[N54B30A]

Hey guys,

I posted this on the Zpost, but I feel like I may get better feedback here. My brother just bought a z4 35is DCT, car has around 15k miles. We put the Jb4 and DCI on the car with E30 on map 5 and saw a little bit of what looks like transmission slippage at around 3000 rpm in 6th gear. Ive owned 4 N54 cars, 2 autos, 2 manuals. None of them have ever slipped at FBO with E30. I was wondering if this is something that can be taken care of via transmission tune since it seems like the car is disengaging the clutch once it sees a torque value out of the accepted torque range.

[BQTuning]

Its a DCT not to be treated as a 6AT.

You cannot use JB4 alone with out a Back-End Flash on a DCT car.

Remedy: Get rid of the JB4 and get a Flash tune that will keep all operating values in check for the DCT to operate correctly.

[N54B30A]

Originally Posted by ********

Its a DCT not to be treated as a 6AT.

You cannot use JB4 alone with out a Back-End Flash on a DCT car.

Remedy: Get rid of the JB4 and get a Flash tune that will keep all operating values in check for the DCT to operate correctly.

Does the flash control any DCT transmission parameters? Is this something i can flash with my MHD app?

[BQTuning]

Originally Posted by sahyoun

Does the flash control any DCT transmission parameters? Is this something i can flash with my MHD app?

It controls what the TCU on the DCT sees by what is reported by DME keeping everything realistic with true load.

When you mask the DME or fool it to think its doing something it is not then the DME will report false unrealistic data to the TCU.

[N54B30A]

Originally Posted by ********

It controls what the TCU on the DCT sees by what is reported by DME keeping everything realistic with true load.

When you mask the DME or fool it to think its doing something it is not then the DME will report false unrealistic data to the TCU.

So is a TCU tune even necessary to help reliability and prevent slippage? Or does the TCU already optimize itself for the input load?

[rhm135]

A MHD tune will quickly solve this problem.

[N54B30A]

Originally Posted by rhm135

A MHD tune will quickly solve this problem.

So theres no need for a TCU tune? Would a TCU tune help at all in terms of longevity and clamping pressure or will the TCU automatically adjust those values to accommodate for the added torque?

[Mike@N54Tuning.com]

With the 335is DCT the back end flash map is strongly suggested for anything over around 375whp as it dramatically increases the trans clamping pressure. And it's free to upload, posted to N54tech. You can also upload it via MHD if you have an MHD license for the car.

Mike

[N54B30A]

Originally Posted by Mike@N54Tuning.com

With the 335is DCT the back end flash map is strongly suggested for anything over around 375whp as it dramatically increases the trans clamping pressure. And it's free to upload, posted to N54tech. You can also upload it via MHD if you have an MHD license for the car.

Mike

What is the DME software version for a Z4 35is Sdrive? On the jb4 flash sticky, I only see the "ILA0S" listed for the 335is, is the Z4 35is the same? When I download the map release .zip folder, I only see INA0S, IKM0S, IJE0S, and I8A0S, so i'm not sure which one to use for a z4 35is since I dont even see ILA0S listen in the zip file for the 3/15/17 map release.

[LMB335IS]

I had the same issue years ago before. Even with the original BEF mine would slip, but I know Terry has upgraded the BEF's quite a bit since then. At the very least you need the BEF via MHD, ideally a custom flash via MHD would be even better.

[rhm135]

Originally Posted by sahyoun

What is the DME software version for a Z4 35is Sdrive? On the jb4 flash sticky, I only see the "ILA0S" listed for the 335is, is the Z4 35is the same? When I download the map release .zip folder, I only see INA0S, IKM0S, IJE0S, and I8A0S, so i'm not sure which one to use for a z4 35is since I dont even see ILA0S listen in the zip file for the 3/15/17 map release.

INAOS

[N54B30A]

Okay, perfect, I think I got it now. Thanks for the help guys! My z4 post hasnt gotten a single reply as expected.

[BQTuning]

Originally Posted by sahyoun

Okay, perfect, I think I got it now. Thanks for the help guys! My z4 post hasnt gotten a single reply as expected.

You placed it in the Z4 general section instead of the the technical section "Engine, Transmission, Exhaust, Drivetrain, ECU Software Modifications " like you did here

Most of us are on this side of Isle for general N54 stuff, and keep E89 Z4 specific related stuff over on that side.

Ya did the right thing though