LS2 Knock Sensitivity

[ShoddyHog]

I have an 06 GTO with 60,000 miles. I've been logging random KR at WOT since having the cam in my sig installed. After running a test using Xylene to boost the octane, I've come to the conclusion that what I'm seeing is false knock. Here is my thread on ls2gto.com if you'd like to read the full story:

http://www.ls2gto.com/forums/showthread.php?t=223373

In my readings here, I've seen Russ Kemp state the following:

Yes, the LS2 & LS3 knock sensors are too sensitive. I double the decay rate table & halve the base attack rate table.

Russ Kemp

I see the Decay Rate table, but where / what is the attack rate table? Also, what risks do I run, if any, IF I'm wrong and what I'm seeing is real knock instead of false? I'm almost positive it is false because I can't hear it ping at all, but "almost" is sort of scary.

Thanks,
Gerry

[SMOKINV8]

If you want to verify its not detonation related knock, drop a little timing in conjunction with your higher octane gas. You'll see it either consistently lessen or go away completely if its real.

Here's the tables you're looking for.

[ShoddyHog]

Thank you. Last week, I studied the tables, and decided that Base Retard wass the table Russ was talking about, but it is nice to have confirmation on that. When I did my Xylene test, if I remember correctly, I'd set my timing tables back to stock, and I still had KR, but it may have been reduced. I think what I'll do to make sure is try to find a place in St. Louis that sells racing gas and do the test again. I don't want to blow this thing up.

After doing the tweaks Russ suggested, I did several WOT runs on Saturday...the log looked much, much better, even though there's still a little KR. I'll attach my log in case anyone wants to comment.

I should add that when doing the runs below on Saturday, there was NO audible knock, and the car wall pulling like a mule....or in my case, a goat

Thanks for the help!
Gerry

[quicksilver]

Hey Shoddy, missed ya at the last GTO meet, im Enid06M6 on the LS2GTO board. So how hard was it to tune for your cam? All street tuning? Just curious, the mod's look better and better when you can tune for them your self without having to pay every time you do something major.

Scott

[ShoddyHog]

Yeah, I ended up missing it because I thought I lost my transmission output shaft seal. I was wrong.

http://www.ls2gto.com/forums/showthread.php?t=231284

How hard to tune for the cam? That's a tough question to answer, mainly because we each have a different level of patience, persistance, and knowledge. I'd say it was fairly easy...but it just took me quite a while, and many, many hours of reading, tweaking, and staring at log files. If you're someone who has little time or easily gets frustrated, you might be better off hooking up with a good tuner....

But there lies the problem. Who is a good tuner...and what do you get for your $400 tune? If you tune your own car, you know what you have...and you know it is right. You'll put the time into it to make it what you want. I find tuning the car fascinating. Beats the hell out of the timing light and dwell meter I used years ago, even if it is more complex.

I don't regret getting HP Tuners a bit. I'm soooooo glad I did, or I wouldn't be nearly as happy with my cam as I am now. The thing drives like a dream, has no surging or bucking above 1250 rpm. Now, if I could just get it to start every time.

Oh...and I've done nothing but street tuning.

Gerry

[ShoddyHog]

Hey Shoddy, missed ya at the last GTO meet, im Enid06M6 on the LS2GTO board. So how hard was it to tune for your cam? All street tuning? Just curious, the mod's look better and better when you can tune for them your self without having to pay every time you do something major.

Scott

I tend to be long winded. ^^^^See my above post^^^^ Yeah, using HP Tuners is pretty easy...get the Pro version and a wideband, then doing the important things - dialing in your VE table and PE fueling is pretty easy once you do it one time. After that, it is just a matter of learning what your car likes and how you like it. There's always someone around to help or answer questions. Best thing I've done for the car other than the mods themselves.

Gerry