What hp level requires a FPR and a return line?
What hp level requires a FPR and a return line? I have procharged 347 setup. It will making 625-650 rwhp. I will be running either the racetronix 340 or a single 450 in tank pump.
As of now, i have stock fbody fuel line setup.
My research has shown me that the stock rails and feed line will be fine for my horsepower level but my question is do I need to run a return line and an aftermarket fuel pressure regulator with my setup?
As of now, i have stock fbody fuel line setup.
My research has shown me that the stock rails and feed line will be fine for my horsepower level but my question is do I need to run a return line and an aftermarket fuel pressure regulator with my setup?
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
A big pump will likely overpower the in tank reg.
So you will need to resolve this.
Whether you choose to do a flow/return with a FPR up front, or an easier setup with a FPR at the back, doing away with the in-tank reg...entirely up to you.
So you will need to resolve this.
Whether you choose to do a flow/return with a FPR up front, or an easier setup with a FPR at the back, doing away with the in-tank reg...entirely up to you.
I have procharged 347 setup. It will making 625-650 rwhp. I will be running either the racetronix 340 or a single 450 in tank pump.
As of now, i have stock fbody fuel line setup.
My research has shown me that the stock rails and feed line will be fine for my horsepower level but my question is do I need to run a return line and an aftermarket fuel pressure regulator with my setup?
As of now, i have stock fbody fuel line setup.
My research has shown me that the stock rails and feed line will be fine for my horsepower level but my question is do I need to run a return line and an aftermarket fuel pressure regulator with my setup?
http://www.ws6project.com/user_stor/...oducts_id=4033
TECH Fanatic
Joined: Jun 2003
Posts: 1,869
Likes: 99
IMO with a boosted engine, you want to install a boost referenced style FPR. You do NOT want to use an FPR where the pressure is static such as the stock in tank regulator where pressure is approximately 58 psi all of the time.
Why? When in boost the boost referenced FPR will increase volume/pressure to compensate for the positive pressure in the intake (boost) that is pushing against the outside tip of each injector. The stock regulator or C5 regulator does not adjust.
It's all explained in any good link from FPR sites that sell FPR's.
https://www.turbosmart.com/news/how-does-an-fpr-work/
https://aeromotiveinc.com/wp-content...c_Boost_01.pdf
Why? When in boost the boost referenced FPR will increase volume/pressure to compensate for the positive pressure in the intake (boost) that is pushing against the outside tip of each injector. The stock regulator or C5 regulator does not adjust.
It's all explained in any good link from FPR sites that sell FPR's.
https://www.turbosmart.com/news/how-does-an-fpr-work/
https://aeromotiveinc.com/wp-content...c_Boost_01.pdf
Last edited by dlandsvZ28; Jun 3, 2019 at 09:13 AM.
Teching In
Joined: Apr 2006
Posts: 33
Likes: 1
From: Delaware
I started with a 340 racetronix and c5 regulator kit from ws6store. In my opinion dont waste your money or time on that c5 reg kit. I found that no mater what you did it would not regulate the fuel pressure as it should with the 340 pump. It just over powers the reg. I just got a cheap adjustable fuel pressure regulator from summit and ran a 6an return line and it is working fine on my car.
Trending Topics
I started with a 340 racetronix and c5 regulator kit from ws6store. In my opinion dont waste your money or time on that c5 reg kit. I found that no mater what you did it would not regulate the fuel pressure as it should with the 340 pump. It just over powers the reg. I just got a cheap adjustable fuel pressure regulator from summit and ran a 6an return line and it is working fine on my car.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever
Verdad Gallardo
On The Tree
Joined: Mar 2010
Posts: 124
Likes: 8
From: Navarre, FL
I have a late C5 which has C6 style fuel system and I put a drop in 450 in it. Running around 12 psi and its making somewhere in the mid 600s hopefully on a centri SC setup.
I thought I could get by on stock regulator / fuel system but it's enough of an issue/compromise that I wish I would have done a rail mounted FPR with return line from the start.
Mine does not overpower the regulator, I get 60psi at the rail fine during most operations. Problem is at WOT / high rpm I see fuel pressure drop to around 54psi, maybe a couple data points at 52psi as well. I'm down to 40psi effective pressure, which is making even my 80 lb/hr injectors hit near 80 duty cycle which sucks. I have a boost a pump too, so it's not a pump volume issue, there is just a noticeable pressure drop in the stock fuel line at this flow level.
I also ran into a weird tuning issue where "Baro" gets updated to 104 kPa after I hit boost. I'm at higher elevation where baro is actually around 85 kPa, and this change now shifts my operating point on the IFR table and makes idle/cruise fueling not consistent and before I figured out what was going on I was chasing my tail.
While the setup "works", it's far from ideal and I would recommend doing a proper rail mounted FPR with return line from the get-go.. will save you hassle down the road.
Unfortunately for me I have to drop the tanks to switch over now.... huge PITA.
I thought I could get by on stock regulator / fuel system but it's enough of an issue/compromise that I wish I would have done a rail mounted FPR with return line from the start.
Mine does not overpower the regulator, I get 60psi at the rail fine during most operations. Problem is at WOT / high rpm I see fuel pressure drop to around 54psi, maybe a couple data points at 52psi as well. I'm down to 40psi effective pressure, which is making even my 80 lb/hr injectors hit near 80 duty cycle which sucks. I have a boost a pump too, so it's not a pump volume issue, there is just a noticeable pressure drop in the stock fuel line at this flow level.
I also ran into a weird tuning issue where "Baro" gets updated to 104 kPa after I hit boost. I'm at higher elevation where baro is actually around 85 kPa, and this change now shifts my operating point on the IFR table and makes idle/cruise fueling not consistent and before I figured out what was going on I was chasing my tail.
While the setup "works", it's far from ideal and I would recommend doing a proper rail mounted FPR with return line from the get-go.. will save you hassle down the road.
Unfortunately for me I have to drop the tanks to switch over now.... huge PITA.
On The Tree
Joined: Jun 2019
Posts: 184
Likes: 66
From: HTown, Texas
I started with a 340 racetronix and c5 regulator kit from ws6store. In my opinion dont waste your money or time on that c5 reg kit. I found that no mater what you did it would not regulate the fuel pressure as it should with the 340 pump. It just over powers the reg. I just got a cheap adjustable fuel pressure regulator from summit and ran a 6an return line and it is working fine on my car.
Restricted User
Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
To be technical, no setup requires a return line.
A return line is used to maintain pressure by sending unused fuel back to the tank.
You could dead-head a pump at 120 PSI to the fuel rails without a regulator or return line and make whatever power your lines are able to flow.
A PWM setup can be used to pulse the fuel pump to maintain a set fuel pressure without the use of a regulator or return line. Vaporworx sells probably the best bang/buck setup.
A return line is used to maintain pressure by sending unused fuel back to the tank.
You could dead-head a pump at 120 PSI to the fuel rails without a regulator or return line and make whatever power your lines are able to flow.
A PWM setup can be used to pulse the fuel pump to maintain a set fuel pressure without the use of a regulator or return line. Vaporworx sells probably the best bang/buck setup.