New Product: High-Flow Billet Fuel Rails
10-26-2013, 12:35 AM
#76
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So when Jordan Carver appears, is that the RL equivalent of Godwin's law?
10-28-2013, 11:43 AM
#78
Developer
Thread Starter
Speedtoys - the two pictures you have posted are not from our website or our current product.
See for yourself: http://www.928motorsports.com/parts/...l_rail_kit.php
Yes, you found those pictures on Rennlist on an old thread. And as you said, things evolve.
We did first come out with a "kit" that included the lines and fittings you have shown in those old pictures. But this same thing happened back then - there was no agreement on whether to run a dampener or not, to use stock or after-market FPR's, etc, so that product (the fuel rail kit with lines and fittings) was discontinued in favor of what we now market - the billet fuel rails with -6 AN fittings on each end.
The end user is free to plumb it and add whatever they want to regards dampeners and or regulators.
See for yourself: http://www.928motorsports.com/parts/...l_rail_kit.php
Yes, you found those pictures on Rennlist on an old thread. And as you said, things evolve.
We did first come out with a "kit" that included the lines and fittings you have shown in those old pictures. But this same thing happened back then - there was no agreement on whether to run a dampener or not, to use stock or after-market FPR's, etc, so that product (the fuel rail kit with lines and fittings) was discontinued in favor of what we now market - the billet fuel rails with -6 AN fittings on each end.
The end user is free to plumb it and add whatever they want to regards dampeners and or regulators.
Last edited by Carl Fausett; 10-28-2013 at 12:01 PM.
10-28-2013, 11:53 AM
#79
Developer
Thread Starter
Greg, you are missing the point.
The system cannot flow more than past the smallest restriction. Let these pictures help you.
You have shown a picture of the square body of the stock fuel rail, but conveniently left off the feeder lines at each end - which are much smaller. Although adequate for a stock 928, we found on our high HP applications that they were part of the fueling problem.
Please see the attached pictures below.
And the system plumbed in -6 AN everywhere will out-flow the stock system with its many diameter changes and restrictions.
The system cannot flow more than past the smallest restriction. Let these pictures help you.
You have shown a picture of the square body of the stock fuel rail, but conveniently left off the feeder lines at each end - which are much smaller. Although adequate for a stock 928, we found on our high HP applications that they were part of the fueling problem.
Please see the attached pictures below.
And the system plumbed in -6 AN everywhere will out-flow the stock system with its many diameter changes and restrictions.
10-28-2013, 12:00 PM
#80
Developer
Thread Starter
I would say this: the stock fuel rails and fittings seem to be able to handle 500 HP well enough.
We've all done it many times.
But when we get north of 600 HP, you need larger system lines, and those little feeder lines on each end of the fuel rail just don't cut it.
The customer that buys our fuel rails is either:
1) doing it because they like the way the look
2) doing it because they want to clean up the engine bay of fuel lines and/or they have their own ideas on how the lines should be routed
3) doing it because they need more fuel than the stock system can provide
Not for everybody. But then, those who have them, like them.
We've all done it many times.
But when we get north of 600 HP, you need larger system lines, and those little feeder lines on each end of the fuel rail just don't cut it.
The customer that buys our fuel rails is either:
1) doing it because they like the way the look
2) doing it because they want to clean up the engine bay of fuel lines and/or they have their own ideas on how the lines should be routed
3) doing it because they need more fuel than the stock system can provide
Not for everybody. But then, those who have them, like them.
10-28-2013, 12:06 PM
#81
Nordschleife Master
Carl, wasn't your initial view that the greater volume inside the rail would reduce the pulses? There's nothing wrong with changing one's story to a more plausible one, just wanted to know if you in fact have changed your view.
Personally, I think that there's no evidence whatsoever that the stock fuel rails don't flow enough fuel for any 928 that currently exists. Todd Tremel produces 900+ wheel hp on e85, which is much more flow than any other 928 engine. He runs stock fuel rails.
Then there's the convenience of the stock rails with the stock intake manifold. Is there any logical justification for using aftermarket fuel rails for any 928 engine that runs the stock intake manifold (99.9%+)? I say no.
Personally, I think that there's no evidence whatsoever that the stock fuel rails don't flow enough fuel for any 928 that currently exists. Todd Tremel produces 900+ wheel hp on e85, which is much more flow than any other 928 engine. He runs stock fuel rails.
Then there's the convenience of the stock rails with the stock intake manifold. Is there any logical justification for using aftermarket fuel rails for any 928 engine that runs the stock intake manifold (99.9%+)? I say no.
10-28-2013, 01:14 PM
#82
Developer
Thread Starter
Your welcome to your opinion. But measure the volume of the system, do not stop at the rail and only the rail. I still suggest our rail, which is -6AN internally, through the fittings and -6 in the feeder lines - holds more volume and moves more fuel.
I accept the opinion of Kinsler injections systems as being correct.
I accept the opinion of Kinsler injections systems as being correct.
This is from Kinsler: http://www.kinsler.com/page--efi--4.html
"Since EFI injectors turn on and off, the interrupted flow causes pressure waves to bounce around in the fuel rails, especially at wide open throttle where the flows are the highest. In a group fired system you often trigger two or more injectors at a time in a given fuel rail. The simultaneous pluses can reinforce each other at some rpm to give unusually high pressure pulses, sometimes causing poor fuel distribution. It often helps to run a larger diameter fuel rail. Kinsler extruded aluminum fuel rails are .680 inch inside diameter. A large diameter smoothes out the pulses quite well when compared to smaller sizes. Running higher overall system pressure also helps. We often run about 72 psi instead of the more normal 36 to 43. The amplitude of the pressure spikes will remain about the same, but will be relatively smaller based on the percent change in injector flow. We also like the better atomization achieved with the higher pressure and it sometimes gives better power and economy. Be careful about running the fuel pressure too high, as some ECUs don't have enough current to lift the disc or pintle in the injector consistently off the seat against this added pressure, which will result in poor fuel distribution. Be sure your fuel pump is capable of supplying the engine with the volume required at a higher fuel pressure."
"Since EFI injectors turn on and off, the interrupted flow causes pressure waves to bounce around in the fuel rails, especially at wide open throttle where the flows are the highest. In a group fired system you often trigger two or more injectors at a time in a given fuel rail. The simultaneous pluses can reinforce each other at some rpm to give unusually high pressure pulses, sometimes causing poor fuel distribution. It often helps to run a larger diameter fuel rail. Kinsler extruded aluminum fuel rails are .680 inch inside diameter. A large diameter smoothes out the pulses quite well when compared to smaller sizes. Running higher overall system pressure also helps. We often run about 72 psi instead of the more normal 36 to 43. The amplitude of the pressure spikes will remain about the same, but will be relatively smaller based on the percent change in injector flow. We also like the better atomization achieved with the higher pressure and it sometimes gives better power and economy. Be careful about running the fuel pressure too high, as some ECUs don't have enough current to lift the disc or pintle in the injector consistently off the seat against this added pressure, which will result in poor fuel distribution. Be sure your fuel pump is capable of supplying the engine with the volume required at a higher fuel pressure."
10-28-2013, 03:10 PM
#83
Nordschleife Master
Carl -- Thank you. I think we're all entitled to our own opinions. Hopefully, we'll converge on logic and facts during this polite exchange.
I don't think that the fuel rail volume makes that big of a difference after the rail is already large, such as the 928 S4 fuel rail. What makes more of a difference is whether the pulses see some surface that has some give. A fuel damper is an excellent device for that. Flexible fuel hose with some give also dampens the pulses.
Your website says that the stock rails and their connections are a "restriction". You go as far as calling them "bad restrictions." At what power level or fuel flow level, do you think these restrictions become "bad" in the sense of causing fueling problems?
We are having good success with modified stock rails fed thru two Bosch fuel dampers:
I don't think that the fuel rail volume makes that big of a difference after the rail is already large, such as the 928 S4 fuel rail. What makes more of a difference is whether the pulses see some surface that has some give. A fuel damper is an excellent device for that. Flexible fuel hose with some give also dampens the pulses.
Your website says that the stock rails and their connections are a "restriction". You go as far as calling them "bad restrictions." At what power level or fuel flow level, do you think these restrictions become "bad" in the sense of causing fueling problems?
We are having good success with modified stock rails fed thru two Bosch fuel dampers:
10-29-2013, 02:50 AM
#84
Former Sponsor
Greg, you are missing the point.
The system cannot flow more than past the smallest restriction. Let these pictures help you.
You have shown a picture of the square body of the stock fuel rail, but conveniently left off the feeder lines at each end - which are much smaller. Although adequate for a stock 928, we found on our high HP applications that they were part of the fueling problem.
Please see the attached pictures below.
And the system plumbed in -6 AN everywhere will out-flow the stock system with its many diameter changes and restrictions.
The system cannot flow more than past the smallest restriction. Let these pictures help you.
You have shown a picture of the square body of the stock fuel rail, but conveniently left off the feeder lines at each end - which are much smaller. Although adequate for a stock 928, we found on our high HP applications that they were part of the fueling problem.
Please see the attached pictures below.
And the system plumbed in -6 AN everywhere will out-flow the stock system with its many diameter changes and restrictions.
This is a picture of a cross sectioned 90 degree "feeder line" at the end of the stock rail (this one happens to be the tightest of all the 90's and was cut exactly through the middle of the 90 degree bend) compared to a Goodridge swept tube 90 degree hose end...which is the hose end you use.
"The system cannot flow more than past the smallest restriction. Let these pictures help you."
[/URL]The "feeder line" measures .290" x .320", ID.
The Goodridge fitting measures .230", ID.
Sorry.
Just the facts.
.
Last edited by GregBBRD; 10-29-2013 at 03:14 AM.
11-04-2013, 12:07 PM
#85
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BUMP - Because of the silence
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
11-04-2013, 12:29 PM
#86
Archive Gatekeeper
Rennlist Member
Rennlist Member
I do love the patina on that vise.
11-04-2013, 03:21 PM
#88
Archive Gatekeeper
Rennlist Member
Rennlist Member
I don't think that's duct tape, that's 40 years of precision motor-werking.
11-04-2013, 03:33 PM
#90
Todd takes off the ends of the stock rail but still uses it and its handy injector fastening system. I am not sure of his AN size on the rest of his lines.
And yes, he uses these pieces with 9xx hp, and with e85, which means that its 9xxhp but with 40% more fuel to do so at some RPMs.
And yes, he uses these pieces with 9xx hp, and with e85, which means that its 9xxhp but with 40% more fuel to do so at some RPMs.