Page 1 of 4 1 2 3 ... LastLast
Results 1 to 10 of 31
  1. #1
    David 1 FAST VE's Avatar
    Join Date
    Jun 2005
    Location
    Southaven, MS
    Posts
    1,958
    +1
    1

    Air Fuel Ratio ?? Help, Get me to the Bug

    Today I ran 78.5 @ 7500 RPM's which made me feel good.

    Bad thing is that the AFR was 14.7 under 100% load and EGT's in the # 3 cylinder were 1580 degrees.

    My EGT sensor leads were to short so I only had #3 hooked up.


    What are you guys shooting for when tunning as far as EGT's and AFR #'s?

    I understand that EGTS are all different but what is the ballpark?

    Running this lean do you think the ski would feel like a dog?


  2. #2
    1101rwhp Wolverine's Avatar
    Join Date
    Sep 2006
    Location
    Orlando
    Posts
    184
    14.7

  3. #3
    Moderator
    I build Horsepower
    NitroShark's Avatar
    Join Date
    Jan 2006
    Location
    Greenville,SC
    Posts
    1,388
    +1
    13
    If you are using the instrument grade Autronics A/F meter (and expensive but very accurate) then 14.7 is way to lean and you should have had a meltdown. My guess is your numbers of A/F are off and not using it. but if you are....

    Try to fuel around 11.6-11.9 under 100% load.

    EGTs can not be compared on a internet forum because the placement of the sensor needs to be identical to the users.. and I mean its not were its placed but ALSO how far in you put the tip of the sensor.

    You will get apples to oranges for sure

    i run 1480-1500F on my Ski and 1860-1880 on my nitro Top Fuel race bike.. numbers only mean to you what you have to your combo.

    shawn

  4. #4
    Quote Originally Posted by 1 FAST VE View Post
    Today I ran 78.5 @ 7500 RPM's which made me feel good.

    Bad thing is that the AFR was 14.7 under 100% load and EGT's in the # 3 cylinder were 1580 degrees.

    My EGT sensor leads were to short so I only had #3 hooked up.


    What are you guys shooting for when tunning as far as EGT's and AFR #'s?

    I understand that EGTS are all different but what is the ballpark?

    Running this lean do you think the ski would feel like a dog?
    [email protected]? What pitch impeller are you running? AFR 11.7-12.2

  5. #5
    Been there and back! BDNJ's Avatar
    Join Date
    Jul 2005
    Location
    Silver Bay, Toms River, N.J.
    Posts
    1,536
    If you see 14 afr under a load @ wot, you better back off quick. I have run 13.0 and made it out ok, but never 14, or 14+.

    It's going to be hot at the bug...the hotter the air, the more expanded the air molecules are. This means you might not need quite as much gas as normal. You still need to add fuel for your set up though.

    Brendan
    Last edited by BDNJ; 06-02-2007 at 08:55 PM.

  6. #6

    Join Date
    Jan 2006
    Location
    Rydal, Georgia U S A
    Posts
    3,936
    +1
    14
    More fuel
    ,more fuel 1580 degrees... Too hot! Race fuel will let you live for a little while, MS109

  7. #7
    David 1 FAST VE's Avatar
    Join Date
    Jun 2005
    Location
    Southaven, MS
    Posts
    1,958
    +1
    1
    15/21 3 Blade prop

  8. #8
    EZ Dock of Long Island Shibby1485's Avatar
    Join Date
    May 2005
    Location
    Long Island, NY
    Posts
    9,464
    +1
    4
    Quote Originally Posted by 1 FAST VE View Post
    Today I ran 78.5 @ 7500 RPM's which made me feel good.


    check ur PM in 5 minutes... i'll find those links for you on and the closed loop a/f tuning with the stuff u have

  9. #9
    David 1 FAST VE's Avatar
    Join Date
    Jun 2005
    Location
    Southaven, MS
    Posts
    1,958
    +1
    1
    Shawn I have an idea if it will work.
    Looking through my map 2/3 of it is way off compared to the Igni map that everyone is running.

    Can I build a timing map by inputing the same curve that other guys are running or are there other variables to consider that make them to far apart to do this.

    1/3 of my map is very close to the Igni map but the other 2/3 is totally different.

    What do you think?

    I am running the same ARF gauge that everyone else here is running. I know it is not an Autronics but it is better than nothing.

    There is only one place to install the sensor in the manifold so everyones is more or less in the same place as far as placement.

  10. #10
    David 1 FAST VE's Avatar
    Join Date
    Jun 2005
    Location
    Southaven, MS
    Posts
    1,958
    +1
    1
    Thanks Shibby

Page 1 of 4 1 2 3 ... LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 94 SLT 750, Help point me to the correct tech references.
    By ghostinstallations in forum Polaris Open Discussion
    Replies: 12
    Last Post: 08-24-2011, 02:46 PM
  2. Air : Fuel Ratio on the hose?
    By sweetbats in forum 4-Tec Performance
    Replies: 12
    Last Post: 11-30-2008, 10:26 AM
  3. HELP i need to get me and my ski to the bug
    By rapidacceleration in forum Mudbug Nationals PWC.Life Rally
    Replies: 1
    Last Post: 05-30-2007, 10:07 AM
  4. Welcome me to the 70mph club!
    By camar0 in forum Sea Doo Open Discussion
    Replies: 32
    Last Post: 05-25-2007, 08:48 AM
  5. I can't wait to get out to the water tomorrow!
    By Green Hulk in forum 4-Tec Performance
    Replies: 32
    Last Post: 01-16-2006, 08:05 AM

Posting Permissions

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