Just started logging and street tuning with the S366. I'm going to get my tune as close as I can at 17PSI before adding water to tune for 20PSI.

I have started to encounter what I suspect is fuel pressure drop. This only occurs after I the car has been running a while and it is intermittent. It scares the **** of me. Car will go lean at some point (sometimes under boost!). It is difficult to replicate. Sometimes it is low RPM, sometimes it is hammering it.

SO - I want to eliminate a sketchy fuel pump from the equation. I want to remove the Walbro 255 I have had in the car for 5 years and add something good for the S366. Say 500 ish hp.

WHAT is a good, relatively inexpensive pump to get me there with minimal fabrication in the tank? I only want one pump. Yes, I have rewired the pump to run at full voltage all the time.

I am leaning towards the Aeromotive 340 or Walbro 400lph.

 

Introducing the Walbro 400 Fuel Pump! – Dynosty

aka, do it

 

Fuel Pump Comparison Test : Real Street Performance Engine Parts, Pistons Rods Cams Valvetrain and More

 

The Aeromotive 340lph does look like a closer fit.

Now as far as longevity. I have had trouble with Walbro pumps in the past in race cars and now I think one is taking a dump in my barely driven FD.

 

I highly recommend logging fuel pressure.

I have run an Aeromotive Stealth to 454whp with zero signs of drop. I have seen it actively support 530whp with no issues, though that is definitely its relative limit.

I plan to run dual Stealths with integrated check valves. One dies, the other will keep trucking. I have always avoided dual pump setups. For the same reason as others, if one dies the single pump will allow the car to go lean. But dual pumps that can support the power individually creates the appropriate redundancy. This is why I used check valves. If one were to die, it wouldn't bleed pressure from the other.

 

i just ordered the Aeromotive 340lph pump.

If its not the pump, I suspect an electrical short circuit somewhere and not fuel pressure at all.

Either way, I have been wanting to ditch the Walbro.

 

This is the general consensus. Walbros are unreliable, the Aeromotive is the way to go. Dual walbro 255 is probably a good option, too.

 

Scott,



Upgrade your filter and lines at the same time.
Who has your best answers?

 

Im still in the process of my build and I'm going with the dual walbro 255. Ive always heard they are not the best in terms of reliability but at $100 a pump its cheap. And if you're running an after market ecu, I'm going with an AEM ems, you can wire in a pressure sensor by the fuel rails and run it to the ecu as a failsafe. I.E. if pressure drops the ecu will pull timing.

 

The Stealth is $155.....

 

^^^ What that guy said.

I also learned something new today - and that is that there is such a thing as submersible fuel hose.

I always thought that if gas and oil (I premix) are in the hose, it should be able to have gas and oil on the hose (when its in the tank).

It will be like a science experiment when I change the pump out - I want to see if my off the shelf fuel injection hose has deteriorated from being submerged in fuel.

 

It will deteriorate and break. Buy Gates submersible hose. A little pricey, but it will get the job done. I am looking forward to the day when manufacturers move to AN fittings off the pump so we can start running internal hard lines. Ditch this submerged rubber business.

http://www.jegs.com/p/Gates/Gates-Fu...34981/10002/-1

 

Take a look at Weldon Racing Pumps.

 

Also don't forget to do a rewire with a 40 amp relay, use 10 gauge wire for 12v min

 

I already ordered a foot of Gates submersible hose and the 40 amp 10 gauge wire was ran years ago.

 

I have. And their intank options are pretty limp. Even still, their top external is only rated 340-370gph.

Not impressed....