Forced Induction Superchargers | Turbochargers | Intercoolers

Best way to run FPR?

Thread Tools
 
Search this Thread
 
Old 11-17-2014, 08:10 AM
  #1  
11 Second Club
Thread Starter
iTrader: (28)
 
Mike 02T/A's Avatar
 
Join Date: Jul 2004
Location: FL
Posts: 398
Likes: 0
Received 0 Likes on 0 Posts

Default Best way to run FPR?

What's the best way to run the Fuel Pressure Regulator?

I've switching out the stock rails, etc. Is it better to run fuel feed into regulator, then hit the back of both rails or hit both rails FIRST and regulator after that ? Thought about running it the first way and capping the front off the rails off.
Old 11-17-2014, 08:32 AM
  #2  
TECH Resident
 
N20zuki's Avatar
 
Join Date: Jun 2009
Location: Elizabeth City NC
Posts: 856
Likes: 0
Received 2 Likes on 2 Posts

Default

Rails first then to the regulator.
Old 11-17-2014, 09:25 AM
  #3  
8 Second Club
iTrader: (19)
 
oscs's Avatar
 
Join Date: Jan 2013
Location: Cypress, TX
Posts: 3,903
Likes: 0
Received 4 Likes on 4 Posts
Default

Originally Posted by Mike 02T/A
What's the best way to run the Fuel Pressure Regulator? I've switching out the stock rails, etc. Is it better to run fuel feed into regulator, then hit the back of both rails or hit both rails FIRST and regulator after that ? Thought about running it the first way and capping the front off the rails off.
I had it ran this way and it worked fine but the problem with running it that way is IF your regulator fails in such a way that prevents fuel flow than you will lean out. The though process behind running the regulator after the rails is simply the opposite of what I just said. If the regulator fails you will get whatever pressure your pump is putting out.

Best way to set it up IMO is to have the pump feeding both rails (T) and then (T) them back into the regulator after the rails or use the regulator as your (T)

Last edited by oscs; 11-17-2014 at 09:33 AM.
Old 11-17-2014, 09:28 AM
  #4  
TECH Fanatic
iTrader: (16)
 
Ryans99ls1's Avatar
 
Join Date: Dec 2007
Location: OH & MI
Posts: 1,483
Received 76 Likes on 41 Posts

Default

The general thought is that you want the regulator to compensate for the pressure loss across the rails. By placing it after the rails, you should have no less than what you have it set at at all times. Both ways have been shown to work though
Old 11-18-2014, 06:47 AM
  #5  
TECH Veteran
iTrader: (7)
 
forcd ind's Avatar
 
Join Date: Sep 2007
Location: woodbine, md
Posts: 4,119
Received 236 Likes on 165 Posts

Default

I thought this out to, since I was plumbing mine and ordering fittings
some said to tee into one end of the rails, tee out the other end to the reg
some said just go in one rail, cross over on the other end, and back out to the reg-it seemed to me you could starve the far side injs. by feeding one side first, but I guess there's enough vol. it doesn't happen
If you look at a Nascar engine, they just go in one end, cross over, then out the other end to a reg-so that's what I settled on, lol
Old 11-18-2014, 09:30 AM
  #6  
kjm
Launching!
 
kjm's Avatar
 
Join Date: Jun 2013
Location: New Orleans
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Default

I think it depends on rail size and crossover line. If I was running a real small rail and crossover line I would probably feed into both rails and then out from both into regulator. But if you have a large high capacity rail and crossover. I will feel comfortable just going into one across to other and the regulator.
Just my thoughts
Kerry
Old 11-18-2014, 11:35 AM
  #7  
Moderator
iTrader: (2)
 
denmah's Avatar
 
Join Date: Aug 2008
Posts: 5,339
Likes: 0
Received 30 Likes on 24 Posts

Default

in an fbody? you can just do a regulator and then feed the stock rails
we are over 700whp on stock rails
Old 11-18-2014, 11:40 AM
  #8  
TECH Enthusiast
iTrader: (13)
 
jasonz28camaro's Avatar
 
Join Date: Sep 2006
Location: Houston
Posts: 593
Received 7 Likes on 7 Posts

Default




Stuck mine here after the rails. -8 feed, y-block to both rails with -6. -6 crossover and return.
Old 11-18-2014, 11:58 AM
  #9  
8 Second Club
iTrader: (19)
 
oscs's Avatar
 
Join Date: Jan 2013
Location: Cypress, TX
Posts: 3,903
Likes: 0
Received 4 Likes on 4 Posts
Default

Originally Posted by jasonz28camaro
Stuck mine here after the rails. -8 feed, y-block to both rails with -6. -6 crossover and return.
Best way to do it
Old 11-18-2014, 06:04 PM
  #10  
11 Second Club
Thread Starter
iTrader: (28)
 
Mike 02T/A's Avatar
 
Join Date: Jul 2004
Location: FL
Posts: 398
Likes: 0
Received 0 Likes on 0 Posts

Default

I'm not building a wild 1k hp car here. Any real harm in going into regulator, feed back of both rails and cap off the fronts?
Old 11-18-2014, 06:17 PM
  #11  
8 Second Club
iTrader: (19)
 
oscs's Avatar
 
Join Date: Jan 2013
Location: Cypress, TX
Posts: 3,903
Likes: 0
Received 4 Likes on 4 Posts
Default

Originally Posted by Mike 02T/A
I'm not building a wild 1k hp car here. Any real harm in going into regulator, feed back of both rails and cap off the fronts?
It's already been explained. There isn't a whole lot of different ways to do this. Pick which ever one your comfortable with
Old 11-18-2014, 07:42 PM
  #12  
TECH Resident
 
N20zuki's Avatar
 
Join Date: Jun 2009
Location: Elizabeth City NC
Posts: 856
Likes: 0
Received 2 Likes on 2 Posts

Default

Originally Posted by Mike 02T/A
I'm not building a wild 1k hp car here. Any real harm in going into regulator, feed back of both rails and cap off the fronts?
Im not building a 1khp car either, But I made this mistake and put my regulator pre fuel rails and I had issues with my injectors not being able to flow properly. I am boosted and run a boost reference regulator, under boost I am running 72psi to compensate for the regulator being improperly placed and the injector duty cycle maxing out at lower pressure. This winter I am going to fix that problem to get the pressure lower and hopefully get more out of it.

Cliff notes yes you can do it, but there is adverse affects and its not hard to hook it up post rails and do it properly.
Old 11-18-2014, 09:33 PM
  #13  
On The Tree
iTrader: (7)
 
dean85gt's Avatar
 
Join Date: Jan 2010
Posts: 149
Likes: 0
Received 0 Likes on 0 Posts
Default

I have the reg before a stock rail and am almost at 700rwhp with zero fuel pressure issues. Works great so why change it



Quick Reply: Best way to run FPR?



All times are GMT -5. The time now is 10:13 PM.