How psi a B204L support?

[Lord Tentacle]

B204L
Has 19t Upgrade
Have tunning software for Trionic 5
Have E85
Have 55lb injectors

How many PSI's will support?

Am not trolling... totaly...

 

[VQ]

25psi

 

[linuxman51]

as much as it will. the e85 will be more of a limiting factor I think.

 

[JohnMc]

Roughly 220 whp worth of injector flow there on E85? Not sure how much boost a B204L needs to get that much air through it.

Get bigger injectors.

 

[CAPT_BLOTTO]

Add a wideband and find out?

 

[Lord Tentacle]

Roughly 220 whp worth of injector flow there on E85? Not sure how much boost a B204L needs to get that much air through it.

Get bigger injectors.

55lb of e85 injector hold be closer to 300whp+ iirc

Stock boost is 7psi for 180hp
My hope was to run 19psi
Don't want to ventilate block though
Didn't know about week rods or crank etc

 

[JohnMc]

http://fuelinjectorclinic.com/flow-calculator

4 cylinders, 90% duty cycle, 225 hp at the wheels:

Injector Size Required
Fuel Type cc/min lb/hr
Gasonline 452.81 43
E85 588.66 56


I've got 1000cc injectors on mine, they're only (heh) good for 450 whp or so on E85.

 

[linuxman51]

yeah. if you run a 50/50 mix you can get most of the benefits of e85 and still get away with smaller injectors, but keeping that ideal ratio is not the easiest thing (As I'm finding with my 940. I'm just going to go straight e85 and be done with it)

 

[JohnMc]

Yep, just pulling up to a pump and filling it all the way up is pretty foolproof.

Well, other than than apparently the alcohol content does vary from batch to batch. So I've heard. I may still stick an ethanol sensor on my car at some point, on the return line. I'm still doing simple 'dual fuel' with a dash switch. But MS3 does it a lot better than I could with MS1. MS1 just switched the fuel/spark/boost tables (using the nos switch). MS3 has actual flex fuel capacity built in, so in addition to that it changes all the other fuel settings as well, such as cranking pulsewidth, accel enrichment, etc.

 

[YellowT5-r]

I was actually thinking about running a FUELAB electronic fuel pressure regulator so I can build a table to run rail pressure off of. Basically, you'd get rising rate just like a normal FPR, but you get the ability to ramp up rail pressure so you can get the flow out of smaller injectors as you start to approach, say 80% duty cycle.

For example, being gentle at 3 bar, my injectors only flow about 680cc's, but if you start pushing them around (within their operating range), they can put out over 960cc's. As long as my fuel pump is game, it could be a way to get another 150HP worth of fuel flow from the same injectors without running around with 85PSI in my fuel rail all the time.

 

[centason]

Turn it up until it goes pop. Then you have found the max, no speculation.

 

[JohnMc]

I was actually thinking about running a FUELAB electronic fuel pressure regulator so I can build a table to run rail pressure off of. Basically, you'd get rising rate just like a normal FPR, but you get the ability to ramp up rail pressure so you can get the flow out of smaller injectors as you start to approach, say 80% duty cycle.

For example, being gentle at 3 bar, my injectors only flow about 680cc's, but if you start pushing them around (within their operating range), they can put out over 960cc's. As long as my fuel pump is game, it could be a way to get another 150HP worth of fuel flow from the same injectors without running around with 85PSI in my fuel rail all the time.

You might end up spending more money getting a fuel system that can flow enough volume* at a ridiculously high pressure than you would just getting a properly sized set of injectors. I think my 1000cc injectors were just a little over $200, and they were direct fit swaps for the Volvo injectors and browntops that preceded them. And they can lean out at idle on gas, no min opening time issues.

And PS: Check with a fuel injector calculators somewhere - flow rates don't go up as much with increased pressure as you think they might. Doubling the pressure doesn't double the flow.


* - You probably know this, but as static pressure goes up, fuel volume goes down. Static pressure goes up when you get into boost on manifold referenced fuel pressures - so just at the point you need *more* fuel volume (high boost) - the pump is putting out less volume. And even with a rising rate FPR, you still have to add boost pressure on top of that. 80 psi of manifold referenced fuel pressure is 100 psi of static pressure (what the pump has to put out) at 20 psi of boost.

Pumps are struggling to put out volume at 100 psi. You'd have to get a MUCH higher capacity fuel system.

 

[YellowT5-r]

You might end up spending more money getting a fuel system that can flow enough volume* at a ridiculously high pressure than you would just getting a properly sized set of injectors. I think my 1000cc injectors were just a little over $200, and they were direct fit swaps for the Volvo injectors and browntops that preceded them. And they can lean out at idle on gas, no min opening time issues.

Oh, I definitely agree...my current plans are actually based around 5 injectors that flow closer to an honest 1300cc's at 43PSI...that was just a bit of old mental masturbation that seemed relevant to the discussion of trying to squeeze more blood from the same old stones.

And PS: Check with a fuel injector calculators somewhere - flow rates don't go up as much with increased pressure as you think they might. Doubling the pressure doesn't double the flow.

Actually, those were the bench numbers (mas betta than calculators) from matching my old set of ID725's - the Bosch gen III's are amazingly agile injectors with things as big as 2000's still being able to fake an idle. They actually make flex fuel a reality since they can idle on gas and go WOT on E whatever feels good.

* - You probably know this, but as static pressure goes up, fuel volume goes down. Static pressure goes up when you get into boost on manifold referenced fuel pressures - so just at the point you need *more* fuel volume (high boost) - the pump is putting out less volume. And even with a rising rate FPR, you still have to add boost pressure on top of that. 80 psi of manifold referenced fuel pressure is 100 psi of static pressure (what the pump has to put out) at 20 psi of boost.

Yeah, that's why I was saying you'd still need the rising rate functionality to maintain differential.

Pumps are struggling to put out volume at 100 psi. You'd have to get a MUCH higher capacity fuel system.

Absolutely, most of the OEM pumps out there will be earning their keep to maintain any appreciable volume at more than 50-60 PSI. I will say though, that after an unfortunate plumbing error, we ended up dead-heading my 044 with a stock in-tank...suffice it to say, it pegged a Strap-On 165PSI fuel pressure gauge, resulting in some amazingly low duty cycle numbers, but not actually damaging anything. I think a pair of those things, and you could probably start getting there for street or strip applications without extended runs at WOT. Road race or rally applications are another issue entirely.