I've been told I need to get one and doing some research I came across this one, this guy WA2GOOD (I see him on G35driver also) is claiming you don't need one?

http://forums.freshalloy.com/showthread.php?t=184515

His dyno looks a bit inflated . . . over 600ft-lb torque on a BB530 JWT kit? I mean that is ALOT of torque even APS TT kit can barely make over 600whp/tq I thought.

Does increasing voltage really hold steady fuel pressure?

Thanks

 

What is your power level, setup, goals...etc

Tom

 

a bit inflated is being kind...everybody remembers their moon dynos.
IMO "fuel" is your best friend for longevity FI(specially on the street-pump gas) and you should NOT take any chances with it... having said that its going to depend on the power goals you see to really tell u if you need or not a fuel return system. IF you are just going for stock block setup 550cc injectors and walboro fuel pump will do. Tuning will play a very important role in how far you can strech it.

 

Dynasty.Zero ....just post your plans and someone will help point you in the right direction.

 

there are several advantages to a RFS. a return fuel system promotes equal fuel distribution to each injector. a returnless setup only sends the equal amount of fuel to the rails that the engine is burning. a returnless setup runs ***** to the wall the entire time and runs the rails in parallel rather then in series to raise the point of pressure drop across the rails much higher.

notice that in high HP supra, they will usually feed the rail at both ends and outlet in the center... this is because of pressure drop across the rail and the ability to get all the fuel thru only one fitting. That long inline rail is going to be very prone to pressure drop. the 350z with stock rails is worse because it runs the rails in a series, meaning in one, out the other end, then a small pipe to the other rail, then a dead end. that small pipe to the second rail is a terrible restriction that restricts the pressure transfer into that rail.

while it wont show a difference in your wideband readings which are an average of all the cylinders, it will show in longevity of your setup.

 

Thank you for the help.

My goals are just a low to midrange 500whp setup. I got the built motor and everything but still using the APS fuel system. So can't tune for anything too high, I was running around 430whp on a stock block before I think I can get a better powerband with the cams I got now maybe shooting for mid 400whp until I get my return system and bigger injectors . . .

Thanks

 

It's not so much about power, its just about what is the best way of doing things. You can make anything work. Can you make 500+rwhp with out a RFS? Yes. Will you have better fuel distribution/safer running car with a RFS? Yes.

At the end of the day it is up to you, keep in mind changing to a RFS at a later date will require to re-tune the car.

-George

 

what about 400whp? You guys think it is "safe" with no RFS with a good tune?

 

400whp is pretty safe withotu a RFS... it wouldnt be an emergency.

keep in mind its also easier to idle larger injectors with a RFS.

On a piggyback EMS especialy. Since the fuel pressure will be lower at idle with the vacuum referenced regulator, you will not need to use as much airflow correction to get to your target A/F... but then on the top end when in boost the fuel pressure goes up to get the most out of the injectors.

even on a standalone its easier, because some larger injectors dont like short pulsewidths and get cause a rough idle, lower pressure at idle means you dont have to drop the pulsewidth so low.

 

Yeah George I definitely want one just a matter of now or a bit down the road . . . . but re-tuning would be more hassles. :/

Might as well bite the bullet huh . . . . lol.

 

The main reason I bring it up is because of the re-tune, if not I would just say get it when your finances allow.

It would suck for you to drive down to get tuned, then come back to get the RFS and have to get another tune

Either way its up to you

-George

 

for 500-550 range get the fuel return......

 

+1 .. cheap insurance when you compare it to the possible alternative ...

FWIW, I run a the F:T basic fuel return on my vortech setup, with a walbro pump and DW 600CC injectors. I'm pushing 365HP on a dynodynamics (maybe 410-420 on dynojet).

Think about it, when you add up the expense of going FI in the first place another $500 is a drop in the bucket.

 

Then RFS, injectors, better clutch, flywheel, then CF hood, then roof overlay, then probably have to get new tires again . . . .

OMMMMGGGGGGG THIS IS NEVERENDING. :/

 

You had me on your side until the roof overlay ... how about brakes instead?

 

^ As soon as you step on it w/ 500+ trq - You'll forget all about the carbon goodies and want to turn up the boost.

 

I just bought brakes.

Roof overlay is Asuka double hump. Looks sick. Gonna get their Type 2 hood also. I like my car to be super super aggressive.

 

really?