rpm 5.5k. over this rpm my car wont shift from 4th to 5th. think its an adaptation prob or maybe a Kind of Software and communication prob.

So did an adaptation reset and switch to old valve body. xhp told me it is not allowed to Mix other valvebodys with tcu (my 21 valvebody what have the same Part number). now will test shifts around 650lb.
 

Scorpstan

Corporal
Feb 27, 2017
111
130
0
Ride
335i
so, i did some runs on street with 950hp 790lbs.
same problem here. i shift at 7k....but trans wont shift. it shift if i left of pedal.
any ideas?

i am close to say that this swap doesnt work how it should be.
 

Attachments

  • Shiftprob.jpg
    Shiftprob.jpg
    108.3 KB · Views: 44
Last edited:

MR-KRAKA

Specialist
May 23, 2020
85
56
0
I’m not sure what all you have for a custom file with xhp but you may need to flash the tcu with a oem gas version for that trans first. Then load xhp. I believe the diesels have a 5500rpm limit odd that it’s only bothering you from 4-5 though. Finding the right file may be tough.

Are you manually shifting? Maybe try letting it shift itself in D or S and see if it’s tied to a certain mode.
 

zomski101

Private
Dec 28, 2019
47
8
0
Ride
335i
so, i did some runs on street with 950hp 790lbs.
same problem here. i shift at 7k....but trans wont shift. it shift if i left of pedal.
any ideas?

i am close to say that this swap doesnt work how it should be.
I had/have a similar issue but it started on just a regular OTS stage 2+ and xhp stage 3 tune and effected my 2 to 3 shift. Seemed to happen when I spun up the tires hard in 2nd and the trans refused to shift until a second after I let off the throttle, didn't happen all the time. I'm just regular 6hp21 trans, tried different tuners, had sutphin trans tune and purchased the rebuilt valve body he offers for a different issue. None of which fixed the problem. Ken did recommend I try selecting the shift bog fix in mhd, which reduced the amount of times it happened.
 

Scorpstan

Corporal
Feb 27, 2017
111
130
0
Ride
335i
I’m not sure what all you have for a custom file with xhp but you may need to flash the tcu with a oem gas version for that trans first. Then load xhp. I believe the diesels have a 5500rpm limit odd that it’s only bothering you from 4-5 though. Finding the right file may be tough.

Are you manually shifting? Maybe try letting it shift itself in D or S and see if it’s tied to a certain mode.
i have a special custom file from xhp which is designed for this swap. load it direkt on the trans. nothing with oem gas Version. just Code my VIN on it that xhp App can see it. than flashed the custom file.

yes i shift manually. can try D or S
 
Last edited:

Scorpstan

Corporal
Feb 27, 2017
111
130
0
Ride
335i
I had/have a similar issue but it started on just a regular OTS stage 2+ and xhp stage 3 tune and effected my 2 to 3 shift. Seemed to happen when I spun up the tires hard in 2nd and the trans refused to shift until a second after I let off the throttle, didn't happen all the time. I'm just regular 6hp21 trans, tried different tuners, had sutphin trans tune and purchased the rebuilt valve body he offers for a different issue. None of which fixed the problem. Ken did recommend I try selecting the shift bog fix in mhd, which reduced the amount of times it Happening

I had/have a similar issue but it started on just a regular OTS stage 2+ and xhp stage 3 tune and effected my 2 to 3 shift. Seemed to happen when I spun up the tires hard in 2nd and the trans refused to shift until a second after I let off the throttle, didn't happen all the time. I'm just regular 6hp21 trans, tried different tuners, had sutphin trans tune and purchased the rebuilt valve body he offers for a different issue. None of which fixed the problem. Ken did recommend I try selecting the shift bog fix in mhd, which reduced the amount of times it happened.
i will try the shift Box fix. thanks
 

Scorpstan

Corporal
Feb 27, 2017
111
130
0
Ride
335i
flashed with shift bog option didnt help.
D and S shifting didnt help too.
I noticed that as soon as the torque is over 740lbs, it no longer will shift. below 740lbs it shifts. don't know anymore what the problem here is.
i think its maybe a kind of limiter in the tcu software or DME but who knows. this project is died for me....
 

nyt

Sergeant
Sep 15, 2019
335
1
292
0
Ride
2010 335xi
flashed with shift bog option didnt help.
D and S shifting didnt help too.
I noticed that as soon as the torque is over 740lbs, it no longer will shift. below 740lbs it shifts. don't know anymore what the problem here is.
i think its maybe a kind of limiter in the tcu software or DME but who knows. this project is died for me....

Why not just adjust your load to torque tables and limit to a bit below there? The TCU should be at full clamping force at those levels, anyway.
 

Scorpstan

Corporal
Feb 27, 2017
111
130
0
Ride
335i
Why not just adjust your load to torque tables and limit to a bit below there? The TCU should be at full clamping force at those levels, anyway.
-we did this now.
-plus got a new file from xhp
-plus support from sutphin....

results are here:
 
  • Love
  • Like
Reactions: wheela and Torgus

nyt

Sergeant
Sep 15, 2019
335
1
292
0
Ride
2010 335xi
-we did this now.
-plus got a new file from xhp
-plus support from sutphin....

results are here:

Very nice. What are you trapping in the 1/4?
 
  • Agree
Reactions: Torgus

RTA

Specialist
Jun 17, 2020
58
23
0
Nice one!

Maybe you might benefit from a ZF TCU scanner / reader, there is quite a bit of info/data in the TCU not accessible via our regular BMW diag toolsets. These TCU's store a lot of interesting info about temps, events, errors.

See below some vendors pushing ZF diag stuff, no experience but maybe useful to know that there is some good tooling out there like:



I have been working with a ZF factory tech in Germany in the past on my former ZF gearbox, learned that those TCU's are full of interesting diag stuff. He had a specific ODB ZF diag box.
 

LexxyT

New Member
Dec 28, 2022
1
0
0
Hi all, sorry to hijack your thread here... so I'm not sure if you can (or want to) help me as I have a 2016 ford xr6 non turbo with a 6hp21. I'm just interested in putting an external cooler on it but I've had conflicting answers as to the size of the transmission cooler outlets. Apparently on the 6HP21 they are 10mm OD push in fittings and on the 6HP26 they are 16.4mm OD. I was wondering if anyone could confirm? Are the 6HP21's the same between Ford and BMW? Cheers!
 

peyton370z

New Member
Apr 21, 2023
2
0
0
I am about to test the 6hp28.
I made my own adapter rings. I have
put more clutches in for maximum performance.
custom map via xhp has already been uploaded. The only question I have is the maximum rpm. I couldn't set this in the app. waiting for answer from
hey are you able to message me about the adding of more clutches? thanks
 

Boorda

Corporal
Jul 15, 2018
145
62
0
45
Royse City, TX
futemire.com
Ride
328xi, 335xi M Sport
Thought about doing an 8HP swap?


Haven't completed mine yet, but I'm working on putting in the ZF8HP70 in my E90 and controlling it with a Turbolamik TCU controller.
The ZF8HP70 has an output shaft around 34mm in diameter.
Snagged the gearbox from a 2016 435d and got the DomiWorks n54/n55/s55 to n57 adapter to bolt them up.



And just for those who don't know here is what the ZF transmission model nomenclature means:

  • "ZF": This stands for "Zahnradfabrik," which is German for "Gear Factory." It's the name of the company that manufactures the transmission.
    (BMW part numbers replace ZF with GA, so if you're looking for and 8HP also try GA8HP70, etc..)

  • "8": This number indicates the number of forward gears the transmission has. In this case, it's an 8-speed transmission.

  • "HP": This stands for "Hydraulic Planetary." It refers to the type of gear system used in the transmission, which is a combination of a hydraulic torque converter and planetary gearsets. This type of system is common in automatic transmissions because it allows for a wide range of gear ratios and smooth shifting.

  • "70": This number is a measure of the transmission's torque capacity. It's not an exact number, but a relative one. The higher the number, the more torque the transmission can handle. Basically, take the last two numbers, add a zero, and this is the torque the gearbox is designed to handle in Newton meters. In this case, the "70" indicates that this transmission is designed to handle a relatively high amount of torque around 700 N-m (520 Lb-ft).

  • "X" or "Z": Letter is often used in ZF transmission codes to indicate that the transmission is designed for use in all-wheel drive (AWD) vehicles.
 
Last edited:

Boorda

Corporal
Jul 15, 2018
145
62
0
45
Royse City, TX
futemire.com
Ride
328xi, 335xi M Sport
BTW with the Turbolamik you can do crazy stuff with the gearbox like Trans-Braking and Clutch by wire which is so good drifting guys almost can't tell it's not a real manual transmission.