If you weren't aware, knock at 70 load is a well known phantom knock area.

Are you logging TPS and finding knock at a constant TPS or are you seeing knock upon throttle tip-in? You may just need to adjust your knockfilter tables or try to tune it out if you think it's real.

If real.... you may find MIVEC that gets aggressive too quickly can cause occasional spool knock. Or your car may be asking for more or less timing/AFR at that location. Instead of constantly backing off timing/afr you may find the knock goes away if you lean it out a bit and give it more timing during spool which usually goes against what you hear. Another hint is to watch the MAP/MAF to see if the airflow/pressure is stable when this knock occurs or if the ECU is taking too long to do the OpenLoop crossover.

Obviously don't blindly do anything without the proper research. Good luck!

 

Would it be possible to remove the EGR system and add timing in the maps where it would usually activate during cruise rpm and loads while using one step colder plugs?

 

Good tips I will try the same logging on the same road with the JDM mivec map just to see if the behavior is coming from my mivec tuning.

I do see it at relatively constant TPS, but it also behaves like tip in knock. I am currently thinking I am too lean at cruise and that may be contributing. still trying to figure out how I can log what to know when I am in open or closed loop.

 

fireroasted

Check this out: http://www.swri.org/3pubs/ttoday/Sum...n-and-Cool.pdf

Then look at the stock EGR duty table. 50-80 load at 3000 rpm is where most of the action is at highway cruising speeds. EGR duty is 100% at that point in the map, probably to help stop the knock that would be induced by the more advanced timing.

If you deleted your EGR you won't have its anti-knock effect so you must also either zero out the EGR advance table or turn it off completely with Mr Fred's EGR System Enable/Disable patch.

 

Interesting read, and different from what I had learned. Thanks. I do have the EGR delete and the MrFred disable of the system. I am still chasing this though, so I will add zeroing out this table and doing a before and after to see if I can log any variances even though it shouldn't impact anything (because of the disable).

 

Any luck?

 

Well it's taken me a while to get time and back to logging. I was stuck in mechanical and suspension work for a couple months and then the holiday. I did a few fresh logs and then clear the values in the table for EGR and did the same logs on the same exact route. No difference. So the conclusion is that the EGR disable checkbox actually does disable the system and therefore not advance timing. This is at least deduced form the test that I did not experience any difference, more or less, when I zero'd out the values or put the vales back in. I also completed the test twice just to be sure there weren't other factors obscuring the testing.

I also switched back to the stock MIVEC map just to test or retest ACIDTONIC's comment about that. I was able to reduce the knock counts pretty consistently, by a couple ticks, but didn't get them down far enough to ignore. So a bit of the knock seems real because I was able to reduce it by the use of less advance in those fields in the MIVEC map.

I have purchased a 15 gallon pump and tank and filled that with 100 octane. So my next test will be to repeat all tests I did today buy using 100octane to see if the knock counts go away or remain unchanged.