Without a fuel pump I ran my IX with the following mods:
Buschur Intake
TBE
MBC @ 22psi
Jestr e-flash

Ran it for a few months like that. Even a few runs at the track. Never had any significant knock show in evoscan.
Just added the fuel pump over the weekend to support future mods.
You don't *need* the walbro to run 21psi. But hell, for $76 shipped and about 15 minutes of your time, there is no sense not to do it.

BTW, you *will not* need an install kit with it.

 

Upgrade pump and you will have more room for future upgrade. Leave stock fuel pump and you may be fine. Only reason why I can not say for sure is because of the MBC you are using. Generally, there is no taper with MBC in top end and tuner can not program to adjust boost curve to compensate for the high injector duty cycle..... On the other hand, if you were using stock boost solenoid and it was tapered at the top.... I am 99% sure that stock fuel pump will be sufficient enough... (Injector duty cycle should have not gone beyond 90)

Some people say it is an insurance to upgrade fuel pump with W brand but it may not be... I don't necessaraily think that $100 pump will have better quality than stock parts although I don't see any people complaining about W pump beside it is being noise at prime....

I would check the injector duty cycle from your tune. If it peaks at near 100, yes you should upgrade your fuel pump. This also means a trip back to your tuner. If it was around 90s at peak, I would not upgrade stock fuel pump...

 

I'm in touch w/ my tuner often, I'll definetly have him check out where it peaks.

 

the guy is asking a pretty blatantly clear "technical" question... One i would also be interested in knowing. On a stock IX w/ boltons and stock turbo... how much boost can u run on the stock fuel pump. Its a clear question and everyone who says "just run it" "maybe ok" "better safe than sorry" clearly just does NOT know, period. He's looking for someone who DOES KNOW to chime in w/ facts on the flow capabilities of the stock IX pump. i just ran through this entire thread and walked away w/ nothing... so in the end you will buy a pump because "everyone" guesses its better to be safe... when noone knows when safe ends or begins w/ the stocker... amazing..
i agree u should upgrade when continuing to mod, we ALL do... we just all want to know what the limits are of the stock pump for INFORMATION sake... anyone?

 

Newb: Check the abrasive tone when speaking to those in this thread who have offered help to the original poster.

The answer is that yes, the IX pump will support 22psi with basic mods (intake, TBE, MBC, flash) with no problem. Take into consideration that AMS runs a 360whp IX daily with the stock IX pump. The IX pump itself, to my knowledge, hasn't been flow tested like the VIII has. Therefore, we don't know its physical limit. It is safe to say that the IX doesn't flow as much as the Walbro 255. Somewhere in there, there's a margin which someone may exceed if they get too aggressive with the stock pump. Also consider that even if it did flow, say 240lph, it may not do that reliably. It's not worth the risk for such a cheap/easy mod. No, you don't have a precise answer, but yes, you do have an answer.

 

All this info is out there
https://www.evolutionm.net/forums/sh...fuel+pump+test

 

my car spike up to 22.7 lb of boost then drop to 18 is that ok with stock xi fuel pump

 

ive been runing 22 psi for 20000 miles on the stock pump and my 02 has never done nething our of the norm

 

I have had my walbro for almost a year now and I rarely hear the whine. I have heard it a few times when it was really hot down here and low on gas. I say get it. Its better to be safe you know and its only 90 bucks or so.

 

You can safely run 23-24 PSI on the stocker with a good tune, so why not add the pump and get more power?? Just my .02

 

ahh, see...! this guy (quoted above) at least gives the op an answer... *thumbs up*

and to those that got testy... (not necessary)
I was merely stating that the 'others' were giving the op a hard time about just using a pump w/out stating facts regarding the true limits of the IX pump's capability. (which was his original question) It was a simple question that deserved a simple answer, period. Meaning it could have ended w/ the above answer instead of 3 pages of "opinions"...

 

Its an easy install a 90$ safeguard and more reliable than the stocker. And mods are addictive so chances are youl be getting (and needing) one anyway. But reflash your ECU when you do it b/c itl run richer