Best C8 AFM Disabler
Thread Starter
Instructor
Joined: Sep 2019
Posts: 212
Likes: 159
From: Conifer, Colorado
Best C8 AFM Disabler
Having owned a 2017 C7 Grand Sport I am a bit paranoid about cylinder deactivation. I know GM has been doing it for decades, but some folks suffered valve lifter failures.
So what have you folks found that works good and a reasonable price. There are a lot of them out there on the market.
Looking for some good advice.
David
So what have you folks found that works good and a reasonable price. There are a lot of them out there on the market.
Looking for some good advice.
David
Thread Starter
Instructor
Joined: Sep 2019
Posts: 212
Likes: 159
From: Conifer, Colorado
I purchased a Range device for my C7 Grand Sport and it worked just fine. I understand the Track driving mode does disable the AFM, but that driving mode is a bit aggressive for everyday driving. I had also read the Carbyte device does not work on a 2025 model year C8. The Range device will likely work just fine on my C8 but it appears to be the most expensive one on the market. That's why I'm asking you Corvette experts. Maybe the Range device is the best bet. And I might speculate that the problems with the AFM valve lifter 10 years ago has likely been resolved on late model GM V8s.
David
David
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Joined: Aug 2016
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From: Garden Valley CA
I don't think there are any AFM disablers that will work on a 2025 (short of a tune). Along with Track Mode and setting the Z-Mode Powertrain to highest value, Manual Mode prevents AFM.
Pro
Joined: May 2023
Posts: 603
Likes: 280
From: About an hour north west of Albany, NY
Maybe I missed it, but last I knew, Range didn't offer a C8 AFM disabler. A quick check of their website, seems to confirm that. I'm running a Carbyte on a '22. It works as advertised. I don't like the "only works at over 165" coolant temp part, but it's the only reasonably priced solution for folks wanting to disable AFM on their C8. And apparantly even that is only available to us with earlier year C8s.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,614
Likes: 12,157
From: NE South Carolina
Having owned a 2017 C7 Grand Sport I am a bit paranoid about cylinder deactivation. I know GM has been doing it for decades, but some folks suffered valve lifter failures.
So what have you folks found that works good and a reasonable price. There are a lot of them out there on the market.
Looking for some good advice.
David
So what have you folks found that works good and a reasonable price. There are a lot of them out there on the market.
Looking for some good advice.
David
- C7: Didn't use the Interstate so had no use for 7th gear. (Still don't.)
- C7: Never found 6th useful.
- C7: So rowed thru the lower gears and shifted to 5th.
- 5th was 0.71:1 OD Combined with 3.42:1 dif = 2.43:1
- C8: (Z51/E-Ray) 5th gear is 0.66:1 OD (typically max Z-Mode uses)
- C8: In 5th Gear Combined wDif/Intermediate = 3.43:1
- About = to my 1st new car a 1967 and my '74 280Z!
- C8: past >65 mph in Z-Mode may use 6th =0.51:1 OD
- C8: 6th gear Combined wDif/Intermediate = 2.63:1
- Combined with Dif/Intermediate gear is= 2.63:1 close to the C7 Grand Sport in 5th of 2.43:1
- C8: 8th gear is a somewhat crazy 0.33:1.
- Combined with Dif/Intermediate gear = 1.70:1 Crazy Low!
- IMO it's there primarily for GM to get the best possible mpg in EPA test cycle.
- Just because it's there don't have to use!
- Like different more responsive car! in Z-Mode.
Last edited by JerryU; Today at 06:08 AM.
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