I was just wondering what people thought would be a safe knock threshold on 93 oct? I heard anything up to three is pretty normal/safe

 

You can have 0 counts one pull and 5 counts the next, so long as 4 counts and up are not consistant, chronic exposure shouldn't be a problem.

My car knocked like a dickens stock from the factory, but knocking with added timing and boost must be anally monitored like above

 

I typically see anywhere from 0 to around 1-2 counts of knock that sometimes last for most of a pull.

 

okay thanks guys...just another quick noob question (we all gotta start somewhere) what are the areas that you look at most when logging. I look at knock, rpm, TPS...I know I should be looking at more but until I get my wideband, I don't really know what I'm looking at

 

Hi

the amount of knock you are going to tune for would also depend on the aplication of the car. Short runs like drag racing might be able to take far more timing and give reasonable knock values than a car that is used for longer track sesions.

MB

 

On a car with stock internals, I would tune for 0 knock.

l8r)

 

Properly tuning your car can be a very lengthy process. I am not a drag racer, but go on extended spirited runs -- sometimes with no knock and others with a bunch of knock. To me it tells me several things: (1) that I need to make my tune more conservative in areas and (2) I may be running too much boost (see signature).

Although I dont know what 1 - 2 counts of knock will do to your car (health wise), it is a bummer on performance. I did a long spirited run yesterday on "private property", of course, and found knock (1 - 2) at certain points w/ TPS ~45 - 50%, and then on a few 3rd gear WOT runs (where I have been able to get 0 knock before) got 2 counts @ 6750 - 7000 (AFRs still too lean @ 11.9) and 1 count of knock from 7200 - 7400 (AFR 11.5) with timing only 14 where it should be 16 (so obviously the ECU is pulling 2* of timing). Then on a 4th gear WOT (starting at 2.8K) run, saw 1 count from 3K - 3750, then at 4500 saw 2 counts until 4750, then 1 count from 4900 - 5200, and no knock up to 6400 (where I let off). In most of the areas I am seeing knock, my AFRs are 12.5 (low RPM) and 11.9 @ 4K +.

I still have the lean spool on which I know is causing the leanness up to 7K, but I am still working on the AFRs and hope to have this rectified in the next day or so. I believe my tuning challenge right now would be GREATLY reduced if I could pull REAL ECULOAD rather than calculated load.

 

I know that the car doesn't even start to pull timing untill it has 6 knock counts or higher; and on stock tune w/ 91 octane you'll get 1-4 knock counts all day long.
So I don't think 1 or 2 knock counts is all that detrimental unless it's very consistent over a broad RPM range and Load range.

 

I tune for 0-3 counts. You get 1 degree of timing pulled per knock count of 3.

 

Remember when your knocking your slower

 

Correct, but I think if someone is getting 1 or 2 knocks sporadically it's probably due to the hyperly sensitive knock sensor on our Evo's.

 

I've read that 1* of timing is pulled for every 3 counts of knocks. I've also read it takes 6 counts of knocks for the ECU to pull 1* of timing. So which one is correct?

 

The former. It takes 6 counts to decrement the octane number.

 

I get between 1-2 knocks at spool up on second gear only. After that, I get 0 knocks across the board to 7800 RPMs at fifth gear.

Good thing is that I get the same results on every pull.

Things can be different when gas quality varies much from pump station to another. Even more when it varies within the same brand.

To answer your question... 0 knocks is the safest but IMO 1-2 wont hurt.