Page 1 of 2 12 LastLast
Results 1 to 20 of 23
  1. #1
    Member Sam-SS's Avatar
    Join Date
    Feb 2006
    Location
    Treasure Island, FL
    Age
    85
    Posts
    109

    Red
    '99 Camaro SS

    How do I know when larger fuel injectors are needed?

    I was wondering how one knows when it is time to install larger injectors? My engine dynos at 404 RWHp and has most all of the free mods, CNC heads, Crane Cam and SS long tube headers w/3" "Y", intermediate pipe and muffler.
    My tuners have had problems in getting good drivability
    and when they get it worked out after a while it seems to fall back to occasional jumping, bucking, idle serge etc.

  2. #2
    Visualize°Design°Create SSwt00SS's Avatar
    Join Date
    Dec 2005
    Location
    DFW
    Posts
    9,285

    '18 CTS-V
    '13 ZL1

    your stock injectors are fine. im running a H/C/I/E car and putting down 444rwhp and im still on the stock injectors...

    whatever the issues that your tuner is having is a result of his tuning, not your injectors. your tuner would be able to tell you if your injectors are either maxed out or close to being maxed out...

    also, what size heads and what are your cam specs...?

  3. #3
    Member stephen02ws6's Avatar
    Join Date
    Jun 2007
    Location
    Dalzell, Illinois
    Age
    35
    Posts
    899

    red with black stripes
    2002 Trans Am WS6

    I was just told that you need to change the injectors after 400 horse.

  4. #4
    Visualize°Design°Create SSwt00SS's Avatar
    Join Date
    Dec 2005
    Location
    DFW
    Posts
    9,285

    '18 CTS-V
    '13 ZL1

    Quote Originally Posted by stephen02ws6 View Post
    I was just told that you need to change the injectors after 400 horse.
    sorry, i dont buy into that. my stock injectors are still performing and supporting nearly 520 flywheel hp and they are not maxed out. there is a difference between being TOLD and having it 'recommened' to swap out injectors...

    however this winter i plan to install the TSP 231/237 cam i have and install an UD pulley as well. it will be at that point, that I will install new injectors from 28lb/hr to only 36lb/hr...

    without knowing the specs of the cam the guy is running, the LSA, if he has an A4 or M6, gears, etc..., there are too many factors that could be the reason that his tuner is having issues w/drivability fine tuning, etc...

  5. #5
    Wants to be Snowboarding FuhBreezeE's Avatar
    Join Date
    May 2007
    Location
    DFW
    Posts
    7,603

    Stg IV a4
    '99 TA Ws777

    Quote Originally Posted by SSwt00SS View Post
    sorry, i dont buy into that. my stock injectors are still performing and supporting nearly 520 flywheel hp and they are not maxed out. there is a difference between being TOLD and having it 'recommened' to swap out injectors...

    however this winter i plan to install the TSP 231/237 cam i have and install an UD pulley as well. it will be at that point, that I will install new injectors from 28lb/hr to only 36lb/hr...

    ...
    Sean @ LG said the 99's have 26lb injectors, I upgraded mine to Ford 30lb injectors (36lbs in reality) It helps on warm starts and always gets enough fuel to that bad boy, do it.

  6. #6
    Visualize°Design°Create SSwt00SS's Avatar
    Join Date
    Dec 2005
    Location
    DFW
    Posts
    9,285

    '18 CTS-V
    '13 ZL1

    ah, i thought 98's only had the 26lb/hr injectors...

  7. #7
    Blown, Stroked, & Sprayed

    Ed Blown Vert's Avatar
    Join Date
    Aug 1999
    Location
    Arizona
    Posts
    51,361

    Black
    383 Procharged & N20 Vert

    You need to check the duty cycle of the injectors. If you are at 80%, then you should upgrade.

  8. #8
    Wants to be Snowboarding FuhBreezeE's Avatar
    Join Date
    May 2007
    Location
    DFW
    Posts
    7,603

    Stg IV a4
    '99 TA Ws777

    Quote Originally Posted by SSwt00SS View Post
    ah, i thought 98's only had the 26lb/hr injectors...
    That's what I thought, Sean said differently...

  9. #9
    Member Sam-SS's Avatar
    Join Date
    Feb 2006
    Location
    Treasure Island, FL
    Age
    85
    Posts
    109

    Red
    '99 Camaro SS

    Quote Originally Posted by SSwt00SS View Post
    sorry, i dont buy into that. my stock injectors are still performing and supporting nearly 520 flywheel hp and they are not maxed out. there is a difference between being TOLD and having it 'recommened' to swap out injectors...

    however this winter i plan to install the TSP 231/237 cam i have and install an UD pulley as well. it will be at that point, that I will install new injectors from 28lb/hr to only 36lb/hr...

    without knowing the specs of the cam the guy is running, the LSA, if he has an A4 or M6, gears, etc..., there are too many factors that could be the reason that his tuner is having issues w/drivability fine tuning, etc...
    Sorry that I started this thread and have not kept up with it. I had a problem that I had to take care of.

    To answer your questions, the cam is a Crane 228/238
    @ .50 w/1.8 rockers giving .600 lift at the valve. Heads are LS6 heads CNC ported by Texas-speed, LS6 Intake,
    80mm throttle body, Granateli MAS. The car is M6 w/3.73 gears. Long tube SS headers, 3" Y pipe,
    3" intermediate pipe and 3" muffler by Brassani.
    Injectors and ignition are stock. Car has 74k miles on it.
    Dyno at 404 RWHp. I dono what LSA is that you mentioned.

    Since I started the thread, I have installed an 80mm
    throttle body and this seems to have helped the drivability. The biggest problem that I now have is
    it dropping from my normal idle of 950rpm down to
    say 600 rpm occasionally and then it returns to normal.
    Also, when taking off from a city traffic light in slow
    traffic, I have to be careful as sometimes it will bog,
    dropping the RPM, at off idle when letting the clutch out.

    Ok, that is the long and the short of it.

    ...>>Sam

  10. #10
    Grand Imperial Wizard Sarge's Avatar
    Join Date
    Aug 2005
    Location
    Texas Department of Corrections
    Posts
    18,128
    Retired Outlaw Sum Bitch

    Simple. Your tuner should be logging the duty cycle of your injectors. If the exceed 80% then you need more injector. Period. I dont give a rats butt what RWHP you are putting down.

  11. #11
    Senior Member ss~zoso~ss's Avatar
    Join Date
    Dec 2004
    Location
    )
    Posts
    9,128

    SS: NBM, tan top
    1998-SS, 2010 Jetta TDI

    Quote Originally Posted by SSwt00SS View Post
    ah, i thought 98's only had the 26lb/hr injectors...
    98's have the biggest injectors 28.8lbs/hr

  12. #12
    Junior Member
    Join Date
    Nov 2006
    Location
    Texas
    Posts
    25

    Pewter
    2002 Z28

    For that size cam, you are way under powered, especially if you have heads and an M6 car. Your tuner does not know what he is doing. With cheap (in cost but not in quality) heads $1300 and a cam .644/.598 and full bolt on's I am getting about 470rwhp. Now I do have the fast 90/90 set up but you should hit about 440 to the wheels easy.

    Change tuners. Trust me thats where it's at. I have 37# injectors but the stock ones would do you fine.

  13. #13
    Member Sam-SS's Avatar
    Join Date
    Feb 2006
    Location
    Treasure Island, FL
    Age
    85
    Posts
    109

    Red
    '99 Camaro SS

    Quote Originally Posted by Zoilus View Post
    For that size cam, you are way under powered, especially if you have heads and an M6 car. Your tuner does not know what he is doing. With cheap (in cost but not in quality) heads $1300 and a cam .644/.598 and full bolt on's I am getting about 470rwhp. Now I do have the fast 90/90 set up but you should hit about 440 to the wheels easy.

    Change tuners. Trust me thats where it's at. I have 37# injectors but the stock ones would do you fine.
    Problem is that I am on my third tuner, all well respected in this area. I agree with your assessment but no one
    has been able to figure out why it does not make more
    power than it does. It is easy to say that the tuner does not know what he is doing but with three different respected tuners doing their best and making no progress, one has to say what else could be the problem.

    ...>>Sam

  14. #14
    Junior Member
    Join Date
    Nov 2006
    Location
    Texas
    Posts
    25

    Pewter
    2002 Z28

    Quote Originally Posted by Sam-SS View Post
    Problem is that I am on my third tuner, all well respected in this area. I agree with your assessment but no one
    has been able to figure out why it does not make more
    power than it does. It is easy to say that the tuner does not know what he is doing but with three different respected tuners doing their best and making no progress, one has to say what else could be the problem.

    ...>>Sam
    how long are these tuners taking to tune the car? More or less? In terms of hours I mean

  15. #15
    Member Sam-SS's Avatar
    Join Date
    Feb 2006
    Location
    Treasure Island, FL
    Age
    85
    Posts
    109

    Red
    '99 Camaro SS

    Quote Originally Posted by Zoilus View Post
    how long are these tuners taking to tune the car? More or less? In terms of hours I mean
    16 to 20 hours each for the first two. Maybe 8 hours for the last one. Four sessions with 12 total pulls on the dyno. I have spent 6 or more hours behind the wheel with one of the tuners in the passenger seat with a laptop working on the driveability issues. The last tuner has made the best progress in drivability but there has been no change in the
    RWHP with any of them.

  16. #16
    Junior Member
    Join Date
    Nov 2006
    Location
    Texas
    Posts
    25

    Pewter
    2002 Z28

    Quote Originally Posted by Sam-SS View Post
    16 to 20 hours each for the first two. Maybe 8 hours for the last one. Four sessions with 12 total pulls on the dyno. I have spent 6 or more hours behind the wheel with one of the tuners in the passenger seat with a laptop working on the driveability issues. The last tuner has made the best progress in drivability but there has been no change in the
    RWHP with any of them.

    who installed your stuff? Do you absolutely trust the people. You sure what you bought went in the car?? Maybe they put a small choppy cam and cheap heads and kept the good stuff for them. Just a thought only.

    That is a lot of time. My guy did it in about 4-5 and car runs like a champ on the street as a daily and vicious at high rpms. Don't know what else to tell you.

  17. #17
    Member Sam-SS's Avatar
    Join Date
    Feb 2006
    Location
    Treasure Island, FL
    Age
    85
    Posts
    109

    Red
    '99 Camaro SS

    Ok, I finally got some figures on the FI duty cycle. It is running up to 90%.

    So from what i have read here, it seems as if I should change injectors from
    the stock '99 LS1 units.

    I keep hearing of the Ford injectors being a good choice. Could someone shed a bit more light on this. How big should I go? What part number so I
    can search for them? How big should I go?

    As a reminder, this is a '99 LS1 in my SS with heads, cam and headers.
    404 RWHp.

    Thanks much,

    ...>>Sam

  18. #18
    Junior Member
    Join Date
    Nov 2006
    Location
    Texas
    Posts
    25

    Pewter
    2002 Z28

    ^ Personally I know and have heard around the world of LS forums, a lot of people using Racetronix brand. I have em, my friend with an 00 750hp Maro has used them for over a year, Pat G. and many others. No issues.

    You can find them almost anywhere for about $290 shipped or less brand new. Me and Pat use 37lbs. Definately enough for your app. However if you are going to use a power adder in the near future, then you may want to go with something larger. Maybe 42-50. But bigger is not always better, just depends on what you have now. Some 37's would be just fine.

  19. #19
    Senior Member mrr23's Avatar
    Join Date
    Jul 2005
    Location
    orlando, fl
    Posts
    7,364

    black
    2014 camaro 2ss/rs

    98, 01-02 has 28# injectors
    99-00 has 26# injectors

    sam, at 90% i wouldn't bother. 80% is a nice safety margin to keep them cool. if you want to get injectors, go with SVO 30# injectors. that will be more than enough.
    Cold Air Intake, Muffler Delete, Vinci High Performance Dual Valve Springs, Hardened Pushrods, Yella Terra 1.85 Rockers, Some Hydropdipped Stuff, Strut Tower Brace, Some SS Badges, boost/vacuum gauge, fuel pressure gauge, some checkered stripes, drilled/slotted rotors, ZL1addons Stealth wickerbill, Ruxifey LED side markers

  20. #20
    Member Sam-SS's Avatar
    Join Date
    Feb 2006
    Location
    Treasure Island, FL
    Age
    85
    Posts
    109

    Red
    '99 Camaro SS

    Quote Originally Posted by mrr23 View Post
    98, 01-02 has 28# injectors
    99-00 has 26# injectors

    sam, at 90% i wouldn't bother. 80% is a nice safety margin to keep them cool. if you want to get injectors, go with SVO 30# injectors. that will be more than enough.
    Hi Robert,

    I am having a problem with one cylinder bank going lean between 1200 rpm and 1800 rpm. Everything has been checked that can be thought of but the problem persists. I have checked O2 sensors, exhaust leaks, intake leaks, and anything else that I can think of. It is going lean by about 300mv. This is driving me nuts. The thought is that the only possibility left is the injectors.

    This is the last of my problems. Other than that, I can report that all of the other problems are now gone (for good I hope). I am checking the gas mileage now to see if it has come back up to a reasonable level. I would
    hope for around 14 to 15mpg around town.

    ...>>Sam

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Question: PCM Tables Values for Larger Fuel Injectors
    By sscamaro2000 in forum Computer & Tuning
    Replies: 1
    Last Post: 06-17-2010, 02:49 AM
  2. LS1 all yr fuel injectors, oe fuel rail, pump,more
    By Frost in forum Parts For Sale / Trade
    Replies: 7
    Last Post: 04-27-2009, 02:26 PM
  3. ls1 and lt1 injectors needed
    By c5formula in forum Parts Wanted / Trade
    Replies: 3
    Last Post: 03-06-2009, 07:01 PM
  4. Do I need larger fuel injectors?
    By richwebb78 in forum Internal Engine
    Replies: 23
    Last Post: 12-26-2007, 02:13 PM
  5. smaller fuel injectors means more fuel?
    By Ger-Fire in forum LT1
    Replies: 5
    Last Post: 10-12-2006, 03:06 PM

Bookmarks

Posting Permissions

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