Zf6hp28 atc300 combo xdrive

135boost

Corporal
Oct 28, 2017
242
1
133
0
Finland
Ride
135is
Hi again.

So, did borrow my 135 e82 xdrive to a friend and he blew it after 6km.
I had 16 000 km with same engine without bigger mecanical issues.
I build new even stronger engine with closed deck insert and wiseco boostlines with625+
Bolts combined to 14x11mm arps, je pistons, race bearings etc and 235cfm head with schricks as
In previous engine.

It took almost a year to get all parts with quite much difficulties but yesterday was first drive with
The thing again... combined to that not so ofen found transmission.

So, keep story short, i built a xdrive version of a rwd 6hp28 with a hefty amount of mods.
6hp21 bellhouse
6hp28 center section of housing
6hp21x rear part of housing
6hp28 internals with 31 friction discs
Modified every drum and every piston to get those fit
Combined rear drum to 21x output shaft
Did my own bearing housing and shims to it
Used 6hp28 little modified mecatronic unit
Combined that to 6hp21 tcu unit
Wrote own bin to tcu with tunerpro.

First drive, everything worked flawless and even without adaptations
It was surpricedly smooth, i was waiting for some jerky shifts but nothing...

Next is to try some easy pulls with it to see if behaiviour is still good...

Then a question to someone to help me out of a programming issue.
Xdrive control unit is in responce of locking transfer case clutch (what i'm at the moment
Modify to accept 2 extra friction plates from 6 to 8) depending of driving situations.
On my knowledge logic is keeping clutch engaged at wot acceleration even if there is no slip
On wheels but what is not so well known is that it on my knowledge realase it at some 170-180kmh speeds.

That realase sequence has somewhere that speed info, propably hidden in transfer case ecu.
What i need is something tools and knowhow to manipulate that value from 170 to 250kmh because of wheelspin risk
When shifting from 3rd to 4th gear wot .

And yes, 1000 hhp/1000nm is creating such a issue.
 
  • Like
Reactions: wheela

135boost

Corporal
Oct 28, 2017
242
1
133
0
Finland
Ride
135is
Think that trans is good for prox 1100nm, weak spot is propably same E clutch shaft.

First and third row is 6hp21 and 2nd / 4th is 6hp28
 

Attachments

  • d4fe8dbeacf2bde1c778b142a0dd2c16_0.jpeg
    d4fe8dbeacf2bde1c778b142a0dd2c16_0.jpeg
    237 KB · Views: 14
Last edited: