????on knock & knock retard

[PSI GUY]

i've been trying to figure this out for a while...don't know where i should post it so i'll try here. wondering if knock counts and knock retard are directly related. car currently running 18-20psi of boost w/ 4-10 KNOCK COUNTS @ wot but shows 0 KNOCK RETARD & NO COMMAND FROM ESC. after reseaching this subject i came up w/ the following:knock sensor picks up noise from motor read as a frequency, ESC "filters" frequenies to ECM, ECM will only see a certain frequency band that is not "filtered" by ESC MODULE, ECM then responds to that frequency by retarding timing. am i way off here? have gone through checks for false knock causes and have not found any on my car. i don't hear any knock at WOT but i do run open exhaust. hoping to better understand what is going on before i hurt the motor
p.s. forgot to add the above boost&knock numbers are on 93 octane pump gas

[Eric Marshall]

Don't feel bad, it confuses a lot of people!

Try this article researched and written by Dennis Leek:

http://www.turbotweak.com/Knock.pdf

It explains how the whole system works.

[PSI GUY]

great info! reading through that helps but i still don't understand why my car is not retarding timing. is it possible ESC MODULE and/or ECM is bad? car seems o.k. otherwise.


p.s. didn't know you were in illinois, been trying to find info/pricing on your chips....going to be installing alky soon and have read great comments about your chips.
thanks again!

[Eric Marshall]

Yep, just moved to Illinois about 5 months ago.

What scantool are you using?
The counts accumulate over time and will eventually get to 255 and reset to zero. So its possible that there are counts already stored before you went WOT. If the counts are increasing during WOT, then I would think you should have some knock retard, unless some of the chip parameters have been modified.

[PSI GUY]

the scanner is a micro processor systems pro-link 9000(older style"shop"style multi car scanner). current chip is a red armstrong 93 burned to my combo(had the same issues with a pete barton/ans chip), car resets knock count on every key cycle and i'm keeping track of knock counts on each run. when i ordered red's chip i did not ask for any deletion of knock retard in the chip, thinking it's a little deeper than a chip problem because i've had same issue with 2 different chips. at this point i'm not even sure if i know what the car would feel like when timing gets retarded. car runs rich at WOT(850-900 o2's) but i got car running better at idle/cruise than before(had high BLM's-car looked like a deisel out the tailpipes),car still smells rich but blm's in the 124-134 range now.

[HairDrier]

Red's chips usually run richer than other burners. What Fuel pressure are you running and I assume you have no exhaust leaks before the turbo?

900 O2's is pretty high and could be robbing you of some power.

You are not running a Bosch O2 sensor are you?

[PSI GUY]

41psi(line off),checked it with top engine cleaner(no smoke except at tailpipe),new 4 wire heated 02 from caspers(good cross counts,very active). blue top injectors,stock apearring turbo w/ .82 exhaust and .62 inlet(LOTS of turbo lag-been told it's due to too much fuel,going to try lower base fuel pressures when it warms up outside). i've seen that comment about red's chips alot and will be going to a different one shortly(ERIC-how much for one of your custom chips). car is definately improving with each mod/tuning adjustment but i'm getting CONCERNED about having no timing retard-scared to push the limits of this car until i'm satisfied all the components are up to it.

[HairDrier]

What size is the turbo in terms of wheel size? What converter are you running?

[turbodave]

Knock counts and knoc retard are not directly related. The ESC monitors the knock counts, and depending on strength, frequency of occurance, and other variables may or may not issue retard commands.

It's quite common to have knock counts in the range you're seeing without having to retard the timing.

[1badTTA]

Knock counts and knoc retard are not directly related. The ESC monitors the knock counts, and depending on strength, frequency of occurance, and other variables may or may not issue retard commands.

It's quite common to have knock counts in the range you're seeing without having to retard the timing.
Yea but can you get Knock Retard without Knock counts? What about seeing KR about 10+ frames ahead of Knock counts on Direct Scan?

[Eric Marshall]

PSI GUY,
A lot of scantools show O2's 100mv higher than the typical scanner that the turbo buick crowd uses (like Scanmaster, Turbolink, DS). So you could actually be in the 750-800 range.
Also, I suspect that your scanner has the knock counts and knock retard backwards.

Knock retard is based directly on knock counts (thats the only way that retard is calculated). The problem is Directscan doesn't show you the whole story. The knock count as displayed on Directscan is showing you how many times that it accumulated 256 counts. So if Directscan shows a count of "1", then that means the real counts got up to 256. If it gets to 512, then DS will show "2".

So you could have all kinds of knock counts (and therefore retard), but it might not register on DS.

Its a 16-bit thing and DS is only showing you the "most significant byte" or the first half of the number.

Does that make sense? Kinda funky huh?

[PSI GUY]

so you think the scanner may be bad? i have tried it on other vehicles and
scanner would show knock,knock retard,and ESC commands. i do not have a
direct scan,this scanner is about a 1992 vintage scanner with multiple car applications. was hoping not to upgrade scanners right now but may have to bite the bullet. i have seen this scanner go up to 60-70 knock counts on other cars i've worked on-would this rule out your 256=1 scenario?

hairdryer-think it's a "stock" modified turbo,don't have wheel sizes/just housings. was sold as an upgraded stock replacement. using no name 3000 stall converter that a buddy got me that owns a trans shop-car's always had bad 60 times(probably due to the driver :goldcup: )but i think i should be able to leave w/ more than 5# of boost!

[Eric Marshall]

It can't say for certain that its wrong. It's only a hunch since the data doesn't seem quite right. It would be nice if you could borrow some other scantool to compare results.

[PSI GUY]

eric,thanks for all the help. i was thinking that car may have: 1) rich knock(because of high o2#'s), 2)bad ecm, 3)bad esc module. i'll try to beg,borrow,or steal another scanner. is their a way to test esc module? are you still doing chips? if yes, what would price be and how do i get one? thanks again for your input on this matter!