Forum » Practical Dyno Tuning » IGNITION MAPS NA engine 11.8:1 comp. ratio

IGNITION MAPS NA engine 11.8:1 comp. ratio

Practical Dyno Tuning

Discussion and questions related to the course Practical Dyno Tuning

Page 1


I built a stroker engine on a BMW e36. its 3.2 liter and comp ratio 11.8.

I run it on pump gas. I use stoke ECU.

So i went to the dyno for the first time. To make the adjustments on my maps AFR and Timing.

The problem is the dyno could create some resistance (increase break) but it could not keep a certain RPM.

I tuned my maps how i learnt it here on HPA. It was a bit tricky cause first time and i could set the timing only with WOT runs...

So didn't really go through my timing.

I finally made 283 HP and 350Nm. I'am happy with these numbers but i think my maps have not a "clean shape"

I listened to knock with a home made headphone instrument. I didn't hear knock but it was hard to hear something (alot of noise during the ramp runs).

So if somebody could tell me what he thinks about the maps. I know it needs some more advance in the high RPM.

Attached Files

Your power results look pretty good. It's hard to be too specific about your timing numbers as every engine is different so just saying the compression is 11.8:1 isn't enough to specifically say what the correct timing is. The only advice I can give is to reiterate what we teach in the course which is to advance the timing until the engine either stops showing an increase in torque/power, or alternatively you reach the knock threshold.

If I'm looking at your maps correctly, your timing reduces at high rpm and WOT which would be uncommon. Id certainly try a little more timing and see if this shows an improvement. I'd also try generating some knock under low rpm and moderate load just so you can confirm that you can actually hear knock occur. I generally try to create a smooth shape to my ignition maps too as jagged or rough ignition maps can cause driveability issues.

Ok. Thanks for the response Andre.

I will try to find a better dyno. But here in France tuning the maps is not very common so we don't have alot of dynos.

I smoothed the shape of my map and added some degrees in high rpm.

The car drives great, i think i will leave it like this for the moment.