Meine44

I called that company.

The Curtis counter is NO LONGER AVAILABLE

reno808

just get a zt-3 they are not expensive

URG8RB8

If you buy the M-tune and run E-85 you won't need to log knock as long as you don't go absolutely crazy on your boost. Not that you can't if you want too, just don't think you will need it. I have spoken with Josh about this quite a bit. E-85 is extremely forgiving. Plus it helps our farmers, Ha!

Tom M'Guinn

Sure you asked for the right thing? The Curtis counter in the link above is the one I use, and Digikey's website show 556 available and ready to ship today...?


As far as hooking it up, you could either connect it directly to the KLR pin as described in the thread below, or if you wanted to filter out non-WOT knock counts, you could connect the input of the counter to the "in-bounds" LED output of the V-Knock (with the duration of that output set as short as possible to avoid masking rapid-fire knock counts).

https://rennlist.com/forums/944-turb...k-counter.html

https://rennlist.com/forums/944-turb...-pictures.html

Reno -- I don't think the Zt-3 has provisions for a user input, does it?

Tom M'Guinn

If you don't need engine data, you're not running it hard enough.

URG8RB8

I hear you Tom, but most people monitor knock and then have no idea what to do with this information! I suppose I will eventually install a knock counter, but still doubt it will change anything. Without a truly active system such as the J&S Safeguard on my other car, I think it is a bit of a waste of time. Now on normal crappy CA 91 I see the need for it.

Meine44

That is exactly the answer I was looking for. I would want to hook the counter up to the "in-bounds" led of the V-knock.

As far as the counter, I must be looking at the wrong one. Did you wire a reset switch to yours?

Tom M'Guinn

Yeah, I guess the more you are able to tune your own car, the more useful a knock counter is (or wideband, or EGT, etc.). Although, I'd say even the tuning-impaired (aka Ed) can use the knock info if for nothing else but to know when to turn down the boost.

The KLR was pretty impressive for it's time and I understand it was the inspiration for the J&S system. At the risk of taking this thread down a rabbit hole, the KLR not only knows the "signature sound" knock makes on a 951, but knows where in the cycle knock can occur for each cylinder, which allows it to disregard stray sounds occurring off cycle, and it can retard timing for just the cylinder(s) knocking. To visualize that, the picture below shows the ref sensor trigger (as viewed by the DME processor) on top and the ignition pulses on the bottom. The KLR listens in a window where knock might occur or each cylinder, and can then pull knock only on the cylinder(s) where it hears the knock. The J&S unit adds other product features (rev limits, more granularity, some tuning options, etc.) but in terms of pulling timing in reaction to knock, they're pretty close cousins from what I can tell...

Tom M'Guinn

If you click on the link posted above, it shows the counter I use, and this afternoon they had 556 available. Yes, I added a reset switch -- I'd have to look at the datasheet, but it was just a matter of attaching a push button between the reset pin on the counter and ground.

Meine44

I'm going to look into the counter that you mention then. My goal is to get a wideband 02 to monitor my AFR's and a knock counter to dial in my boost.

I just have a manual boost controller and a MAF and chipset from the previous owner, which can't accept tuning. I'm just looking for a way to monitor my car and keep it safe until I can make the upgrade to a better system.

Crazy Eddie

Guilty as charged

Tom M'Guinn

Sorry, couldn't resist

Crazy Eddie

Yea, that was a lay up for sure

reno808

yeah i was wrong the zt-3 has no inputs. you would need to get the zt-2....

Meine44

Considering I would need to install a Wideband 02 sensor for an Air/Fuel gauge,
it would make sense for me to pony up the dough for the ZT-2 right away.


Goodbye tax monies.