So I've gotten just about every little thing sorted out on my car finally, but I'm having an issue that I can't seem to figure out and, unfortunately it's knock-related.

My mods are in my sig, tune is 100% my work. I was just out bedding in my new brake pads and, consequently, had to run up to 60 MPH in quick burts about 10 times. The first 5 or 6 "pulls" I was giving about mid throttle, 10-15 psi and my knock light (Tephra V7) was going ape**** so I was getting out of it constantly. Engine temp was not "cold" but not fully warmed up yet at least on the first pull or two. Subsequent pulls, the engine was up to temp.

So anyway, I get done with about 8 pulls, all giving some bit of knock as soon as boost started to build. By the 9th and 10th pulls and every time I tried to get it to knock afterward, no knock.

Is this a common thing on these cars? I don't normally beat on my car when it's "cold" but it seems to be something beyond just temperature. I can be putting around on the way to work and the engine will be fully warm but the first time I get on it a little, the knock light usually gives me a slow flash. After that? Nothing, at least nothing higher than 4 counts which is what I have my light set to.

Should I look into getting some det-cans or something to troubleshoot this further? I'm not sure what all is involved with det-cans but I can do some research. Any ideas or opinions are welcome. Thanks guys!

Todd

 

I notice this too. I see it if the coolant temps are below +-122*F.

Did you log it? I'm sure you didn't since you were breaking in brake pads. You can try to simulate it again while logging. I can take a look at it for you if you want to send it or post it up.

If it is what I think it is, it could be partial the engine not being at optimal temps, but it could also be timing.

 

I should have grabbed the laptop but I did not. I did just take it back out and did several part throttle runs and logged everything, zero knock. I think I got a 1 count somewhere. I then did a WOT run and it too was clean, registered 2 counts during spool but was knock-free for the remainder of the run.

I saw the other thread about knock and someone mentioned throwing in 100/110 and see if that cures it. I may try that, just have to find the appropriate gas pump now, lol.

 

Do some logs tomorrow morning after it's been sitting all night and try it again. I wouldn't be surprised if it knocks a little. Post it up.

 

Can do. Thanks Christian!

 

I let it cool down completely and just took it out for a drive. I made some ignition timing changes in the 3500-4250 RPM range, 100-160 load and it seems to have helped. I didn't get but 1-2 counts out of the 5 times I tried and most attempts were clean. I did get a 4 count when I nabbed it in first after a WOT run so I revisited the map and took another 1-2* out where applicable. I will try it again tomorrow and we'll see what we get.

On a happier note, I'm up to 417 awhp (VD) on my standard tuning road at 25 psi. Going to try and get up to 27 and see what she does. The WOT was completely knock-free so that was nice. AFR's are 11:1 on the nose above 6500 RPM, 11.3/11.4 below that.

 

Idea,

Don't beat on any car until it's warmed up.

 

On this particular morning, yes the engine was "halfway warm" or whatever, but I wasn't seeing more than 5 psi at most. I don't think that qualifies as beating on anything.

Thanks for the input though.

 

What ignition changes did you make? I'm assuming you took timing out due to you later saying "took another 1-2* out where applicable."

What is the timing at when knock occured?

What is the coolant temp when knock occured?

We want to resolve your issue and help others who are reading this thread.

I have ideas on why it's knocking, but I'd like to see your data 1st.