rufretic

iTrader: (37)

First off, I'm trying to keep cost down or I would just go to a Big Stuff computer.

Right now I have dual inline 255 walbros with I believe -8s to a Y into the stock feed line. Feed goes to my drivers side rail, then to the passanger rail. Then I have an aeromtive presure regulater at the end of the rail and then back to the stock vent line as a return. I have 80lb injectors maxed at 114% at only 800rwhp. These injectors should be good for more than that I thought. I'm running 112 octane.

Is it possible my stock feed is holding them back? Could my fuel system be enough if I just upgrade the feed line(what size?) and then use the stock feed as the return?

Another topic, but is meth a good option rather than upgrading the fuel system?

Old Geezer

iTrader: (3)

What is your fp when the duty cycle goes high??
FPR boost referenced?

rufretic

iTrader: (37)

I'm not sure on the fp at wot.
Yes, the FPR is boost referenced.

highpockets

iTrader: (22)

I found on mine a large,twin nozzle progressive meth system took nearly 15% off my duty cycle at WOT. Course,if it runs out,its gonna be a pretty pile of scrap metal ! And since it only sprays under boost,I kept my part throttle drivability and idle characteristics that the smaller inj gave me.Install the Meth,retune,and verify WOT FP,then see what your DC is.

fknsmshn

iTrader: (1)

You should figure out what your fuel pressure is at the rails first off.

Old Geezer

iTrader: (3)

kinda what I was thinking.....
If the vent is now the return, what are you using to vent the tank???
How do you have the regulator plumbed?

rufretic

iTrader: (37)

It's 58psi, I don't know what it is at wot because I'm not taking it there until I get a few bugs worked out. It's been on the dyno for tuning and that's how I know they are at 114%, my tuner told me. He didn't say if my pressure was dropping or not but I don't beleive it was because one, he would have mentioned it, and two, he wouldn't of made more pulls with it knowing fuel pressure was dropping making it dangerous. Basically, I just need to get the duty cycle down, weather that means upping the pressure to help boost the injectors, changing the injectors or adding meth. I don't like the risk involved with meth, I don't like the $$$$ involved with a new computer and larger injectors or driver box and low imp injectors. So that leaves me with trying to give it more pressure at wot one way or another. I figure I can upgrade the pumps but that's pretty pricey too, for two big pumps. If adding size to the feed line can help then that's my cheepest/easiest thing to try. I don't care to do it if it won't even make a difference though.

One of the lines is open at the top of the tank because only the return is hooked up there, the feed comes from new plumbing at the bottom of the tank, my two pumps are inline, not in tank.
Here's a pick of the regulator:

The feed goes to the passenger rail and then over in the back to the drivers rail, then hits the regulator and then down to the return.

onfire

iTrader: (17)

Save yourself a lot of money and grief and do it the right way first...even if it means running less hp for a while.

Is the regulator plumbed as a rising rate 1:1? Can't tell from the picture. If your base is 58psi, then it should hit 68psi at 10lbs of boost,etc,etc.

If it is plumbed that way and if the fuel pressure is rising 1:1 with boost, it's time to turn the boost down and live with the existing injectors......or buy bigger injectors...anything else is asking for trouble.

Talk to your tuner and make sure of the above.

Killer looking set-up BTW.

MIGHTYMOUSE

iTrader: (59)

verify that you are adding fp with boost

if you are then get the injectors checked or swap with somebody..60's could do better than your 80s are looking

you got a **** ton of money tied up in everything else, spend another 100 bux to get the -8 line up to the front (yes know everybody and there mom uses stock lines these days and makes 1200rwhp i dont care)

while you are in the tank make sure your walbro set up, however that is.. does not have a kink in the hose, a leak, split etc. also make sure the pick up is not too close to the bottom of the tank and starving the pump.

last thing how are the pumps wired? is your alternator healthy?
i have dedicated relays and dedicated grounds directly to my pumps to make sure they get plenty of good juice.

rufretic

iTrader: (37)

Thank you, and thanks for the help once again. I do think it's set-up the way your saying, it is deffinetly boost refferenced. I am bringing the boost down, but I'm not sure how much. It was at 26psi with an open F2. Now I'm adding a 90 elbow and air filter. I'm not sure how much that will drop it but I'm hoping at least 3-5psi. I'd like to be around 20psi. If it is still too high, then I'm forced to start changing pulleys. I'm not sure why my boost is so high in the first place, 402 and nothing is restrictive and I'm not even close to spinning this F2 at it's max impeller speed. The only thing I can think of is the stock 317 heads I have on it, I bet when I change to some better flowing 6 bolt heads my boost will go down and power up but I just can't afford them yet.

I do realy need to talk to my tuner to see what my best option is but he told my less boost too

Good info MM. The fuel system is boost refferenced. I think the 80s are ok, they where brand new from speed when I swaped from my 60s and put it on the dyno for the tune. I think my numbers are messed up because of the loose converter that was in it. It was a N/A Vig 4000 and it was flashing to 6300rpms lol. I'm pretty sure I was just blowing through it and not getting a true rwhp reading. I'm in the process of swapping that for a super tight Chance converter thanks to onfire So once that's in and the new filter set-up is on, I think it's time to go see what it's doing on the dyno again. Once we know exactly how much fuel I'm going to need, then it's time to start figuring out if I need to upgrade the whole fuel system. For right now, I thought it might just be worth it to change to a bigger feed line to see if that helps and I can get away with things the way they are so I can go track test it. If fuel is still a concern after my next tune session, then no track for me this year

qqwqeqwrqwqtq

Agree with all of the above.

Right now it is at 72psi base pressure, boost referenced regulator, 26+psi boost.

My suggestion was to pulley it down, especially considering the production heads.

Elbow/filter will not signifigantly reduce boost unless it's horribly inefficient/undersized.

onfire

iTrader: (17)

Right now it is at 72psi base pressure, boost referenced regulator, 26+psi boost.

My suggestion was to pulley it down, especially considering the production heads.

Elbow/filter will not signifigantly reduce boost unless it's horribly inefficient/undersized.

Ding,ding,ding....we have a winner.

If Jim is your tuner, you have the best. He'll guide/tune you to super power safely.

Forget the filter....Pulley it down, add the Chance and then let Jim tune it. The 800rwhp means nothing really if your old converter flashed to 6300. It's possible that you could make +800rwhp with a good converter and lower boost with your existing fuel system.

rufretic

iTrader: (37)

I guess it's time to start pulley shopping. Thanks guys.

Thyme_CA

iTrader: (2)

Just a thought, is the regulator doing it's job with the higher boost.

I've seen AEM regulators stop increasing pressure after 19psi...

rufretic

iTrader: (37)

It's possible but I think the idea Jim and onfire are trying to get across is that I don't need 26psi lol. So the best route is just lower the boost a little and I'll be fine.

Thyme_CA

iTrader: (2)

Pffftt Lower the boost.... what kind of attitude is that !?

rufretic

iTrader: (37)

The kind that saves your brand new engine until you can put on some nice strong 6-bolt heads instead of stock heads Once everything is built to handle the higher boost, then it's not hard to swap the pulley back on and up the boost.

BigRich954RR

iTrader: (1)

LOL So True What Injector are you running? at what Psi is it 80lbs?

Thyme_CA

iTrader: (2)

That sounds logical...

Not my style, but to each their own.

rufretic

iTrader: (37)

Yeah, it wasn't mine either but then I blew my engine trying to run 9s with the stock block and stock 4l60e, got damn close to with a 10.1. But now I have a **** ton of money invested and I'm not about to blow it getting too cocky with the boost. If I was rich I'd say **** it but I'm not so if I blow this engine I'm stuck with no boost and no fun and for a long time. I'll be just fine with 20psi. I'm not looking to break records, I just want a consistent 9 second car and a lot of people are running a lot faster than that with a lot less boost than I'm making. So what's the point? To say I run more boost than you? Not worth it.