current set up is stock fuel lines to filter - red top facett pump - regulator - weber 45 no return
im running out of fuel at the top of 4th and will be going 48IDA soon so want to run 10mm fuel line and use stock feed as a return via a t from the IDA
question is are you guys using the stock line from the tank to the pump and then 10mm from there?
if not how do i get around this (surge tank?)

thanks
Mark

 

is this a gslse or 12 model? if its a SE then the stock fuel return line is plenty sufficent.

 

we didn't have the GSL-SE FI engines in the UK but everthing else is GSL-SE spec 114 x 4 PCD bigger diff etc
my stock fuel lines are 8mm feed and 6mm return

Mark

 

I run 3/8", supply and return, whatever that is in mm. What are the specs on the facet pump? Have you changed the fuel filter, drained the tank, cleaned it out and pulled fuel pickup unit from the tank, checked the intank filter screen and the pickup tube for restrictions?

 

i had the tank out a little while ago and cleaned it all out the filter was ok, just ordered a new filter pre pump
how did you run 3/8 for both into the tank?

Mark

 

double post

 

i have a facet red top pump 6.0-7.25 psi, flow rate 35 galls/hr, thread 1/4tr nptf.
i am now going 51IDA so need to sort this, running 10mm from the pump forward is not a problem its getting 10mm lines out of the tank, are you guys running a surge tank or stock 8mm to the pump then 10mm after and seeing a increase?
p.s. the 51 has a extended fuel bowl
thanks
Mark

 

Have you tried adjusting your floats? 3/8ths is the largest fuel line size to come in an RX, that being the GSL-SE. Going to that size will flow more fuel... maybe if you up the pressure?

I dunno, its 3:45am here. Time for me to go to bed.

 

My fuel system in my 1982 S2 RX-7 goes

stock fuel pickup, standard 8mm line, through EFI fuel filter, through Carter Gold Lift pump, through more 8mm fuel line, into my EFI hardware surgetank.

The surgetank has a port to bleed back to the main petrol tank
A return port from the engine bay
The fill port from the lift pump
and a 1/2" port to go to the main pump.

I have 1/2" lines without a filter to my 044 , then that drops to 10mm to go all the way to my fuel rail. My fuel rail ends with a 7/16th fitting, fuel returns to surgetank via standard feed lines.

I would suggest similar, get a less agro lift pump than me. Maybe try a pierburg. and 10mm fuel lines should be heaps for anything you ever want to do.

My car is fuel injected but it gives you an idea on what you can do.

Also really a 13B street port shouldn't need that much fuel or a 51mm carby

 

thanks, i'am looking to go Bridge port in in the next 12months and the 51IDA came up at a good price, it was running on a steet port anyway with 4Omm CHOKES, F11 EMULSION TUBES 235 MAIN JETS 120 AIR i may drop the mains to 210 / 220 but it should be ok on a street port
running 3.5psi at the minute
the BPort will need better fuel lines so i may aswell do it now, i have another fuel tank inlet so might just get them to put a 10mm line in that and pull the tank off and swap them over
anyone else done this?

 

I suspect that your 35 gph pump and 1/4" barbs are what's choking the engine of fuel. Bump your pump up to a 72 gph and use 3/8" barbs and you should be good. I don't see any need to install larger hardlines in the tank, the TII lines are the same size as the 12As. The 13B SE's are the oddball with a 7/16" supply.

 

GSL-SE had 5/16" send and return.

3/8" is about 10mm

5/16" is about 8mm

1/4" is about 6mm

 

Jeff, my error on the 7/16" but the the SE supply line is larger than the 12A and the one I parted out had a return line that was the same size as the 12A supply.

 

has anyone heard of the OEM 30 year old fuel line rupturing and causing a fire?

 

Sure, the hardline on the widebody that went down the back side of the bin was leaking where it made contact with the body panel. Since it was between the tank and the pump, it was under suction instead of pressure. Had it been between the pump and the carb, the story might have been different.

 

Thanks Guys, mine is a GSL-SE model (as close as we got in the UK we didn't get the 13B FI they were all 12a but i have rear vented discs etc)
i was on a tunnel run in London last night and had lots of fuel problems, i now don't think its the lines, the car was staling and under fueling randomly i had no or very little pressure with just the ingnition on pump was running so it mush be a blockage, i changed the first filter after the tank the other week and the regualtor filter seemed ok, only other things to check are the pump filter and the one in the tank which you can bet its the one in the tank!

Mark