stock fpr with walbro 255?

[neonshaun]

I'm planning on changing out the fuel pump on my stock NSX.
I've searched around, and in the past, many people have mentioned that the 255hp walbro would be bad for the stock fpr.

Is there any truth to this? Or can I just swap the 255 in?

 

[jwmelvin]

With my Deatschwerks DW200, the stock FPR could not flow enough to maintain the correct pressure at idle. I don't know about the Walbro.

 

[Old Guy]

With my Deatschwerks DW200, the stock FPR could not flow enough to maintain the correct pressure at idle. I don't know about the Walbro.

Were you still using the fuel pump resistor or did you by-pass it? If you by-passed it, that might be responsible for an inability to control fuel pressure to the set point at low engine loads. Some fuel pressure regulators are acutely sensitive to back pressure on the return line and the higher flow in the return line will increase back pressure. On another car I had a 90 deg elbow fitting on the return line and it severely messed up the regulators ability to track fuel pressure at low MAP values. I had to change the fitting to a large radius sweeping elbow (which complicated the installation).

 

[jwmelvin]

Were you still using the fuel pump resistor or did you by-pass it? If you by-passed it, that might be responsible for an inability to control fuel pressure to the set point at low engine loads.

That's a good point. I don't remember for sure but I had bypassed the resistor before changing the pump and I don't think I went back to having the resistor in the circuit. I wish I had tried it; installing the AEM regulator was an additional expense I would have preferred to avoid.

 

[neonshaun]

well, the fuel pump is ordered... i suppose I should get a pressure gauge for the fuel filter to see if I really do need a different fpr...

 

[Lude_2_NSX]

I have a walbro 255 and stock fpr, no issues.

 

[neonshaun]

I have a walbro 255 and stock fpr, no issues.

Good to know, thanks!
I thought it was a more popular swap, not many responses though...