Ms42 tub28 cam swap m54b30

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Jooo000
Posts: 1
Joined: Wed Jan 05, 2022 6:35 am

Ms42 tub28 cam swap m54b30

Post by Jooo000 »

hello
I plan to replace my intake cam.
I compared ms43 b25 / b30 and find all its differences in ms42 (duration, reference position, vanos table ...)

I cannot find the function of its two maps if anyone has any idea.

c_fac_cam_sp_in_isapwm_min_
(German is fak_st_ms_vti)

definition:

calibration factor inake camshaft setpoint pulse width modulation idle speed actuator minimum

value

b30 0.828
b25 0.398
b28 0.398

c_cam_in_ref

definition:

calibration modifiable by application correction camshaft

value:

b30 -7.9 crk
b25 -1.9 crk
b28- 1.9 crk

thank you very much
MMM9120
Posts: 2
Joined: Sun Jan 15, 2023 2:58 pm

Re: Ms42 tub28 cam swap m54b30

Post by MMM9120 »

This is good info, I did a m54b30 intake cam swap into my m52tub25, I used romraider to change my ecu flash but it doesn't have c_fac_cam_sp_in_isapwm_min_ or c_cam_in_ref tables, tunerpro ms42 definition has it. c_cam_in_ref is c_cor_cam_in_ref for tunerpro. I changed c_cam_ini_in initial camshaft position from 120° to 126°, c_cam_op_in intake cam duration from 228° to 240°.

c_fac_cam_sp_in_isapwm_min_ table was set to .83 when I checked over my rom, I guess it automatically calculates this number. c_cor_cam_in_ref was still set to -1.9°, changed to -7.9°, going to reflash next week when the car is running again and see if this improves anything.
MMM9120
Posts: 2
Joined: Sun Jan 15, 2023 2:58 pm

Re: Ms42 tub28 cam swap m54b30

Post by MMM9120 »

Update,
since reflashing all the correct parameters for the b30 cam, my fuel injection is much cleaner and I can run stock fuel tables. Before changing c_cor_cam_in_ref to -7.9, I had to run additional fueling to get the same AFR, maybe it relates to when the fuel injectors fire in the cycle. Performance is at least back to stock since then, applied the ms43 vanos tables off ms4x.net for the b30 to good effect, next steps are perfecting the fuel table before fiddling with vanos for a little bit and then extracting as much timing as possible. I wish there was good documentation available for how DISA operation affects the engine at various loads/rpms.
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