Carbs
+ Reply to Thread
Results 1 to 11 of 11

Thread:
Carbs

  1. #1
    Senior Member SBS933's Avatar
    Join Date
    Jun 2012
    Location
    Socialist Republic of California / Parker Az.
    Posts
    975

    Default Carbs

    Can a good carb shop add horsepower to a motor with mods, if so how much out of a single carb without any further motor work ?

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Senior Member
    Join Date
    Dec 2007
    Location
    Olympia, Washington
    Posts
    586

    Default

    Depends how far out of tune the carb. is.

  4. #3
    Senior Member SBS933's Avatar
    Join Date
    Jun 2012
    Location
    Socialist Republic of California / Parker Az.
    Posts
    975

    Default

    Quote Originally Posted by Oldelmn8tr View Post
    Depends how far out of tune the carb. is.
    Lets say the carb is right out of the box

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    Senior Member
    Join Date
    Dec 2009
    Location
    Northern Indiana
    Posts
    132

    Default

    Just my .02. Out of the box a carb is set up in a will work ok for most condition. It is not set up to optimize a highly modified engine. Given sufficient engine details and how you are using it, a carb tuner or custom builder can provide an improvement. Exact numbers are hard to determine without side by side dyno pulls with each carb on the same engine. In some instances improvments of 5% or so can be had. I am not sure if it is because the custom carb is that good or the original carb was that bad. It will be interesting to hear more from others on this one.

  7. #5
    Senior Member
    Join Date
    Dec 2007
    Location
    Newbury Park, Ca/Mohave Valley, Az
    Posts
    8,169

    Default Baseline/homework....

    You would need a solid baseline to work from. Unless you have unlimited access to a dyno, you're going to have to do a lot of "homework" collecting data from the "out of the box" version of the carb, vs the re worked version.... First and foremost, you would need to know what the current air/fuel ratio is. There are several EGT systems out there that are very valuable tuning aids, and allow for spot on a/f ratios in various locations... Once all that is established and you have a performance baseline to work from, it is possible a carb "guru" could find a little more, but if you've done your part to gain every bit you could, the amount of improvement will be minimal... As mentioned, a percentage of gain will be based on how far off it was to begin with.... On a side note, if you need to go up, or down, more than 4 jet sizes to get it better, chances are it's the wrong carb for your application....
    Ray
    LOUD BOATS SAVE LIVES

  8. #6
    Senior Member
    Join Date
    Mar 2009
    Location
    WHITTIER CA
    Posts
    534

    Default

    I just dynoed a motor and a stuck fuel bowl was good for 50hp on paper just my .02

  9. #7
    Senior Member MACHINEHEAD1's Avatar
    Join Date
    May 2008
    Posts
    473

    Default

    The WOT mix on a lot of the newer carbs is really good out of the box. The carbs with the adj. air bleeds and billet blocks (Holley, Quick Fuel, Pro Form, ect.) are really really close. I just finished a 410W at Westech with a box stock 750HP Holley. Never touched it. 491HP worth of air. Strapped on the 3310-10 (end use) and ended up with stock metering plate and up 2 sizes on the primary, the cruise was a little lean (14.4) for my application. 486HP. Both WOTs were 12.4-12.6. The only way to know, is the AFR gauge as mentioned before. If it pulls more rpm with your combo, stop there. Between myself, Steve Brule' and my dad Ken Crocie, I dont think the 750HP holley was going to get much better. Also at the end, ran an older (09' ish) Mighty Demon 850 with stock jets. Didnt touch it. 489HP. WOT AFRs were all nearly the same. If you are running Comp Eliminator or something, send it to a "guru". Then dyno it. And you might find some power.

  10. #8
    Or Seth, either one Budweiser's Avatar
    Join Date
    Dec 2007
    Location
    Tower Park Resort, Lodi, CA
    Posts
    3,270

    Default

    Speaking in terms of WOT... Once the carb is tuned for the day, whacha got is whacha got.

    Any additional horse power is going to show up through mods that INCREASE AIRFLOW through the carb.

    Who knows what milling the airhorn and other mods may net? It could be zilch on one engine and "oh wow" on another.

    If you're not racing, IMHO... don't sweat it. If you're talking about NASCAR... I think those guys would pay more than a comfortable mans salary for 1/25 HP gain.

    If you do not know how to properly tune a carb, money spent having it done by someone who does WILL pay off. Just getting it tuned correctly.

    Good Luck!
    -Seth-
    Last edited by Budweiser; 08-02-2012 at 08:44 AM.

  11. #9
    Senior Member SBS933's Avatar
    Join Date
    Jun 2012
    Location
    Socialist Republic of California / Parker Az.
    Posts
    975

    Default Good Input

    I just got my carb back and it was jetted on a dyno, hope to see the gains i had lost due to years of use. I was told by a motor builder that a good carb guy can really do things up. He told me they did a dyno test and a carb builder brought in a carb and added 25 H.P. just bolting on his carb. I thought i would try to get some input before i flap my gums around people that could tell me i don't know shit. I do know if you can't process what a carb is dumping then you are either gonna suffer or gain nothing.

  12. #10
    Senior Member tkriley13's Avatar
    Join Date
    Jan 2009
    Posts
    1,013

    Default

    Quote Originally Posted by Slow Boats Suck View Post
    Can a good carb shop add horsepower to a motor with mods, if so how much out of a single carb without any further motor work ?

    Call C & J Engineering and ask for Johnny!!!! The best money you`ll ever spend!!! His son is on here as Piston maker I think??? Sorry my phone took a flight and I havent put their number back in yet....Tom

  13. #11
    CP-Carrillo Piston Maker's Avatar
    Join Date
    Apr 2009
    Location
    In the Dungeon
    Posts
    297

    Default Thanks Tom!

    Quote Originally Posted by tkriley13 View Post
    Call C & J Engineering and ask for Johnny!!!! The best money you`ll ever spend!!! His son is on here as Piston maker I think??? Sorry my phone took a flight and I havent put their number back in yet....Tom
    Yes he's my Dad and he does a great job......but I'm biased

    Here's his info, if interested: http://www.performanceboats.com/jet-...gineering.html

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in

Tags for this Thread

Digg This Thread

Posting Permissions

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95