Cross-posted from Spyderchat...
I'm finishing up a forged 2zz build that I am going to run N/A and then turbo later using a Link ECU wired as a "standalone", but retaining the OEM ecu for gauges, A/C, etc (not quite piggyback, not quite standalone).
While I have the intake manifold off and easy access to the back of the motor where the OEM knock sensor is located, I'm wondering where/how I should add a wideband Knock sensor (the Bosch donut-style sensors seem to be popular), while keeping the OEM single-wire knock sensor in place to keep the OEM ECU happy.
I see this 11mm non-threaded hole right near the top of Cylinder #4. It's marked in RED in the attached picture. I don't think it's used for anything else and figured I might be able to thread it to accept a stud.
Alternatively the bolt for the water/coolant bypass pipe's mounting bracket may also be a decent candidate. It's marked in BLUE in the attached picture.
Picture hardlinked here: knock sensor options.jpg
What have you folks with aftermarket engine management solutions done for adding a second Knock sensor?
RALEIGH, NC
125k miles, Fortune Auto 500 Series Coilovers (4k/6k), Hard Top, 6spd w/ LSD, TTE Exhaust, TTE Spoiler, TTE Roll Bar
Advanti Storm S1 wheels in 16x8 with 205/45/r16 Continental ExtremeContact UHP All-Seasons
OEM's spend many manhours trying to optimize the best location for a good signal from a knock sensor. Anything other than the stock location is going to be a guess, but it should not be far away from the OEM one. Perhaps you can mount them on the same bolt?