-6an vs -8an, ready...Fight! (formerly "this will provide 1000whp correct?")
#1
TECH Apprentice
Thread Starter
iTrader: (5)
Join Date: Oct 2008
Location: Cary, NC
Posts: 333
Likes: 0
Received 0 Likes
on
0 Posts
-6an vs -8an, ready...Fight! (formerly "this will provide 1000whp correct?")
dual walbro 255s each with -6an line y-blocked into a single -6an, then up to the front, -6 crossover, aem fpr to stock feed as the return.
alot of what i have read says -6 is too small and get -8. i have heard from a couple reputable people that -6 line will support 1200 whp. its about the pressure not the line size, larger line was used to reduce pressure loss between the pump and the carburator since they are only running a couple psi. now a days we can over come the couple psi pressure loss by running the extra psi.
alot of what i have read says -6 is too small and get -8. i have heard from a couple reputable people that -6 line will support 1200 whp. its about the pressure not the line size, larger line was used to reduce pressure loss between the pump and the carburator since they are only running a couple psi. now a days we can over come the couple psi pressure loss by running the extra psi.
Last edited by IKnowtheFuture; 02-08-2012 at 11:21 AM.
#2
TECH Enthusiast
iTrader: (4)
Join Date: May 2006
Location: Metro Detroit
Posts: 589
Likes: 0
Received 0 Likes
on
0 Posts
What transmission? thats cutting it close, I ran out of fuel on a 255 walbro at 519rwhp, so in theory, 2 pumps may be able to support 1000. But why not run -8 instead of -6? its only like a $15 dollar difference in materials
Trending Topics
#8
! hope this will help you with your set up
http://www.supramania.com/forums/sho...ed-setup/page4
#10
FormerVendor
I personally see no problem with the -6 line at 1k rwhp. We've used the stock feed line on a few cars at well over 1000rwhp and running mid/low 8's in the 1/4.
#11
TECH Apprentice
Thread Starter
iTrader: (5)
Join Date: Oct 2008
Location: Cary, NC
Posts: 333
Likes: 0
Received 0 Likes
on
0 Posts
"some people have it stuck in their heads that they must increase their line size when making big HP numbers like a thousand or more. A #6 AN line can easily support 2000 HP as long as you have enough pump head !!!"
http://forums.corvetteforum.com/c4-f...line-size.html
http://forums.corvetteforum.com/c4-f...line-size.html
#12
TECH Apprentice
Thread Starter
iTrader: (5)
Join Date: Oct 2008
Location: Cary, NC
Posts: 333
Likes: 0
Received 0 Likes
on
0 Posts
your saying the -6 is acting as such a large restriction that it will heat the fuel a significant amount, so much so that -8 is necessary?
you don't think the -8 is more susceptible to heat soaking the fuel being a larger surface area.
I am starting to feel like -8 line is like carrying a 5 gal drum of water with you to drink everyday. It's just not necessary.
Anyone else have experience they'd like to share?
you don't think the -8 is more susceptible to heat soaking the fuel being a larger surface area.
I am starting to feel like -8 line is like carrying a 5 gal drum of water with you to drink everyday. It's just not necessary.
Anyone else have experience they'd like to share?
#14
over build and never have to replace good parts. i did -12 to my pump, then -10 from the pump to a Y block under the hood, then -8 to each rail, then -8 from each rail to the regulator and -8 from the regulator to the cell. works perfect and will support gobs of power.
#15
9 Second Club
Although that does depend on the dyno. Some do read much higher than others.
If you have so much -6 hose, just run 2 x -6 lines from pumps to rails and a single -6 return.
Job done, and no chance of lack of fuel flow ability.
#16
TECH Apprentice
Thread Starter
iTrader: (5)
Join Date: Oct 2008
Location: Cary, NC
Posts: 333
Likes: 0
Received 0 Likes
on
0 Posts
I am running stock feed and a -6 return. will anything bad possibly happen if the line is too small? I'm assuming the fuel pressure will drop a noticeable amount. I've never personally had a car with too small line so this is new to me. If it's not going to pop my motor I might run it and see.
I am only going to make around 800whp (+/- 100) for a while, but I've heard and was wondering about the 1000whp with -6.
I am only going to make around 800whp (+/- 100) for a while, but I've heard and was wondering about the 1000whp with -6.
#17
I run -10's to the twin A1000'S. The second pump is on a hobbs switch and also has a one way check valve after the pump and filter. From there both pumps connect to a Y block and a single -10 line to the firewall where it meets another Y block. I then run -8 to each rail and a -8 return line back to the trunk. I am running E85 which is a bit different but I am still worried I should have -12 lines. I am only 600rwhp right now but plan to be 800 to the wheels when all is done. I personally would not run -6.
#18
TECH Enthusiast
iTrader: (13)
Join Date: Nov 2005
Location: Pittsburgh PA
Posts: 665
Likes: 0
Received 0 Likes
on
0 Posts
your saying the -6 is acting as such a large restriction that it will heat the fuel a significant amount, so much so that -8 is necessary?
you don't think the -8 is more susceptible to heat soaking the fuel being a larger surface area.
you don't think the -8 is more susceptible to heat soaking the fuel being a larger surface area.
Like on carbs, they run lower pressure and larger lines to get the volume rate or mass rate of fuel required. Carb pump at low pressure may support 800 hp lets say, but at higher EFI pressures it may only be good for 600. Look at the charts Aeromotive gives for instance. Higher pressures cause less lbs/hr of flow = less hp potential.
That said, i have dual walbros for now. -6 feeding a Y into -8 supply to -6 return. ~700 whp so far pump gas only thru 5000+ stall Th400 on stingy mustang dyno. Plenty left in it, I think it will easily do 1000whp. Only 48psi base pressure and 15-18 psi boost on old setup and the new setup is much much nastier so it should push the fuel system.
#19
TECH Apprentice
Thread Starter
iTrader: (5)
Join Date: Oct 2008
Location: Cary, NC
Posts: 333
Likes: 0
Received 0 Likes
on
0 Posts
correct me if i'm wrong: say the -6 adds an extra 3 psi resistance over -8. If you have a base fuel pressure with -8an @48 psi and you turn up the fuel pressure to 51 psi, isnt that the same as having -6an in the sense of working the pump harder and heating the fuel more? and for that matter, if a base pressure is at 48 psi with -6 ("45" with -8) wouldn't I be working the pump alot less than at 58psi, so it would solve the problem of heating the fuel.
#20
TECH Enthusiast
iTrader: (13)
Join Date: Nov 2005
Location: Pittsburgh PA
Posts: 665
Likes: 0
Received 0 Likes
on
0 Posts
Not 100% sure on that but its not only pressure related, but volume flow or mass flow related as far as speed delivered.
I took this from another forum.
The fine balance is pump flow rate in gallons/hr or liters/hr vs pressure. If you need 90 gpm of fuel, you may need more pressure to deliver that flow fast enough for the motor to handle without having pressure loss in the system. But as you increase pressure more and more, the flow rate drops say 75 gpm. Now you may not have enough fuel period to produce the power you are at.
I took this from another forum.
Let's talk about the most popular fuel pump out there, The Holley Black Pump. The pump free flows 140 gallons of fuel per hour. We will look at the psi of the pump and relate it to velocity or feet per second. That Holley flows 140 gallons per hour free flow with no outlet line. When the proper outlet line is on the pump it flows 120 gallons per hour at 9psi and 90 gallons per hour at 14psi.
There have been cases where guys will run a -10AN feed line between the regulator and pump and will only have 9psi line pressure coming up the car which should be excellent as they are flowing more gallons per hour. The problem is it can't keep up with that gallon per hour flow because it can't deliver that volume fast enough (velocity or feet per second). With the proper line it will flow 90 gallons per hour at 14psi but will maintain this because it can deliver the flow fast enough at that pressure to hold both flow and psi. The same system with too small of a line will hit too much pressure before it can establish flow and choke. So when you speed it up (psi) you do deliver more fuel even though the flow is less, but you can speed it up too fast to where it kills the flow. It is a fine balance
There have been cases where guys will run a -10AN feed line between the regulator and pump and will only have 9psi line pressure coming up the car which should be excellent as they are flowing more gallons per hour. The problem is it can't keep up with that gallon per hour flow because it can't deliver that volume fast enough (velocity or feet per second). With the proper line it will flow 90 gallons per hour at 14psi but will maintain this because it can deliver the flow fast enough at that pressure to hold both flow and psi. The same system with too small of a line will hit too much pressure before it can establish flow and choke. So when you speed it up (psi) you do deliver more fuel even though the flow is less, but you can speed it up too fast to where it kills the flow. It is a fine balance