Question about Fuel Return systems.
07-11-2007, 12:18 PM
#21
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Originally Posted by doug
then keep your power under 400 ... get smaller injectors (not sure what size.. i guess Sharif can suggest this to you) and forget the RFS..
when you do it.. you want to do it right once.. not Stg 1 / XXX injectors... Stg 2 / XXX injectors ... Stg 3 / XXXX Injectors
too much buying and selling parts
when you do it.. you want to do it right once.. not Stg 1 / XXX injectors... Stg 2 / XXX injectors ... Stg 3 / XXXX Injectors
too much buying and selling parts
GOOD POINT!!!
i guess thats why i was sayign 650cc-800cc injectors(still not 1000cc but they are good)... an pressure regulater can be used later still...
10-08-2007, 01:16 PM
#23
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Man i already pm'd you a long time ago explaining that i could not find the tires and asked for a address to send you a check to refund you the 30 dollars for shipping cost. The sale was for the wheels and tires that were mounted. I was basically GIVING you tires becuase i had no need for them and asked that you just paid for the shipping. PM me with a respones.
10-08-2007, 01:32 PM
#25
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Originally Posted by Equate
Chris'smax send me my tires! its been 5 months!
dude, stop being a **** and take this to pms. youve bumped 7 threads now and we get your point. Chris has already replied to you.
10-08-2007, 04:27 PM
#26
Originally Posted by CUxtopher
dude, stop being a **** and take this to pms. youve bumped 7 threads now and we get your point. Chris has already replied to you.
10-08-2007, 04:40 PM
#27
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I don't know if I should put this out, but I have heard from a few reputable tuners that a return system is not necessary even for 500+whp applications. There are people running return-less with over 500whp without any problems.
10-08-2007, 04:55 PM
#28
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Originally Posted by supra crazy
He bumped 7 at the same time... So im guessiing he really wanted a reply since he wasnt getting any from his PM's
no i did reply to his previous pm.
10-08-2007, 05:18 PM
#29
Originally Posted by DMK
I don't know if I should put this out, but I have heard from a few reputable tuners that a return system is not necessary even for 500+whp applications. There are people running return-less with over 500whp without any problems.
10-08-2007, 05:37 PM
#30
Shop preference? I suppose. A shop's preference on what the acceptable risk to your vehicle is. Slight risk, acceptable risk to some, but a risk nonetheless that increases as you push the hp envelope. Can you just picture your sub pounding out those low notes, with each beat, you see your AFR gauge spike lean - ha - okay maybe that's a bit dramatic!
Not saying that a return fuel system can't have problems - the external regulator can go bad for one - but I doubt it would be subject to the same level of unpredictability as a pump regulated by an analog voltage.
Not saying that a return fuel system can't have problems - the external regulator can go bad for one - but I doubt it would be subject to the same level of unpredictability as a pump regulated by an analog voltage.
Last edited by rcdash; 10-08-2007 at 06:59 PM.
10-08-2007, 06:05 PM
#31
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Yes, this does boil down to shop preference.
We have done well over 100 TT VQ35 cars, some with built motors and some without ranging from the mild 360whp tune to an exotic 750whp tune and they are ALL returnless. With the JWT TT FMU, boost regulated fuel pump system.....In our (Meaning Me, Mark B. & Jim Wolf) openion, a returnless system is obsolute as long as you can maintain constant fuel pressure. Spend the money you would save on something else.
We have done well over 100 TT VQ35 cars, some with built motors and some without ranging from the mild 360whp tune to an exotic 750whp tune and they are ALL returnless. With the JWT TT FMU, boost regulated fuel pump system.....In our (Meaning Me, Mark B. & Jim Wolf) openion, a returnless system is obsolute as long as you can maintain constant fuel pressure. Spend the money you would save on something else.
Last edited by WA2GOOD; 10-08-2007 at 06:08 PM.
10-08-2007, 07:46 PM
#32
Originally Posted by WA2GOOD
Yes, this does boil down to shop preference.
We have done well over 100 TT VQ35 cars, some with built motors and some without ranging from the mild 360whp tune to an exotic 750whp tune and they are ALL returnless. With the JWT TT FMU, boost regulated fuel pump system.....In our (Meaning Me, Mark B. & Jim Wolf) openion, a returnless system is obsolute as long as you can maintain constant fuel pressure. Spend the money you would save on something else.
We have done well over 100 TT VQ35 cars, some with built motors and some without ranging from the mild 360whp tune to an exotic 750whp tune and they are ALL returnless. With the JWT TT FMU, boost regulated fuel pump system.....In our (Meaning Me, Mark B. & Jim Wolf) openion, a returnless system is obsolute as long as you can maintain constant fuel pressure. Spend the money you would save on something else.
I think a lot of us are still waiting for you to post a 750whp DJ number, or something even remotely close to that. 
You know, I talk to Jim Wolf quite frequently as well, since we install a lot of his kits, and he also recommends return fuel systems, and better EMS's for high powered cars. So there is obviously some miscommunication going on between you guys.
Also, so where are these 100 VQ35 TT cars you have built? That's a lot of cars! about 1-2 per week....impressive.
Lastly, where exactly do you build all these cars? Can we see pics of your shop? Do you have a shop?
Honesty and integrety is the most important virtue in this business, I am sure you would agree with that...right Scott?
10-08-2007, 08:50 PM
#33
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Originally Posted by Sharif@Forged
Still tossing out those crazy high numbers. I think a lot of us are still waiting for you to post a 750whp DJ number, or something even remotely close to that.
You know, I talk to Jim Wolf quite frequently as well, since we install a lot of his kits, and he also recommends return fuel systems, and better EMS's for high powered cars. So there is obviously some miscommunication going on between you guys.
Also, so where are these 100 VQ35 TT cars you have built? That's a lot of cars! about 1-2 per week....impressive.
Lastly, where exactly do you build all these cars? Can we see pics of your shop? Do you have a shop?
Honesty and integrety is the most important virtue in this business, I am sure you would agree with that...right Scott?
I think a lot of us are still waiting for you to post a 750whp DJ number, or something even remotely close to that. You know, I talk to Jim Wolf quite frequently as well, since we install a lot of his kits, and he also recommends return fuel systems, and better EMS's for high powered cars. So there is obviously some miscommunication going on between you guys.
Also, so where are these 100 VQ35 TT cars you have built? That's a lot of cars! about 1-2 per week....impressive.
Lastly, where exactly do you build all these cars? Can we see pics of your shop? Do you have a shop?
Honesty and integrety is the most important virtue in this business, I am sure you would agree with that...right Scott?
All's I can say is "people who live in glass houses should not through stones"
Sharif, just go back to doing what you do best. That's being a message board politician and keep on selling peoploe things that they do not need, so you can keep padding your pockets.
Just my observation.
Curtis
Last edited by ShamrockG; 10-08-2007 at 08:56 PM.
10-08-2007, 09:05 PM
#35
is there something i missed here? why are all these accusations coming up?
although i'm not as knowledgable in regards to FI compared to others here, i don't doubt scott is feeding people here BS. Unless proven otherwise, he hasn't done anything wrong, nor have i heard/read anything bad about him, Mark, or Relentless.
although i'm not as knowledgable in regards to FI compared to others here, i don't doubt scott is feeding people here BS. Unless proven otherwise, he hasn't done anything wrong, nor have i heard/read anything bad about him, Mark, or Relentless.
10-08-2007, 10:16 PM
#36
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Truth be told I've seen or heard of just as many or more blown motors with return fuel systems than with a returnless one. For tunability I'd say do it at higher whp, but I don't see why it's needed for moderate power goals on the stock block.
10-09-2007, 04:30 AM
#37
Originally Posted by ShamrockG
Well from what I have learned about FP and Mr.S here recently from current and past customers of FP, not to mention all the things I was told by a few more unhappy FP customers this weekend.
All's I can say is "people who live in glass houses should not through stones"
Sharif, just go back to doing what you do best. That's being a message board politician and keep on selling peoploe things that they do not need, so you can keep padding your pockets.
Just my observation.
Curtis
All's I can say is "people who live in glass houses should not through stones"
Sharif, just go back to doing what you do best. That's being a message board politician and keep on selling peoploe things that they do not need, so you can keep padding your pockets.
Just my observation.
Curtis
I'm not going to get in between Scott and Sharif as I personally like them both and a little competitive jousting is not unusual on the boards. I have purchased products from both of them, run into problems with products from both (albeit minor), and both have excelled at remedying the situation to *my* satisfaction.
I think Sharif is just elucidating, with a bit more cutting cynicism than usual, that horsepower #s may not be comparable between shops that use different dynos (Dynapack vs DD for example). As such, stating just the horsepower # can be a bit misleading to the uninformed consumer.
Clearly the debate between returnless vs return fuel systems will continue...
Last edited by rcdash; 10-09-2007 at 11:00 AM.
10-09-2007, 05:52 AM
#39
Originally Posted by Sharif@Forged
Still tossing out those crazy high numbers. I think a lot of us are still waiting for you to post a 750whp DJ number, or something even remotely close to that.
I think a lot of us are still waiting for you to post a 750whp DJ number, or something even remotely close to that. 
I think I offered to pay for that Dyno Jet Dyno run (at Sam's/GTM shop) over two years ago - VRT lives on...
10-09-2007, 07:36 AM
#40
In regards to the RFS debate, on low boost, where your margin for error is much greater, you can get fairly consistent results at 5-7psi max. With higher power applications, the correct fuel system is a return fuel system.
Here is why:
1) Fuel injectors are designed to operate within a defined pressure band. OEM fuel fittings also have pressure limits as well. Undistutably, running an 8:1 FMU, and 100+psi of fuel through an injector and fuel system designed for 50-60psi of fuel pressure, is incorrect. Having a few cars running this setup on the track, doesnt make it correct, safe, or proper. It's half-arsed. High fuel pressure, and high duty cycles will cause an injector to overheat, and possibly stick.
2) Perhaps if one were to review the concept of a pressure differential, it would be more evident as to why a 1:1 rising rate FPR is needed to offset the pressure inside in the intake manifold. Yes, with a large enough injector, or a massively unsafe level of fuel pressure, you can also offset the pressure differential, but again its inconsistent at best, and unsafe at the worse.
3) Last piece that is often overlooked in returnless fuel systems, is voltage variations in the electrical system. The pump output is directly proportional to the level of voltage supplied to the pump. Our OEM electrical regulates voltage between 13-15.5V, meaning fuel flow and pressure will vary by up to 15-20%.
Hope that helps clarify why we feel that return fuel systems are required for high powered applications.
Here is why:
1) Fuel injectors are designed to operate within a defined pressure band. OEM fuel fittings also have pressure limits as well. Undistutably, running an 8:1 FMU, and 100+psi of fuel through an injector and fuel system designed for 50-60psi of fuel pressure, is incorrect. Having a few cars running this setup on the track, doesnt make it correct, safe, or proper. It's half-arsed.
High fuel pressure, and high duty cycles will cause an injector to overheat, and possibly stick.2) Perhaps if one were to review the concept of a pressure differential, it would be more evident as to why a 1:1 rising rate FPR is needed to offset the pressure inside in the intake manifold. Yes, with a large enough injector, or a massively unsafe level of fuel pressure, you can also offset the pressure differential, but again its inconsistent at best, and unsafe at the worse.
3) Last piece that is often overlooked in returnless fuel systems, is voltage variations in the electrical system. The pump output is directly proportional to the level of voltage supplied to the pump. Our OEM electrical regulates voltage between 13-15.5V, meaning fuel flow and pressure will vary by up to 15-20%.
Hope that helps clarify why we feel that return fuel systems are required for high powered applications.