Ti Automotive (Walbro) 274 vs 285 vs 295


Major General
Staff member
Aug 11, 2017
I'm working on a few of these setups right now for Z4s and 335i, along with active cooling. I believe this chart is correct. The overlays help I believe. @martymil are you running a 25A fuse for spike headroom on the pump amperage? Most datazap logs I've examine show values inside of this graph, but a request spike can be there. I also noted that a number of logs I examined had bizarre fuel pressure zig-zap spiking.


Walbro 535.png
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Mar 27, 2020
I have been running ek3 stock fuse and 535 after martymill chimed in... might not need it but i figured if it gets hot and running hard cant hurt for 20.00 and little time.. I finally tapped into exhaust flapper valve red white wire + 12v when on after shut off stays on 15 seconds than shuts off..ran over to a startech copper heatsink with fan .took some ek thermal paste between zip tied tight. for bracket just bent piece of aluminum drilled a hole put 1 bolt to hold firm .. I also soldered a couple single pins to make easier to hook up incase need replace fan some point going to add a 3a inline fuse tommorow


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Nov 18, 2018
Managed to get my 535 pump installed recently, and thus far its been functioning flawlessly. Thanks again guys! @martymil
I should report that mine is working great, (535) after only a few weeks.
Did you guys end up going bucketless?

Not sure if keeping the bucket with the 535 pump would be worthwhile? I'd still like to keep bucket though.
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Oct 18, 2016
Put a few different fuel pumps on a flow bench. The shots are angled upward and the glass gives a parallax effect so the numbers are actually higher. Also the mineral spirits fluid has a different viscosity than fuel so you can only compare between them. The control was the walbro 450(274) it was brand new so flows less than broken in. ~73 psi @ 13.5v