My car hates timing. I cannot run increase timinging to what most people run without inducing knock. AFR is a safe 11.3 on 93 and still it knocks with relatively low timing.

I am using Denso IW24 which are 1 step colder plugs and I am starting to think that I should try regular cooper in the same heat range (BPR8ES). Is it possible that the Denso are more knock prone than others? I can't think of anything else. Car has basic bolt ons and making 350 awhp.

 

are you still running a catalytic converter? A 20G at 24 #'s with cat is going to create some backpressure and excess heat in the cylinder during compression/combustion, it's doesn't seem that far off you'd be struggling with knock.

Your sig says you have a TBE, but can't tell if you have a cat or not. There's always water/meth injection.

 

I have seen different spark plugs cause knock. I would try the bpr8es, and see if that helps. Its cheap, and if it solves your problem, it would def be worth the 5 minutes it takes.

 

No I do not have a cat. I have a WORKS resonated test pipe. The axleback also has a resonator, so no cat but 2 straight thru resonators of 3". No neckdown anywhere on the exhaust. I also have a TItek V2 O2 housing. I was hoping for more timing and a little more power. I will try the BPR8ES but Pep Boys and Advance Auto do not have them in stock.

 

Old spark plugs, fouled, or wrong heat range can definitely cause knock.

 

Post up a screenshot of your log map where you are getting the knock. that will help a lot when trying to figure out why its knocking.

 

any logs ???

 

Bad plugs will cause misfires which also can cause "knock" to be detected but I think to say the plugs cause knock is semantics. I would change plugs, run .020 gap, and then see what it does.

 

Pressure test the intake system and check carefully for leaks.

 

You could have bad plugs or boost leak. Like they said, getting the br8's wouldn't be a bad idea

 

The fact that you can gap BPRs so easaly is a big asset too. I used to run BPR7ESs at about a .24 gap. Even then I need the water/meth becuase this was in PHX with wonderful 115 degree ambient air a lot of the time and on 91 octane gas.

Another thing to check is the oil seals around the plugs. Some oil in there will trigger detonation events sometimes.

Back pressure does not sound like the problem in this case.

 

just my thoughts on this when tuning my car we where getting all kinds of knock, went a step colder and the knock was gone ! let you be the judge

 

If I were you I would switch to the NGKs. Using the wrong heat range plug can cause knock, but even worse pre-ignition which will mess your day up.

 

The current Denso IW24 are the correct heat range (one step colder same as BPR8ES). If I run 8 or more deg at 6250 RPMs I get knock. Load is about 250-260 at 6300. Maybe I have bad gas.

 

I am glad you post this thread. my evo8 hates timing too and I have switched between BPR8ES and IW24. I've been getting knocks in 4th gear, I think my BPR8ES is getting old, I am going to try IW24 again to see if the knock will go away.