i just bought a return style fuel system from OTTP. does anyone run this kit backwards? like insted of using the factory fuel lines for the fuel delivery, use them for the return and use the big line supplied in the kit for the delivery and use the fuel pressure reg for incoming fuel pressure insted of just a system, pressure monitor? idk if this makes sense but it does is my mind. anyone follow me? im sure the large line supplie in the kit has a higher flow rate than the stock fuel lines...

 

What your saying def. makes sence. I'm looking into getting the return setup but I never thought about it like that because very few people are getting to the limit of the stock fuel system.

 

It doesn't work that way, sorry. Your understanding of the fuel system and the kit isn't complete.

This isn't an old school low pressure carburated fuel system or something where you need to move to bigger fuel lines to get enough fuel. The system works well as is. ZZP is running their BRFPS on their (and customers) high HP cars, and a return style setup similar to OTTP's on Ryan's 600+ HP turbo LSJ without touching the stock lines.

That being said, I assure you that you should simply install the kit as it is intended or you will risk messing up the system. First of all, the regulator cannot be used for 'incoming fuel pressure' as that is not how regulators work, and the only thing incoming is 'fuel flow'. Regulators work by reducing the physical space of the regulator passage thereby restricting flow so that a pressure builds up before the regulator (in the fuel line and rail in our case). The 'uneeded fuel' is then returned to the tank via the return line. The ZZP BRFPS kit returns the fuel back to the tank via the stock return line back by the tank, instead of at the rail like the OTTP kit. Also, the lines will not physically work your way, as the stock fuel canister assembly in the tank has crimped hard lines on it for (R) return and (S) sending lines. You would have to modify those lines and the sending unit much more than necessary, instead of using nice plug and play connections. I also believe that may cause problems with the fuel pump as it would have to pump more volume (flow) through a bigger line to achieve the same pressure.

It is easy to get to the limits of the stock fuel system running E85. Even easier if you are on a small pulley TVS. This however is not the only reason to use a boost referenced fuel system. The setup is easier to tune and since the fuel pressure will lower and raise due to engine demand, the idle is like a dream, and you don't have to worry as much about top end fueling.

Boost referenced fuel setups work great as-is. I would install the OTTP kit normally and enjoy the benefits, rather than try to re-engineer a proven and reliable setup for zero gain.

 

You still need enough flow to support X amount of horsepower. Correct nobody has gotten there but eventually you will need a pump and feed setup large enough to support a lot of horsepower. I don't know everything there is to know about race engines and fuel system setups but I know enough from following some of your recent threads to not take any of your advice on setting up a fuel system.

 

I answered all of the OP's questions and gave supporting advice. You will run out of available custom-made size >1000cc injectors before you will tax the fuel lines. A pump is recommended if you have the crappy 05' pump, or still don't have enough flow with your stock pump. The other stock pumps flow rather well. So what's the problem with what was said? Everything was factual in nature. If you've never dropped the tank, looked at the lines, canister, pump, etc, and proven you need more flow, then you may want to pull your head out of your ass. If you want to prove otherwise by tremendously beating ZZP's 600+whp car with stock fuel lines, or GM's 1,000+whp dragster engines, then by all means, please go ahead... Your car is yours, as the OP's car is his own, do whatever you like with them...

If you and/or the OP would like to think critically of what I have suggested, and think of workaround for the problems I advised, by all means please help the community by creating a new variant of the return style setup that is better than ever.



Concerning attacking me personally, think whatever you want. I had a bad part that caused me problems with my setup. From that experience I have learned much about the LSJ's fuel system. Now my car runs better than ever. My datalogging proves more fuel isn't necessary. Through your unintelligent responce of trying to bash me instead of talking about fuel systems of the topic at hand, you have only proven the 'Cobalt scene' is fail. This ain't my first rodeo, cowboy...

 

If you have the ability to read then take a look at my first post. I said there is no need to do this since nobody is maxing out the factory fuel system. I haven't attacked you personally. All I'm saying is even you had no idea why you couldn't get the zzp kit to work and then you re-did your work and all of a sudden it worked. Nobody ever said let's all get together and re-invent the wheel. An idea was posted which is feasible but unnecessary which again I stated in my first post. I would never attack your mechanical prowess. I'm sure your the best and you have all the info and answers everybody has. The cobalt community should be pleased to have you a part of it.

 

I'm not sure why you feel the need to be a smartass. My reply contained technical material concerning the OP's statements and questions. This was supposed to lead to more in depth technical discussion of the Cobalt's fuel system.

It is a very interesting idea none-the-less, however I am not sure it is worth the work for the intended results. Anything can be engineered better if enough work is put into it. I would recommend anyone looking to consider an upgrade such as this to consult what others have done with additional fuel pumps, surge tanks, etc. It may also be beneficial to look at the size of the fuel lines and components of other similar F/I 4 cylinder platforms such as the Evo's who are routinely making 800+awhp.

I do doubt however that anyone could, would, should need that much fuel. Blower cars need more fuel than turbo cars, and the the highest whp blower cars used E85 on 98lb/hr injectors just fine. Big turbo cars with loads of power have been done with a return style system and upgraded pump. It would be hard to say where larger injectors, push/pull pump(s), and a boost referenced setup running higher fuel pressure would max out at.

 

I'm not being a smartass. I do agree with everything you just stated.

 

No probs. Hopefully the OP gets hit kit working good.

You're turbo, now you need to grab a return kit

 

it was just a thought fellas. no need to get all hot about it. anyway. thanks for the info it was greatly appreciated

 

Unfortuenly I'm still on 60's which are maxed. I'm going to get the 80's first and then save up and get the OTT setup.

 

If you're 60's are maxed, you could try a cheap fuel pump rewire first. It may give you a little headway. If not the ZZP BRFPS kit isn't but $20 more than 80's... Just a thought.