Well... yes and no.

The Whinebro can flow enough for 550 HP @ 40psi of pressure.

It can NOT flow enough at 80 psi... not even close.

And as for the fuel pressure being proven time and time again that is a strange statement. The fuel pressure is regulated by the fuel pressure regulator. IF the regulator is set at a 1:1 ratio then in theory at 35 psi of boost at 45psi base pressure the end pressure SHOULD be 80. In reality it is usually NOT the case because the fuel pump can not pump enough fuel to hold that pressure. Pressure drops to a level where the pump flow = the HP requirement.. the injectors may be too small to flow that amount at such a low pressure though.

So yes, a whinebro can flow enough for 550 but NOT at 80 psi. And since the pressure will be lower, the injectors will flow whatever they can at that pressure.

 

The chart shows flow vs psi, I think whats also important is pressure (x flow) vs volts DC.

With my walbro, whether in high or low operation, it's noisy sometimes and quiet sometimes and I don't know why - EGR system, tank pressure?

 

Trina, have you hooked up a fuel pressure gauge to measure the difference between a stocker and walbro ?? All these calculations are good, but they are just that .. numbers .. what about actual performance??

I'm asking because prior to changing to a 'whinebro' the stock fuel pump pressure was very consistent in dropping from 3bar referenced to approx 2.0bar referenced fuel pressure!!! (at 1.5bar boost) (actual figures read 3bar idle, 4.5bar fullboost and by 5500rpms starts drops to 3.5bar)

You're not just buying insurance when going to the 255, it allows growth potential

I definitely agree going beyond certain hp a walbro is no longer enough though

lastly, as for the whine .. for mine, it sometimes appears whenever I have less than 1/2 tank of fuel .. but never when tank is above that

 

The 255LP is not enough for a 35R at 35 psi, but the HP version is. At 35 psi, I'm assuming we're talking about race gas by the way I Don't like any formula that attempts to equate fuel flow to HP. They almost NEVER apply to our cars, or at least no one knows or uses the correct numbers. Because of all of the variables it is nearly impossible to size a fuel system by HP potential. It makes much more sense to size it based on the fuel you intend to use, the target AFR you plan to run on that fuel, the boost pressure it will take to get that flow on your setup (stroker vs stocker gets interesting here), and the max airflow your turbo will flow.

For the sake of doing the math, let's assume Sunoco 117 with a Specific Gravity of .724, and a target AFR of 12.5:1 which is common for race gas. The LP version will support only 51 lbs/min flow, but the HP will support 67. The 56 trim wheel is rated for 65 lbs/min, and indeed that is the most I could ever get out of it. So it's big enough, but there is very little headroom available, not enough to make me comfortable. And just for the sake of arguement, the same scenario but with pump gas (SG of .76) and a target AFR of 11:1 (common for pump gas) the supported airflow drops to 48 and 62 respectively.

What you make for power at those airflow numbers is up to your tuning ability and your setup, but on average multiply by ten. By sizing the fuel system to the turbos max flow you buy some insurance against the rare occasion something may go wrong, like the boost level getting away from you (disconnected WGA, etc). There should be some more info about how this philosophy applied to my last blown motor here. The same math can be applied to injectors (even easier).

 

Now that I have the attention of experts, let me ask if anyone has an idea what happened here.

I was in 2nd gear, 21 - 22 psi, and the rpm was over 7K and then the acceleration started to fall abnormally, not sharply, but smooth, it felt like fuel starvation (had 1/2 tank gas) or as if I lifted throttle a little. No SES faults, car seems normal, I even confirmed compression is still same.

1. Was this fuel starvation (need for concern)?
2. My car knocks up at about 7300 rpm (it's history when tuned), was this just the ECU's response to it, like the switch of timing and fuel map?

Any clues?
Setup: HKS rs, cams, mbc, cust tuned, TB exh, Walbro, BPR8ES 0.028, 93 oct, rest is stock.

 

Could very well have been reduced ignition timing advance due to knock. If I get more than 5-6 degrees of retard I can feel it.

Unlikely to be a fuel issue since you state that you have a pump (255 I'm assuming), and the stock injectors are just big enough for the maximum airflow the turbo is capable of (~42 lbs/min vs 43-44 lbs/min). But an interesting tidbit for those people still running unrewired stock pumps, according to the math, the stock EVO pump at ~20 psi will run out of fuel around 34-35 lbs/min. Sure enough, that's where my WBO2 would start to seperate from the calulated AFR value on the log. At 14 volts the pump will mathematically support ~44 lbs/min, and up to 42-43 lbs I have seen no signs of running out of fuel. I can not get any more out of the turbo. Injector duty cycles are at 102% or so, but at a target AFR of 11:1 that's not a problem. It never surprises me to see EVOs maxing out the stock turbo (cams and 2x psi) running 12.5:1 AFR. That's what I got, and have seen on a dozen other cars that are in the same situation. The EVOs stock fuel system is surprisingly well sized for it's turbo's flow capacity, which is how I like to run as stated in my previous post, but the crappy 18 guage wire ruins it.

 

whinebro?lol

mine doesnt seem to make any noise

 

Well you can figure out the exact BSFC for any car using a formula on that Excel sheet I made. To figure out the fuel reqiurements you need to have the BSFC of the vehicle for the amount of boost you want to run with the same type of gas you plan to run it on. It is very simple.

The BSFC also takes into account whatever AFR you plan to run. It is not a guess in any way, it is a precise measurement.

The whinebro HP (Which everyone should be using I really hope) will not flow enough for a GT35R at 35 psi. It may flow it, but not at the correct pressure. The injectors will be compensating by opening longer. You can use any calculator you want, the Whinebro HP can not flow crap at 80psi of pressure. Quite obviously not enough for a GT35R at 35 psi. The pressure drops, injectors must stay open longer to compensate forcing you to buy larger injectors.

 

The HP version still flows well enough at 35 psi for a 35r by my data, 201 lph. Thats enough for 67 lbs/min at 12.5:1 and a fuel specific gravity of .724, as I stated above. And I'm not using any calculator, I'm using one that I put together myself that has been verified by WBO2 and airflow data collected on my car and dozens of others. It has proven to be accurate to within 1 lb/min. I have tested the LP to 30 psi on a T67/TO4R and the calc was within .1 or so lb/min, but I have not tested the HP to 35 psi on any turbo, so if you are uncomfortable taking it that high, then don't But I will say this. I have proven the LP to 30 psi at GT35R airflow levels (64 lbs/min, 35r max is 65 lbs), and the whole entire point of the HP is that the relief valve opens later allowing for "normal" flow at higher pressures. I Would have no problem running that pump on a 35R, but in reality I would most likely be running a larger pump or dual pumps just because I like to have some extra headroom available for when things go wrong, as I stated earlier.

Also, if you are logging wideband O2 data, as anyone maxing out a 35R should be, you will easily see the pump dropping off and not associate that leaning out to the injectors, or try to compensate with them. Unfortunately this is much easier to do on the DSMs than it is on the EVOs.

We are both trying to make the same point, just using different math/methods to prove it, yet I sense some frustration in your post. Hopefully that's not the case and I'm just too sensitive

 

The only reason I upgraded was because road racers were saying that stock pump gets unstable after 15 minutes of heavy use. When the stock pump gets hot it starts to flow less. The W255 maintains rock solid fuel pressure no matter the temp or amount of use.

 

LoL. Thats a new term for me. I know quite a few guys with 'whinebro' pumps and i have never noticed any increased noise.

Personally, i'm going to get one when i get my Stage 1 kit finished for peace of mind, reliability, and that extra pressure it can handle. IMO, stressing a stocker fuel pump to its limits would definitely shorten its lifespan. I'd rather have more than enough fuel on demand than 'barely enough'.

 

Trina, have you had the chance to map out the Bosch 044 Motorsport fuel pump in that little excel chart you have? I'd be interested to see where it sits between the stocker, the 255HP and the Denso.

 

I have been out of town for a little bit but yes, I do have the numbers for the "Bosch 044". When I get back to town I will post up my new calculations.

The pump flows on the site right now are not exact. I do have the exact pump numbers from RC Engineering now so those will be the new numbers. They are all slightly different.

 

Just so you know, Buschur Racing has a new super HP Walbro pump which flows a LOT more fuel at 80 - 90 psi. Big Al told me that his 900 whp was at Buschur Racing last week and that his twin Walbro 342's were running out of steam at high boost of 45 psi. Buschur installed the new Super HP Walbros and his a/f went dead rich and the fuel pressure remained steady even at 90 psi.

The new pumps are available from Buschur racing and are a direct drop into the stock location.

Hard wiring with a relay is also suggested.

Dan

 

The point is it can, but its already in the red zone. Walboro 392, Apex GTR-N1, Dual 255's y'd together (this doesnt mean its 510 however, research that one on your own), or the Bosch 044.

Bringing all of this up only insulates the fact that EVERYTHING needs to be carefully examined. Fuel line size becomes the next biggest restriction, both feed and return.