The UM car I was in with 4 bars from Bosch definitely had a bad idle. Some people just don't notice cause they don't care about minor fluctuation during idle.
Good number very similar to mineHere are my preliminary results with the M560is Turbo for those of you wondering, also are still a work in progress and not fully revised. These are Virtual dyno logs and dynojet results.
*(Its wierd that all Virtual dyno logs are close to dynojet results, except the m560is e48 which consistently shows more hp on the street logs than on dyno��*[emoji3603])
*Havent ran 4 bar sensors on dyno yet
Turning up the boost on e48 with the new 4bar sensors is gonna be fun, but gonna have to keep the tq down for sure!
P.S. I have no idea if this dyno reads high or low and and just using it to compare gains. Not looking to get in a BS numbers argument! ��
So I’ve been testing out the 4 bar sensor and there is definitely an issue at very low throttle angles right at the transition to decel. The sensor can’t read the high vacuum properly and results in -34% fuel trims and unstable a/f in that area. The result is a bit of a dead spot in the throttle in that transition as well as slightly jerky on/off throttle transition. This is most noticeable around 2000rpm in the 0-10% throttle range. I could see a lot of people not noticing or being bothered by the resulting drivability issue, but its not correct regardless. I’ve been able to smooth out the transition some with some tuning tricks, but at the end of the day, it’s just masking a real deficiency. For those talking about UM cars, I’ve only had one such car on my dyno, but that car also had a hard stutter at that spot, so I don’t think there’s anything too different going on.
FWIW, we’re at sea level and this issue would likely be much less prevalent or even cured at higher elevations. Maybe the folks reporting no issues are just at high enough elevations to get back into range of this sensor.