[da_trem]

Hi all,

found this interesting picture of a modified outlet Hp pump restrictor on Instagram..what might be the benefit of enlarging it, is this a potential problem for us with stage 2+ and above?.



http://www.cumminsforum.com/forum/07...y-cp3-mod.html

[Owen81]

I'm no expert by any means but I'm sure if they designed the outlet like that for a reason. It would have been much cheaper to just drill a hole lol

[335dsleeper]

True but, I'm pretty certain this part came off the 1 series with the M57 swap... which I believe trapped in the 123-124 range.

There are a lot of things designed for a specific goal, which usually doesn't include optimization for 200% power increases.

Originally Posted by Owen81

I'm no expert by any means but I'm sure if they designed the outlet like that for a reason. It would have been much cheaper to just drill a hole lol

[da_trem]

I'll be changing my injectors seals . Will try this mod at the same time.

I'm also tempted with this;

http://www.cumminsforum.com/forum/07...y-cp3-mod.html

If flow could only be increased by, say, 10%, that would be great for future mods.

[TDIwyse]

Originally Posted by da_trem

I'll be changing my injectors seals . Will try this mod at the same time.

I'm also tempted with this;

http://www.cumminsforum.com/forum/07...y-cp3-mod.html

If flow could only be increased by, say, 10%, that would be great for future mods.

I took a 335d HPFP apart and posted some info about 5 years ago in this thread: http://www.bimmerfest.com/forums/sho...&postcount=101

Seemed like the 335d unit has about 2.5-3X more opening area than the Cummins variant in that link (slightly smaller triangles, but there's 4 of them).

[da_trem]

TDI,

with all the hp/tq you have, did you end up modifying the pump or left it alone?..

At some point, will the entry/exit of the cp3 pump be a bottleneck?

[TDIwyse]

Originally Posted by da_trem

TDI,

with all the hp/tq you have, did you end up modifying the pump or left it alone?..

At some point, will the entry/exit of the cp3 pump be a bottleneck?

I haven't touched the oem HPFP on my car. Proper utilization of water/methanol can significantly supplement the diesel injected from the HPFP.

I don't have the highest mid rpm torque, but I'm purposely trying to avoid that due to the extreme stress it can cause on the drivetrain. Since I don't use this car as a tow rig, I don't see the advantage of a huge mid rpm torque peak. I prefer letting the car downshift and run at higher rpm's for the brief periods of time where I want peak power.

With the new additions of the Pro Turbo hybrid turbo and the extra rpm range allowed by the xHP TCU mapping, I'm still able to get all the fuel I can burn in the shift range with the oem HPFP and water/methanol injection strategy I'm utilizing (with the exception of extreme cold/high ambient pressure conditions where AFR data suggests more fuel could be utilized).

[da_trem]

Good to know.

Quite surprising to see how that little pump can flow.