Performance Factory saves you guys money (stock block boosted cars)
05-28-2007, 07:36 PM
#42
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from my undertsanding the return system is more for the high hp cars and the only time ive seen them being run on a car with all stock internals is to be on the safe side, so both sides are correct because its a more like a back up for you if your not running high boost and its required if your going high hp. now idk much about the after for 350z but if your going FI and aiming for a big build shouldnt you be running a stand alone rather than a piggy back, and any stand alone that cannot control the bigger injectors is prolly not reliable. But as for the return system its better to be safe than sorry but if your low on cash you shouldnt be going FI because you gotta pay to play and the return system is to be ont he safe side though it is not required.
05-28-2007, 08:47 PM
#43
basically this is a blind claim with no supporting evidence. a car running and driving and making HP doesnt prove anything in this situation.
yes, i am very biased, but i also know a hell of a lot about fuel systems and design.
if you want to prove your point; datalog fuel pressure at 2 points, 1 being the inlet of the passenger side rail and the 2nd being at the back of the driver side rail. compare logs at increasing HP levels, and be sure to post back the results. if you can prove to me that there is no pressure drop across the rails causing uneven individual cylinder tuning then i would thank you for the time spent testing and openly admit that the RFS only GREATLY aids in properly tuning the car to run clean... I mean the 1:1 alone is so worth it, especially if your running piggyback EMS that suck at controlling larger injectors. What more could you ask for when you compare the 1:1 to a static pressure, the 1:1 will have lower pressure at idle to help you clean up the idle, and then as you get in boost it will have higher pressure to get more out of the proper size injector rather than an oversized hog.
yes, i am very biased, but i also know a hell of a lot about fuel systems and design.
if you want to prove your point; datalog fuel pressure at 2 points, 1 being the inlet of the passenger side rail and the 2nd being at the back of the driver side rail. compare logs at increasing HP levels, and be sure to post back the results. if you can prove to me that there is no pressure drop across the rails causing uneven individual cylinder tuning then i would thank you for the time spent testing and openly admit that the RFS only GREATLY aids in properly tuning the car to run clean... I mean the 1:1 alone is so worth it, especially if your running piggyback EMS that suck at controlling larger injectors. What more could you ask for when you compare the 1:1 to a static pressure, the 1:1 will have lower pressure at idle to help you clean up the idle, and then as you get in boost it will have higher pressure to get more out of the proper size injector rather than an oversized hog.
05-28-2007, 08:57 PM
#45
Originally Posted by Audible Mayhem
after doing tons of research playing around will all the options for fuel delivery. we have decided to say that a return fuel system is not need for a stock block turbo build at all. we have tons of cars running around as of now with ZERO issues with a walbro and larger injectors (650cc for the most part). you will have to buy injectors for any of the builds and all the injector prices are about the same (440,550,650s)
way this works... 650cc injectors are good for 600+ hp all day long IF you are raising the fuel pressure up at a 1:1 ratio. if you leave the stock fuel pressure of 50 psi then 650s are only good to around 450-460 ish which is plenty enough for stock motor builds.
basically you can save 1000 dollars+ for a return fuel system plus no money for install with the added benefit of not causing unnecessary fuel issues with too many new components.
just another way we are trying to provide the BEST, cost worthy ways of making your car faster and reliable..
dont always believe the hype..
way this works... 650cc injectors are good for 600+ hp all day long IF you are raising the fuel pressure up at a 1:1 ratio. if you leave the stock fuel pressure of 50 psi then 650s are only good to around 450-460 ish which is plenty enough for stock motor builds.
basically you can save 1000 dollars+ for a return fuel system plus no money for install with the added benefit of not causing unnecessary fuel issues with too many new components.
just another way we are trying to provide the BEST, cost worthy ways of making your car faster and reliable..
dont always believe the hype..
just installing a walbro and set of injectors is asking for trouble, now I could agree with you that a complete return system is not 100% needed in some cases, but something is need to maintain a higher press as the fuel system demands get bigger like the aps, jwt and PE kits all these kit don't come with return fuel system but some sort of fuel press modifications for stability .
Sam
GT MOTORSPORTS
Last edited by Sam@GTM; 05-28-2007 at 09:05 PM.
05-28-2007, 09:09 PM
#47
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yes but riddle me this when you go FI on stock internals will you be getting the same life out of the engine as compared to when it was N/A. Thats why we need to upgrade the internals even if your running low boost because sooner or later something will give up. same with the fuel system the return system is more like forged pistons when going FI its a good to get that because it increases the reliablity but it is not REQUIRED unless your shooting for a big number. thats the point hes making. some people can mange to go FI by cutting corners and this is just an option, my personal opinion is i would go with the return system because i know how addictive power is and sooner or later you will be leaning towards more power. Your reliability goes down the sh!tter once you go FI so having a return system isnt such a bad idea.
05-29-2007, 05:35 AM
#49
i couldnt disagree more, the stock fuel system is very very consistent, even with lots of hp, its stays right around 50 psi all the time. the only reason anyone would need to add this to a stock system is to make someone some more money.
also, as far as the drivability, think about this, say you have 750cc injectors and your car with a return fuel system and are at part throttle, like 2 psi and 25% TPS. do the injectors work correctly??
well, they will... thats my theory, oversize the injectors and run them at less duty cycle with a constant 50 psi from the factory...
also, yes i drill out the stock fuel pressure regulator with a little bit larger bit, little smaller than a 3/16ths i believe. keeps it a nice even stock fuel pressure with a walbro. very very easy to tune, very consistent fuel pressure...
also, as far as the drivability, think about this, say you have 750cc injectors and your car with a return fuel system and are at part throttle, like 2 psi and 25% TPS. do the injectors work correctly??
well, they will... thats my theory, oversize the injectors and run them at less duty cycle with a constant 50 psi from the factory...
also, yes i drill out the stock fuel pressure regulator with a little bit larger bit, little smaller than a 3/16ths i believe. keeps it a nice even stock fuel pressure with a walbro. very very easy to tune, very consistent fuel pressure...
Originally Posted by Sharif@Forged
I must say you are talking a big risk. We have logged fuel pressure without RFS's, and the trend on each pull on the dyno is slightly different. You are replying on an electric pump to maintain your dropping fuel pressure trend....rather than a mechanical FPR, raising fuel pressure 1:1. There is no way I would do an engine build without an RFS, IMHO.
In addition, with larger injectors you will experience 70psi plus fuel pressure at idle, which makes getting a clean start and idle very challenging with 750cc injectors. Sure, you can drill out the fuel pump housing as TN suggests with their kit, but its still a guess, basically. I could see doing this with 440cc-550cc injectors and low boost (5-7psi), but not with high boost on built engines.
When we build cars, our #1 goal is reliabilty and consistency. Making some good dyno numbers is not enough. We want a customer car to run consistently from day to day, and last a very long time.
I admire your desire to try new things, but this is not a good idea.
Edit, i see you are just suggesting this on stock blocks.....but stock blocks require even MORE due dilegence to keep them in one piece.
In addition, with larger injectors you will experience 70psi plus fuel pressure at idle, which makes getting a clean start and idle very challenging with 750cc injectors. Sure, you can drill out the fuel pump housing as TN suggests with their kit, but its still a guess, basically. I could see doing this with 440cc-550cc injectors and low boost (5-7psi), but not with high boost on built engines.
When we build cars, our #1 goal is reliabilty and consistency. Making some good dyno numbers is not enough. We want a customer car to run consistently from day to day, and last a very long time.
I admire your desire to try new things, but this is not a good idea.
Edit, i see you are just suggesting this on stock blocks.....but stock blocks require even MORE due dilegence to keep them in one piece.
Last edited by Audible Mayhem; 05-29-2007 at 05:39 AM.
05-29-2007, 05:42 AM
#50
guys would you like to check out the 8 cars at my shop right now with no return systems that run fine with no fuel issues, one with a built motor and 15 psi. i am not debating this, i have done a scientific study and showing my results. ryans car runs 9 to 10 psi , AJs stock block now runs 12 psi with 650s injectors.
as long as you use a lot bigger injectors and have consistent fuel, then its all in the hands of the tuner...
notice that all the people defending the RFS are the ones selling it....
maybe its just the way i set up the buckets, but my fuel pressure stays right on 50 throught the whole runs just like a factory system does.
as long as you use a lot bigger injectors and have consistent fuel, then its all in the hands of the tuner...
notice that all the people defending the RFS are the ones selling it....
maybe its just the way i set up the buckets, but my fuel pressure stays right on 50 throught the whole runs just like a factory system does.
Last edited by Audible Mayhem; 05-29-2007 at 05:45 AM.
05-29-2007, 05:49 AM
#51
i guess i will just ask this, to the opposite side, have any of you tried to take a car with say 410 to the wheels on a stock block, just throw in a walbro, drill out the stock fuel pressure regulator just a bit and tune it on 650cc injectors...
05-29-2007, 06:16 AM
#52
Jeremy, your point is not just to show what you are doing without a RFS, but also to critize other shops for recommending an RFS. Claiming that all other shops are recommending RFS's just to make a quick buck is rediculous, and insulting to the shops that have been in business far longer than you have, and have a long track record of solid results.
Having some cars that are running your setup is not scientific proof. I ran my car with an RFS at 400whp+ and 9psi for a while, but I would never do it on a customer's car, and the testing was hardly scientific. We also ran non-RFS setups prior to the introduction of the bolt on RFS.
Have you hooked up a pressure gauge and logged the fuel pressure? We have, and it drops big time (not as much with the TN setup) And if you perform the TN mods to the fuel pump assembly, you ruin the assembly if you decide to go with an RFS later, since you have drilled holes in the assembly. Not to mention, that you pump is going to flow differently, based on main voltage levels to the car, which also vary...again...more inconsistency.
Anything is possible, and there are bad, good, and better ways of doing things. Why take chances? Maybe your customers are much prone to risk-taking, which his cool for them. But most customers want reliability and repeatability.
Having some cars that are running your setup is not scientific proof. I ran my car with an RFS at 400whp+ and 9psi for a while, but I would never do it on a customer's car, and the testing was hardly scientific. We also ran non-RFS setups prior to the introduction of the bolt on RFS.
Have you hooked up a pressure gauge and logged the fuel pressure? We have, and it drops big time (not as much with the TN setup) And if you perform the TN mods to the fuel pump assembly, you ruin the assembly if you decide to go with an RFS later, since you have drilled holes in the assembly. Not to mention, that you pump is going to flow differently, based on main voltage levels to the car, which also vary...again...more inconsistency.
Anything is possible, and there are bad, good, and better ways of doing things. Why take chances? Maybe your customers are much prone to risk-taking, which his cool for them. But most customers want reliability and repeatability.
05-29-2007, 08:10 AM
#53
my point is simple, its just saying that a RFS isnt necessary for someone doing a stock block SC, ST or TT kit and show that you can save well over 1000 dollars by doing so.
i have TT kits (one built motor), tons of ST kits, and a handfull of Vortech kits running around with a simple walbro.
this again isnt a debate, i am showing wht i am doing and sharing that with everyone just in case people are close to having the money but cant quite reach their goals with all the additions that have been "forced" into their plans...
i am not criticizing anyone or any other shops, if anything backing up my statements with a reactive statement.
you do what you do, i will safely do what i do for less money down here in florida providing real world FAST cars, proven time and time again...
i have TT kits (one built motor), tons of ST kits, and a handfull of Vortech kits running around with a simple walbro.
this again isnt a debate, i am showing wht i am doing and sharing that with everyone just in case people are close to having the money but cant quite reach their goals with all the additions that have been "forced" into their plans...
i am not criticizing anyone or any other shops, if anything backing up my statements with a reactive statement.
you do what you do, i will safely do what i do for less money down here in florida providing real world FAST cars, proven time and time again...
05-29-2007, 08:39 AM
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It's gettin' hot in here 
Over the last year, RFS have become something of a debate again. A few years ago it was gospel...
I'm glad to see that boundries are be pushed and that "truths" are being questioned. Great work Jeremy
Over the last year, RFS have become something of a debate again. A few years ago it was gospel...
I'm glad to see that boundries are be pushed and that "truths" are being questioned. Great work Jeremy
05-29-2007, 08:40 AM
#56
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I am curious as to how a car that puts down 450whp in Florida is faster than one that puts down 450whp in another state assuming that the drivers have equal skill and that the elevation between cities/states isn't a huge difference.
05-29-2007, 08:50 AM
#58
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Originally Posted by Audible Mayhem
you lost me on that statement Gman 
Originally Posted by Audible Mayhem
you do what you do, i will safely do what i do for less money down here in florida providing real world FAST cars
Not everyone is into drag racing. I've never been to a track, but I bet I beat my car more than most people on this forum. I do a lot of highway driving so that's where my "real world" comes into play. Does that make my car any slower than other vq35's putting down the same power, but that go to drag strips? The point is if everything on two cars is equal then the drivers will determine which one is faster not the tuner.
05-29-2007, 09:03 AM
#59
well the thing is that its all about the driver and the tune on the car, our shop stock block car runs 11.5s now and will go low 11s this week. thats pretty fast.
basically dynos can be altered and 1/4 mile times cant so which one do you want to believe when you drive your 450 hp car around...
basically dynos can be altered and 1/4 mile times cant so which one do you want to believe when you drive your 450 hp car around...
05-29-2007, 09:05 AM
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Originally Posted by Audible Mayhem
well the thing is that its all about the driver and the tune on the car, our shop stock block car runs 11.5s now and will go low 11s this week. thats pretty fast.
basically dynos can be altered and 1/4 mile times cant so which one do you want to believe when you drive your 450 hp car around...
basically dynos can be altered and 1/4 mile times cant so which one do you want to believe when you drive your 450 hp car around...