Nos and A/F gauges-#'s
+ Reply to Thread
Results 1 to 10 of 10

Thread:
Nos and A/F gauges-#'s

  1. #1
    Senior Member H20MOFO's Avatar
    Join Date
    Dec 2007
    Posts
    4,288

    Default Nos and A/F gauges-#'s

    I'm a little hesitant to spray, since 2005, I've gone through 3 boat motors.lol I used to think that the main way to go wrong(with nos) was to be too lean. A few months a go there was a thread that said too rich was just as bad. I have a set of dry headers and a wideband and was wondering if the std. a/f #'s would apply when the nos was on, or not???? I realize there are a lot of other variables(timing ect). For argument/discussion sake here lets say it's a 200 shot.
    Another Hot Boat refugee

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Resident Ford Nut Sleeper CP's Avatar
    Join Date
    Dec 2007
    Location
    San Diego County
    Posts
    10,072

    Default

    Quote Originally Posted by H20MOFO View Post
    I'm a little hesitant to spray, since 2005, I've gone through 3 boat motors.lol .
    Did they die because of Nos? If so what type of system, plate or fogger?

    S CP

    "Dark Sarcasm"
    Going fast is only half the fun ... what you make go
    fast is the other half.
    " A Government big enough to give you everything you want is big enough to take away everything you have"

  4. #3
    Senior Member H20MOFO's Avatar
    Join Date
    Dec 2007
    Posts
    4,288

    Default

    Quote Originally Posted by Sleeper CP View Post
    Did they die because of Nos? If so what type of system, plate or fogger?

    S CP
    Naw....never sprayed before. Killed the 1st motor before I made my 1st pmt on the boat.lol The guy that sold it to me said it was "around" 11 to 1, turned out to be closer to 12 to 1. Personally I think I got some bad gas because I was mixing 110 and still burned a hole between 5 an 7 in the cyl. head big enough to stick your pinky finger in. The second motor went about a year and a half,long story short I lost a cam lobe and lifter.
    Another Hot Boat refugee

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    Resident Ford Nut Sleeper CP's Avatar
    Join Date
    Dec 2007
    Location
    San Diego County
    Posts
    10,072

    Default

    Quote Originally Posted by H20MOFO View Post
    I have a set of dry headers and a wideband and was wondering if the std. a/f #'s would apply when the nos was on, or not???? I realize there are a lot of other variables(timing ect). For argument/discussion sake here lets say it's a 200 shot.
    From all my Nos system reading and books I don't recall the answer, but I don't think the A/F numbers change all that much. Cyclone or CS may have dyno sheets showing this when they get back from the Regatta maybe they'll pipe in.

    I have a dyno sheet from a guy's engine I'll see if the A/F #'s were about the same.

    Edit: The 528" Ford made 825 hp at 6,600 with a BSFC of .397 with an A/F of 12.67
    on the Nos it made 1,145 hp at 6,400 with a BSFC of .394 with an A/F of 11.32 I can't tell you if that number is typical. I'll look in some of my Nos books when I get a chance.

    S CP
    Last edited by Sleeper CP; 08-15-2009 at 11:07 AM.

    "Dark Sarcasm"
    Going fast is only half the fun ... what you make go
    fast is the other half.
    " A Government big enough to give you everything you want is big enough to take away everything you have"

  7. #5
    Senior Member H20MOFO's Avatar
    Join Date
    Dec 2007
    Posts
    4,288

    Default

    Quote Originally Posted by Sleeper CP View Post
    From all my Nos system reading and books I don't recall the answer, but I don't think the A/F numbers change all that much. Cyclone or CS may have dyno sheets showing this when they get back from the Regatta maybe they'll pipe in.

    I have a dyno sheet from a guy's engine I'll see if the A/F #'s were about the same.

    Edit: The 528" Ford made 825 hp at 6,600 with a BSFC of .397 with an A/F of 12.67
    on the Nos it made 1,145 hp at 6,400 with a BSFC of .394 with an A/F of 11.32 I can't tell you if that number is typical. I'll look in some of my Nos books when I get a chance.

    S CP
    Thanks, I didn't know if there was a different ideal # to shoot for or not. I wondered if the extra 02 in the nos would maybe show a false lean? Based on the #'s you've posted, I'd guess probably not. Maybe I'll ask over on the bullet and prepare for the beating.lol Anyone have any thoughts on on whether or not a pyrometer would help tell if you were about to melt chit? Or do you think it would happen to fast to show up on the meter? Sorry if I'm beating a dead horse here, I'd feel better if I could see via some type of gauge if my motor was or wasn't getting abused. Or if I did, or didn't have it set up right.
    Another Hot Boat refugee

  8. #6
    Resident Ford Nut Sleeper CP's Avatar
    Join Date
    Dec 2007
    Location
    San Diego County
    Posts
    10,072

    Default

    Quote Originally Posted by H20MOFO View Post
    Anyone have any thoughts on on whether or not a pyrometer would help tell if you were about to melt chit? Or do you think it would happen to fast to show up on the meter? .
    Been there done that.....16 yrs ago. Shit happens way to fast.

    Just get a good system and try it. No need to reinvent the wheel.

    S CP

    "Dark Sarcasm"
    Going fast is only half the fun ... what you make go
    fast is the other half.
    " A Government big enough to give you everything you want is big enough to take away everything you have"

  9. #7
    mo balls than $cents$ IMPATIENT 1's Avatar
    Join Date
    Dec 2007
    Location
    hugo,okla
    Posts
    11,729

    Default

    look for around 12ish on the a/f ratio, anything more than that on nitrous is getting alil fat, or it is at my altitude anyways(think i'm 500ft above sea level) and that's where my gullwing like to be with the 505 on the 450hp shot. basically shooting for almost the same a/f ratios the blown/boosted guys.

    Dare to be different, if it turns out great you can claim you planned it that way.

    Jetboatperformance.com

  10. #8
    E-7 Sheepdog (ret) SmokinLowriderSS's Avatar
    Join Date
    Dec 2007
    Location
    Newton Ks.
    Posts
    6,834

    Default

    Quote Originally Posted by H20MOFO View Post
    I'm a little hesitant to spray, since 2005, I've gone through 3 boat motors.lol I used to think that the main way to go wrong(with nos) was to be too lean. A few months a go there was a thread that said too rich was just as bad. I have a set of dry headers and a wideband and was wondering if the std. a/f #'s would apply when the nos was on, or not???? I realize there are a lot of other variables(timing ect). For argument/discussion sake here lets say it's a 200 shot.
    As long as you are burning the same fuel (ie, gasoline), the same mixture ratio needs aply.

    The "extra" oxygen is countered by extra fuel, maintaining balance.

    An O2 sensor, obviously, reads un-burned O2, and the only way you get more un-burned O2 is to not counter it (the additional from the N2O) with additional fuel.
    "As democracy is perfected, the office of president represents, more and more closely, the inner soul of the people. On some great and glorious day the plain folks of the land will reach their heart's desire at last and the White House will be adorned by a downright moron."
    H.L. Mencken

    OBAMA: Some people deserve this.
    The rest of us are being dragged along kicking and screaming.

  11. #9
    B1 Racing cs19's Avatar
    Join Date
    Dec 2007
    Posts
    6,523

    Default

    Ask 10 different people and youll get 10 different answers on this one. Some say shoot for high 11s on the bottle, some say its the same as off the bottle. Saw some stuff recently on a dyno where 12.5 was targeted and the plug readings were real nice.

    Chris.
    B1Racing.net

  12. #10
    Senior Member STV_Keith's Avatar
    Join Date
    Dec 2007
    Location
    Lost Wages, NV
    Posts
    2,145

    Default

    Typically, I shoot for 1/2 point richer A/F on the squeeze than off. In a N/A motor, that's normally 12.8-13:1 on the motor, then 1/2 point richer on the squeeze. If its forced induction, then 11.5-11.8:1 minus the 1/2 point.
    Keith-


+ 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

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