airguide speedo calibration
Printed From: CorrectCraftFan.com
Category: General Correct Craft Discussion
Forum Name: General Discussion
Forum Discription: Anything Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=574
Printed Date: December-02-2024 at 5:59pm
Topic: airguide speedo calibration
Posted By: 79nautique
Subject: airguide speedo calibration
Date Posted: June-28-2004 at 4:31pm
I was out over the week-end and did some runs in perfect conditions to compare speedo's with my buddies Ranger and to see how well the engine mods turned out (we did this before with the stock engine and I got smoked out of the hole and on top end)
Well my speedo reads 7 mph slower than his. Can I adjust this out on my speedos or is it to much of a change? Also when I peg the speedo's will I have to recalibrate again?
As for the speed runs, the results where a little different this time around. I ran against a late 90's Ranger that will do 70 mph.
I left him coming out of the hole and he had my at 58 mph on his speedo on top end.
Now I have to decide to use the 13x13 3-blade or get a new 4-blade with increased pitch. And the exhaust note is SO SO SWEET, even with the mufflers.
-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique
|
Replies:
Posted By: yellowdog
Date Posted: June-29-2004 at 12:29am
'79,
The Airguides on the '78 have an adjustment screw on the front face. Takes a small allen wrench.
Had to re-adjust ours when I replaced the pitots. Readings were about 6 mph low. I did it with the boat moving and both speedo's returned to '0' when at rest.
As for re-adjusting when you peg out, I'd think you would have to given the way the Airguides work. If interested, I have a pair of brand new Teleflex black faced 70 mph speedos that will fit in the Aiguide bezel.
Don
-------------
Caretaker of the wife's '78 Ski Nautique
|
Posted By: 66polyhead
Date Posted: June-29-2004 at 1:23am
|
An Airguide tournament speedo. is calibrated between the first and last bouy on a slalom course, (800 ft.). The driver passes the first bouy at 35 m.p.h., the judge in the observers seat starts the stop watch, the driver passes the last bouy in 26.3 to 26.6 seconds. If not the driver repeats and the speedo is adjusted accordingly. I'll try to post the chart in the next few days.
|
Posted By: Morfoot
Date Posted: June-29-2004 at 8:35am
I recently tuned my speedo's in on my 88' using a buddys GPS. Don't know if you have acess to one but they work great if for anything but dialing in the speedo's.
-------------
"Morfoot; He can ski. He can wakeboard.He can cook chicken.He can create his own self-named beverage, & can also apparently fly. A man of many talents."72 Mustang "Kermit",88 SN Miss Scarlett, 99 SN "Sherman"
|
Posted By: 79nautique
Date Posted: June-29-2004 at 11:54am
Don,
Do those speedo's look like the stock ones? The majority of the time I won't be running it above 50 but I'm looking at increasing the prop pitch and the speed will pick up so those 70 mph mau come in handy
-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique
|
Posted By: yellowdog
Date Posted: June-29-2004 at 4:27pm
66 polyhead,
Gotta question the numbers. At 35 mph you should cover 800 ft in 15.58 seconds. OR; 35 mph is 51.334 ft/sec; so you would cover 1357.7 ft in 26.45 seconds. Going the other way, covering 800 ft in 26.45 seconds is 30.2457 ft/sec or 20.62 mph. I think?
-------------
Caretaker of the wife's '78 Ski Nautique
|
Posted By: yellowdog
Date Posted: June-29-2004 at 4:33pm
'79,
No, they are a bit different in that the dial is evenly divided, without the exagerated spacing between 25 & 35 mph. I'll try to post a picture of the gauge face later tonight.
By the way, congrats on the success of the re-build! How does that hull react at over 50?
-------------
Caretaker of the wife's '78 Ski Nautique
|
Posted By: 79nautique
Date Posted: June-29-2004 at 6:08pm
it rides real nice now I'm not making any turns at that kind of speed but in a straight line it handles nice and smooth. Also keep in mind that the water conditions where pretty close to glass and I wouldn't run that hard if it was rough or choppy out. A little chop and it's ok, I ran down a cobalt that had it cranked up and got a thumbs up from the guy has we went past, maybe he just liked the exhaust tone. I would say I have a good 10-15 mph on most ski boats and my buddy thinks theirs' more speed to be had. I think it's running a little lean still. I have a bigger carb but want to change the oil before a start changing anything.
-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique
|
Posted By: 66polyhead
Date Posted: June-29-2004 at 11:54pm
Sorry, Don was quoting off the top of my sunburnt head, didn't have my chart, or a abbacus in front of me. When I learn how post a pic. link on here, I have quite a few Airguide sheets, new, and old. Maybe I'll just let Keith do it for me!
-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=220&yrstart=1925&yrend=1970" rel="nofollow - KY Wildcat
|
Posted By: yellowdog
Date Posted: June-30-2004 at 9:15pm
'79,
Just took a good look at those Teleflex speedometers. I doubt if they are what you would want. The total sweep is 270* with the first 90* being 0 - 40 mph; the middle 90 is 40 - 60; ad the last 90 is 60 - 70. These are really for boats that spend the majority of their time well above 40 mph. The spacing up to 30 mph is so small that accuracy at ski / wakeboard speeds is minimal. I knew there was another reason I didn't use them.
I'll part with them if you really want them, I just don't think they are practical for a ski boat.
Don
-------------
Caretaker of the wife's '78 Ski Nautique
|
Posted By: 66polyhead
Date Posted: July-01-2004 at 1:28am
Sorry guys, I was wrong on two accounts. Start to end slalom course is: 259 meters, 850 feet. ADJUSTMENT: The allen socket screw in the front of the instrument is used to precisely adjust the speed indication with the boat underway.
Refer to the speed and time chart below, as providedby the American Water Ski Association's Official Tounnament Rules, showing the time required to complete a run at a given speed.
Run the boat through the slalom course at an indicated speed of 36 MPH and have your observer check the time by stopwatch. If the time is between 15.88 and 16.28 seconds, no adjustment is necessary. If the time is less than 15.88 return to the course 36 MPH and adjust the reading upward. If the time is more than 16.28 seconds adjust to a lower reading. additional runs may be required for exact reading or to match reading on dual installations.
The table is based on a slalom course of 259 meters or 850 feet and this length may be used as the basis of a measured course where a slalom course is not available.
SLALOM COURSE
SPEED TIME
MPH KMPH SECONDS TOLERANCE
22 36 26.33 25.75-26.95
24 39 24.14 23.65-24.65
26 42 22.28 21.86-22.72
28 45 20.69 20.33-21.07
30 48 19.31 19.00-19.64
32 51 18.11 17.83-18.39
34 55 16.95 16.65-17.25
36 58 16.08 15.88-16.28
-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=220&yrstart=1925&yrend=1970" rel="nofollow - KY Wildcat
|
|