9.5* KR w/ ONE knock count!?

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djwaggoner

New member
Is that 'normal'? It happened on the 2-3 shift and to a lesser degree on 1-2 (only about 4*).
Started the run w/ knock count of 5 & ended w/ 8, so not that bad. I was amazed to see so much retard tho'.
Stock engine/turbo/inj, Ultimate T1-16 & boost max 17. 5. Inj duty cycle <90 & Zeitronix WB @ mid 11's.
Is there a problem I should be finding before turning on the meth and advancing timing?
Thanx
 
midnightbluS10

midnightbluS10

Banned
Re: 9.5* KR w/ ONE knock count!?

Don't pay attention to knock count. It's said to be unreliable in the later versions of DM. Do a search for "knock count" and you'll see what I'm talking about.

edit: Here's one reference to it.

Tooky said:
In old versions of DataMaster, the knock count was useful. In all recent versions it's pretty meaningless. Check out this reference I wrote:
Tuner's Guide to DataMaster

Here's another guide where I talk about tuning a truck and show pics of the DataMaster logs of what it looks reading Knock Retard at WOT:
Real World Tuning Example:
Vortec/PT67GTQ Syclone on C16

Like this:
adam_dm_006alky_18psi_2d_knock.png
Click to expand...

and

powertuneplus.com said:
#2. Knock Count: In DataMaster old version 3.3.0, this counter shows how many times your truck has knocked "significantly" since the ignition was turned on. Normally you will see a low number like 2-5 every time the truck is running due to "knock events" triggered during starter cranking, etc. Nothing to be worried about. If you know the truck normally starts at 5 Knock Counts, and you're driving around some day with the laptop off but the truck felt like it was slow on a run, you can quick connect DataMaster (before turning the key off!) and see what the Knock Count is. If it's in the 30's for example, you could conclude that it's probably been knocking. (Recording with DataMaster at WOT is the only way to be 100% sure.) In the example pictured above, the Knock Count is at 59 mainly because I was stuck in the staging lines at the dragstrip for 1-2 hrs and had to restart the engine many times as the line moved forward.


Notice: DataMaster v3.4.1 and higher (all versions released ~2001 and later) use a different Knock Count formula that results in high numbers in the hundreds or thousands. For that reason, I have always continued using old DataMaster v3.3.0.
Click to expand...
 
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djwaggoner

New member
Re: 9.5* KR w/ ONE knock count!?

I've read that whole website several times & it is _great_ info - helped me a lot!

I am running DM 3.3.1 tho', so I _think_ the counts are valid. It jumped from "0" to 9.5* KR in 1 cell, then tapered off to zero again.....?
Total cts for the run were <10 & the newer DM reportedly gives 100's to 1000's. Hmmm
Thanks for the thoughts. Is it normal for KR to jump so dramatically?
 
cloneman315

cloneman315

Active member
Re: 9.5* KR w/ ONE knock count!?

thats why i run good fuel watch my wbo2 and dont run a knock sensor they suck!!!
 
turbodig

turbodig

Active member
Re: 9.5* KR w/ ONE knock count!?

It's possible. Would depend a lot on how the chip was programmed, but a very aggressive knock attack rate table could make that happen.

I suspect, though, that there was more than one count, it's just that DM didn't see it. The counter rate can happen at a faster rate than the ALDL data routines can read and spit it out.
 
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djwaggoner

New member
Re: 9.5* KR w/ ONE knock count!?

That's what I was wondering...which would mean that it's _real_, & I have to solve it.
May just mean turning on the alky...
Thanks, Dig....you're a font of knowledge on these systems.
 
turbodig

turbodig

Active member
Re: 9.5* KR w/ ONE knock count!?

Where the counts are is as important as how many.

If the counts start during the shift up to the very bottom of he RPM pulldown, it's likely a noise-related thing like a motor mount or converter/flexplate bolts or a downpipe exhaust banging on something.

If the counts start a bit after the low RPM pulldown, it's likely real, and due to a fuel or timing issue in the lower RPM (~2800-3200) areas at higher MAPs.

I use the pattern of knock counts as much or more than I use the KR number itself.

If you don't have a cat, put some 108 octane in the tank (don't blend it) and see if the counts/knock remain.
If they don't, your problem was real.... octane doesn't make noise go away.
 
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djwaggoner

New member
Re: 9.5* KR w/ ONE knock count!?

My KR occurred just after the RPM started to drop at the shift both 1-2 & 2-3 @ 3K+ RPM.
So, I'm thinking 'false' knock from what u say.
I am running a cat (CA) & 91 octane, but have Razor's alky - found out the pump sticks & doesn't pump, tho'... I had AFR < 12 on the WB & was planning to pull fuel out once I got the AFR down around 11 & boost/timing advanced - but have to fix the KR & the alky pump prob's 1st.
Thanks for the thoughts - the search is on for noise sources!
 
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