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11H Requesting Knock Retard Feedback

1

11H

GUEST
Hey all ...

I want you all with the 5.3 avalanche to do me a favor ... I need this observed with STOCK TUNING ... (No Hypertech, Diablo, or Superchips tuning please... Bone stock only...)

I want you to observe your Knock Retard on the highway with the cruise set at 70-75 MPH ... Preferably you can find some sloping stretch of road about 7 or 8 miles long to monitor ... (Or more would be better) ... Please just set the cruise, don't use your foot ...

I need this done with 100% 87 octane fuel ONLY ... You will need some sort of scan tool to observe KR ... The Predator, Autotap, etc ... This is for the non-boosted guys only with mild mods or stock avalanche 1500's ... No trailer, no passengers, just the truck and driver...

Please report feedback info when you can ... Please include mileage of truck, driveline related mods, gear ratio, 4x4 or 4x2, and year of avalanche ... I would also like rough elevation, fuel brand, and outside temp ... Then obviously your KR you are getting ... Example: If you blip .78 to 4.18 and that's the norm, give that ... And also the single most highest KR you read ...

... Now to my point ... My truck with current mods on the highway in 100 degree heat with cruise set above 65 MPH, blips some KR from between .30 to 5.5 on slight grades with the cruise set ... (usually I have been seeing mostly in the range of 1.5-2.5 with the 4 or 5 being rare) ... I am just letting the truck drive itself and I get this about 70% of the time ... Although I get no KR under any other condition unless I lug the motor in overdrive... WOT is 0.00 and under regular to aggressive acceleration I get 0.00 ... It only happens under my mentioned conditions under light load / cruise ... weird

... My truck has done this since new and I am trying to figure if it's part of GM's programming or something to be concerned about ... If I get similar feedback from you all, I will dismiss it as "GM designed tuning" ... BTW, I have not noticed any audible knock or pre-ignition on the dyno or on the road ...

Thanks in advance for your efforts...

11H
 
I dont have what you are looking for but thought this was interesting, my 02 8100 at light load and light throttle runs 40 to 55 degrees advance with small kr, it is goog there is knock reduction
 
Wvusquatch said:
Sorry cannot help you as I have the FIPK and wires, or I would de-tune it down! Can you use the monitor features of the Pred on another vehicle?

You're fine with those mods Robert ... Go do some testing ... You're still "mild" ... Thanks!

11H
 
AVALAUNCHIN said:
I dont have what you are looking for but thought this was interesting, my 02 8100 at light load and light throttle runs 40 to 55 degrees advance with small kr, it is goog there is knock reduction

Thanks bud ... No you don't have a 5.3, but you're still worth putting in the shake of things ... What fuel? How much KR? ... As much detail you can give about conditions is great ... Ya, I want mostly the 5.3, but the 8.1 info is good too ... (y)

11H
 
Well I need to wait until the next tank of gas as this one had about 5 gallons of super with the 87. So I will run it down, to almost empty! Any special brand of gas you wouild like? I mean I have cheap stations (Racetrack, QT) then I have Shell, Chevron, and BP's! So just let me know! What are you specifically looking for?

Robert
 
Wvusquatch said:
Well I need to wait until the next tank of gas as this one had about 5 gallons of super with the 87. So I will run it down, to almost empty! Any special brand of gas you wouild like? I mean I have cheap stations (Racetrack, QT) then I have Shell, Chevron, and BP's! So just let me know! What are you specifically looking for?

Robert

Scroll up and you'll see what I'm after ... (y)

11H
 
Hi 11H,

I just thought of something interesting.

The next time you are testing try holding steady speed manually. Add throttle in a similar way that generated knock in "cruise". Back out for half a second and then resume throttle immediately under the same conditions. I'm betting you'll get ping on the first throttle application but not on the second.

Anyone else get the same thing?

kw

 
Redshift said:
Hi 11H,

I just thought of something interesting.

The next time you are testing try holding steady speed manually. Add throttle in a similar way that generated knock in "cruise". Back out for half a second and then resume throttle immediately under the same conditions. I'm betting you'll get ping on the first throttle application but not on the second.

Anyone else get the same thing?

kw

I see what you're after ... (I think heheh) ... Maybe the KR learn is "attacking" on the 2nd apply ... I have been doing some looking into this KR tables and it seems that KR learn/attack is more aggressive under light throttle at higher temps ... I will say that I filled up with 91 octane and drove home stock, and I still blip some KR like before ... But not as much as running 87 fuel ... (But it's hard to measure that since humidity is 60% higher this week and the temps are 25 degrees lower...) ... I am thinking more and more this light load KR at 20% TPS or so is attributed to slow sensors and/or aggressive mapping ...

I have been thinking about installing water injection to keep things in the chambers cooler and control carboning that plagues these engines over time ... Think it's worth it ? ... I want to do it mainly for some KR cushion when I load up with some weight ...

11H
 
and/or aggressive mapping ...

I think this might be the key! It appears to me the PCM adjusts to a cruise condition, setting up parameters for maximum mileage and minimum emmisions. There are tables for "tip in" KR and "burst" KR. I haven't a clue how they work.

Check out this site for water injection. http://www.aquamist.co.uk/cp/cp.html

They use a valve that is connected in parallel with a fuel injector. The valve releases water at a rate corresponding to the fuel flow. They have a dealer in Kansas City that is real helpful. I added the valve to my system, much better than the "all or nothing" setup I had.

kw
 
11h,

My engine bay/ exhaust is still stock, if you want, I can meet you out by your place, and we can go out hwy 60 east up the hills, and you can get your info first hand from my truck. (plus you can compare with the same road, same temps)

I do not have the needed monitering device, don't know if you have one that could be used to get the info off my truck or not.

Just an option for ya.

Grey
 
GreyAvalanche said:
11h,

My engine bay/ exhaust is still stock, if you want, I can meet you out by your place, and we can go out hwy 60 east up the hills, and you can get your info first hand from my truck. (plus you can compare with the same road, same temps)

I do not have the needed monitering device, don't know if you have one that could be used to get the info off my truck or not.

Just an option for ya.

Grey

That's cool ... You have an 03 that would be good to try out ... How's monday or tues sound? >:D

11H
 
work hours might be an issue, I am back on days....

work till 2:30, up in central Phoenix, figure (with traffic on the 60) would not get out to your place till 9pm >:D

ok, more like 4 ish

let me know... :2:
 
One time, at band camp, I walked into the showers when the girls were in there. They said "knock retard!". Is that what this thread is about?

kw
 
Redshift said:
One time, at band camp, I walked into the showers when the girls were in there. They said "knock retard!". Is that what this thread is about?

kw
that was funny as H E double hockey sticks...hehehehehe

Thanks we need more humor....hehehehe
 
Redshift said:
One time, at band camp, I walked into the showers when the girls were in there. They said "knock retard!". Is that what this thread is about?

kw

OMG ... ok ... that was funny ... when I posted this thread, I had thought it would have gotten this sort of view ... ;D

11H
 
Redshift said:
One time, at band camp, I walked into the showers when the girls were in there. They said "knock retard!". Is that what this thread is about?

kw

Redshift,

WAY TOO FUNNY.........That will go down as a classic. It's about time we start having fun again!

NJ George

 
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