[Lambobimmer]

There is a very small population of Z4 owners that go FBO and I need some advice before I install hyprids and inlets. One thing I will mention, the E89 Z4 is the only N54 model in which BMW did not include a lpfp sensor so I have no way to monitor the psi on my lpfp. All of the logs are showing how the hpfp react to the different lpfp's that I used. I would love to hear some theories on why BMW choose to not include a lpfp sensor on the Z4

I removed my stock lpfp bucket last year and replaced the stock bucket with the Walbro 450 pump. I ran it for a few month and I was not very happy with it. It make a lot of noise and I think that it performed worse than my stock lpfp. Here is a log from an E50 map that I did last July.

http://datazap.me/u/lamboworld/e50-log?log=0&data=1-19

I got fed up with that pump because of the reduced power and the noise that it made and switched to the AEM E85 pump. That pump had about the same results with power but it also made nose but just not as much. Here is a log from that pump on E50.

http://datazap.me/u/lamboworld/e50-f...0&data=1-18-19

As you can see, both pumps produce very similar results. Each pump caused the hpfp to dip into the 1600psi range.

I again got tired of the excessive whine and noise and decided to buy a brand new stock lpfp assembly. I am really shocked about how much better the stock lpfp performs over these other two pumps. Check out these logs on E50

http://datazap.me/u/lamboworld/bqe50...0&data=2-20-21
This log has a maximum boost of more than 21psi.

Here is a E50 log from a 1/2 mile event:
http://datazap.me/u/lamboworld/wanna...0&data=2-20-21
This log was from the same tune as the other log but I was at a higher elevation and therefore never hit 21psi.

As you can see, rarely does the hpfp with the stock lpfp dip below 2100psi on E50.


I am getting ready to upgrade to hybrid turbos with inlets and I plan to use E50 or E60. It looks like I can probably get away with using the stock lpfp and hpfp, but I am interested in hearing some opinions.

[Bme30]

Pm BuraQ. He will have answers