Biggiesacks

Im sure, mine works fine too. You really can't get much simpler then one hobbs switch and one relay though.

kikiturbo

syphon needs to be thrown away and second low pressure pump installed in the other side of the tank... that solves this problem and the issue of fuel starvation on the track

Pal215

iTrader: (12)

That is extreme, but very correct.

LetsGetThisDone

iTrader: (1)

Easier to just install a surge tank.

On the topic of the 525, there is so little gain over the 450, I would just make the jump to a double pumper.

kikiturbo

I would disagree on that... having a surge tank still requires the stock-ish venturi... On the other hand, surge tank is better when running very low on fuel....

LetsGetThisDone

iTrader: (1)

Surge tank resolves starvation on the X's down to the fuel light flashing. The uses the same venture styl fuel transfer as the 8/9, except the X can have fuel starvation issues with as much as 3/4 of a tank of fuel. If the surge tank resolves starvation for the X, it will surely fix it for the 8/9. My car doesn't have fuel issues on track until it's under 1/4 tank.

kikiturbo

I never said that surge tank would not solve the fuel starvation issues.. quite the contrary. My only point is that the issue with venturi still exists unless you replace the venturi with and additional fuel pump. Also, if you run the original fuel pump hanger with a very large pump, there is the question of fuel pump wiring and the OE fuel filter.

Yeah, the X is bad because it doesnt have that fuel bowl inside the tank... only X RS have it AFAIK.

2006EvoIXer

iTrader: (1)

I took a closer look at the graphs, the 525 pump flows about 8-10% more than 450 pump between 30-40 psi of boost. So what is an extra 30 lph (500cc/min) of fuel worth? 50whp? Can this be enough for a Black on E85 in kill mode?

RazorLab

iTrader: (8)

I have a F90000285 waiting to go in my surge to replace the F90000274 that is currently in there. I maxed my F90000274 out at 29psi @ 640whp past 8k so I was going to see what the 285 does out of curiosity.

However, I have to get my cylinder head situation fixed first, but after I can show some data.

2006EvoIXer

iTrader: (1)

Looks like it will be really close. My gut tells me it will be a little shy of maxing out a Black, which means the Black will live longer.

Pal215

iTrader: (12)

Well, it also depends on the rest of the fuel setup. I'm currently around 60% duty cycle on 2150cc injectors and the F90000274 with 37psi on the FP Black, I don't know how much more boost is safe to make on an FP Black, but I don't think i'll be using the entire 40% left of injector to max it. Wouldn't that say that the Walbro450 can max out an FP Black?

LetsGetThisDone

iTrader: (1)

2150's will make a smidge more our if the walbro 450. But you'll still run out of pump around 650-670

RazorLab

iTrader: (8)

IDC isn't connected 1:1 with the max output of your fuel pump.

Here is a log of my car with my walbro failing to keep up with fuel demand out the top. AFR starts leaning out .5 AFR past 8,000rpm. IDC of my ID1700's are 82% tops.

https://datazap.me/u/razorlab/sedyno...&zoom=801-1143

If I drop the boost the AFR stays flat 11.5 out the top.

Pal215

iTrader: (12)

I see. So it is possible to run out of fuel pump long before duty cycle. The pressure in the fuel rail must drop dramatically as well in these situations.

RazorLab

iTrader: (8)

Yup, here is the same log with FuelPressure plotted as well: https://datazap.me/u/razorlab/sedyno...&zoom=801-1143