JasonS4+Festicle

a wideband O2 sensor I recently installed in my car.

I'm going to be using APR ECUx - did some preliminary testing which raised a few questions:

1. I thought the max knock sensor voltage was 29.8 - I've seen higher with ECUx - never higher than 29.8 with VAG-COM....any ideas why?

2. The resolution with ECUx is MUCH, MUCH better - I'd occasionally see cylinder 2 or 5 bounce off of 29.8 for one reading (when using VAG-COM), now, having increased resolution with ECUx shows it can stay up there (or go even higher) longer - is this a true "knock"? I don't hear anything.

3. How "safe" is it to run with cylinders 2 and 5 much higher than the others? For example, if 2 and 5 are high 20's but all others are not out of the high teens....is this "safe"?

Any help would be much appreciated....I should have some decent info tomorrow.

Also, has anyone else noticed that adding timing using Lemmiwinks makes the car have MUCH higher knock sensor activity than, let's say, adding boost.

ATH

I don't think you want any cylinder much above 20...

nyet

adding boost past a certain point isn't going to accomplish much except raise your iat's, esp with k03s (see also compressor maps).

timing, on the other hand...

JasonS4+Festicle

2 and 5 are "loudest" but that's where the knock sensors are mounted (I think).....

So when I push things toward the limit, my limiting factor is ALWAYS cylinder 2 and 5...not sure how close to the limit I should go with 2 and 5.

ATH

You are correct that 2 and 5 are the loudest, so those should be set to the limit, and ignore the others (they will be in the low teens). I guess 20 is really conservative, but I don't think you want anything in the high 20's...

JasonS4+Festicle

higher for very brief intervals.......

We'll see what my testing shows.....I'll make some changes to see.

Mark P

I've never measured with VAGCOM to see how they compare. Perhaps the slower sample rate misses something, but I can't imagine it's that different.

<img src="http://ctny.audiworld.com/mark/s4/misc_data/k03_chip_comparo/knock_all.gif">

JasonS4+Festicle

the data together and post it.

I'd love some thoughts on where to go next with setting.

Mark P

and have it automatically graph. I've posted one before that you can use as a starter if you want.

PSmalls::DoggieStyle

Wow, always thought the sensor didn't read over 29.835