Hey I just did a TII swap. I left the NA fuel pump. My buddy had a walboro 255 that he sold me for cheap so I took it. I'm wondering if I can just swap this in without doing any other mods to the car, or should I get a new fuel pressure regulator or bigger injectors etc.


It's a basically stock S5 jspec, intake + catback. Running about 11-12 psi max but not constantly.

 

How are you running 11-12 psi with just a stock s5 jspec? I have same setup with Full RB exhaust and im 8.5 or 9 max...

You can keep your stock injectors and just put in a walbro255 or FD pump. If youre running that high though I would guess it is safer to have the bigger injectors.

 

Honestly I dunno how I'm running that much boost. Previous owner did something to it. It's reliable at that though.

 

when you put that pump in you may run into flooding issues

 

If you've run under boost with an NA pump, I can almost guarantee you that the engine has been detonating. The NA pump flat out does not work under boost; the flow rate is practically 0 at high fuel pressures. It's time for a compression test to find out if the seals are on their way out.

Walbro pumps are drop in. You will definitely have it overwhelm the stock FPR, but it's manageable. Fuel pressure will increase across the board, so your idle may get extra rich. A walbro by itself is the BARE MINIMUM to run 10+ psi on the stock turbo. You need bigger injectors, fuel control & a wideband to truly have a safe build. Anything else is a gamble.

 

go for the 3rd gen pump

 

I already have the Walboro.


So group consensus says that I should get bigger injectors, FPR + wideband just for safe measure.


How can I avoid the rich idle? FPR? What's a good brand to get? Maybe an adjustable one if they make them?

 

i ran 12psi on my old TII. daily driven, you just cant go over 12psi on stock injectors.

 

I accidentaly hit 14..... It didn't do anything but I won't do that on purpose again.

 

Don't give people this crappy advice. I've been down the blown engine road twice after running 10 psi on a stock fuel system. Pushing the engine on stock fuel is a noobie mistake. One that cost me when I was getting started, and one that I see far too many people making still.

 

I use a Walbro 255, the rich idle doesn't bother me, as long as it runs, and mine runs perfect when under boost and cruising. I've retained the stock fuel pump relay, but have rewired and relocated it to the back, and run heavier wire.

I run 8-9 psi though, don't need anymore for taking out the trash thats around here.

 

If youre hitting 14psi on what you believe is a stock setup, then maybe you have a boost creep issue. You should really find out whats going on with you car

 

No I didn't have the boost/vacuum line right next to the turbo hooked up. That's why I hit 14psi. But I max out now at 12. Previous owner did the same.