The Dragon

iTrader: (6)

I get maaaaybe 1* here and there at WOT . . . but only rarely. Most of the time I have no Knock at WOT.

Every now and then, when I put the accelerator down at 16 or 1700 RPM's I get a Knock spike from 3 - 6.9* <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

It doesn't happen everytime. With my exhaust set-up, it does get pretty loud when throttle is applied at that particular RPM (almost sounds amplified at that RPM).

Do the knock sensors decrease as RPM rises in order to compensate for the expected higher exhaust note??

This would explain it if true. Because, as I mentioned above, my tone at that RPM with throttle is pretty nasty <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Thanks!

NoGo

iTrader: (2)

You are getting KR becuase you are overloading the engine. The same thing happens when you mash the throttle in 6th gear.

If you have LS1 edit, you can reduce the chance of this happening by reducing the timing in the lower left hand corner of the High Octane Timing Table. G/cyl in excess of .6 and from 1000 rpm to 2000 rpm usually does the trick.

It is not good for your car to overload it. It is not your exhaust note that is causeing the KR. Your engine is actually detonating.

The Dragon

iTrader: (6)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NoGo:
<strong> You are getting KR becuase you are overloading the engine. The same thing happens when you mash the throttle in 6th gear.

If you have LS1 edit, you can reduce the chance of this happening by reducing the timing in the lower left hand corner of the High Octane Timing Table. G/cyl in excess of .6 and from 1000 rpm to 2000 rpm usually does the trick.

It is not good for your car to overload it. It is not your exhaust note that is causeing the KR. Your engine is actually detonating. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"><img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> I didn't think that 15 or 25% TP at that RPM would overload it <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />

Dang . . . thanks for tellin' me <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Thank you for the info too <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

The Dragon

iTrader: (6)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NoGo:
<strong>
. . . If you have LS1 edit . . . High Octane Timing Table. G/cyl in excess of .6 and from 1000 rpm to 2000 rpm usually does the trick. . . </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm pretty sure it is, but could this also be referred to as the High Octane Spark advance vs. RPM in the Ignition section?

02BlackWS6

You know...thats kind of what is going on this my car. I have a A4 but when the converter locks up and I give it gas it sounds like it's lugging. I ATAP'd it and it showed 3* to 6* of KR. But once the converter unlocked it dropped. I think it's my tuning. I'm still running the tuning I had with my S2 heads and TR224 cam. Ed Wright probably bumped up the timing in the lower rpm's so my car didn't feel lazy. But now that I have smaller heads and cam the tuning is probably off.

Den

NoGo

iTrader: (2)

One side effect of multiplying the entire timing table by a fixed number is increased KR on the freeway.

Some cars suffer from it, other cars it doesn't bother.

My personal machine doesn't flinch on the freeway. In fact, I have never had a problem with highway KR.

I have done tuning on several customer cars though where it was an apparent problem.

Just FYI.

The Dragon

iTrader: (6)

I'm looking at the Table with the heading: .08Gms/Cyl at 400.

RPM increments of 200 beginning at 1000 increase along the top from left to right with the g/cyl increments of .04 increasing from .08 to 1.2 top to bottom.

At .6 and 1000 RPM's, the # is 11; at .6 and 2000 RPM's # 17. At .48, it's 17 and 28 respectively for 1 and 2K.
Do I decrease the #'s below the .6: they would be the higher values eg. .64 - 1.2 g/cyl.

Do I use a whole value or multiply a percentage?

Again, thank you for all the help! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

NoGo

iTrader: (2)

Looking at the table you should be able to see where GM has already taken timing out for the condition that we are talking about. (.52 to 1.2 g/cyl)

I would highlight from .48 to 1.2 g/cyl and 400 to 1000 rpm. Reduce this section by 3. If you have any cells that exceed -4 (ie -5,-6,-7) put them at -4.

Highligh from .6 to 1.2 g/cyl 1200 to 1800 rpm and drop this timing by 2.

.6 to 1.2 at 2000 rpm drop this timing by 1

That will drop the timing for your initial hit when you are mashing the throttle at low RPMs. It should also help out with highway KR. If you overload the engine though, you are always going to get some form of KR until the rpm picks up and the engine can handle the load.

Good Luck,
Kevin

BigTex

iTrader: (16)

Interesting. I have a truck and experience a similar issue. With my vehicle being heavier and with less torque to work with, I have more of this problem.

I was getting a "surging" type problem in OD on the freeway with an increase of throttle. My timing would be in the upper 20s then drop to the low teens then back to the 20s. This happened pretty fast and would show no knock initially. If the converter unlocked, all was well. But, if I nursed it along and tried to keep it happening, KR would show up and get pretty high.

After looking for adjacent cells with big gaps in timing (there werent any), I noticed I had really low timing in the lower left of the table where I was seeing this problem. My solution was to increase my timing here to create a more even progression to higher timing in the cells to the right. It didn't cure my problem completely, but it lessened the effects. Also my gas mileage went up about 20% after I increased timing.

What is the best way to tune for higher load situations (freeway in OD and low rpms)?

Stab & Steer SS

I get the same thing with the Predator tune,with the converter locked especially or with low speed heavy throttle application.I'm thinking this is normal because if I downshift into 3rd (A4) the same manuevers do not show any KR or very little like .2-.4 degrees.

Is this normal assuming no false knock?

Also I think a loose converter,deeper gears or massive weight reduction would really do a good job of eliminating this kind of KR.


Chris