fuel line size upgrade lesson learned

[belsie]

Why not use the vent line as the return since it is larger and somewhat convenient?? Then switch hoses at sending unit bringing larger vent line to return post and use old return line for whatever venting is necessary? Should be able to use safe double clamping method on engine end of conversion from reg. to vent line on top of frame since pressure is less on return.

 

[TurboTnZ06]

its not the reg, its the return, we usually upgrade the feed line and use the stock feed as the return, problem solved and both get an upgrade
Mike

I never tested to find out, I had an accufab adjustable regulator, that sucker had a tiny outlet dia. I was told by others that it needed to be drilled out in order to work with a serious pump. I ran everything new and bigger so I wouldn't have to worry about not having enough fuel.

 

[belsie]

this ^, I agree and its what i do when you dont want to spring big bucks for fuel lines

When doing it this way what do you do with filter area on old feed line? Do you run the new feed line in same area or relocate? Any pics or drawings would be great.........

 

[pacecarta]

flip the filter around,
run the new basically following the old feed line , from tank area above axle between frame and body , i put the new AN inline filter by the trans crossmeber and run the new feed line above the prop valve and above the motor mount

 

[pacecarta]

Why not use the vent line as the return since it is larger and somewhat convenient?? Then switch hoses at sending unit bringing larger vent line to return post and use old return line for whatever venting is necessary? Should be able to use safe double clamping method on engine end of conversion from reg. to vent line on top of frame since pressure is less on return.

the vent line is bigger and would help but i usually find they are rusty inside and sometimes clogged

 

[belsie]

Finding a clean G-Body V-6 carburated feed line could work also and would be 1 piece front frame to tank, I would think

 

[Mike T]

i tested an aero 340 on a double pump setup and found that it wasnt delivering 340lph and fell much shorter than expected at operating pressure with only 1/2 gallon per minute at 70psi which is only about 120lph and that was on AN lines .. so much for their claims . with that output you wont have issues with idle fuel pressure on stock lines but you wont be running high hp on it either
changed to twin reds pumps and saw 1 gallon per minute per pump or around 240lph at 70psi

Now I'm questioning the output of my 340 as a possible reason as to why my static pressure is fine. I have never measured actual flow but I do have a little dyno info.
Using the following info is there a formula that will give us a rough estimate of lph?



Dyno info
93 pump gas
Peak HP 443
43 base FP
22 psi BP
60's @ 92.7 DC
10.27:1 AFR

 

[NY_GN]

All right, stand down everyone. I installed the new -6 steel braided return line and was able to dial in FP at 42.

Mission accomplished, time for a beer!

 

[pacecarta]

Now I'm questioning the output of my 340 as a possible reason as to why my static pressure is fine. I have never measured actual flow but I do have a little dyno info.
Using the following info is there a formula that will give us a rough estimate of lph?



Dyno info
93 pump gas
Peak HP 443
43 base FP
22 psi BP
60's @ 92.7 DC
10.27:1 AFR

the info you need is with the base at 43 and with 22psi boost ...was your fuel pressure 65 psi? , if pressure was lower than you have a delivery issue and would need more injector , but without alky your injectors dont seem too far off but ill also say without alky your target AF of 10.27 is way too rich and mostlikely hurt the Hp

 

[pacecarta]

All right, stand down everyone. I installed the new -6 steel braided return line and was able to dial in FP at 42.

Mission accomplished, time for a beer!

good to hear that you got it working
you should also look that with the vac line on it drops 1/2 psi for every in/hg of vacuum

 

[Mike T]

the info you need is with the base at 43 and with 22psi boost ...was your fuel pressure 65 psi? , if pressure was lower than you would need more injector , but without alky your injectors dont seem too far off but ill also say without alky your target AF of 10.27 is way too rich

The dyno was pump gas only but I do need to get an alcohol kit. At 20 psi BP the mechanical (no logging) FP gauge usually reads low 60's. I was not in the car on the dyno run but I would assume since I'm getting the 1 to 1 rise it would have been right at 65 psi @ 22-23 psi BP. I'm running SD and I think the rich condition may have been due to the IATS being in the wrong location.

 

[Mike T]

All right, stand down everyone. I installed the new -6 steel braided return line and was able to dial in FP at 42.

Mission accomplished, time for a beer!

I know you are probably sick of messing with fuel lines by now but since you have the old return out you should try blowing compressed air through the hard line and the rubber lines to see if there was another restriction compounding your problem.

 

[TRICKSIXPA]

All right, stand down everyone. I installed the new -6 steel braided return line and was able to dial in FP at 42.

Mission accomplished, time for a beer!

Post some Pictures!! Then have a beer.
The question I have is, if you run a new line all the way to the sending unit how do you get the line to hook up to the tube, for us that has a sending unit with non -AN fitting on it. -6AN which is basically a 3/8" hose how to get it to fit on to a 1/4" tube??
Once its on is that gonna cause a restriction? For any of you that have the Racetronix -AN sending unit did they make the tubes larger going into the tank or just weld on the fittings to a regular unit?

 

[pacecarta]

the restriction of the tube on the hanger really isnt a big deal ,the an line gets rid of most of the restriction
i used a rubber hose and a hose barb adapter fitting to 6an from frozenboost.com , similar fitting can be had for transmission coolers with hose barb to 6an

https://www.frozenboost.com/stainle....html?osCsid=c18c1f8df575826da5a889245181780b

also got the ptfe lines and hose fittings from them as well as a -8 hoe barb fitting for the feed ,

 

[NY_GN]

I know you are probably sick of messing with fuel lines by now but since you have the old return out you should try blowing compressed air through the hard line and the rubber lines to see if there was another restriction compounding your problem.

I blew compressed air through it when I changed the pump and it was grimey. I got what looked like instant coffee out of it. The tank is pretty clean. Stock lines just didn't flow enough for the new pump.

 

[NY_GN]

Post some Pictures!! Then have a beer.
The question I have is, if you run a new line all the way to the sending unit how do you get the line to hook up to the tube, for us that has a sending unit with non -AN fitting on it. -6AN which is basically a 3/8" hose how to get it to fit on to a 1/4" tube??
Once its on is that gonna cause a restriction? For any of you that have the Racetronix -AN sending unit did they make the tubes larger going into the tank or just weld on the fittings to a regular unit?

When I changed the pump, I cut the bulbed end to widen the tube on the sending unit for the return line(saw it on a post on here). I put on new larger hoses, which made it easy to transition to the braided lines last night. I'll post the pics when I get a chance; YOU KNOW HOW HARD IT WAS TO GET ALL THAT GRIME OFF?%*$@

 

[TRICKSIXPA]

I got my fittings today got to button up the bottom line by the frame rail then I'll see if my $20 fix works.

 

[TRICKSIXPA]

Just an Update after removing the saginaw fitting down at the frame with the return line my pressure is dropping to 40 at idle and bouncing to 50 psi's
Im gonna be upgrading my return line to -6AN all the way back to the sending unit. I believe with all the bends and curves that the 1/4 OEM return line does while going around the frame it is too much for the fuel to get back to the gas tank as quickly as it is being pumped out.

 

[NY_GN]

Just an Update after removing the saginaw fitting down at the frame with the return line my pressure is dropping to 40 at idle and bouncing to 50 psi's
Im gonna be upgrading my return line to -6AN all the way back to the sending unit. I believe with all the bends and curves that the 1/4 OEM return line does while going around the frame it is too much for the fuel to get back to the gas tank as quickly as it is being pumped out.

I'll be honest, I left the old return line in place and anchored the new line to it, but once I got to the axel I went up an over with the hotwire kit on the drivers side rear and ran to to the sending unit. Went quick. I'll post the others later.

 

[NY_GN]

Just an Update after removing the saginaw fitting down at the frame with the return line my pressure is dropping to 40 at idle and bouncing to 50 psi's
Im gonna be upgrading my return line to -6AN all the way back to the sending unit. I believe with all the bends and curves that the 1/4 OEM return line does while going around the frame it is too much for the fuel to get back to the gas tank as quickly as it is being pumped out.

-6 is the way to go and steel braided lines look good.