Here's how it works.
The clamp itself will limit the upper voltage that will get passed through to the ECU. It doesn't matter if the true voltage is 0.9v or 0.6, the clamp will pass through 0.39v (or wherever it happens to be set). We don't set it right for stoich because we'd prefer to have the stock ECU help out a bit by trying to correct for what it sees as a lean condition.
The click is from a pressure switch. Below the threshold (right around ambient pressure), the O2 signal is passed through unmolested. Above it, the clamp is used and the O2 signal is limited to a slightly lean condition. You'll hear the switch click once or several times as you go into boost, but it won't continue to make noise once it's changed over.
There's no way for the ECU to "learn" around this as far as I know, as the ECU doesn't realise there's anything to learn. If you're finding that the clamp is less effective, I suspect it's due to a mechanical problem elsewhere such as a failing fuel pump.
If you want to check if the clamp is working, check the voltage of the O2 signal at the ECU (ie, AFTER the clamp). It should dither around at idle and cruise, centering at 0.45v. Once you go into boost, the pressure switch should click and the O2 signal should steady at 0.39v. I believe that's the voltage we set them to. If the voltage stays at 0.45v or goes higher, there's a problem.
Keith
Flyin' Miata
The clamp itself will limit the upper voltage that will get passed through to the ECU. It doesn't matter if the true voltage is 0.9v or 0.6, the clamp will pass through 0.39v (or wherever it happens to be set). We don't set it right for stoich because we'd prefer to have the stock ECU help out a bit by trying to correct for what it sees as a lean condition.
The click is from a pressure switch. Below the threshold (right around ambient pressure), the O2 signal is passed through unmolested. Above it, the clamp is used and the O2 signal is limited to a slightly lean condition. You'll hear the switch click once or several times as you go into boost, but it won't continue to make noise once it's changed over.
There's no way for the ECU to "learn" around this as far as I know, as the ECU doesn't realise there's anything to learn. If you're finding that the clamp is less effective, I suspect it's due to a mechanical problem elsewhere such as a failing fuel pump.
If you want to check if the clamp is working, check the voltage of the O2 signal at the ECU (ie, AFTER the clamp). It should dither around at idle and cruise, centering at 0.45v. Once you go into boost, the pressure switch should click and the O2 signal should steady at 0.39v. I believe that's the voltage we set them to. If the voltage stays at 0.45v or goes higher, there's a problem.
Keith
Flyin' Miata
I guess if the clamp is always going to limit the voltage to a certain point, then that adjustment screw won't help you Matt.
