Vanos Dual vanos map tuning E46 MS42

[se93]

Hello to all

I would like to get some feedback regarding the proper way to start in tuning the vanos maps on the MS42 Siemens DME for a naturally aspirated engine. A good starting point would be great as i am fully aware that a dyno is absolutely necessary for proper tuning. Can anyone chime in and provide some good feedback regarding this issue. Is it true that on the dual vanos system, the exhaust vanos maps are best left alone and where some degree of power is obtained from working with the intake vanos maps?

I have enclosed a snapshot of one of the intake vanos maps and have made several mdofications. Some feedback will be appreciated to assist and determine if i am in the correct direction with regards to vanos map tuning.

Thanks in advance and a nice day to all the fellow members!!

Regards,
Mark



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[Stanton]

There is alot to write about this subject, too muc to cover by simply chiming in!!

In short, for best torque, start by advancing intake cam. So as to increase lift at tdc and improve VE for a given load/speed event. You need to be on a dyno to optimise each process point.
For part load/cruise, swinging both cams will reduce pumping losses. Valve open/close events are critical to manifold/cylinder pressures so it can be a mine-field. Its not as easy as just looking at your file im afraid.

[se93]

There is alot to write about this subject, too muc to cover by simply chiming in!!

In short, for best torque, start by advancing intake cam. So as to increase lift at tdc and improve VE for a given load/speed event. You need to be on a dyno to optimise each process point.
For part load/cruise, swinging both cams will reduce pumping losses. Valve open/close events are critical to manifold/cylinder pressures so it can be a mine-field. Its not as easy as just looking at your file im afraid.

Hello Stanton

Thanks for your reply. Is it advisable to advance the intake vanos maps for best torque in the low/mid, high or a combination of both? Thus its true then that the exhaust vanos maps do not make any more power and thus are not dealt with in terms of making more power?

Regards
Mark

[Stanton]

It's all relative, it's impossible to say whether altering exhst cam position will or won't make better torque, as we don't know it's position in relation to what gives best torque.

The best advise is to read up on how cam timing affects engines operation, then suck it and see. At least then you'll have an idea what direction to go.

[se93]

Hi to all

Any more input will be appreciated.

Regards,
mark

[Stanton]

The only way anyone can possibly help is if you post dyno data of some successive runs with varying iterations of cam timing. Then we can make a judgement of what the engine wants....