Component Selection & Design for 500 HP Fuel System

[Indycars]

IVE ALWAYS PREFERRED THE LARGER AN#8 fuel line size

Did you use aluminum or steel fuel line ???

Do you have a source for 1/2" steel fuel line, all I can find is aluminum in 1/2" ???

 

[grumpyvette]

I used the flex line with braided stainless weave in my last race car , I had the line professionally fabricated and ran it thru STEEL tubing for mechanical protection , this required very careful measurement and sliding the protective tubing over the flex tubing before the ends on the flex tubing were fabricated by the local hydraulic supply shop, check with the local professional hydraulic supply

viewtopic.php?f=55&t=4381

 

[bytor]

my current EFI 383 has a walpro 255 that provides 40 psi but uses 3/8" lines , and it will supply the required fuel to maintain about 500 hp.

What EFI setup are you running?

 

[grumpyvette]

viewtopic.php?f=32&t=430

 

[Indycars]

Filter Selection and Mounting Episode:


I've been looking at filters that could be used in my 500 HP fuel system. From what I've
read, it’s standard practice to have two filters. The first filter is a "pre-filter"
goes between the fuel tank and pump and should filter out any particles bigger than
100 microns. A Micron is "One Millionth of a Meter". One Micron is .00003937 inches,
so a 100 micron filter should stop anything larger than 0.003937 inches (0.004") or
slightly larger than the thickness of a piece of paper. Notebook paper is normally
about 0.003".

The pre-filter purpose is to stop anything big enough to damage the pump. But it cannot
be very restrictive or it will cause the pump to cavitate, hence the reason for only
filtering down to 100 microns. The filter element is usually a pleated stainless mesh
that can be cleaned and reused. Unlike the main filter that is paper and is just replaced
with a new filter when it becomes too dirty and restrictive.





Like everything in automotive you can pay as much or as little as you want. The
manufactures don’t have any standards that are required of the numbers they
report and they all seem to have a different way of talking about how restrictive
their filters are, such as; flow rates(GPH), flow rate(GPH) @ x psi, good for x HP,
and pressure drop without flow rate. Count your self lucky if you get the pressure
drop across the filter at some flow rate. But even when you do it doesn’t help much
when the others don’t do the same so you can compare apples to apples. In the end
you have to rely on the manufactures name or if you can find someone that has
experience with the product in question.

I plan on installing two filters……one with a 100 micron and one with a 5-10 micron
rating. I’ve narrowed it down to those filters listed below. The 100 micron filter will
be an “Inline” filter and the main filter will be a “Canister” type.



I don’t have room for an inline filter between the pump and carburetor. The TBucket
is too short and there are so many things going on along the frame rails that it will
have to be of the canister type because they are shorter horizontally. Between the
tank and pump I have a vertical drop of 9 inches, here I can use an inline filter and
it will fit very nicely in the area shown in the photo below. After measuring for the
canister filter , I may have to relocate the pump as far as I can to the rear (about 6”),
so I can squeeze in the 10 micron canister filter before the fuel line goes inside the
frame. The canister filter is 3.25” without any fittings, I’m planning on needing
4.5” to 5” total with fittings.




The 9 inch drop will also add some head pressure (0.23 psi) feeding the pump that
most cars don’t have with their gas tanks mounted low in the frame. That’s not a lot
of pressure, but it is a positive pressure and not negative. Also that’s with the tank
nearly empty, with the tank almost full that adds another 12 inches. Along with the
added head pressure, 100 micron free flowing filter and the 1/2 inch line that feeds
the pump, I should never have to worry about cavitation.



http://www.engineeringtoolbox.com/pump- ... d_663.html

p = 0.434 h SG
where
p = pressure (psi)
h = head (ft)
SG = specific gravity [SG for Gasoline ~ 0.72 ]

You can download the Excel file for the the chart below. It has links to Summit for
all the filters:

 

[grumpyvette]

please don,t think this comment is negative, its more of thought designed as a discussion starter on the subject,
now not that it really matters a great deal in this application, but Im rather curious why you ran 3/8" tube 30" inside the frame at that point, I can see the potential for extra fuel line protection in the area from 15" behind the firewall to 15" in front where I usually use the EMT metal tube or a bit of 1" roll bar cage tube, to give a bit extra protection in case the blow proof bell housing fails in a clutch/flywheel failure/explosion, but back that far I don,t see the reason?? and I also don,t see the reason to reduce fuel line size before the fuel rail entrance.
and yes the two quality fuel filter design, is a really good idea. but Id put some though into mount location and easy access, because you'll be replacing them occasionally and if possible access without needing a lift is a good idea.
you might also consider a hidden but fairly accessible fuel line cut-off near the fuel tank, as it makes fuel filter swaps less messy and potentially dangerous from spilled fuel and its also a secondary security measure to make driving your car off without being authorized a far less doe-able deal for thieves

 

[Indycars]

please don,t think this comment is negative, its more of thought designed as a discussion starter on the subject,
now not that it really matters a great deal in this application, but Im rather curious why you ran 3/8" tube 30" inside the frame at that point, I can see the potential for extra fuel line protection in the area from 15" behind the firewall to 15" in front where I usually use the EMT metal tube or a bit of 1" roll bar cage tube, to give a bit extra protection in case the blow proof bell housing fails in a clutch/flywheel failure/explosion, but back that far I don,t see the reason?? and I also don,t see the reason to reduce fuel line size before the fuel rail entrance.
and yes the two quality fuel filter design, is a really good idea. but Id put some though into mount location and easy access, because you'll be replacing them occasionally and if possible access without needing a lift is a good idea.
you might also consider a hidden but fairly accessible fuel line cut-off near the fuel tank, as it makes fuel filter swaps less messy and potentially dangerous from spilled fuel and its also a secondary security measure to make driving your car off without being authorized a far less doe-able deal for thieves

Some great questions Grumpy!

The 3/8" fuel line was run that way 15 years ago, before I even thought about having an engine with enough horsepower to possibly come close to needing a larger 1/2" fuel line. Street rods are not just about going fast, but also about looking great. Keeping the installation of all systems clean and out of sight. Where a race car is all about function over all other priorities.Once you have cut one hole in the frame for entry of fuel line, you have to cut another to exit with. So why not run it the full length ?

To make sure we are all talking about the same components. When you say "I also don,t see the reason to reduce fuel line size before the fuel rail entrance", do you mean the RED components should be 1/2" and the 3/8" is the reduction in size you are pointing out. Or do you mean all the 3/8" from the pump forward until it reaches the carburetor float bowls???

I was planning on 3/8" from the pump forward to the carb. My 1/2" lines would be.....tank to pump and the return line.



I do have plans for a 1/4 turn ball valve for the convenience during filter changes. It's just having to decide where to start and stop a post to the forum. It took me an 1-1/2 - 2 hours to create that last post, with taking the pictures needed, putting comments on the picture, doing research for head pressure calculations, writing the text and getting examples of what 100 microns looks like ....etc .....etc.

 

[grumpyvette]

THANKS FOR THE DARN NICE, and CLEAR FUEL LINE DIAGRAM, THIS IS ONE MORE IMPRESSIVE AND HELPFUL THREAD!

Like I STATED EARLY in THIS THREAD< THIS IS MORE OF A SUGGESTION THAN SOMETHING THATS REQUIRED OR MANDATORY IN THIS CASE, the area I high -lighted (BADLY) in purple is the area ID have also made in 1/2" or AN #8 but its not likely to be overly restrictive ,the area I high lighted in light yellow/orange, near the fuel tank fuel line feed, is where ID stick the fuel cut-off, but if it was my car ID keep it all consistently AN#8 up to the fuel rail, a AN #6 line size will support the current engine but it might be marginal if you significantly up-grade power levels later

 

[Indycars]

The only reason I'm saying it will be 3/8" is that it is already in place. It' s totally
possible that when it comes time to actually install the system, I may find that
it's just easier to remove it. If I do remove the line it will go back as a 1/2" line.
I'm also wondering if I can flare it to 37° while it's still in the frame. If I
can't and I have to remove the 3/8" line, then I will go back with 1/2".

 

[Indycars]

Probably not a big concern for you guys with an OEM fuel cap and vent.....but if you
are starting from scratch like on my TBucket then I've learned there is much more
to consider.

But then again if you have built that record breaking engine for your factory car......
your fuel tank vent may not be keeping up with your fuel system and keeping it from
performing like it should. Go ahead and buy 300 GPH fuel pump for $500, but it
maybe as easy as fixing your fuel tank vent.

If I got you wondering, then tomorrow I hope to explain. BUT until then think about it .......

 

[grumpyvette]

sure sounds like you found out that if the tanks not vented, to allow air to enter to fill the space that fuel leaving the fuel tank left,you can reduce the fuel tanks internal air pressure enough to cause fuel flow issues, you very quickly find you can,t get the fuel pump to suck fuel and prime the pump or continue to pump fuel.
theres plenty of vents that are designed to allow air to flow into a fuel cell but prevent fuel from draining out of the vent in case of a roll over.

thats what they make ROLL OVER VENTS and one direction air vents for

https://www.pegasusautoracing.com/group ... HECKVALVES

http://pitstopusa.com/c-135667-fuel-sys ... vents.html

http://www.bing.com/images/search?q=Fue ... 0663496171

http://www.bing.com/images/search?q=Fue ... 2EA755CB26

 

[Indycars]

I wanted to take a closer look at fuel tank cap I was using and how well it might be venting the tank. Since the engine that I’m putting in the Tbucket now will use nearly twice as much fuel under WOT, then venting could become a problem.

Safety was another concern after looking at the cap I was using. It clearly wouldn’t take much for it to come off, especially in a roll over situation. Not the way I want to leave this world ……slowly in a fire.

FuelTankCap_OldSetup_3327
FillerNeckDimensions_3341

When fuel is leaving the tank, then air must enter, so the tank doesn’t develop a vacuum. This condition would certainly NOT help the fuel pump stay up with demand. Watch the YOUTUBE videos to see how no venting will affect your fuel flow.

http://www.youtube.com/watch?v=ou-i32eM ... re=related
http://www.youtube.com/watch?v=2WJVHtF8GwI


I have three caps in mind that I found, not sure how easy it would be to weld on the cast version of the three caps. The CB Performance cap is already vented, that would certainly make things easier. What ever I use will have to be welded in, to replace what I have now.

http://www.cbperformance.com/catalog.asp?ProductID=1268
CB Performance_FlipTopCap_6522


http://www.meziere.com/ps-136-120-pn6500.aspx
http://www.summitracing.com/parts/mez-pn6500
Mesiere6500N_Cap&Specs


http://www.speedwaymotors.com/Weld-On-A ... 34154.html
SpeedwayMotorsFillCap&Neck_91076409_L


Roll over vents are made in a couple of sizes. Can’t remember where now, but I read the the vent line should be the same size as the inlet line to the pump. So I will probably go with a -8 AN valve.

http://www.speedwaymotors.com/tip-valve ... 8,451.html
SpeedwayMotores_RollOverVent_458364_R


http://www.summitracing.com/parts/mrf-mp-3125
MagnaFuel_MP-3125_w


Since I don’t want dirt getting into the fuel system, I will run a line somewhere and put a valve cover breather on the end.

http://www.summitracing.com/parts/vpe-2166
Filter_VPE-2166


If I locate the vent valve as shown, should I be concerned about how I route the vent line ???

VentValveLocation_3331

 

[Indycars]

At this point I'm ready to put some prices on each component of the system that will
be needed to supply 500 HP. The only components not priced are the AN Fittings and
that can't be determined until each piece is known in detail. So to compensate I made
my best educated guess as to how much at $100.

It's no surprise that when I selected only premium parts the cost was way over my
budgeted goal of $500. Knowing ahead of time that the cost would be over budget
I did not use the Aeromotive pump with the nicer ORB connections in System #1,
since that would have been another $52 for a total price of $786.35 dollars
(734.35+52) for System #1.

In system #2, 3 items changed ( Underlined in Table)….. Pump, Pre-Filter and Post-Filter,
reducing the price by $128 to $606.35.

At this point I will have to accept some No Name and questionable products, to
even come close to the goal of $500 or I could eliminate some components like the
"Pre-Filter and the "30 amp Relay & Wiring". The pumps usually draw less that 5 amps,
so just a switch is a possibility, eliminating $22.95 from the total cost.

So I have some choices to make, go over budget or accept a less than desirable fuel system.



NOTE: The column for links will take you to Summit, but this only works if you have “Excel”
or “Open Office” and download my Excel file. If you just clicking on the cell with the links it
will open your browser and go to Summit or if you have to….you can copy and paste the URL.

Open Office is free and can be downloaded at the link below:
http://www.openoffice.org/download/

Download my Excel File below.

.

 

[grumpyvette]

yes! thats exactly why its taken me over 6 years to collect only about 1/2 the components I need to do the CORRECTLY DONE, the big block swap in my personal 1985 corvette, I just don,t have the required cash flow to do it correctly yet and I refuse to do it 1/2 assed.
this is a rather addictive hobby that costs a bit more than anyone with, anything close to a middle class income has available
Ive helped 7-8 guys now do that big block into their C4 corvette swap and every last one lacked a few things that I wanted to do,
now they all ran decent but they all had minor issues ID like to avoid, with some guys the radiator they used was stock and marginal, some guys wanted to use the stock trans or rear differential on others the gauges were not ideal, I want every last thing on my car to be flawless

viewtopic.php?f=32&t=151

viewtopic.php?f=38&t=6


SOMETHING LIKE THIS LOOKS GOOD, BUT Id make a few changes, my 1968 vette had crower injection like this

 

[bytor]

The pumps usually draw less that 5 amps,
so just a switch is a possibility, eliminating $22.95 from the total cost.

I have been thinking about the right way to power an electric fuel pump in my EFI setup. I stumbled across these guys. http://www.racetronix.biz/itemdesc.asp?ic=FPWH-013&eq=&Tp=
They have some neat fuel pump wiring harness for fuel pumps. I find it interesting that they recommend powering the fuel pump directly from the alternator terminal. I wonder how much benefit you would actually get doing it this way?

I would probably assemble my own harness for my C3 based on the same concept. http://www.racetronix.com/RX-G7-FPWHG.html



Factory wiring:
As experienced drivers we all know from observation that there are certain electrical items on our car that when turned on cause the lights to dim, blower motors to slow down and the voltage meter reading on the dash to drop. There are various things that cause this such as battery condition and alternator output but for the most part it is factory wire resistance. In an ideal world car manufacturers would use heavier gauges of wire to reduce resistance in order to prevent voltage drop but that would add much cost, weight and bulk to the harnesses. As a tradeoff car manufacturers try to find a happy medium to satisfy the load requirements for a given circuit in the car without negatively impacting the operation of the device requiring the power at the end of the circuit. The C4's factory fuel pump power circuit was designed to provide power for the light current demands of a factory pump. Typically this circuit is comprised of 16 gauge wiring. Current demands can more than double when a high-performance fuel pump is installed. If we take a step back to high school physics, Ohm's law tells us that when we double the current flowing through a circuit with a fixed resistance the voltage loss across that circuit doubles. The power loss is quadrupled across this circuit which is given off as heat (wasted energy) which can cause electrical contacts (connectors / relays) to heat up and eventually fail. Starving a pump for voltage will cause it to slow down which escalates current demands even more thereby compounding the problem. For those who did not take physics we can consider this scenario... We all know someone who has a high-power car stereo system with heavy power cables running to the amplifier or someone with off-road driving lights using a dedicated circuit with relays. We know what would happen if these amplifiers and lights were hooked up to the same factory circuits which supply the the factory stereo or headlamps! So we pose the question 'how is a high-performance fuel pump any different?' Installing an external fuel pump requires a dedicated power circuit. Just because the factory wiring to your pump is convenient think twice about cramming a 20 amp fuse in panel and consider what you are doing!



The harness:

The factory circuit which supplies the pump is much longer and more complex than many people realize. The circuit looks something like this. Pump connector > in-tank bulkhead connector > external tank connector > relay > fuse box > steering column ignition switch > fusible link > starter solenoid > battery > alternator. Some of these circuits which the fuel pump sources its power from are shared which can compound the voltage drop problems.

The Racetronix harness bypasses the entire factory circuit path to provide maximum voltage at all times to your pump. The Racetronix harness uses heavy 10 gauge copper wire to reduce voltage-drop to very low levels so as not to impact pump performance. Our power feed comes off the back of the alternator where voltage is highest. The voltage at the alternator's output is typically 0.5-1.5 volts higher than at the battery voltage depending on the charge current. It then runs through a weatherproof fuse holder and then to the back of the car. The Racetronix harness has connectors which plug inline with the factory harness at the back of the tank. No cutting or splicing is required. High-quality weatherproof fuse holders and relays are used for maximum reliability. The Racetronix harness has a redundant ground upgrade as it is necessary to improve the harness on the negative side of the pump's supply as well. The only function the factory harness serves is to trigger the relay in the Racetronix harness (0.1 amps) and to supply the level sender signal to your dashboard fuel gauge. If the need should arise the Racetronix harness can be unplugged in a matter of minutes. Some people even use this feature to disable the vehicle and prevent theft by C4 savvy joy riders. All current series II Racetronix harnesses are equipped with a 30 amp intermediate power connector just after the relay. This connector allows any aftermarket pump booster (MSD / KB / BW) to simply plug into the Racetronix harness. Adding a pump booster (voltage amplifier) can increase pump output volume by as much as 35-40% when run at apx. 16.5 volts (pressure dependent). An extra connector set is included to be installed on the pump booster's power leads making it a plug & play interface.

 

[Indycars]

I want every last thing on my car to be flawless

I hear you and I try to keep my work flawless, it's the one thing I CAN AFFORD. But decisions have to be made.

My purpose for this thread was to document the process of setting some goals, researching the needs of 500 HP fuel system and selecting the components that will do the job. The goals can be revised, but I had to start somewhere.

I believe system #2 provides a quality fuel system that will perform and be reliable. But to go much below this would mean comprising the system.

Grumpy,
I'm interested to see if there are any changes you would make. What components would you change?

 

[Indycars]

I find it interesting that they recommend powering the fuel pump directly from the alternator terminal. I wonder how much benefit you would actually get doing it this way?

The more voltage you can get to the pump does make a difference. I found this on the Aeromotive website. I zoomed in 400% on the image to measure and get the numbers you see.

http://aeromotiveinc.com/products-page/ ... fuel-pump/


,

 

[grumpyvette]

system #2 looks good but Id swap to one of these cut off valves, it should work fine and save a few buck$, Ive used them in the past
cut off valve
http://www.harborfreight.com/1-2-half-i ... 66231.html
or
http://www.harborfreight.com/3-4-quarte ... 66233.html

your lucky here because you would have a hard time selecting components or designing a system that won,t work reasonably well as long as you use at l;east AN#6 and preferably AN#8 lines and a decent pump and fuel pressure regulator, the only reason I keep stressing AN#8 is Ive had several cars built with AN#6 lines that ran decent and made 450-550hp, that ran even better and smoother once we upgraded to AN#8 lines and fittings , so if I expect to make near 500 hp I just avoid the issue by using AN#8

viewtopic.php?f=55&t=211

 

[grumpyvette]

A few more detailed, pictures of what your doing as you progress with the fuel system instal or upgrades, would be great if your making any progress, on the car?
darn! I wish you (Indycars) and (DORIANL) , and several other members were all located within the immediate local area, theres so many times Id like to drop over and help out!

 

[Indycars]

A few more detailed, pictures of what your doing as you progress with the fuel system instal or upgrades, would be great if your making any progress, on the car?

My main focus is the trans, but when I get held up for any reason, the fuel system is what I will do to stay busy. But at some point I will need the body and engine in place to move forward.


darn! I wish you (Indycars) and (DORIANL) , and several other members were all located within the immediate local area, theres so many times Id like to drop over and help out!

We need a retirement village with central shop with every tool possible available, with a Summit and Jegs warehouse just down the road for quick access to all the HP parts we need. Also they will give us a key in case we need something on Sunday or at 2 am in the morning.

Anything else you guys think we would need???