I know the Walbro 255 LPH fuel pump is already a highly recommended upgrade, but after my recent experience I think it should be one of the first things you do.

With just 3" exhaust (high flow cat) and EBC, I have been testing and tuning with a Power FC. At 20-21PSI of boost I kept getting intermitent knock especially when running sustained high loads. The knock occured even with a good amount of fuel added and pulling timing, WTF.
The other day I installed the Walbro fuel pump, and all of a sudden my intermitent knock is gone! I have been steadily pulling fuel running leaner and putting in more timing and still no knock! My EGT's are also looking better at leaner A/F values!

After seeing this I would say anyone running more than stock boost should upgrade there fuel pump. Slightly bigger injsctors and maybe a fuel rail are next on my list.

 

I trust Silver Surfer's choices - thanks for the heads-up. This was going to be one of my future mods (along with the injectors). I'm glad to see it made a difference. Some of these mods are not registerable on the butt dyno...

 

I agree with the slightly bigger injectors, but if you take a look at the stock fuel rail, you are not going to gain anything with the Walbro and 660 or 680 injectors on it. The stock rail is a pretty good design.

 

i talk to a guy from AMS
and he said do not replace the stock fuel rail cause it will flow beter
he also said their talons with alomst 1000 horsepower
have the stok fuel rail thats amazing i will keep my stock one

 

Yep, that's why I said I was only going to change the pump and injectors.

 

How hard is it to swap this out??

 

Yea, I haven't really looked at the fuel rail yet, I just have a guy trying to sell me one. Hence the "maybe", thanks for the input.

BTW Does anyone have experience with the reliability on these Walbro pumps?

 

I had 50K on my WRX walboro no problems at all

 

Piece of cake. I think Evomoto.com has a step by step on the fuel pump. Only thing I found tricky on the injectors was those damn little spring clips retaining the wiring harnesses. There is one tiny plastic lip that holds the retainer you have to treat like a china doll. I now only have three of the original four retainers.

 

A couple audi guys I still talk to love the walbro 255lph on their 2.0T conversions. Seems to work fine...does anyone have specs on the sometimes mentioned Supra TT fuel pump?

 

Have you measered fuel pressure before and after the new fuel pump was installed?

 

I assume these guys have the same Walbro I do, which is not the high pressure version. By using the one we have, the stock FPR is employed, meaning no change in pressure. The change comes in at high rpm, where the Walbro flows a higher volume of fuel. I don't think the Walbro really gains you anything until you get over 340 whp.

 

If I don't plan to go much over 300whp (if I even make it to 300) should I even bother with this?

Would doing this make my vehicle easier to tune up to 300whp?

 

The fuel pump replacement is not bad (15-20min), they could have made the opening a little bigger though, wrangling that fuel pump assembly with the retaining ring through the opening is a little tricky, and it's all plastic so you need to be careful.
It looks like the fuel filter is built into the entire fuel pump assembly, what's up with that? Anyone price that sucker yet?
I can tell you one thing, your not going to find it at the local auto parts store. I have 18K on my car so I should replace it pretty soon.

 

Well I never fully looked into it between the HP and regular Walboro units but the way I understand how the FFPR works is based off the manafold pressure so I think it is definately worth it to get the HF walboro that way you can sustain more flow at higher RPM and boost pressures without worry of instantly running lean- Remember the EVO is capable of spinning 7600 RPM stock thats gettin into severe duty if you are running good boost to redline.


Also the Supra pump has been discussed on every forum for some reason people thing a oem pump costing 2.5X the price of a walboro is better quality- Well maybe but it sure cant flow as much as the WB HP- it tanks out hard when trying to flow high pressure at high RPM/Boost- I know 2 guys that ditched the supra pump on the WRX in favor of the "crappier" walboro