Nettlez Posted September 16, 2016 Report Share Posted September 16, 2016 I have recently built up a bmw m50 2.8l engine with 0.140" head gasket spacer and wired in a G4+. There is a BMW E36 plugin base map but this is mean for a 2.5L single vanos engine, I have edited it to suit my non vanos engine sensor wise as they have different cam sensor and ignition timing. My question is with my engine now being lower compression than what the base map was meant for what would you need to alter to make the base map more suitable? Advance ignition timing? As with the base map on it runs very rich 10:1AFR even though its mean for a 2.5L and it struggles to idle and will die as it warms up if no throttle is applied, only needs 5% and it will say running but then once it gets to around 80 degrees the afr starts to yoyo from rich and lean. The car is booked in for mapping in roughly a month, its been to one garage but it seems a bit out of there norm so im just trying to get a good understanding of what effect the changes I have made have on the mapping side of things. Attached is my edited base map. Thanks in advance BMW E36 G4+ Xtreme Plugin rafe edit - idle stepper 4 wire not 3.pclr Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 17, 2016 Report Share Posted September 17, 2016 I wouldnt expect the head gasket spacer to effect things too much at light loads and idle etc.Have you done the trigger calibration already? With timing locked does the timing drift when you rev it? Do you have stock injectors? Quote Link to comment Share on other sites More sharing options...
Nettlez Posted September 17, 2016 Author Report Share Posted September 17, 2016 Yer I have done trigger calibration, just at idle though not with it revving. What are you thinking? No injectors are Siemens 600cc ones. Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 17, 2016 Report Share Posted September 17, 2016 Checking that the timing is stable over a range of RPM is a quick and easy verification that VR polarity is correct. I just took a quick look over your map, it mostly appears to be a reasonable starting point. One suggestion however; set idle control to open loop for now. Closed loop takes a fair bit of work to get right and there is no point messing with it until most of the other tables are fully tuned. Quote Link to comment Share on other sites More sharing options...
Nettlez Posted September 17, 2016 Author Report Share Posted September 17, 2016 I think my vr polarity is correct as I took a scope to check it, I can upload that too if you want? Yer that sounds like a good idea as it was struggling to idle. So am I not right in thinking that because of the 0.140" hg spacer it will be running richer? I'm just thinking its got considerably less compression so it won't be as efficient? Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 17, 2016 Report Share Posted September 17, 2016 So am I not right in thinking that because of the 0.140" hg spacer it will be running richer? I'm just thinking its got considerably less compression so it won't be as efficient?No I dont expect the lower compression and less squish will make a big difference to idle and low load VE. The biggest effects will be the difference in capacities, the different valve timing and the different injectors. Tweak your master fuel a little more. Quote Link to comment Share on other sites More sharing options...
Nettlez Posted September 17, 2016 Author Report Share Posted September 17, 2016 Ok will try setting up open loop and tweaking master fuel. By tweak to you mean lean off? as when the car is running this map that's mean for a 2.5L with higher compression its running around 10:1afr at idle even though its bigger? I would have thought a 2.8 would have wanted more fuel hence why I wondered if it was the compression related. Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 17, 2016 Report Share Posted September 17, 2016 I just noticed you have some really odd idle ignition control table. 50deg retard all over? So turn off idle ignition control for now. After that, start engine and adjust your master fuel up or down (pg up & pg down keys is easiest) until your AFR is in the ball park. Scott 1 Quote Link to comment Share on other sites More sharing options...
wildwestaussie1 Posted October 2, 2016 Report Share Posted October 2, 2016 head spacers went out in the 1980"s,custom pistons are affordable now Quote Link to comment Share on other sites More sharing options...
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