Knock light
Safety Car
Joined: Nov 2011
Posts: 3,555
Likes: 637
Given that everything I've read indicates our cars have to pull timing with 92 octane once they warm up, sometimes I wish I had a light on the dash to indicate knock. By that I mean a light that lights up when the computer has heard knock and is going to pull timing - so that it'd flicker or flash with each knock detection event, or light up if it were constant.
I can think of two ways - the first is simpler if possible, hooking into the knock sensor circuit itself somehow.
The second would be to monitor the datastream on the ALDL port like a little mini scan tool that then lights up an LED. That'd take a little bit of hardware, but is likely safer.
Has anyone heard of any pre-existing solutions or products that do anything similar? I found this MSD product, but you'd need a bung to screw it into the block, and I'm not even sure we have a spare hole!
https://www.summitracing.com/parts/msd-8964
I can think of two ways - the first is simpler if possible, hooking into the knock sensor circuit itself somehow.
The second would be to monitor the datastream on the ALDL port like a little mini scan tool that then lights up an LED. That'd take a little bit of hardware, but is likely safer.
Has anyone heard of any pre-existing solutions or products that do anything similar? I found this MSD product, but you'd need a bung to screw it into the block, and I'm not even sure we have a spare hole!
https://www.summitracing.com/parts/msd-8964
Last edited by lordofwar; May 15, 2018 at 09:06 PM.
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
So what -would- be an appropriate parameter to watch in the DIC with a DashLogic to be informed about knock?
I actually above thought you could watch knock COUNT, which I assumed to be how much knock it saw, not the amount of retard. Wouldn't that work?
Knock count doesn't -mean- it's pulling timing yet, but it does tell you something about what the engine is "hearing" for knock, doesn't it? And it should be separate from traction management and torque management and so on...
I actually above thought you could watch knock COUNT, which I assumed to be how much knock it saw, not the amount of retard. Wouldn't that work?
Knock count doesn't -mean- it's pulling timing yet, but it does tell you something about what the engine is "hearing" for knock, doesn't it? And it should be separate from traction management and torque management and so on...
older GM stuff and other makes do have it.
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
as mentioned earlier by dar, knock will learn down. if you have been driving around in your car for any meaningful amount of time then you will log no knock as it has already learned down. with HPT the easiest way to log knock and adjust accordingly is to make the high and low tables the same and you know that it won't learn down then. you can shape your high table that way without interference from knock learn.
Pro
Joined: Dec 2014
Posts: 581
Likes: 158
From: Florida
I would want to know that if I'm getting knock retard and I do something to remedy it that it is working. I would want to see the computer going from retard to advanced if I put better gas in or octane booster. I had an issue with knock retard in my GT500 that wasnt resolved with 100 octane gas and I was able to know this by monitoring that.
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
I would want to know that if I'm getting knock retard and I do something to remedy it that it is working. I would want to see the computer going from retard to advanced if I put better gas in or octane booster. I had an issue with knock retard in my GT500 that wasnt resolved with 100 octane gas and I was able to know this by monitoring that.
