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VEMS and a Knock Light
Posted: Thu May 23, 2013 9:10 am
by WOMBAT
Though not an accurate/perfectly reliable tool for tuning, is it possible to use an output to flash a dashboard light to alert me that there may be knock? This is more to keep me safe as weather/changes in fuel occur. I don't want to be senselessly driving my car in a dangerous state.
Re: VEMS and a Knock Light
Posted: Thu May 23, 2013 9:57 am
by Mcstiff
It'd prob be easier to set up a SAAB APC like audifreakjim runs/ran. VEMS supports knock control but I've not heard anyone report the correct settings for the 20vt.
Of course, the criticism of the APC setup is that it is not tuned for the 20vt harmonics
http://mswanson.com/~jgreen/APC/APC.html
Re: VEMS and a Knock Light
Posted: Thu May 23, 2013 7:29 pm
by alxdgr8
WOMBAT wrote:Though not an accurate/perfectly reliable tool for tuning, is it possible to use an output to flash a dashboard light to alert me that there may be knock? This is more to keep me safe as weather/changes in fuel occur. I don't want to be senselessly driving my car in a dangerous state.
On my 944t engine, I've got a J&S Safeguard system that has a dual display gauge that shows knock and AFR. The Safeguard was developed from the OEM 944 KLR system so it has all the correct filtering for it. I think they've designed it so it's more generic though and you can set threshold levels. It could be tied into VEMS, pull timing independently, or just be set to display it.
Re: VEMS and a Knock Light
Posted: Thu May 23, 2013 8:15 pm
by Mcstiff
VEMS can deal with the input and output a warning light; we just need to figure out the filter values.
Re: VEMS and a Knock Light
Posted: Fri May 31, 2013 1:43 pm
by vt10vt
It's not a knock light but Nick has a really nifty safety net set up with his VEMS that watches actual vs. target AFR's. It doesn't necessarily protect you from timing/ignition mishaps but *I would think* it would still alert you to anything major enough to do damage...
Re: VEMS and a Knock Light
Posted: Sun Dec 01, 2013 8:39 am
by JohnP
alxdgr8 wrote:WOMBAT wrote: ... The Safeguard was developed from the OEM 944 KLR system so it has all the correct filtering for it. I think they've designed it so it's more generic though and you can set threshold levels. It could be tied into VEMS, pull timing independently, or just be set to display it.
Alex: I read about the 944 Turbo's individual cylinder knock retard in a 1987 Road & Track Magazine. The fact that it could be done is all it took, and I became obsessed with designing my own version.