- Thread starter
- #26
Artago
15+ Year Contributor
- 2,090
- 26
- Nov 30, 2006
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North Vancouver,
BC_Canada
Run straight WG pressure (lowest boost possible), and log a pull to redline keeping boost at 0 or as close to it as possible. Check the log for knock. Then change your timing by a couple degrees and do it again. If you can repeat this a couple of times and get knock at the same points, you've found your phantom knock.
Definitely fix your AFR's. Anything less than 10.8:1 or so is rich and prone to knock.
As for how much knock is ok, IMHO any real knock is bad knock. Not necessarily because of danger to the engine, but it means that cylinder pressures or temperatures are too high (or identifies other tuning issues), and you still loose power due to timing being pulled. Personally I tune for zero knock, with the understanding that I'm going to get the occasional <1 degree of retard. If it gets to be around 2-3 degrees and happening often, I start looking to see what is going on.
If my CEL comes on and the factory boost gauge jumps towards half way or higher, I starting having a panic attack. (ok.. not quite).
I'm already running WG pressure. Here is a quick pull I did merging on to the highway (couple weeks ago).
I'll lean it out and try again after work.
Tom
did you ever have valve contact with those pistons or any type of damange. a friend of mine had a similar problem and it turned out that at some pint he floated a valve and the damage it left caused a hot spot and he would show knock and low throttle and even free rev
That's what I got going on (knock at low throttle and free rev).
How can I check for that? Bore scope? Or is there an easier way?
Tom