-Does the Walbro 255 flow more than the Aeromotive 340 Stealth?
-Is the Aeromotive 340 really a drop in fuel pump?
-What is the max bhp the Aeromotive 340 Stealth can support?
-Which fuel pump should you choose?
Note: Data used in this article is from Turbo and High Tech Performance magazine. This should be used as a guide only. There may or may not be errors in the data.
Answer 1 – Does the Walbro flow more?
No, the Walbro 255 does not flow more fuel than the Aeromotive 340 Stealth
Answer 2 – Is the Aeromotive 340 fuel pump really drop-in?
Technically yes, up to around 40PSI the Aeromotive pump can be used with the stock wiring assuming your stock fuel pump fuse is rated to 15 amp.
Personally I like to have more headroom in my wiring (4 amps). I don’t like the idea of running a constant 11-12 amps through 15 amp rated fuel pump wiring especially if we are talking about an older car.
For me, the Aeromotive is not a drop-in pump as I would need to run fatter wiring to support the current it needs.
The Walbro 255 fuel pump on the other hand draws much less current and I would have no reservations about using it with the stock wiring.
Answer 3 – What is the max hp the Aeromotive 340 Stealth fuel pump can support
At 0 PSI boost the Aeromotive can theoretically support a 1000bhp. Power handling reduces as boost increases. At 55 PSI boost power handling is down to 600bhp.
From 0 PSI boost the Aeromotive has around a 200bhp edge on the Walbro. The difference reduces down to around 100bhp at 40 PSI boost.
Answer 5 – Which fuel pump to choose?
Depends on the boost you want to run and the power the engine will be making at this boost pressure. Up to around 600bhp and 35 PSI of boost the Walbro is the choice. If you need more than that, the Aeromotive is better suited, especially if you are running more than 35 PSI of boost.
Why not choose the Aeromotive 340 regardless? It flows more fuel
It comes down to the size of the wiring the pump needs. If you are happy running the Aeromotive with your stock wiring and are happy to pay extra, sure the Aeromotive is the choice. If you want to give your wiring an easier life I personally would go for the Walbro, unless I needed to more power than the Walbro can support.