Quick question guys:

I currently run the regular Walbro 400 in my car zero. Would I be able to buy the E85 version pump and simply replace the old or will my fuel tables need to be adjusted to make car run right.

Thanks guys,


Tim

 

New E85 compatible Walbro fuel pump - Buschur modified

 

Anybody out there that could help with my previous question? Thanks!

 

From what I've read, the new one flows somewhat higher than the older one, so there is a greater chance of fuel line or FPR overrun. What are you running for supply line, return line, fpr, and have you drilled out the siphon hole?

 

Is the Walbro 400LPH as loud as the 255LPH?
I don't think I have heard about the whine .. if there is a whine.

 

The Walbro 400 is more quiet than a Walbro 255.

 

The Buschur site says that new pumpe will support 800+whp, is there any reason to do a double pumper anymore?

 

David! You are requested here..

 

https://secure.buschurracing.com/cat...oducts_id=1873

Quote from the page
The conservative horsepower rating of this pump is that this pump can support 800 HP on 12 volts and up to 950 HP on 13.5 volts!

Now that could be for Gas, and not E85, but even still if you remove 30% from 800 you get 560hp if the above numbers are rated for gas.

So even if it is 560 not a bad pump to bridge the gap when going an FP Green or Red.

 

^ I wonder if those are hp #'s or whp?

if whp, would they be mustang #'s since it's a buschur reference or dj #'s?

 

Perhaps comparison to a double pumper would be helpful. I made up the chart below many months ago. Can't remember if I ever posted it, so I'll toss it in here. The Walbro 400/460 flow rates are directly from Walbro and not AMS, so take the comparison for what it is. I think its safe to say though that the Walbro 465 is right up there in flow capacity with dual Walbro 255s. A potential problem (not the only one) with the Walbro 460 is that the fuel has to go through the factory fuel filter located in the pump carrrier, and no one has ever flow tested that filter. Both DB and I have had a suspicion for a long time that the filter creates signficant back pressure. If it creates more than 5 psi of back pressure, it puts the Walbro 460 at a disadvantage compared to the dual Walbros that use an external filter that is known to have very little backpressure. I wouldn't be surprised if the factory filter creates 10 psi of back pressure at 500 whp worth of fuel flow.

 

Without data its a useless debate. You would need to construct a rig to measure the pressure differential across the pump to quantify filter restrictions(400 filter vs 255 filter vs no filter). You could then calculate the difference between a single 400 filter vs. 2x 255 filters at a given flow rate.

From what I remember the filter on my 400 was much larger than the 255 and being a mesh piece I doubt it would create a restriction unless clogged. I wonder if the 460 filter is even larger. Since the 400 filter is larger than the 255 this means Walbro accounted for the increased flow and I imaging kept the pressure differential across the pump consistent with the 255. A call to Walbro could confirm this.

If your flow data is correct the double pumper is an overpriced option with added complexity over a single 460. Thanks for posting the information and I will be upgrading my 400 to a 460 soon in preparation for E85.

 

Actually I'm talking about the filter inside the pump carrier and not the fuel pump sock. Most people don't realize that there is a cellulose fuel filter inside the fuel pump carrier. Its that semi-u-shaped portion of the fuel pump carrier. Anyhow, there's also another challenge with running the W460 - It hard not to overrun the stock fuel return system with this pump. With stock wiring, it does ok at idle, but as soon as full voltage kicks in at light throttle, it overruns the stock fuel return system. The issue is far worse with the standard full voltage rewire that everyone uses to get maximum potential out of the pump. Not trying to dissuade anyone, but instead, just get the info out there.

 

Even if we assume the internal filter does cause some restriction, this has been accounted for in your pump flow data. Therefore, even with an assumed restriction the single 460 flows as much as 2x 255's at 80psi.

Regarding the overrun issue you have provided the ability of the stock ECU to change the voltage switch point as a function of load, which works very well.

 

AMS did all their testing on the bench without an Evo pump carrier. I'm sure that Walbro did the same.