Corvette Mag Article on CAG bypass
03-23-2005, 06:57 PM
#1
Melting Slicks
Thread Starter
Corvette Mag Article on CAG bypass
The current issue of Corvette Magazine has an article on installing the CAGS bypass. There is a sidebar explaining in some detail why CAGS exists. The explanation is exceptionally clear.
I'm wondering if some kind soul would like to include the text in the FAQ?
I'm wondering if some kind soul would like to include the text in the FAQ?
03-23-2005, 11:21 PM
#4
Melting Slicks
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Originally Posted by Easy Ed
Where can you get the CAGS bypass kit? I have had my C-6 Vert since last Friday and can't wait to say goodbye to CAGS...
03-25-2005, 12:25 PM
#5
Instructor
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03-25-2005, 12:41 PM
#7
Melting Slicks
Thread Starter
CAGS is Computer Aided Gear Selection. (Chevy speak for 1-4 skip shift)
Now for a quick summary of why.
The EPA mileage test cycle has a low speed section where a higher gear yields huge improvements in the rated fuel economy. There is a loophole in the test procedure that makes it easy for automatics to do well. If the car automatically upshifts under light throttle, then the higher gear is okay for the low speed test portion. The computer for the A4, of course, is tuned for this situation. Side note: the speed involved is 15-19 MPH.
With a manual, the trick is to make it work like an automatic. What GM has done is to add CAGS to the MN6 so that it will force a 1-4 shift under light throttle between 15-19 MPH (the same speed as used in the EPA test). Therefore, as far as the EPA is concerned, the car 'automatically' shifts to 4th, so it can be included in the test procedure. The result is a higher EPA rating and no gas guzzler tax. In the real world, CAGS has no effect on mileage.
The CAGS eliminator, or bypass, merely eliminates the electrical connection to the solenoid on the transmission while hiding that fact from the diagnostic system (otherwise, you'd throw codes all the time).
So, you save money (no gas guzzler tax), and the issue is easy to eliminate. Win-win, IMHO.
Now for a quick summary of why.
The EPA mileage test cycle has a low speed section where a higher gear yields huge improvements in the rated fuel economy. There is a loophole in the test procedure that makes it easy for automatics to do well. If the car automatically upshifts under light throttle, then the higher gear is okay for the low speed test portion. The computer for the A4, of course, is tuned for this situation. Side note: the speed involved is 15-19 MPH.
With a manual, the trick is to make it work like an automatic. What GM has done is to add CAGS to the MN6 so that it will force a 1-4 shift under light throttle between 15-19 MPH (the same speed as used in the EPA test). Therefore, as far as the EPA is concerned, the car 'automatically' shifts to 4th, so it can be included in the test procedure. The result is a higher EPA rating and no gas guzzler tax. In the real world, CAGS has no effect on mileage.
The CAGS eliminator, or bypass, merely eliminates the electrical connection to the solenoid on the transmission while hiding that fact from the diagnostic system (otherwise, you'd throw codes all the time).
So, you save money (no gas guzzler tax), and the issue is easy to eliminate. Win-win, IMHO.
03-25-2005, 01:50 PM
#9
Making CFOT Great Again
Originally Posted by Hoonose
Typical toy-head governmental crapola!
You'd think someone would use some common sense and give GM the OK to eliminate this whole mess.
You'd think someone would use some common sense and give GM the OK to eliminate this whole mess.
Now, tell me which you prefer.
03-26-2005, 05:19 PM
#11
Intermediate
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dvtav8s
Originally Posted by mforman42
The current issue of Corvette Magazine has an article on installing the CAGS bypass. There is a sidebar explaining in some detail why CAGS exists. The explanation is exceptionally clear.
I'm wondering if some kind soul would like to include the text in the FAQ?
I'm wondering if some kind soul would like to include the text in the FAQ?
03-26-2005, 05:52 PM
#12
Burning Brakes
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St. Jude Donor '05
Originally Posted by dvarapala
GM has the OK - all they would have to do is charge us a $1000 gas guzzler tax (like I paid for my '03 Cobra).
Now, tell me which you prefer.
Now, tell me which you prefer.
I Prefer the $17 CAGS Elimnator & save the $983 for other things... Thanks for GM for saving us money & making it easy & cheap to get rid of...
03-26-2005, 05:53 PM
#13
Race Director
Cadillac is not hitting you with a gas guzzler tax, your friendly feds did that. The CTS-V, I guess because of weight and aerodynamics falls into the guzzler category where a corvette doesn't in spite of nearly identical HP.
