Sorry ahead of time for bringing up this question once again but many peoples opinions vary soo much with this that I want knowledgable opinions only please thus I DO NOT WANT opinions from anybody affliated with or associated with ZZP. I just dont respect nor value any opinions from them at all especially with their theory about meth injection not creating more whp. Ive gained over 40whp by running a 90/10 mix on my progressive devils own system so we can put that theory to rest once and for all. What I do want to know is if the return style fuel system from OTTP is worth the money and factual pros/cons of this set-up. Please feel free to make your input.

 

i dont know a whole lot about this but i do know that colder fuel is better then hot fuel. Where does the unused fuel go if you dont have a return system? It sits there untill it gets used right? absorbing heat? yup, and a return line recycles that hot fuel back into the tank so it gets cooled off. Thus you are getting cool fuel to your injectors. I dont know how the ottp fuel return works but thats how most work.

 

would a return fuel system improve gas mileage? I know you wanted the meth issue to go to rest but i think they ment without tuning it, it does nother. I got my car tuned very quickly (nothing major) and gained 14whp with meth 50/50 mix..like i said not a huge change in the tune but i know if u dont tune it does nothing. I'm thinking about getting the return fuel system tho cuz i have the tvs on its way.

 

well the thing about saving gas is usally ppl buy it when the go bigger injectors and bigger fuel pump... you wont be getting better gas millage then you would with your stock set up but i would think you would get better gas millage w/o it. I know it get scientific but hotter fuel has less energy then colder fuel or sum **** so with cold fuel you get a better explosion in the cyclinder. It might not be noticable better gas millage but you would get something

 

hotter fuel is good for gas mileage...gasoline atomizes better when heated alllowing for more of a complete combustion.

a return system IS beneficial because it allows for even distribution to all 4 cylinders. with our returnless setup, under heavy load, the cylinder at the end of the rail tends to suffer from not getting as much fuel as the first 3. it is my belief that this is the major reason why converting to return-style is beneficial

 

hate to go way off from what this thread was intended for but i got another question from your statement. And it is abit of a noob question. I know the 4 piston is the weakest. But u mentioned the 4th cylinder suffers more then the first 3. Would getting this system help that 4th piston last longer/be stronger? I know adding all these mods to the car increases power which increases the stress on the motor but like i asked...would it help the piston?

 

it would help save it from dying

lets say your tuned for 11.8 WOT air/fuel ratio on the cobalts stock returnless system. the actual afr of the 4th cylinder could be a unit higher or more!
if you're stock you're really not pulling enough fuel to make it much of a problem, but once you pulley down and require more fuel, it starts to become an issue.

to answer you're question, if you run the car hard often, then yes it could help it last longer.

 

a return system with a crossflowing rail will help with even fuel distribution. with my friends cavalier ecotec, we had an issue with breaking pistons in #1. the car had a return system, however the regulator was right beside the fuel inlet, causing #1 to starve (inlet and regulator was at #4). once i built a crossflow rail, problem solved.

one other huge advantage of a return fuel system is it allows you to run a boost referencing fuel regulator (like the aeromotive regulator in the ottp kit). what this does is reference manifold vacuum/pressure to raise and lower fuel pressure. this creates a steady pressure on the injectors.

 

euridite post.....

 

??? euridite?? What does that mean?

 

did you mean "erudite"???

erudite-adjective
characterized by great knowledge; learned or scholarly

 

Oh, ok lol. out of my vocab range

 

This is interesting... I wonder if we could do this with the LNF... cuz it really makes sense.

 

it cannot be done with direct injection, thats a whole different beast

 

KINDA what I was thinking, considering we don't have a fuel rail...

 

i know nothing really about the fuel system but what about just increasing the size of the fuel rail wont that allow more fuel to the #4? cuz i talked to Wilson Manifolds and they said they could make one.

 

Not really. Pressure in a vessel is going to be the same. So the 4th injector would get the same as the 1st. The real problem is the intake manifold doesn't flow air evenly, giving more air to the 4th cyl and leaning it out.

 

Yes the system is worth it... with the LSJ with the non-return style. You starve the number 4 cylinder of fuel since the fuel is taken away by the 3 preluding cylinders.

It allows a better fueling from smaller injectors.... So you could in theory get more from the 42s and the 60s before you need to upgrade it.


So YES it is worth it... and NO it won't work on the LNF's we DO NOT have a fueling issue... we just need access to the pressure!

 

This type of thinking is exactly what has kept the Cobalt market so slow for so many years.


If you can find a post, email, conversation of any type where a ZZP affiliate said that you can't gain power from meth injection, I would love to see it. The fact is that you completely misunderstand the point that we try to make time and time again. We have said repeatedly that methanol is a great fuel and that power gains are to be had. Unfortunately, people somehow confuse water and/or washer fluid with methanol, which is just plain silly. While your 90% methanol mixture may work great, straight water or typical washer fluid will not. Please process this statement thoroughly before quoting it or commenting about it. Thanks.

LNF motors still use a fuel rail. It is just located under the intake runners.

 

the fuel rail isnt a restriction itself. if you check out the cover of the l61 build book you can clearly see the 1400hp drag motor using a stock l61 fuel rail, just modified with -6 lines. granted there are 3 fuel rails for 12 injectors, but they are feeding 4 160lb injectors each.

 

So, in theory... would a return style system ever be able to be made for the LNF? I am just curious... never been elbows deep into my engine... so sure how it works as compared to a normal MPI engine.

 

IDK who told you this but it's not right. It might sound right but it's not. In an vessel that contains pressure like a fuel rail the pressure is going to be equal through the whole thing. With the pressure being equal and the injectors flowing the same amount the #4 injector will spray as much as #1.

That being said. I'll re-enforce that the problem lies with the stock intake manifold flowing more air to cyl 4. That causes the lean issue.

 

Easiest way to fix it..??

 

pressure is equal unless the pump can't keep up....

 

Correct. Fluid dynamics ftw. Fluids do not compress like air does, so when you have a pressurized body of fluid it does not matter where the outlets are located, the pressure throughout the body is constant.

There's no reason whatsoever to buy a return rail system unless you're pushing some serious boost into your engine. It's useful for the TVS kids who boost above what the stock computer can process (I think the limit is somewhere around 18 PSI but I forget what table that value comes from)