Partial throttle rough running

[kulixo]

Hi!

Last year I built my engine and installed a N53 head+cams, and ever since I had issues with rough running / misfires during partial throttle.
I'm currently in the process of tuning with Wedge so hopefully he will figure something out, but I wanted to ask here as well.

The car runs fine on very low throttle input, and during WOT as well.
But anything in between causes misfires and rough running, up until about 3.5-4k RPM were it starts running good at any throttle input.
It's worse when the engine is cold, and when running on 98ron it's a bit better (running 100% E85 usually).

I teared down the engine not long ago for other reasons, but took the opportunity to double check and make sure everything is fine hardware wise, which it seemed to be.

Here is an example: https://datazap.me/u/kulixo/v2-map-1-light-throttle?log=0&data=22
first, at low throttle input everything is fine. When I increase to about 35% pedal input hell breaks loose.
Even doing throttle blips during downshifts or just revving in neutral causes issues if I don't smash the pedal, like in this log when I downshift: https://datazap.me/u/kulixo/v1-map-1-blip?log=0&data=22

Any insights are appreciated.

 

[kulixo]

For anyone finding this thread, the solution for me seemed to be to add more fuel to the low-load areas (0-100 load, 0-4000rpm).
Around 13-13.5 AFR made it happy.
I'm not sure if the N53 Head/cams simply wants a richer mix, or if I'm perhaps masking some underlying issue with this fix.

 

[ShocknAwe]

Glad you found a fix! I've found the N53 head and cams to be a temperamental niche setup. Needs just the right wgdc and airflow, just the right fuel mix etc. Nice when it finally clicks though.