[Walked U]

Ok i thought id bring up this topic since alot of people are starting to put dps, larger fmic ect on their cars.

I just got done recently adding a few more mods on my car. With those mods I custom ordered more gauges to make sure everything in running correctly, such as an afr/ egt/ lambda/ intercooler temp gauge, ect.

Now my question is whats normal afr for a DI car? I see dynos with people with stock cars running 14 across the board. Procede dynos seem to have 12 across the board, as where AA seems to keep the stock afr curve.

I plan on getting a tune myself within a week or 2. So it would be nice to know the saftey parameters of the afr and lambda so i dont blow anything up before i get there...

[533ogetnom]

pretty lean because DI its more precise and accurate, thats the extend of my knowledge

[Walked U]

Originally Posted by 533ogetnom

pretty lean because DI its more precise and accurate, thats the extend of my knowledge

Lol same here.

Reason why i brought it up. it would be nice to know when lean becomes too lean.

[scalbert]

Originally Posted by Walked U

I plan on getting a tune myself within a week or 2. So it would be nice to know the saftey parameters of the afr and lambda so i dont blow anything up before i get there...

Probably the only way this shareware information will get out is once more people start having custom tunes. It is a bit in the dark right now but once more people start tuning, or having the ability to tune, we should collectively be able to detrmine the proper A/F curves.

[Tang]

You just need to scan the DME and monitor total ignition advance while adjusting the boost, air/fuel ratio, and timing curve. 12.5:1 in the midrange down to 11.8:1 up top as read with no cats on the car is a good starting point.

[scalbert]

Originally Posted by Tang

You just need to scan the DME and monitor total ignition advance while adjusting the boost,

I am still not convinced that the total timing, as returned via OBDII commands, include the base timing and any knock retard. Things may have changed or BMW does things differently. But on the GM and Honda/Acura vehicles I referenced, the total timing was just the base timing.

It has been a while though and my memory isn't as good as it use to be. In the end, i would still prefer to see individual values for the base timing and any KR (or timing correction, etc.).