Even the drift 500 horse and the 300 horse boat-racing engines use them.

WopOnTour's suggested multiple times that the fuel system was holding the car back and that they were able to pickup 3 tenths on the drag strip by increasing fuel pump voltage to keep pressure as steady as possible at WOT.

I don't know what data you want me to provide, as I don't have any dyno testing for before or after on any vehicles that have had this conversion.

If you do not understand that a returnless system has higher fuel flow at idle and lower fuel flow at WOT, I don't know how else to convince you. Hell, the fuel enrichment table on the LSJ computer is almost entirely to compensate for the ****-poor fuel system.

 

how bout my 400+hp street driven cobalt.... I need to do something as my fuel system isn't keeping up after 5800 rpm.
Btwn the 144-156% IDCs' and dropping fuel pressure up top, I need to do something asap.

 

^ proof lol

 

thats wonderful. but its still all speculation.
anyone can say anything they want online.

Im not saying the mod isnt a valid modification in some circumstances, and its obviously done quite well.

All im saying, is that there isnt a shred of proof out there justifying its use on a 250-300hp cobalt.

when there is, ill be fully behind it. id love to see that proof.

until then, this has about as much credibility as the "twincharging" idea

 

Subscribed for later readations.

 

Ummm....

I'm not about to argue twincharging with you. As there are valid points both for and against it.

The only arguements against a return-style fuel system have already been presented. Even you yourself, have no points against it.

 

I never said i have any points against it. because I DONT.

i guess i need to say this a THIRD time.

Im not saying its a bad mod, im not saying it isnt valid in some cases.
im saying NO ONE HAS A SHRED OF PROOF THAT IT HELPS A 250HP COBALT AT ALL.

read it again....please.....ive tried to explain it 3 times now.

and there are actually some negatives to return fuel systems, just go read up on it if your really interested.
and while your at it, you can note that basically every major auto manufacterer has gone to returnless about a decade ago.

btw....paul....whats to say a higher pressure pump and better injectors wouldnt fix your problem?.

 

No, I have read up on it, and there really aren't any negatives. All major auto manufacterers have done a lot in the name of cost savings and federal emissions and crash standard laws. Note the fact that there are no inline fuel filters in vehicles assembled in the last six months....

 

I think the solution here is to installed a fuel regulator that can hold the fuel pressure after the car is turned off. The one i have installed doesn't do that task.

Actually, my fuel pump is Walbro 255 lph. Problem is, it doesn't come with check valve. Still the fuel pump is so long it would be difficult to place the check valve in combination with the pump inside "black module" on the fuel tank.

Yes, I agree with you. But since I would be upgrading in the future, I considered the return-system as an option. Still, I have some brand new 60's in case i needed more fuel input.

I can tell you though, that, before I installed the system, I got KR (identified the first time I dyno). After installation, KR was gone. I think KR would have gone probably with a good tune. But this proves that at high rpm my car specifically was getting lean somehow.

 

read harder.
theres plenty.


if you plan on going alot bigger i can see it being worth doing.

your using 42lbers? what pully?

thats probably the cause of your leaning out. not the fuel system.

 

Yes, I was using 42's before the return-style. Still today I'm using 42's. Stage 3 pulley

 

subscribed to use later

 

subscribed!

 

just waiting for the Earl Performance check valve to arrive on the mail and replace the one I have installed (Aeromotive check valve does not work)

 

Was the Aeromotive valve bad, or it just won't work for what you need?

 

I have contacted Aeromotive, they say the check valve should be ok. So it seems it's not working for my application. I will be selling it after receiving the Earl check valve.

 

damn man,
well my setup is finally going in this week, I dont mind having to prime the system for now, pretty much used to it with every othercar I've owned anyway

 

hey Paul, yeah I don't mind prime my car, you'll get used to it. But still, it would be nice not to have to. I'll let you know after installation of the Earl Performance check valve.

 

a return style system is a waste of money on these cars. i was running 403whp with 73# injectors, the stock fuel pump, and fuel rail. (granted i would recommend upgrading the fuel pump at this point, but that's it)

return style systems require an evap canister system to pass emissions

return style systems dump heated fuel back into the gas tank (not a huge deal)

return style systems without an evap system will pump heated gas vapors back into the tank WITH NO WHERE TO ESCAPE without having a vented gas tank

returnless style converted to a return style takes more than some tubing and an AFPR.

lastly, the guy has no idea what he's talking about, he copied and pasted an entire webpage from a company that is used as an advertisement (this was post #13 on page #1)

he copied from this webpage: http://www.centuryperformance.com/fuel.asp

returnless style systems are installed regularly on injected drag cars @ well over 1000hp. carb'd cars are more apt to have a return style.

----with that said, this is not to knock someone for doing the mod, but understand without a COMPLETE return system with evap capabilities, it may not pass emessions, it is not needed WHATSOEVER for 400hp and less on these carsand it introduces more failure points.----

 

i think you have spent more than I did.


1.Which failure points? I haven't see any.
2. It already pass emissions. I did a test.

 

emissions? what's that? lol.
I know what the deal is on return style setups, and everything will be taken care of properly. I just need fuel and since eventually I'll hook up the hahn port fueler when the built motor goes in, I'm going to need to have a return line to support 2 rails

 

a failure point is every connector, piece of pipe and new equipment that is added into the system. why would you even ask that?

what state did you pass? if they did a gas tank test and you passed without an evap canister system, that is a bad thing. you should really read up on the stuff, it is clear that you added the return system to avoid buying software and tuning the system properly. you did not need that system to alleviate a fuel starvation issue with a measly 240hp.

 

First and foremost, I agree that it is always a good idea to use as few components as necessary; follow the keep it simple rules.

Secondly, I have to ask, did you find a way to properly reference boost to fuel pressure with a different pressure regulator in the tank for you setup?

Third, ALL current gas tanks are vented. While the slight amount of heat caused by a return-style system will most definately cause there to be slightly more pressure on the system, it is not a significant difference for anything other than emissions rules.

Finally, ANY modification to the emission system is against the vast majority of state and federal emissions rules. In most places using any fuel component that is not original equipment would be breaking these rules, not having a cat is breaking these rules, and most importantly USING A TUNE OTHER THAN STOCK is breaking these rules.

 

Well, FYI, i have a return-style and still have my warranty if any problems arises. Dude I live in PR. Puerto Rico, The emissions levels required to pass may not be the same as yours. Until today the car is doing better than when I had the returnless. For some reason I got KR when returnless. After going return-style the KR disappeared. That's all i got to say. Basically, that was my problem, fuel starvation.

I agree with you though that I could bought a tuning software to tune properly. First, I would have spend double the money, and I can't find someone here in PR that knows, for example use HP tuners. The guy that detected my KR was using EFI live. Second, I don't know how to tune. Still, since I'm waiting for Harrop TVS, I think my fuel system is ready and will be upgraded with some 60's. Now, I will have to either:

1. Learn how to tune
2. Look for someone here in PR that uses HP tuners or other software compatible

I think this is a good question.

 

Question...you ever prove those numbers? And if you think return style is pointless on these cars...you havent tried to tune em at higher levels while keeping them within the safe zone on idcs