s50b32 dyno results....... advice wanted :(

[Arron 226]

howdy all

had my race car on the dyno last weekend and thinks are not looking the way they are ment to...... we are lacking quite a bit of power from where we should be

hatched is the dyno chart

we peaks at 160kw at the wheels

as can be seen on the chart there is alot of hesitation then a huge jump around the 3k mark, from what we have been reading is it possible for that to be a sign that the vanos needs to be rebuilt? 9had the engine scanned afterwards and the exhaust cam is out by upwards of 4 degrees)

also from the a/f ratio we can see that it is running rather rich, we have since had the car scanned and nothing has shown up. we have since found a air leak so have sorted that but if anything we thought that would make it run lean (unless it has put the o2 sensors outside their reading range so it has gone into a "safe mode"

do any of you have any things to check or look at to work out why it is running so rich??

the a/f ratio is between 11.6:1 and 12.1:1 so it is reasonably rich

possible dud o2 sensors, or any other reasons you could think of

we are currently looking at buying our own a/f ratio meter so we are able to keep looking at if things we change/try change the a/f ratio

any thoughts,advice or info that you guys have would be appreciated

Attached Images

[hybrid 1039]

Firstly: what gear did they do the pull in ? If it was anything but the 1:1 gear you will get incorrect power measurement. I use a ZF 5 speed, 5th gear is my 1:1 gear. As is it in the 6 speed as 6th is an over drive gear.

Here is mine on stock headers / modified mainly straight through exhaust and cold air box with pod filter. Also my telemetry from my logger project from that run. For vanos problems you should be looking for a big difference between the intake and exhaust cams DME target values vs the actual sensor values.. the graph below shows how it should look.
o2 sensors are irrelevant when you are running the DME in open loop EG flooring it on a dyno. stock o2 sensors are only used in closed loop for efficiency/emissions.

As you can see in my AFR chart there is still some tenability left in the stock ECU. Certainly it can be made a lot smoother. Keeping in mind the stock DME is programmed for smooth power delivery and fail-safes.

[No name user 379]

Take it to Rapid in Timaru

[hybrid 1039]

I assume the 4* variation on the exhaust cam came from INPA (BMW's software)? I've seen the VANOS test pass with more than 4* variation so it's not that bad but it could be better (mine is around ~2* max variation). Did they actually run the VANOS test do you know?

Nah its from the software Ive written. INPA doesnt show a lot of stuff thats hidden in the data stream(s). Even the workshop tools GT1 are basic representations of whats in the datastreams.

I can't add much more than Josh. Mine runs about 185 rwkw (so Josh's graph makes me sad).

Dont worry too much, different dynos, different days, different humidity / air temp and most imporantly different air intake temp (IAT) most likely, heatsoak is a bitch on these.

[Arron 226]

Cheers for the thoughts guys

It was dynoed in 5th gear which for us is 1:1

It was scanned on a snap on scanner but he is coming back over shortly with the BMW program and we will be doing the Vanos test

[handgrenade 189]

Does anyone have a dyno graph of a healthy s50b32 engine with the VANOS enabled and working, and also with the VANOS disabled?

I would be interested to see the difference between what would just be a 3.2L high comp engine, versus the same engine with BMWs tech added.

[nigelaston 20]

I will try and find my old graph. s50 made 180rwkw

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[sweetm3 180]

http://bimmersport.co.nz/topic/43521-m3-evo-32-1997-hackar/

Here's a link to mine

[Jamez 2147483647]

Here is a pic of my S50B32 dyno plot, the black line being before the engine rebuild.

Engine has as 2nd oversize pistons but made 300rwhp with standard size on the toruqe performance dyno after a freshen up. Non standard parts are Autronic SM4 ECU with a 80mm drain pipe as teh intake onto the standard airbox.

The black line the power before any rebuilds when it was getting 190psi on compression test. Rings, bearings etc were then replaced and it went to 210psi using the same method and required a lot more fuel and the ignition to be retarded 2 degrees. Still have vanos working.

In terms of advice I can't really help apart from suggesting to do a compression test as that seems to make a huge difference in power output.