Page 1 of 2 1 2 LastLast
Results 1 to 10 of 17

Thread: Afr/Rrfpr ?

  1. #1
    Autism Speaks. Its Time To Listen gOt BoOsT's Avatar
    Join Date
    May 2011
    Location
    Cali
    Posts
    1,413
    +1
    51

    Afr/Rrfpr ?

    Have a question and looking for some input...if your off boost afr's are dialed in what would the regulator set up as rising rate do to your afr's under boost? Would the afr stay the same since the fuel and air added are equal? TIA

    ~Will


  2. #2
    Eric Ocman's Avatar
    Join Date
    Aug 2008
    Location
    Cataula, Georgia, United States
    Posts
    4,700
    +1
    77
    Any time your under vac it would lean them out a tad IF you are tapped into the manifold.. IF you use your throttle body port everything would be unaffected until the boost comes in.

  3. #3
    Autism Speaks. Its Time To Listen gOt BoOsT's Avatar
    Join Date
    May 2011
    Location
    Cali
    Posts
    1,413
    +1
    51
    Quote Originally Posted by Ocman View Post
    Any time your under vac it would lean them out a tad IF you are tapped into the manifold.. IF you use your throttle body port everything would be unaffected until the boost comes in.
    thanks for the quick response Eric. so if i was using the t/b port, what would happen to the afr once boost hit and it started adding fuel?

  4. #4
    Brd-Prey's Avatar
    Join Date
    Mar 2012
    Location
    Lakeland, FL
    Posts
    242
    +1
    11
    The pressure in the fuel rail will rise 1 psi for every pound of boost. So, your engine will get additional fuel because injector flow rate is based on the fuel pressure. More pressure more fuel pass for a given time open. So, if your engine needs to have its fueling tables reflec that your injector flow rate is higher under boost.
    Real life example. I got a tune from Vtech, dont know if Jonaton missed me saying I had a rrfpr or I didnt mention it. But the tune I got was for a normal setup not a RRFPR set for 1 psi for 1 pound of boost. So what happened my AFR was 13.7 at idle but when I went in to Full throttle I had 9 to 1 AFR which is way to rich. So I unplugged the vacuum line from the manifold and plugged it. Now my AFR was 12.3 at wot which is perfect. So why have a RRFPR because if you throw a larger charger on there you will get more fuel out of the stock injectors when you need it most. Plus you can dial up RRFPR pressure if you need even more fuel.

  5. #5
    Eric Ocman's Avatar
    Join Date
    Aug 2008
    Location
    Cataula, Georgia, United States
    Posts
    4,700
    +1
    77
    Quote Originally Posted by gOt BoOsT View Post
    Quote Originally Posted by Ocman View Post
    Any time your under vac it would lean them out a tad IF you are tapped into the manifold.. IF you use your throttle body port everything would be unaffected until the boost comes in.
    thanks for the quick response Eric. so if i was using the t/b port, what would happen to the afr once boost hit and it started adding fuel?
    It will rise one lb of fuel pressure per pound of boost. That's what it should do at least.

  6. #6
    boost junkie skidoochris's Avatar
    Join Date
    Mar 2012
    Location
    Davison, Mi
    Posts
    4,494
    +1
    476
    actually a rrfpr does not add more fuel
    it just keeps the SAME fuel flow at any boost level
    and you can add a begi and get up to 5:1
    so every pound of boost you get 5 psi more fuel psi
    that is how you get MORE fuel

  7. #7
    Eric Ocman's Avatar
    Join Date
    Aug 2008
    Location
    Cataula, Georgia, United States
    Posts
    4,700
    +1
    77

    Re: Afr/Rrfpr ?

    Quote Originally Posted by skidoochris View Post
    actually a rrfpr does not add more fuel
    it just keeps the SAME fuel flow at any boost level
    and you can add a begi and get up to 5:1
    so every pound of boost you get 5 psi more fuel psi
    that is how you get MORE fuel
    Not sure what type of rrfpr that you may have but mine rises with boost using a reference line off my manifold.

  8. #8
    boost junkie skidoochris's Avatar
    Join Date
    Mar 2012
    Location
    Davison, Mi
    Posts
    4,494
    +1
    476
    if you dont want your rrfpr to see vacume you can use a inline check valve

  9. #9
    Eric Ocman's Avatar
    Join Date
    Aug 2008
    Location
    Cataula, Georgia, United States
    Posts
    4,700
    +1
    77

    Re: Afr/Rrfpr ?

    Quote Originally Posted by skidoochris View Post
    if you dont want your rrfpr to see vacume you can use a inline check valve
    The newer skis have a port on the TB for lubing that can be used.

  10. #10
    Autism Speaks. Its Time To Listen gOt BoOsT's Avatar
    Join Date
    May 2011
    Location
    Cali
    Posts
    1,413
    +1
    51
    Quote Originally Posted by Ocman View Post
    It will rise one lb of fuel pressure per pound of boost. That's what it should do at least.
    ya i know that part, but what will it do to the actual afr #? if your afr is tuned to 12.5 and you hit 20 psi of boost with the rrfpr 1:1 what happens to the afr?

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Replies: 8
    Last Post: 10-21-2011, 05:55 PM
  2. need help tuning RR rrfpr with AFR
    By IM2FAST4U in forum 4-Tec Performance
    Replies: 219
    Last Post: 09-08-2011, 09:31 PM
  3. ??? on bad AFR, and RRFPR base setting
    By VX1 in forum 4-Tec Performance
    Replies: 12
    Last Post: 07-05-2011, 06:19 PM
  4. Tuning RRFPR to correct AFR's
    By Sayers in forum 4-Tec Performance
    Replies: 21
    Last Post: 03-10-2011, 11:15 AM
  5. RRFPR ... Rude 1 ... AFR
    By JFizzleJR in forum 4-Tec Performance
    Replies: 22
    Last Post: 05-04-2009, 08:54 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •