FS: Curtis Counter 951 Knock Counter
Posted: Thu May 21, 2026 5:06 pm
For the 951, having some way to monitor knock is especially important on modified cars running higher boost. I previously outlined here how to make your own knock counter using an inexpensive Curtis Instruments 703PR-102 event counter.
I recently discovered that these counters are now out of production, which is a bummer for 951 owners. Not really sure if they stopped making them forever, but all of the normal US suppliers are out of stock. There are certainly other counters that can be used, but they all have their own specs and may not produce directly comparable results to the cars that already have this knock counter in them.
When I learned these were NLA, I found some old stock on eBay and decided to buy them to preserve them for the 951 crowd.
If you want one, send me an email at [email protected]. I’ll sell them for $45 each, shipped to the 50 states. Only 8 available (one is already spoken for), and once they’re gone, they’re gone. 
I recently discovered that these counters are now out of production, which is a bummer for 951 owners. Not really sure if they stopped making them forever, but all of the normal US suppliers are out of stock. There are certainly other counters that can be used, but they all have their own specs and may not produce directly comparable results to the cars that already have this knock counter in them.
When I learned these were NLA, I found some old stock on eBay and decided to buy them to preserve them for the 951 crowd.
If you want one, send me an email at [email protected]. I’ll sell them for $45 each, shipped to the 50 states. Only 8 available (one is already spoken for), and once they’re gone, they’re gone. - curtis-counter.jpg (221.94 KiB) Viewed 338 times