CamminC5

I can't think of any, but I'm not a pro on these cars, and there was obviously a reason GM stopped installing the systems. If I have plans to upgrade the motor/blower later wouldn't it be wise to fo ahead with a beefed up fuel system, and only make the upgrade once??

Thanks

TT Z06

be sure to put a check valve in it to keep the system pressurized when turned off. If not it makes for a 2 start to get it running.

robert miller

But even if you do put the check valve in the fuel line it will still let the pressure go down. But with it in the line it does start better. Robert

HP_Addict

no good reason not to have a return system. GM probably removed it to save cost.

M_T_0

the reason I was given was that the c5 fuel line runs up the tunnel just above the exhaust and the return fuel was heating up the fuel in the tank. but cost is a good suspect.

CamminC5

I don't think that will be much of an issue. I crank the car as soon as the fuel system is primed by habit.

I called a few reputable shops this afternoon and the only con to a return system is the debate of the fuel heating up by cycling through the system, but I don't see this being an problem to worry about. The heat created would be trivial.

Maybe the night crew will chime in with some argument.

Thanks for all your input so far.

Turbo-Geist

Answer 1: If you don't want to make any more power, chase fueling issues, and throw money and parts at the issue, then by all means stick with the return style system. You may even get to join the blown engine club if you try hard enough.

That's probably not the answer you want. I'll try to explain it from my understanding.

Why did gm go to the return style system?

This works great from an N/A standpoint. Now add some pressure to the intake manifold (FI).

Concept: **Fuel Pump Output Pressure - boost level = fuel rail pressure**

In a returnless style system the regulator is near the tank and knows nothing about pressure at the rail. So 58psi (at the pump) - 10 psi (boost) = 48 psi (at the injector)

This works ok for a while because 60# injectors are rated at 43.5 psi and you've got 48 psi so they are acting like 66# injectors. Then you want more power and eventually the loss in pressure at the rail combined with the fact that the pump can't keep up shows up as limited fuel volume and a lean condition.

What happens next?

However, your fuel system is really strained now and your injectors don't have the pressure they need.

HINT: Return style system is needed.

Turbo-Geist

I provided some data in the other thread. I tried all kinds of things short of going to twin 255's. I didn't have consistent, reliable A/F's until I went to a return style system with a 1:1 boost referenced regulator at the fuel rail.

I will say that a meth kit is a must if you are looking to make good power on pump gas.

0Will at RSI

All systems are essentially return style. The difference is whether or not the fuel is being returned before or after the rail. In a typical "Non Return" system the pressure regulator is in the tank between the pump and the rail like a C6. In a performance style return system the fuel is being returned after the rails.

FRCTony

The big advantage to the return style is on boosted setups, because with a boost referenced regulator you can keep pressure consistent which in turn makes tuning easier.

As long as you are using the fuel (i.e. system is matched to requirements), I don't think heating of the fuel would be a problem.

396375

Just do it.

CamminC5

Thanks for the input guys.

Turbo-Geist you gave more than enough evidence to justify the return after the rail system. I'm just looking for more input before pulling the trigger.

So far it's looking good for the return after the rail system, but the system I'm most interested in is out of stock for a few weeks. More time to do research...

Milan

You can add a FPR and a return line pretty easily without having to go a full blown fuel system, depends on how much $$ you want to spend I guess

CamminC5

I've tossed that idea around, but would like to only do this once.

Two quotes I've read this week "This isn't an investment. It's a hobby", and "The bitterness of poor quailty remains long after the sweetness of low price is forgotten."

4SFED Z

Could you please elaborate? thanks

Slow Z06

Hey CHad, Terry got yours finished up yet?

4SFED Z

No fuel pressure issues, Im not happy. Call me to discuss

Milan

Our returnless system isn't really returnless, the return is just in the back of the car closer to the fuel pump. In 99+ cars the FPR is part of the fuel filter. As you can imagine that's not the best place for it.

So what you can do is get an aftermarket FPR and place it AFTER the rails, meaning all the rails are fed with fuel before the regulator gets a chance to regulate FP. Then from the regulator you can run your own line (-6 AN works) back to the back of the car and connect it to the factory return line that was originally going into the fuel filter/FPR.

You would then buy a fuel filter from a 97-98 Corvette and replace the one you took off and call it a day.

Its Bruce

1. FPR on the stock rails (driver's side port)
2. Run return line
3. Purchase '97-'98 fuel pressure filter
4. Tie return line into leftover line on backside of filter
5. Retune for boost referenced systems

CamminC5

Ok. What aftermarket fuel system are you guys using? What do you recommend?

I'm not interested in using the stock fuel system because I only want to do this once, and plan on making more power down the road.

Thanks