scidav87

iTrader: (16)

Putting a twin turbo 370 in my 2000 Camaro. Have 80lb injectors and 2 in-tank Walbro 255lph pumps..with the 2nd pump running off a 1 PSI Hobbs switch. Will that be OK to run making UP TO 1000HP?? Or do I NEED a return type fuel system and rebuild it from scratch?? Witch would SUCK!

Nasty N8

iTrader: (33)

Stock returnless is only safe to about 700rwhp. You need a proper return system to keep good control over the pressures and for the extra volume needed. Give me a call I will help you with your setup.

scidav87

iTrader: (16)

Check this out. Wonder if something like that would work...? Use the factory fuel line to feed the rails and using the stock EVAP line as a return along with dual 255lph pumps?? Or would those be too small to support the proper fuel? http://cgi.ebay.com/ebaymotors/LSx-LS1- ... 1606wt_958

Lonnies Performance

iTrader: (16)

There are a lot of things you could get by with, but if you are truely building a 1000rwhp car, why cut corners & risk engine damage?

Personally I would use no less than a -8 supply & a -6 return.
Engines break rather quickly at this power level.

scidav87

iTrader: (16)

1000RWHP seems VERY unlikely with 91 octane. I was just playing it safe. I hear the stock retunless style is good for 700RWHP and if I just put a regulator up front something like this that should make it good for another 100-150HP I would assume. It seems the stock rails are good for around 1000. My concern is just the size of the lines from the factory. What size are they?...3/8 and 5/16 right? Whats the limit on a 3/8 line?

Nasty N8

iTrader: (33)

The problem with the stock line and rails is the regulator is before the rails you need a flow through to feed the rails properly. With the regulator on the return side of things that way it knows instantly when the pressure drops and can adjust for it. Next is the volume of the line 3/8" is just a hair smaller than -6 so you have very little volume in the line for big hits or heat. The more pressure you try and force threw a small line the more heat it will make. Big fan of do it right the first time you won't have to do it again. If the very least you do a new feed line -8 to the rails and use your stock feed line as the return. Leave the EVAP alone its a good system that works.

scidav87

iTrader: (16)

I can just run the -8 from the factory quick disconnect on the pump assembly via an adapter to a regulator on the strut tower and THEN the factory fuel rails and use the factory supply line as the return. Sound good?

BRUTL

iTrader: (27)

Regulator needs to be on the return side buddy. Read the post above yours.

scidav87

iTrader: (16)

Not totally true. We have a car in town that makes 791rwhp with a 78mm turbo on a 370 iron block running E85, which used nearly 30% more fuel than pump gas would...on factory hard lines and using the EVAP as return and with the regulator before rails. That would be the same amount of fuel running nearly 1000rwhp on pump gas. Hence the question. Just wondering how good of an idea it was, like heat, ect.

Lonnies Performance

iTrader: (16)

You can sometimes get away with a lot by using marginal components.
People have done some surprising things with many stock components, but there is always a risk of leanouts, pressure drops etc.

Sitting on a dyno you cannot detect that you are on the ragged edge of fuel delivery. There are no long term measurements as dyno pulls do not last more than a couple seconds.

There are no effects of G-forces on the fuel lines sitting still. The weight of the fuel tries to resist movement under acceleration, loading the pumps even harder, makig it harder to maintain pressure at the engine under acceleration.

For the quantity of stories you hear of what surprisingly works, there is also an alarming number of leanouts, melted pistons & other horror stories. I hear a lot of these stories when people are buying their second (but correct) fuel system. Unfortunately people are les likely to brag on the 'net about their mistakes. Not many will tell the world when they screw up, but everyone is proud of their accomplishments.

My only comment.... Is saving a few hundred dollars worth melting your $10,000 motor?

lowbirdws6

iTrader: (62)

Good info and well put! Thanks

trnsfmr99

iTrader: (1)

thank you all for this info. @ lonnies performance: assuming i have an identical setup as the person that started this thread, except i'm running 60 lb injectors, what fuel pump (or dual fuel pump setup) would u suggest on my part? difference is i'm running a single t76 turbo and also a single walbro 255 fuel pump and my goal is 700 rwhp?

Lonnies Performance

iTrader: (16)

My dual pump setup will easily support your power goals.

You are in need of some line/regulator upgrades at 700rwhp to maintain stable fuel pressure. At minimum, a front mount regulator is suggested.


Please call to discuss in more detail.

stage274

Would this work? I already purchased and 8 an line and 6 an line. But using the stock feed fuel line as a return, is very appealing to me.

I can run an ls2 fuel rail, and hook the return in the stock location, where the fuel would of have feed in prior. Then use the front of the rail to feed the fuel in with the 8 hose?

What do you guys think, it would look so stock. My goal is to be extremely low key. I went to great lengths to make the car sound and have the manners of a stock car.

The car sounds so bone stock, its not even funny, just with a whistle. I am looking to put 800 rwh, which I will achieve with my f1a blower and nitrous.

But otherwise it looks stock. People just don't know what they're looking at. The blower is hidden, my motor looks stock and sounds bone stock. When my motor was stock, I only dynoed 430 rwh, with my p1, when it was stock. People are under the assumption I can't run much more boost, because it was not designed for such at the factory. He he..

All the imort dsm cars in my area want to race me. I have no clue why?

I have this 9.80 car willing to spot my car ten and the bust, cause they don't know what they are looking at.

Even the elect will have a hard time knowing what I am bringing. Cause the car sounds like it did from the factory. I have stock rear exhaust and cats. Which I am not removing, even if it kills a 100 hp. I will spray it to make it up.

People can keep their race car john force set ups. My friends car has an exaust and a tire, other wise this car is really just a bone stoc car. nobody wants to race him.
I mean nobody, but for some reason, all the import guys flock to me. I swear to god they do, and I love it, and all my friends have a good laugh. They go to a daul power adder car, but stay away from a stock car, with an exaust.

I think it is, because my car looks new, extreme low miles, 18s on it, and sounds so stock, it's not even funny.
Current set up, 383, 9.1, ls6 cam, bowl ported 317 heads. Motor dynoed 494 ftlbs, 454 hp, with a rich carb it. Just a test pull after the motor was built.

I know, I could have of squeezed 25 more hp out of it. Regardless it has 7 lbs, and a 125 shot as it sits. Over 600 rwhp. The motor is in its most detuned state, untill I bolt my new f1a on. 15 lbs, and a 125 shot is coming. I can't wiat.

What do you guys think about this, about the feul line that is? Also can just read my fuel pressure off the regulator. Which needs to be hidden. A feul system would give it away. My nitrous on the car is hidden. I spray it after the blower, to cool the charge really.

You think this would work, to use the stock feed line as the return? I don't see why not.

I don't even know, why I spilled the beans about my car. But I think it is so funny, you have people who flock to it, and actually push me, to push me to sit down, while they spot me.

kwrench61

iTrader: (1)

Was told by fuel pump maker to run -10 on supply and -8 return. Mine will be in 800hp range with single 80mm turbo

stage274

I talked to Ractronics and he said a number 8 is all you need. Especially on high pressure systems.

I just want to know if I use the stock primary feul line at a return, if that would work? For instance is there hidden obstacles for doing it this way? Or why I should not do it this way. But it very appealing to me, I get to keep the stock look.

RixTrix

Regulator in the front provides many benefits.

Easy adjustment
Recirculates fuel (cools fuel and injectors)
Recirculates fuel (purges air bubbles)
Easier to boost reference the FPR (so fuel pressure differential is the same no matter what the boost pressure is)

For a second hard line just get a second main fuel line and run it right next to the original.

stage274

I want to know my options.. For instance do I run my 8 line to the fuel rail, and have a return line come off my regulator, back to the tank ? Or have a return line from the fuel rail, and run that back? Or keep the stock type return line from by the back of the tank, upgraded with the 6 an hose?

I am not sure what route I should go. Or I can modify the ls2 feul rail, where I can have the fuel feed in on the front of the rail, where usually we have the fuel gauge sensor hooked up. And then use the primary stock line as a return. Where it hooks up in the stock location...

I am not sure what the best option is?

Majestic9C1

iTrader: (19)

Build twin turbo 1000 WHP engine

skimp on the fuel system..



seems logical