E85 and upgrading both feed & return lines--???

J

jmendlik

Active Member
Joined
Oct 1, 2001
Long story short---

Purchased the Racetronix DP set up with upgrade option to the Aeromtive 340 pumps (wanted to be the last set of pumps I would have to buy)...It does have the AN fittings on the sender (-8 feed, -6 retrun)

Installed Pumps (second pump on 15 lb hobbs switch) and currently running the stock feed line and filter with a -6 return line (from Erics post : http://www.turbotweak.com/forum/showthread.php?1968-Fuel-Return-Line-mods-for-bigger-pumps here on Turbo Tweak forum) . No issues with being able to control idle fuel pressure.....WOT FP is no issues 1:1 rise with boost...I'm at 21 lbs boost with 66+ lbs fuel pressure...80lb injectors

--66 lbs is measured at the fuel rail with a Caspers fuel pressure transducer on the power logger on the laptop log..



According to Aeromotive-I need to upgrade my feed line to a -10 preferably to handle the flow of both pumps when they are both on.....According to their tech I'm risking the internal pump bypass being activated (100psi setting) by having such a restrictive feedline and could damage the pumps over time...
He said I should but a guage on the line out of the sending unti feed before the filter and see what kind of pressure its at...He thinks Im probably close or over the 100psi bypass of the pump..

any thoughts from the group??


I'm looking into changing the feed line now and was wondering if a -6 feed line would be adequate or do i need to go -8 or even -10???

I can do a -6 feed line (using same 16' line as my return which had the ends pre-installed) with all parts from Jegs pretty economically.....

anyone have simialr issues/concerns/opinions??

Also the tech said that the filter should be changed every 10 hrs of run time on E85...
 
I'm no expert, but maybe the tech doesn't understand your system has a return and a fuel pressure regulator. The pressure in ANY part of the system probably won't be but MAYBE nominally higher than what it is at the regulator. If your return line were the stock size, it's possible that it would run higher. I could be wrong here, but if your idle pressure is 43 line off and 66 at WOT (and the reading is taken at the rail), then the pressure just outside the pump shouldn't be more than about 68-70. Basically, your pressure is regulated by the how far open the regulator is, and the flow capacity of your return line. Your -6 return line can outflow your feed line!!

Did you buy the sender that has the AN fittings on it? If so, the feed is -8 and the return is -6. Since you already have the -6 return, you're halfway there if you're really worried about it. Run a -8 feed from the sender & be done with it. Some of the more knowledgeable guys will likely chime in on this one, but I think that stock feed line supports a hell of a lot of power.

Let us know what you're running at the motor; it will hold the key as to whether your delivery system will keep up.
 
i was recently at PRI show here in Orlando.Most of the vendors seemed knowledgeable and friendly.The exception was the Aeromotive folks ,what a tool the guy was i talked with about e-85.He basically told me i was nuts for running it.
I have a non buick car that runs ONLY e-85 for 10,000 trouble free miles so far and the stainless filter i have on it has never been opened.
I`m converting my T to e-85 soon and will not use ANY of the aeromotive stuff on it.There are other vendors out there that agree e-85 is a good option, i`ll use their parts.
 
Also the tech said that the filter should be changed every 10 hrs of run time on E85...



Really every 10hrs?
 
2GNS4ME said:
Also the tech said that the filter should be changed every 10 hrs of run time on E85...



Really every 10hrs?
Click to expand...
IDK about every ten hours, but it probably wouldn't hurt to check them out after the first ten hours. Sometimes the E-85 can clean some stuff out especially when you're changing out old components. After that I would say once a year.
 
If you will be running both pumps only when under boost, your return line SHOULD be OK. When under boost, most of the fuel should be consumed by motor so return line has little flow. Generally return line will see Max flow at idle since most of pump output has to return to the tank via return line.
Conrad
 
jmendlik said:
Long story short---

Purchased the Racetronix DP set up with upgrade option to the Aeromtive 340 pumps (wanted to be the last set of pumps I would have to buy)...It does have the AN fittings on the sender (-8 feed, -6 retrun)

Installed Pumps (second pump on 15 lb hobbs switch) and currently running the stock feed line and filter with a -6 return line (from Erics post : http://www.turbotweak.com/forum/showthread.php?1968-Fuel-Return-Line-mods-for-bigger-pumps here on Turbo Tweak forum) . No issues with being able to control idle fuel pressure.....WOT FP is no issues 1:1 rise with boost...I'm at 21 lbs boost with 66+ lbs fuel pressure...80lb injectors

--66 lbs is measured at the fuel rail with a Caspers fuel pressure transducer on the power logger on the laptop log..



According to Aeromotive-I need to upgrade my feed line to a -10 preferably to handle the flow of both pumps when they are both on.....According to their tech I'm risking the internal pump bypass being activated (100psi setting) by having such a restrictive feedline and could damage the pumps over time...
He said I should but a guage on the line out of the sending unti feed before the filter and see what kind of pressure its at...He thinks Im probably close or over the 100psi bypass of the pump..

any thoughts from the group??


I'm looking into changing the feed line now and was wondering if a -6 feed line would be adequate or do i need to go -8 or even -10???

I can do a -6 feed line (using same 16' line as my return which had the ends pre-installed) with all parts from Jegs pretty economically.....

anyone have simialr issues/concerns/opinions??

Also the tech said that the filter should be changed every 10 hrs of run time on E85...
Click to expand...

Teflon -8 feed and -6 return are more than enough if you are using standard braided stuff.
 
I would come off the -8 fuel pump w/ a -8 to -10 fitting then run -10 as the feed and -6 as the return. The cost difference isn't that much if your already running new lines and you will have room to grow when/if you go with larger injectors down the road to feed more power. It never hurts to clean your stainless filters after initial install of the new lines/components... I cleaned mine after 4 hours (found some junk) then again after 2 months (found just a little junk). Now I will probably clean them twice a year ( every 10 hours after the initial install is a bit much IMO!)
 
Leave it alone. You will Max out the injectors before you Max out the amount of fuel you can flow through the stock feed line. Revisit Kevin B's thread on his E-85 stock line Turbo T.
 
I'm not concerned with my return line--I know thats good...

My concern is using these highout put 340 twins thru the factory feed line and having too much restrictions on the pumps --I only monitor FP at the fuel rail and its seems fine --45lbs line off and 1:1 rise with boost....

Aeromotive tech seemed concerened with pump longevity using the stock feed line creating backpressure on the pumps (not seen at the rail but could be seen if I had a guage after the pumps but before the factory filter....

I would like to just duplicated the parts used in my -6 return set up ( 16ft line) and run a -6 feed system with aeromotive 40 Micron filter...

Hmmmmmm -8 or -6 feed--what to do??
 
You have a return style system. You can blast the pumps with 15 volts and only be at 43 psi of fuel pressure. All that will do is send more fuel through the return line. They will not be making over 100 psi before the filter which with your setup is what pressure would be needed to open those bypass valves. Do you remember the Aeromotive guys name because Im going to try and call him so we can "talk". Get off the Summit and Jegs site! Monitor your duty cycle, air fuel ratio, crank the boos and enjoy your car!
 
What gain will be had by using a -10 vs. -8 Teflon line for a DP system which flows apx. 500-650LPH???
Think about it. We are not dealing with 7PSI carb systems here.
Walbro_pump_head-a.jpg
 
-6 will support your HP NOW however I recommend a -8 Teflon feed line for the 2x340DP system.
The DP outlet is -8 and the non-restrictive Saginaw to AN adapter fittings are -8 as well. This will keep things flowing and simple.

-6 is fine for the return.

The only -6 line which would be OK with the 2x340DP is our Goodridge 825-series because it has a larger smooth bore diameter which allows it to flow 20% or more than standard -6 Teflon line.
 
Jack - hurry up and get that complete line kit ready for market!! -8 hose for feed and -6 hose for return. Then we can buy a COMPLETE complete DP setup with pumps, sender with AN fittings, with hoses, connectors to rail, etc. E85 rules!!
 
87-WE2 said:
Jack - hurry up and get that complete line kit ready for market!! -8 hose for feed and -6 hose for return. Then we can buy a COMPLETE complete DP setup with pumps, sender with AN fittings, with hoses, connectors to rail, etc. E85 rules!!
Click to expand...

Very soon. Waiting on inventory from Goodridge and time to polish off kit. Hopefully sometime early in the new year...
 
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