All I've got is a straight pipe and a RB header.
I was searching around and saw that a thread about it being too much for a stock n/a s4.
My car always has seemed to run rich, almost too rich for a rotary.
I was thinking about trying to switch back to factory fuel pump and see if it helps out any.
The car came with the fuel pump already.
Any advice?
With gas prices going up to 4 dollars here I need to save every penny I can...
Thanks.

 

Walbro 255s are well-known to drive up fuel pressure with a stock FPR. I've measured as much as a 10 psi increase. Without an aftermarket FPR, you're just costing power by using one on an NA. The pump flows WAY more than you need anyhow. A stock NA pump would be much better.

 

Yeah, that is what I was thinking.
I'm sure I can find one of those for pretty cheap used.

 

+1 for using original pump.

otherwise id use a turbo pump, would work better then the walburo.

 

I just went to the parts store and upgraded to a FD fuel pump when my stock one took a ****, planning of future mods. I did not notice anything different, but I am sure my flow went way up and I got a lifetime warranty on the pump. When I had the car re dyno tuned I knew that it did not have any negative side effects.

 

An FD pump won't overrun the FPR, so your fuel delivery won't change. And that's a good thing when you're talking about installing a pump that can deliver twice the fuel you need.

 

I've had reliability issues with the Walbro, so I would recommend against it alltogether.

 

i have a NA fuel pump for sale if you are interested. for s5 FC.

 

Thanks, but I already had someone pm me that they had a NA fuel pump for sale.
He said 30 dollars shipped.

 

I read something about FD pump and I might do the same.

Cuz I have no idea about the car's history so most of the stuff Im doing are just preparing for the worst.