Speedometer Calibrators???
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,478
Likes: 4
From: Formerly from the Great White North but now residing in the Desert Southwest NM (The Land of Dis-Enchantment?)
Speedometer Calibrators???
Does anyone have any experience with Abbott Enterprises speedometer calibrator or ratio adjuster? The purpose is to give an accurate speedometer reading after a tire or gear change without going in and changing speedo gears.
Team Owner
Joined: Sep 2003
Posts: 25,366
Likes: 2,733
Abbott is a quality product but if the calibration can be done mechanically with gears I believe it to be the "preferred"! It's often debated here!
Why? There's much more than just the "speedo" that relies on the correct signal from the transmission speed sensor!
Have you done the required math for a mechanical calibration? You don't mention the car, trans, axle or tire so I guess the correct response would be Abbott is maybe the better of those DRA/ERA products out there! Is it for the '92 M6 in your "sig"?
Search for "Abbott" and you should find some results!!!
Why? There's much more than just the "speedo" that relies on the correct signal from the transmission speed sensor!
Have you done the required math for a mechanical calibration? You don't mention the car, trans, axle or tire so I guess the correct response would be Abbott is maybe the better of those DRA/ERA products out there! Is it for the '92 M6 in your "sig"?
Search for "Abbott" and you should find some results!!!
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,478
Likes: 4
From: Formerly from the Great White North but now residing in the Desert Southwest NM (The Land of Dis-Enchantment?)
In order to put a 3.90 in my '92 6-speed it is going to require changing both the drive and driven gears and if I don't have to tear out the new exhaust, x-brace, and...I thought I'd check out the unit from Abbott. I'm mostly concerned as to what it does to the feed to the ECM. Anyone know the details?
Team Owner
Joined: Sep 2003
Posts: 25,366
Likes: 2,733
Here's my thoughts on a 3.90 gear with a ZF and a 275, 285 or 315 tire!
It's generally accepted that a 45 tooth gear will correct a 3.75 axle ratio change. If that's to be accepted a 45 tooth gear with a 3.90 gear should be +/- very little and as a "cushion" vehicle speed would be "less".
Math makes vehicle speed 57.6923+ at a displayed 60 mph. Given different "rolling radius" specifications for various tire brands I've thought it would be a wise move to try the 45 tooth with the 3.90 first and check the calibration with a GPS, measured miles etc! This is all "assuming" the 3.75 ratio correction is correct! I don't know! The math I do makes it worth "the attempt"!!
Now if it's actually a 3.92 gear that would make it 57.39+.
My 3.90 gear isn't installed yet but it was going to be my first try to get a "hands on" value!
Another "plus" to the attempt is the cost factor $10 VS $150+ !!!
Another thought, if your gear isn't bought yet can you live with a 3.73 gear? The $150 goes a long way (better than half) the price of the gear package!
It's generally accepted that a 45 tooth gear will correct a 3.75 axle ratio change. If that's to be accepted a 45 tooth gear with a 3.90 gear should be +/- very little and as a "cushion" vehicle speed would be "less".
Math makes vehicle speed 57.6923+ at a displayed 60 mph. Given different "rolling radius" specifications for various tire brands I've thought it would be a wise move to try the 45 tooth with the 3.90 first and check the calibration with a GPS, measured miles etc! This is all "assuming" the 3.75 ratio correction is correct! I don't know! The math I do makes it worth "the attempt"!!
Now if it's actually a 3.92 gear that would make it 57.39+.
My 3.90 gear isn't installed yet but it was going to be my first try to get a "hands on" value!
Another "plus" to the attempt is the cost factor $10 VS $150+ !!!
Another thought, if your gear isn't bought yet can you live with a 3.73 gear? The $150 goes a long way (better than half) the price of the gear package!
Last edited by WVZR-1; May 24, 2009 at 08:35 AM.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,478
Likes: 4
From: Formerly from the Great White North but now residing in the Desert Southwest NM (The Land of Dis-Enchantment?)
Here's my thoughts on a 3.90 gear with a ZF and a 275, 285 or 315 tire!
It's generally accepted that a 45 tooth gear will correct a 3.75 axle ratio change. If that's to be accepted a 45 tooth gear with a 3.90 gear should be +/- very little and as a "cushion" vehicle speed would be "less".
Math makes vehicle speed 57.6923+ at a displayed 60 mph. Given different "rolling radius" specifications for various tire brands I've thought it would be a wise move to try the 45 tooth with the 3.90 first and check the calibration with a GPS, measured miles etc! This is all "assuming" the 3.75 ratio correction is correct! I don't know! The math I do makes it worth "the attempt"!!
Now if it's actually a 3.92 gear that would make it 57.39+.
My 3.90 gear isn't installed yet but it was going to be my first try to get a "hands on" value!
Another "plus" to the attempt is the cost factor $10 VS $150+ !!!
Another thought, if your gear isn't bought yet can you live with a 3.73 gear? The $150 goes a long way (better than half) the price of the gear package!
It's generally accepted that a 45 tooth gear will correct a 3.75 axle ratio change. If that's to be accepted a 45 tooth gear with a 3.90 gear should be +/- very little and as a "cushion" vehicle speed would be "less".
Math makes vehicle speed 57.6923+ at a displayed 60 mph. Given different "rolling radius" specifications for various tire brands I've thought it would be a wise move to try the 45 tooth with the 3.90 first and check the calibration with a GPS, measured miles etc! This is all "assuming" the 3.75 ratio correction is correct! I don't know! The math I do makes it worth "the attempt"!!
Now if it's actually a 3.92 gear that would make it 57.39+.
My 3.90 gear isn't installed yet but it was going to be my first try to get a "hands on" value!
Another "plus" to the attempt is the cost factor $10 VS $150+ !!!
Another thought, if your gear isn't bought yet can you live with a 3.73 gear? The $150 goes a long way (better than half) the price of the gear package!
Team Owner
Joined: Sep 2003
Posts: 25,366
Likes: 2,733
WVZR-1...Current tire is a 275 but probably will go to 315's. Both have about the same rolling diameter. My original intent was to go to a 3.73 but a couple of 3.90's have come available which made me consider that ratio. I agree with you that the cost of a driven gear is better than the ERA or two gears and a speed sender with the extra tranny work. If I can find a good 3.73 I still may go that route...Jack
You don't need a sensor regardles of how you go about it. The sensor in your M6 will do every gear that's 40 tooth or higher. I was hoping you already had the 3.90 and yours would be a good "candidate" for the "test"!!
I did some more math and I believe the "spread" could be wider than what I posted in the previous post. I guess I really need to determine the actual rolling radius first hand. I might get to that today!
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,478
Likes: 4
From: Formerly from the Great White North but now residing in the Desert Southwest NM (The Land of Dis-Enchantment?)
Jack,
You don't need a sensor regardles of how you go about it. The sensor in your M6 will do every gear that's 40 tooth or higher. I was hoping you already had the 3.90 and yours would be a good "candidate" for the "test"!!
I did some more math and I believe the "spread" could be wider than what I posted in the previous post. I guess I really need to determine the actual rolling radius first hand. I might get to that today!
You don't need a sensor regardles of how you go about it. The sensor in your M6 will do every gear that's 40 tooth or higher. I was hoping you already had the 3.90 and yours would be a good "candidate" for the "test"!!
I did some more math and I believe the "spread" could be wider than what I posted in the previous post. I guess I really need to determine the actual rolling radius first hand. I might get to that today!
Racer
Joined: Oct 2008
Posts: 299
Likes: 1
From: Ottawa Ontario
I believe on your 92 you will need to swap out the chip. Just provide your gear information and tire sizes to someone on the forums that can burn you a new chip or I just googled and found this guy that will do it.
http://www.lt1pcmtuning.com/service/
I hope this helps.
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