xX v0oDo0 Xx

iTrader: (1)

Right and wrong, there are drawbacks...FullBlown's setup would perform essentially as well as the entry-level Buschur setup seing as how the Walboro pumps are unmodified...FullBlown's setup is also priced at $360 without pumps, opposed to Buschurs for $450 with two standard pumps included...Essentially, you will pay more for the FullBlown having to purchase the pumps seperately, but you get a metal casing and as you stated you can run AN lines...Also, I do not know how plug and play the FullBlown is, as their description in the sale forum was fairly weak...From what I am gathering, the Buschur-modified Walboro pumps in the higher-horsepower setups (Buschur brothers/Curt Brown) allow for significantly more flow [sheer numbers on the initial post will convey this point]...I believe both setups would allow for lower duty cycles and more-healthy tunes for those with higher horsepower (550-600whp range), but I am curious if the application applies well to making power for the mid-range guys (400-500whp)...Mr. Buschur, would you care to respond?

CO_VR4

iTrader: (83)

The test results that Dave posted also show this:

Gasoline weighs 5.8 to 6.5 lbs per gallon, depending on exact fuel composition and conditions. Use 6 lbs as an average...

At -0- PSI the stock Walbro 255 flowed 515 lbs/hour.
515 lbs/hr divided by 6 lbs/gallon times 3.79 liters/gallon = 325.3 liters/hour

At 40 PSI the stock Walbro 255 flowed 410 lbs/hour.
410 lbs/hr. divided by 6 lbs/gallon times 3.79 liters/gallon = 258.98 liters/gallon.

The stock Walbro 255 flows more than its rated 255 liters/hour at 40 PSI.

David Buschur

iTrader: (53)

Thread went to hell fast.

First off, why do you feel the need to put in a Denso pump? Here's more fuel than anyone is going to use. I just don't get it. Two Denso pumps are not going to fit. There isn't enough room to get them side by side with fittings on the tank top. There is also NO need for two Denso pumps.

I also don't care what Walbro's site says. These pumps were sent to Kinsler, all of them, and flow tested on their flow bench at the same time so I could have some factual data. Our testing was done at 13.2 volts and the pressure I have listed. Who cares what Walbro says? So your 40 psi numbers you listed come out to 67 gph which is 402 lb/hr, mine say 410 lb/hr. Isn't that close enough for you?

Jordo, the factory fuel system is steel lines, other than a few ends which are short rubber. There system comes with a tank top. No pumps. Double check your pricing. Also double check the install and what comes in the kit.

Everyday..........

Drifto

iTrader: (6)

Thanks. I was responding to this quote from Dave:
"The reason these levels are important is it shows the fuel pumps are rated at 255 lt/hr at 0 psi. Nobody cares about that as the car doesn't run at 0 psi of fuel pressure."

From that, I understood Dave to imply that the 255 rating was based on 0psi which from what you just restated and what I state earlier the "255" rating is at 40-45 psi and not 0psi. Maybe I just misunderstood his statement.

CO_VR4

iTrader: (83)

What is interesting about the test results that Dave shared with us is that up to 70 PSI (the equivalent of 27 PSI boost pressure), the volume output of the standard Walbro 255 is the same as the Buschur modified H.O. pump in terms of fuel volume flowed at various pressures, and up to 80PSI (equivalent of 37 PSI boost) it outputs 97.6% of the Buschur H.O. pump's output.

Pressure Standard Walbro 255 Buschur HO Walbro
0 515 510
40 410 410
60 360 362
70 332 340
80 285 310
100 160 250

Buschur offers the dual pump setup in the standard Walbro configuration, which would be more than enough for 99% of the people needing an upgrade.

David Buschur

iTrader: (53)

To answer the question in post #46. Putting more fuel pump than you need into your car is not going to help you. Choose the pump combo you need that will fit the needs of your build, with a little safety margin. If you are planning to build a 400 whp EVO, you don't need to go with the double pumper.

6 lbs/gallon was used in the calculations I made. I don't know what the "fuel" Kinsler uses in their flow bench weighs.

oneguy

iTrader: (23)

So there aren't any downsides to using the stock fuel rail besdies the epoxied ends? Also do you think that the epoxy could become an issue for road racing?

David Buschur

iTrader: (53)

You are correct drifto, sorry. I will go edit that.

covr4, I agree 100% with what you wrote. The HO pump is for high boost applications as it doesn't fall of nearly as much up top. The reason I made these charts and put this information out there publically is so you guys can make educated decisions on what to use. It would have been easier to just say "This is what it costs, call us and give us your credit card number, it's the best."

CO_VR4

iTrader: (83)

Dave, we all benefit tremendously from your willingness to share actual data from your testing. This kind of info is commonly kept close to the vest, and alot of people buy stuff they truly don't need because they just don't know the difference. Kudos to you for making it public, and for steering people to just the upgrades they really need to support the mods and the HP levels they are planning to use.

Drifto

iTrader: (6)

No problem. I wasn't trying to crap on your data. Thanks for posting it up.

David Buschur

iTrader: (53)

Thanks a lot COVR4, I really appreciate that.

oneguy,

The stock fuel rail, as far as I know, has NEVER had a failure. Mitsubishi has a lot on the line to have a fuel rail that could break. It is my poor observation of the rail. The stock rail works, has proven good for 700 whp on our dyno, that's a LOT of power well in excess of 800 at the flywheel. I replaced mine to do this testing to see if it would make any difference at all in the AFR's/duty cycles. It did not, no change what-so-ever. Once I changed it to our new black billet rail I wasn't going to change it back. The new one looks nicer and I am more confident in it, personally.

fatbastard

iTrader: (21)

David,

when you tested the twin pumps, was this with or without the filter?

David Buschur

iTrader: (53)

The information is in post 1 and 2.

Paul Nelson

iTrader: (1)

I ran the stock walbro to 535whp on a dynojet and then i swaped out to the Buschur H.O. pump and was able to push it to 571 whp before the aem showed 99% duty on the injectors with 1000cc percison at 28lb of boost. Not to bad a extra 36 whp

FLAEVO

iTrader: (1)

Dave thanks for all the hard work.You sould have my HO pump buy 1200
tomorrow so you can put the HO double pumper together.I will call tomorrow
because I am going to need a set of your 1000 inj. also.I have the ra# with
the pump.I will post up my numbers after my tune this weekend.
Thanks again Dave for all your work for the commmunity.
Thanks Tom