I decided to make a nifty little excel program that does a bunch of stuff I wanted but I found it very interesting when I started plugging in the fuel pump flow numbers.

The ones that most people will be interested in is the stock Evo pump vs. the Whinebro 255lph(HP). It really isnt all that big a difference. Take a look here:

http://www.thedrunken.com/excel/

At the bottom there are some tabs, click on the one that reads "Pump Flows".

You buy yourself a little more headroom than the stocker but its not nearly as much as alot of people may think.

 

When buying a piece such as a new fuel pump your not per-se buying the highest outputting whatever... you buying peace of mind. Ever see what happens when you starve your engine for fuel... i have , it sucks.

 

fule?

 

So the Walbro is more dependable than the stocker? And that's the only reason to upgrade?

 

What are you talking about ?

 

It puts out more LPH than the stocker... come on man , your not serious are you??

 

good catch

 

Notice that the extra "headroom" is where you want it, at higher fuel pressures which will be demanded by higher boost levels b/c of the FPR. The evo's have a pressure differential of about 3 bar. So at zero boost fp = approximately 3 bar. At about 1.5 bar boost your fp = approx 4.5 bar. 4.5 bar is roughly 65 psi. Per your chart the headroom at max boost is about 50+ lb/hr. I'll take that for safety, and the ease of install and price don't hurt either.

Nice chart BTW.

 

I believe the stock base pressure is around 43 psi. If you are running say 24 psi of boost your pressure should be at 67 psi. So yes, you are gaining a decent amount of headroom at that pressure. But alot of people think they can run this pump with a 35r running 40 psi of boost and make 550 horses with no problem. Take this for example:

Base Fuel Pressure: 45 psi
Boost: 35 psi
Total requested fuel pressure: 80 psi
Total flow from the whinebro at 80 psi = 264 lbs/hr

Now take the horsepower they want to make....

HP Request: 550 hp = 357 lbs/hr

As you can see... the fuel pump can not keep up at that pressure. The whinebro can flow that at around 40-45 psi of fuel pressure. You see the problem

The pump will drop is pressure because the injectors will be taking most of the flow, sooner or later the injectors will be running 100% duty cycle at an unknown fuel pressure. That is why so many people think they need huge injectors... reality is thier pump simply can not flow enough at whatever pressure they are trying to hit.

 

As your fuel pressure drops, the injectors start flowing less, hence the high duty cycles. This is also why running higher base fuel pressure will only get you so far. If you're pump cant sustain whatever pressure your at now, making it higher wont do anything for you. The pumps pressure will still drop to the same number.

 

Everything is application specific. Gotta do your homework for your setup. Can't take everyone's opinion on a forum as gospel either. In the end it's your money, right?

I think alot of people don't realize this. Probably why there are so many dumb posts about silly problems. People don't do their research and learn about the mods they "want" to perform.

I'm glad there are at least a few folks on here who understand.

 

Yes, I frickin' know that.

This is supposed to be a "common sense" first upgrade according to Warrtalon et. al. for safety. It appears it's about flow they say this not reliability then?

 

The whinebro pump is not exactly a failsafe pump Lots of people eat em up. I believe he means safety by it gives you a little more fuel to work with.

It probably tacks on another 100 horses you could make over the stock pump. It is not more reliable.

 

bosch 350 it is then?

 

Fuel Pressure rises with that 35PSI of boost. Base pressure of 45PSI is actually bumped to 80PSI. it has been proven time and time again that the WHINEboro can flow enough for 550WHP. 650 is obviously too much, so just run 2.