sm0kinvette

Planning to upgrade my fuel system for e85.

going to use the stock intake fuel pump. (not sure if its e85 safe)

I want to use one of the ecs blocks that will allow me to feed an external magnafuel pump and use as fuel return.

I will use a hobbs switch to enable the external pump.

I will somehow hook both the feed from the magnafuel pump to stock fuel feed line somewhere near the fuel rail...

Do I need a fuel pressure regulator that raises with boost (1:1)?

darknit

Most all of my fuel system is from Racetronix; they have a ton of E85 fuel parts...

Dual in-tank 340 pumps, -8an Teflon feed, -6an Teflon return, 3/4" fuel rails, E85 rated boost reference fuel regulator, their dual pump wiring(doesn't use factory undersized wiring) with hobbs switch for 2nd pump, and a bunch of fittings... Lingenfelter in-tank fuel pressure block off adaptors(for external regulator to be able to be set above stock pressure)

Also installed dedicated motorsports flex fuel sensor( a must )...

Running 127lb(1300cc) injectors from fuel injector connection... last dyno was 722rwhp @ 9 psi and E57(tuner didn't fully empty 91 before adding E85)

These pumps are very D.I.Y... You have to modify the factory plastic hanger a bit... Racetronix doesn't send any instructions or pictures... Some cussing involved, but definitely a lot cheaper then say FORE... Dropping C6 fuel tanks is the biggest p.i.t.a. thing to do on these cars and I hope its a lot of years before I have to do it again...

The stock pump is a gamble, might last, might not... I think an external regulator is a good addition... Definitely look into a flex fuel sensor...

C5 Pete

Is this a boost application or NA?

schpenxel

1:1 regulator isn’t going to increase pressure unless you block off the in tank regulator and also (obviously) have to run a return line of some sort

I added a regulator to mine but only because I didn’t want to hit the limit of the stock regulator. I didn’t connect it to a vacuum source and set it just barely below the pressure the stock regulator works at. I put the flex fuel sensor in the return line and it’s worked perfect.

ECS doesn’t add one in their stage 1 and stage 1 E85 systems and they work just fine so I’d go the simpler route if I were doing it over.

If you do block off regulator and use a 1:1 regulator you’ll need to update tune also

Ant-Man

Bootleg that **** and let 'er rip. non-referenced.

schpenxel

Winner

sm0kinvette

Wouldnt it be better to have both feed lines go to the flex fuel sensor and from there to the rails?

Ant-Man

You could do that, but I'm just running e85 right now so it doesn't matter to me, either way fuel is going to run through the entire system and get to the sensor. If I re-do the rails and stuff I'll just have it on the return line like schpenxel.

sm0kinvette

i really like the idea of putting the flex sensor on the return line. seems like it would require less fittings. would you do it before or after the fpr?

Trention

I've been working on a system using a remote fuel tank stored in one of the rear wells. Using a high flow pump to supply the injectors and rely on the Z06 pump to supply the remote tank. Not sure if anyone else has considered this but I, for one, won't be pulling my factory tank again. I would rather cut off an appendage that remove the tank. The location of the rear well is perfect for tying into the factory system. Keep in mind this isn't a new idea, I have a few big boost friends that are successfully using similar systems running relatively small intermediate tanks.

Regards,
DaveT

schpenxel

Yeah it's pretty simple, I did it after.. figured there was next to no pressure there so not much chance of anything leaking

Keep in mind you need to keep some small amount of fuel going through the sensor or it's readings will go all over the place. I learned that one the hard way

darknit

I put the flex fuel sensor on the return side of my fuel system, mostly because my feed is -8an and return is -6an and the flex fuel sensor is closer in size to -6an... it is mounted in between fuel rail and fuel pressure regulator...

darknit

kind of wish i would have known more about this idea previous to building my fuel system... dropping the tanks was one of the worst projects i've ever done and I even have a lift in my garage and already had the drivetrain out... I HATE C6 FUEL TANKS

DOUG @ ECS

I realise that I'm biased, but our system is plug and play, fits right in the back nice and neat. No fuss, bolts right in, done. Wiring harness premade ready to go. The price is reasonable IMHO, lines are premade and pressure tested, not sure I would take the time to reinvent the wheel. The price savings isn't much compared to having it all done for you.

schpenxel

That is probably what I'd do if I were doing it over again. I never added up what I ended up spending on mine (mainly because I didn't want to know )

Whis9

chpmnsws6

Very little. Tons of C6's running around on E85 and the stock pump.

FL08C6Z

hi, I'm looking to add an external fuel pressure regulator and set it a little lower than the stock ls7 in tank regulator. Racetronix is telling me I need to block the in tank. Do you have both regulators operating and is it working ok for you?

schpenxel

Yes, it worked fine for years. I sold the car a year or two ago but it worked fine

It's tricky getting the pressure just right, but it can be done. What I did was set it so there was a little bit of fuel flowing through the return line. My ethanol sensor was in the return line so I needed some fuel flowing through it anyways so it would maintain a decent reading and not go haywire

Would have to know more about the system you're building to make sure it'd work but yeah, I did it for years. Their answer is the "right" one and really the right way to do it but it's not the only way.

FL08C6Z

thanks for the response. My setup is: ECS tank threshold, AEM 400lph pump, joining the stock fuel line by y in the engine compartment, feeding MSD rails, both rails running to a Racetronix fuel pressure regulator, and finally returning to the ECS threshold. My e85 sensor is on the stock line right before the Y; I can move it to the AEM side, OR after the y...

the car is being set up with a stage 4 cam and should be in the 650+ whp range.

Thanks again.