Inlet manifold temperature versus timing 850i

[Belgiumbarry]

does anybody know what the inlet manifold temperature sensors on each bank can do in the DME's….? (or EML ??)

I would guess they retard ignition timing with raising air temp …. ????
Or for what is this input used ?
i see 2.3k Ohm at 20° C …. to 0.5k Ohm at 70 °C .

thanks for info !

[cartoonz]

no, they set different trim/baselines for the fuel mixtures.

[BMSman]

When I monitor the inlet air temp in inpa it seems to be about 10 deg warmer than the outside air temp even on cold startup. Both bans read the same. I have wondered if it would be worth correcting this.
Mine read 2.5K at 18deg.C

[Belgiumbarry]

thanks for replys.... i'm still looking for the "dip" we have around 4500 rpm. With the charger ( and A/A intercooler) i can assume air temperature is higher than in oem without . So we thought to do a dyno with "false" sensors outside the manifolds , as we supposed they possibly can retard the ignition .

If this is not the case , we still have our problem …

What we don't understand is that at 4700 rpm we have 410 HP , and then further to 6000 rpm , boost still climbs , A/F remains good ( dual gauge) , but no extra HP.
That's why we thought something is retarding ignition.

PS we only drive 3 sets of the 4 set rolls on the dyno , so all results are x 0.75

BMW 850i - crank pully - WOKKE EML - HP.pdfBMW 850i - crank pully - WOKKE EML - NM.pdf

[E31 850i]

I think the inlet manifold temperature sensors are used to calculate the LOAD signal. Majority for LOAD is air mass flow, minority air temprature.
Diconnect the plugs to the IAT and make a testrun. In this case, the DME uses a replacement value.

Can you look/log the ignition timing? So you can see if timing is retard.
Can you modify your DME chip? For testing, i would programming a linear WOT timing.

This is the stock WOT M70 M1.7 timing. (no waranty)

720	4
1280	12
1920	21
2680	25
3160	27
3320	27
3680	26
3840	26
4000	25
4120	24
4400	25
4720	24
5000	23
5360	21
5600	23
6000	29