Results 1 to 7 of 7

ls1 gets fat on top end

This is a discussion on ls1 gets fat on top end within the Computer & Tuning forums, part of the LSx Technical Help Section category; just a question, had my car dynod a while back it made 433rwhp and 409rwtq, my question is above about ...

  1. #1
    Junior Member
    Join Date
    Aug 2008
    Location
    spokane washington
    Posts
    6

    red
    2001 slp camaro

    ls1 gets fat on top end

    just a question, had my car dynod a while back it made 433rwhp and 409rwtq, my question is above about 5200 the a/f ratio starts to get rich. makes power to 6200 rev limit. still has stock mass air, and stock t.b. could a lack of air on top end cause a rich condition? or can it be retuned to compensate for this..car ran 13.1-13.4a/f till around 5000prm then goes into 12.8-12.6a/f range. this was taken at the tailpipe
    please give any opinions on this thanks
    Bowtiy

  2. #2
    Senior Member 00z28bubba's Avatar
    Join Date
    Dec 2007
    Location
    las vegas, nv
    Age
    29
    Posts
    1,390

    white
    2000 Z28

    im pretty sure that is all in the tune. because if it was the maf or a mechanical error of some sort it would be noticable throughout the power band. hopefully frost can come in and verify if my idea is correct or not

  3. #3
    Senior Member 00z28bubba's Avatar
    Join Date
    Dec 2007
    Location
    las vegas, nv
    Age
    29
    Posts
    1,390

    white
    2000 Z28

    if i remember right alot of people with bolt ons stick with close to 12.6 afr and that 13.1 is a bit off but then again that is what i heard about only bolt on cars. list your mods and you will get a better idea of what going on from someone else

  4. #4
    The Bandit Wesman's Avatar
    Join Date
    Apr 2006
    Location
    NJ
    Posts
    4,033

    SGM
    1998 Trans Am WS6

    Quote Originally Posted by bowtiy View Post
    just a question, had my car dynod a while back it made 433rwhp and 409rwtq, my question is above about 5200 the a/f ratio starts to get rich. makes power to 6200 rev limit. still has stock mass air, and stock t.b. could a lack of air on top end cause a rich condition? or can it be retuned to compensate for this..car ran 13.1-13.4a/f till around 5000prm then goes into 12.8-12.6a/f range. this was taken at the tailpipe
    please give any opinions on this thanks
    Bowtiy
    Has the car been tuned at all?? That makes all the difference.

    Stock mass air should be good for the amount of power you're making, if I remember correctly the stock MAF is good for 500+WHP, when tuned correctly.

    However, I think the stock TB could be causing part of your problem. You can gain improvements in power on stock cars from just porting or upgrading to a new TB, with 433WHP you're probably starving the engine for air with the stock size TB.

  5. #5
    Junior Member
    Join Date
    Aug 2008
    Location
    spokane washington
    Posts
    6

    red
    2001 slp camaro

    Quote Originally Posted by Wesman View Post
    Has the car been tuned at all?? That makes all the difference.

    Stock mass air should be good for the amount of power you're making, if I remember correctly the stock MAF is good for 500+WHP, when tuned correctly.

    However, I think the stock TB could be causing part of your problem. You can gain improvements in power on stock cars from just porting or upgrading to a new TB, with 433WHP you're probably starving the engine for air with the stock size TB.
    the car has been upgraded with futral motorsports fm14 cam, full length headers, fast intake manifold, car has been tuned, and runs exellent... was just thinkin if it could be leaned out on top end a little it might pick up a few more horses.. would the a/f change with a reading closer to the o2 sensors?

  6. #6
    Junior Member 06MonteSS's Avatar
    Join Date
    Oct 2007
    Location
    CT
    Posts
    84

    Laser Blue Metallic
    2006 Monte Carlo SS

    you should run a wideband up as close to the headers as possible for the best readings... readings at the tailpipe will be different...

    you want to be at 12.6-12.8 AFR at WOT... 13's is gettin' a little lean...
    06MonteSS
    2006 Monte Carlo SS -- CAI, Poly mounts, STB's,
    Flowmaster Super 40's, Custom DiabLew Tune!
    Email: 06MonteSS@diablewtune.com


  7. #7
    Moderator Firebirdjones's Avatar
    Join Date
    May 2006
    Location
    Arizona
    Posts
    12,552
    The way it was explained to me this is normal. It's not uncommon to install bolt ons and then the car starts using higher frequencies in the MAF table.

    Since you have a cam, headers etc....your engine is reaching a higher point on the MAF tables than a stocker.

    The higher you go on the MAF table the richer it will get. GM has these cars programmed this way probably for safety/warranty reasons.

    I had the same issues with mine and couldn't figure out why until Frost explained this to me. I had actually added fuel in the MAF table up top which only compounded the problem.

    A simple change in the MAF tables had it running like mad up top.

    It sounds to me as though you are still running the factory rich commanded AFR's in the upper rpm ranges.

Thread Information

Users Browsing this Thread

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

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
  •