Ecumaster forum

Can anyone share some tips on tuning the above??

Started tuning a customers car today and basically there is almost no atmospheric MAP Signal, it idles at about 80kpa then as soon as it reaches about 10% throttle the signal goes to 100kpa and sits there until it starts making boost!

it has bmw M3 throttles and im guessing the balance tube must enter the runner right near the throttle plate so as soon as it opens a little it crosses over the hole so then it only sees the pressure before the throttle not engine vacuum!

Actually I'm thinking about the same problem at the moment after I started with mapping my GTR. I did some research which might help you to get started.

Some people recommend using an alpha-n fuel map with MAP multiplication, others say that this is not that accurate as the MAP value can't just be a linear multiplier to make the alpha-n principle compatible to a turbocharged engine. Those use a primary speed density map with an overlayed secondary TPS vs. RPM map. This has been discussed for example here: http://nissanroadracing.com/showthread. ... 447&page=4.

I'm actually not sure, what is better, especially when using the EMU. Maybe the admins here could give a suggestion, I would appreciate that.

Regards, Ralf

Such configuration is always hard to tune.

I would use alpha-N + MAP mult and MAP based ignition + TPSvsMAP + TPSvsRPM correction tables

Thanks Kuba,
so starting with a very typical VE table can you please give us a bit of an idea what the two correction tables would look like??

also is that TPS/MAP correction for ignition and TPS/RPM correction for fuel?? or are you talking about using them both on the fuel??