FAQ: What is spark knock? What is KR (knock retard)?

Here's a chart of what I'm getting. This was pretty much just a highway cruise because I was going to work and wanted to take it easy. On the way home tonight I'll have more backroads and get a broader scan and then hopefully be able to do the hammer test when I get home. I was reading somewhere how the '96 version of OBDII is slightly different than '97+. I wish I knew where I read it at but could that explain the lack of knock? I'm not hearing any "pinging" but I am hearing a rapid "ticktickticktick". From my understanding the ticking is coming from my flex pipe which makes sense because it quieted down when I wrapped it.

Things I have tried: Various scans with DHP and Torque, reinstalling DHP, reinstalling Windows AND DHP (and all required runtimes).

Things I have yet to try: Hammer test.



KR is yellow, RPM is pink, Gear is blue, and Boost is red.

I've got a 3.2" pulley you can borrow/purchase if you want to find out really fast.

AA wrote:

I've got a 3.2" pulley you can borrow/purchase if you want to find out really fast.

PM coming your way

I got knock (yay?). Now to get rid of it. I'm seeing some pretty huge spikes at the top of each gear. The problem was I wasn't being rough enough.

matt270avian wrote:

I got knock (yay?). Now to get rid of it. I'm seeing some pretty huge spikes at the top of each gear. The problem was I wasn't being rough enough.

Adjust your Fuel Injector and MAF table.

How much KR are you getting? Actual number please.

Quote :

The problem was I wasn't being rough enough.

This is almost always the reason. 3rd gear WOT puts that extra load on the engine to make the conditions right. Big loads under boost usually = KR, at least a little bit.

Better tune your PCM. 3.2" on the way!

Abaddon wrote:

Adjust your Fuel Injector and MAF table.

How much KR are you getting? Actual number please.

That's what I was going to work on this afternoon. Going to get a good scan on the way home and mess with it tonight.

I saw spikes of up to 5.xx before I let off. It would be nothing-nothing-nothing-5.

AA - I doubt I'm going to put that 3.2 on for awhile now that I'm getting results.

5* is "normal" at the top of each gear, especially if it's happening during the shift. The PCM will automatically retard the timing during the shift to control torque. You can change this in the Torque Management tables under "Transmission".

If you're seeing the KR at lower RPMs, then you should be concerned a little. Generally though, the KR will spike up to 5 or 6*, then completely disappear.

You want to see real KR? Throw that 3.2" on there....

Ambient, oil, blower, trans and coolant temps also contribute to KR. If the car isn't fully warm, it can suppress the KR. Then, after you've driven the car for 30 mins, things can change quite a bit.

To put in perspective, I run a 3.4 with my mods, which it gives me zero KR all of the time with normal driving (maybe 1-2º in extreme situations like WOT in 3rd), but on the road course, that same set-up can show up to 8º KR after a few hot laps.

Drag racing is a lot more like daily driving for KR. Let the car cool off between runs, use an ice bag on the blower, and I could slap the 3.2 on there and see about 5-6º at 6000 RPM as I crossed the line.