s50b32 dyno results..... advice wanted

[Arron 227]

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

[BM WORLD 1283]

im no expert on these engines , but have seen results like 190-200rwkw for a good example.

and 170-180 for ones not quite sorted
the 3l normally make around 160-170 etc

yes looks quite rich .

maybe maf faulty or engine temp sensor

also the vanos fail in these engines and will cause massive power drop off.

maybe have a talk with gavin at high velocity

[nigelaston 20]

My s50 showed a 12kw power increase after I changed the vanos seals. If you feel it sluggish of the line. Your vanos needs work...

Sent from my iPhone using Tapatalk

[Rgvkiwi 10]

Definitely an issue there. Nigel previous and my current 3.0 m3 (with cams) and full rebuild makes 280 hp (200 - 210 Kw ?) at the wheels on a realistic to low reading dyno with a vastly different power and torque curve.

I wouldn't say it is massively rich for a race engine though...a bit perhaps but not massive...certainly not enough to make the power like that IMO.

I tend to think maybe Vanos as well......also have you done a compression test?

My e36 328 had corrosion on the ecu board which left it in a constant cold choke situation....was a factory fault with the drain hole leaving the ecu in a puddle....not sure if the m3's have this problem but once again Gavin at High Velocity can work through this (he found the 328 problem).....pm me if you want more info.

Good luck. Keep us informed of how you get on....

Edited July 20, 2015 by Rgvkiwi

[KwS 2425]

my old 3.0 M3 hit just shy of 180kw atw, so that is really really low. That big dip at the start shouldnt be there, should be a nice constant linear increase.

Edited July 20, 2015 by KwS