bigshoe

iTrader: (2)

I have knock retard that goes to 6 degrees at times, I also have the asp pully, i didnt have it autotapped before the pully install.

anyways, from the data that I am gathering from autotap, I was really lean before, now I am close to where I should be with ltrims close to 0 plus or minus 1 or so, and 02's at .90. Now I know that the C5 template i have been using isnt all to accurate, so i modified it to check fuel cells 1-17 instead of 1-19, and I also am measureing injector pulse width, and delivered torque (althugh im not using that info for anything yet, till i learn what to do with it)

my maft is set for 15%rich base, 0% WOT.

What I am wondering is this, say i get the race gas, and I notice that I still have KR, a lot of members here are saying that would be false knock.....

this makes sense if it indeed is false knock caused by detonation as your only problem- therefore, your knock sensors would be too sensitive.

BUT, what if I am getting KR from vibrations from my pully, or something else? couldnt I damage the engine by desensitizing? Or will it be ok if I desensitize it anyway (what i mean by will it be ok= will i end up with the same amount of KR as before, but not cause detonation by advancing the timing since I'm desensitizing?--- ultimately causing more timing, and not wearing the engine any more than without the KO box).

I hope im explaining my thoughts correctly, I am new to this stuff, and I havent seen this answered anywhere. If anyone doesnt understand- PLEASE mention what, I will try to explain another way, right now this is the best i can think of.

thanks in advance

msce2b-dustin

THink I get at what your saying.

False knock isn't actually knock so desensitizing it won't hurt...since its not really knock <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

The knock sensors "listen" for knock based on sound frequency. It listens and if it hears something that might be the beginning of knock then it starts yanking timing. This can be a ton of things. Anything to pullies to punding exhaust to just not having something tightened up securely. The sensors are pretty sensitive. Guess GM feels the average person would rather lose a little power by being over protective and retarding timing for any little thing. They don't know us racers <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

basically to answer your question though....getting rid of false knock won't hurt anything. If you run race gas and the knock goes away then you might have a problem you need to investigate.

Hope this helps a little.

<small>[ May 30, 2002, 09:12 PM: Message edited by: msce2b-dustin ]</small>

bigshoe

iTrader: (2)

Cool, this is good news to me

BUT, the reason I bring all of this up, is I have heard a story of someone actually cracking their crankshaft from using an aftermarket crank pully, it wasnt on an ls1, I forget what kind of engine, but it worried me.

anyways, I cant get rid of the damn knock, im at 15% rich at base, and I have it at part throttle even, usually just whenever i hit the gas abrubtly.

I think it may be time for the KO box......

Torqued, I dont think it changes the timing table, but i havent looked close enough to notice, BUT, what "I think" it does is just subtract the amount of KR from your actual timing, and therefore you have the result in timing----- dont qoute me, its just what some misinformed guy like myself thinks....

<small>[ May 30, 2002, 11:01 PM: Message edited by: bigshoe ]</small>

msce2b-dustin

A pulley can defilantly cause knock retard but i don't see anyway for it to cause detonation. Detonation like a little explosion inside your cylinder (thus the name knock <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> )and can be damaging . I've ran many cars with timing out of whack and you could hear the detonation. Our cars..from what i've seen, stop knock before it gets that bad.
I've heard of a few pullies coming off on differnent cars but if its installed correctly then there is no reason for something like that to happen.

horist

Toss some 100 octane in andif you're still getting 6 degrees it's probably real... if not it's false

Torqued

My problem is that once I hit 4000 rpms I am seeing over 3 degress KR with 100 octane fuel. Spark advance from 4000-6000 is around 20-22, factoring in the KR, my total timing is only mid 20s. With the PP timing is 25-26 and the KR stays the same, around 3.5. To me this seems like false knock. What do you guys think?

Thanks

TTA89

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by horist:
<strong>Toss some 100 octane in andif you're still getting 6 degrees it's probably real... if not it's false</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Ummmm Wanna re-read your post cause its just the opposite.

If you put some 100 octane in the car and you still have knock retard then its probably false knock. If it goes away then its real.

Team ZR-1

As far as the pulley, if it was not balanced properly it would cause misfires since it will
also put the crank out of balance and crank sensor would pick that up and trip the misfire counter(s), so if no real misfire then pully is fine.

As for delivered torque, if your using autotap they have never fixed their bug I told them about 15 months ago and thus you will see bogus values like 1230 ft/lbs :-(
So you cannot not see the true total torque you have, if you could from DelTq you can compute HP at flywheel and rear wheels.
All you can do is look to see when the Deltq values are negative and if your on the gas and see negative values then TM is being triggered.

This is not an issue with Ease scanner for I worked with that vendor on this and they did a patch to solve the OBD-II fault thus with a good scanner you have a dyno built into the PCM.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by bigshoe:
<strong>I have knock retard that goes to 6 degrees at times, I also have the asp pully, i didnt have it autotapped before the pully install.

anyways, from the data that I am gathering from autotap, I was really lean before, now I am close to where I should be with ltrims close to 0 plus or minus 1 or so, and 02's at .90. Now I know that the C5 template i have been using isnt all to accurate, so i modified it to check fuel cells 1-17 instead of 1-19, and I also am measureing injector pulse width, and delivered torque (althugh im not using that info for anything yet, till i learn what to do with it)

my maft is set for 15%rich base, 0% WOT.

What I am wondering is this, say i get the race gas, and I notice that I still have KR, a lot of members here are saying that would be false knock.....

this makes sense if it indeed is false knock caused by detonation as your only problem- therefore, your knock sensors would be too sensitive.

BUT, what if I am getting KR from vibrations from my pully, or something else? couldnt I damage the engine by desensitizing? Or will it be ok if I desensitize it anyway (what i mean by will it be ok= will i end up with the same amount of KR as before, but not cause detonation by advancing the timing since I'm desensitizing?--- ultimately causing more timing, and not wearing the engine any more than without the KO box).

I hope im explaining my thoughts correctly, I am new to this stuff, and I havent seen this answered anywhere. If anyone doesnt understand- PLEASE mention what, I will try to explain another way, right now this is the best i can think of.

thanks in advance</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">

<small>[ May 31, 2002, 06:22 PM: Message edited by: Team ZR-1 ]</small>

Torqued

ttt

98blackSS

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Torqued:
<strong>My problem is that once I hit 4000 rpms I am seeing over 3 degress KR with 100 octane fuel. Spark advance from 4000-6000 is around 20-22, factoring in the KR, my total timing is only mid 20s. With the PP timing is 25-26 and the KR stays the same, around 3.5. To me this seems like false knock. What do you guys think?

Thanks</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">What are your mods?

2MCHPWR

iTrader: (10)

Torqued, those readings are UGLY. get those O2's way over .900 and see if the KR goes away. as it looks now, i'd say the KR is there because you are too lean. put a stock air meter on and get a MAFT to richen it up. just my $.02. good luck!

Torqued

The car is a 98 and has basic mods:

FTRA
MTI Lid
Stock MAF without screen
MMS TB
Dynomax Exhaust
TR55 plugs

I got similar readings with a PACE VV MAF. I'll try and locate a screened MAF end and try that. Any other suggestions?

<small>[ June 03, 2002, 07:24 PM: Message edited by: Torqued ]</small>