[Skydive]

Tzu,

Thanks for the PM, by the way.

I know that Siemens/Continental has tested the "engine" to 200 bar, but I don't know if that means they have tested the whole OE system to those pressures, (including the pumps) or just the injectors. The conversation probably took place in some combination of German and English, so I don't know what if anything was lost in translation. Also, what were the test conditions? Was the pump system test sustained at 200 bar, or did it peak there?

I'm interested in volume rather than pressure. ie: What is the maximum volume rate of the HPFP? Can it *sustain* injectors flowing at 200bar? This is sometimes expressed as "Q Dot".

I'll post the same question to the thread you referenced as soon as I am registered there.

Thanks,
-Michael

[Tzu]

I'm just a hobbyist, not a design engineer for BMW lol.

I know HPF did some good testing on the injectors, and released a small video on youtube about it. The theory of the fuel system would require the rail to be held at reliable pressure. eg if the sensor is reading 200bar, it should sustain 200bar while injectors are pulsed and volume is exiting the system. This is much easier than the DME accounting for minute pressure losses between injections. Of course this will occour, but if the DME schedules 200 bar, it probably assumes constant pressure.

I know shiv did some testing of the LPFP, not sure about HPFP, thats a little more difficult. You can ask him for his results, I dont see him giving it out willy nilly though.

I try to keep Q_dot for heat transfer lol. But any number I give you would be all theoretical. Taking AFR, you can use the specific mass of air to convert to m_tot_gas with respect to vol_cyl injected per combustion. Multipled by 6 cylinders X RPM / 60(sec/min) / 4(strokes/cycle) for m_dot_tot_gas. Divide that by specific mass of gas, and you should have volume flow rate. I'm a little rusty on this stuff.

It's probably just a better idea to bench a HPFP lol. That's a much more realistic route.

[vasillalov]

Originally Posted by Tzu

I know HPF did some good testing on the injectors, and released a small video on youtube about it

Sorry to be so nit picky, but I watched that video as well and I was not impressed a single bit. Their injectors did not have a proper spray pattern. They looked more like the spray pattern you get out of a garden hose.

[cn555ic]

I need a flow test to see how much better it is compared to the Oem intake manifold. Yes the logo would be nice and the aluminum but better flow is critical

[bryce]

Originally Posted by vasillalov

Sorry to be so nit picky, but I watched that video as well and I was not impressed a single bit. Their injectors did not have a proper spray pattern. They looked more like the spray pattern you get out of a garden hose.

if it's the same video i'm thinking of, they used the bosch/ID injectors. these are widely accepted as the best injectors on the market. idle, flow characteristics, etc are superior to RC engineering and other brands. what background do you have in fuel injector design/performance where ID injectors do not impress you a single bit?

[Tzu]

V: In this particular instance, I considered "good" to be the word of choice as pretty much the only vocal people to even TEST the OEM injectors, and compare against other possible replacements. That research is only moving the platform forward, and IMO can always be considered "good." Data is always good! Espically when public.

CN: I actually just completed a study on spraybar effectiveness on another platform. The bottleneck in that particular choice is ensuring proper flow AND spray pattern with respect to OEM spec. Many times, brand new identical PNs had a large variance. This is true with any high pressure injection system. An injector can flow just fine, but if its streaking, you're going to get pooling, misfires and shitty fuel economy.

[vasillalov]

Originally Posted by bryce

..what background do you have in fuel injector design/performance where ID injectors do not impress you a single bit?

Enough to know that the injectors should not be producing thick streams and squirts. Instead they should be delivering fine mist of fuel.

Don't get me wrong here. I own some of HPFs products and I am not here to say anything against them. All I am saying is that the spay pattern of their super duper high flow injectors looked like the one from a garden hose to me (in that particular video).

[bryce]

Originally Posted by vasillalov

Enough to know that the injectors should not be producing thick streams and squirts. Instead they should be delivering fine mist of fuel.

Don't get me wrong here. I own some of HPFs products and I am not here to say anything against them. All I am saying is that the spay pattern of their super duper high flow injectors looked like the one from a garden hose to me (in that particular video).

well, the injectors in the video are not HPF designed/made; they're the bosch/ID injectors used in honda, mitsu, suby, etc platforms with tremendous success

[vasillalov]

Originally Posted by bryce

well, the injectors in the video are not HPF designed/made; they're the bosch/ID injectors used in honda, mitsu, suby, etc platforms with tremendous success

Good to know!

Cheers!

[bryce]

Originally Posted by vasillalov

Good to know!

Cheers!

[ridin135]

Was the price posted and I just missed it or was the price so large that the servers couldn't support it.

[Skydive]

Hi Tzu,

I recall the video you're referring to pretty well actually. Jonathan and I watched it a few times, trying to figure out how it would be relevant to the N54. In fact, it isn't. Those aren't direct injectors, so unless you're resigned to the notion that port injection, (ie: a new manifold, additional injectors, fuel rail, pump, and outboard fuel controller), is the best way to support additional charge air from a big turbo or turbos, it doesn't mean all that much. As I recall the gentleman in the video also assumes that the relationship between fuel volume and fuel pressure is much simpler than it is.

More comments elsewhere as this is HPF's thread and I have run away with it again... Apologies.

-Michael

[e92ben]

Originally Posted by ridin135

Was the price posted and I just missed it or was the price so large that the servers couldn't support it.

Right! What's the price on this thing

[TheStig]

Cannot wait i haven't had a N54 in months and once HPF finishes this project it will make me buy another one. I'm keeping a very close eye on this one.

[ar design]

Originally Posted by Skydive

You're right. At this point, it's all conjecture because nobody has tried to pump more air into this engine than there is fuel supply; (save possibly AR, who state a 530hp from a big turbo on race gas more than a year ago, but we don't know if that was a fuel limit or an air limit.) It's possible that HPF have quietly found those limits and decided that more fuel needed than can be supplied by the factory fuel system. If so, they haven't shown us any evidence of such, and their piecemeal marketing and commentary regarding their upcoming big turbo kit would suggest that they have not yet had an opportunity to find those limits, as it would appear that the key has yet to be turned. (When last he last commented, Chris said they were still fabricating a coolant hard line, so I don't think the test platform was in a state where it could have be used to established any limits as recently as a few days ago.) So... I have my doubts.

However, while there is ostensibly plenty of injector left, and probably plenty of fuel pressure, there's a volume limit somewhere too... and if the stock pump can't sustain volume, it doesn't matter how much room is left in the injectors or how we regulate pressure. While the injectors may have been designed to supply enough fuel to safely operate the car in limp mode with only the low pressure pump, the total volume requirement would be relatively low.

-Michael

The issue was the tune. Always was. Still is.

[Skydive]

Originally Posted by ar design

The issue was the tune. Always was. Still is.

Hi Andrew,

Thanks.

So, are you saying that you had plenty of fuel left at the top of your tune?

What, in particular was troublesome about the tune?

Thanks,
-Michael

[cotmfk]

Originally Posted by ridin135

Was the price posted and I just missed it or was the price so large that the servers couldn't support it.

lolz

[Transport3r]

I'm guessing $1,999.95

[TheStig]

Originally Posted by joshuo

I'm guessing $1,999.95

I Would also have to agree with you're statement. If not more. I'm really hoping the HPF Stage I Turbo for the n54 is in the the 5-8k range

[cotmfk]

I was thinking $199.95. I think you added one too many 9's on your price.

[ridin135]

Originally Posted by cotmfk

I was thinking $199.95. I think you added one too many 9's on your price.

Ya that price is probably one injector

[AaronHoloster]

I am not sure how this is going to work with DI INJECTION and PORT Injection WITH high compression ratio piston setup but all I KNOW is I just happen to have $2000 pocket change for this product clean my intake valve.