Knock counting
#1
Three Wheelin'
Thread Starter
Knock counting
Thought I'd start a fact finding thread here for those using a knock counter (Curtis or other) or for anyone interested in this. I've been playing with 91 and 100 octane gas and boost levels trying to minimize the number of occurrences I get under WOT.
EDIT: I also changed the FQS to -3 timing / 0 fuel
Hopefully we can compare these recordings with some constant variables related to car set-up, octane and boost levels and get some kind of consensus as to what's acceptable.
Here's what I've recorded on 91 octane running 15-16# boost. First off, under spirited driving conditions I get absolutely no knocks through all gears shifting at approx. 5500rpm. When I get a little more aggressive with running the shift rpm's up to about 6000 I get:
no knocks 1st and 2nd
1-3 knocks 2nd to 3rd
2-4 knocks 3rd to 4th
4-6 knocks 4th to 5th.
At WOT it ticks up...
no knocks in 1st to 2nd
1-3 knocks 2nd to 3rd
4-6 knocks 3rd to 4th
6-8 knocks 4th to 5th.
I've been trying to tune the WOT knocks down by making very small changes +/- in my A/F mixtures with little success.
Running 100 octane at 18# boost those numbers are basically cut in half. Would love to run 100 oct all the time...but at $9 a gallon.
I would be interested in knowing how you guys are eliminating these knocks if at all...or is it impossible to tune these knocks out of a modded car?
Please post your results.
Thanks
EDIT: I also changed the FQS to -3 timing / 0 fuel
Hopefully we can compare these recordings with some constant variables related to car set-up, octane and boost levels and get some kind of consensus as to what's acceptable.
Here's what I've recorded on 91 octane running 15-16# boost. First off, under spirited driving conditions I get absolutely no knocks through all gears shifting at approx. 5500rpm. When I get a little more aggressive with running the shift rpm's up to about 6000 I get:
no knocks 1st and 2nd
1-3 knocks 2nd to 3rd
2-4 knocks 3rd to 4th
4-6 knocks 4th to 5th.
At WOT it ticks up...
no knocks in 1st to 2nd
1-3 knocks 2nd to 3rd
4-6 knocks 3rd to 4th
6-8 knocks 4th to 5th.
I've been trying to tune the WOT knocks down by making very small changes +/- in my A/F mixtures with little success.
Running 100 octane at 18# boost those numbers are basically cut in half. Would love to run 100 oct all the time...but at $9 a gallon.
I would be interested in knowing how you guys are eliminating these knocks if at all...or is it impossible to tune these knocks out of a modded car?
Please post your results.
Thanks
Last edited by Fluidplay; 08-10-2009 at 10:27 PM. Reason: addition
#4
Nordschleife Master
You might need to lose more timing...3% of 26 degrees isn't really much... I pulled 2 degrees additional to get rid of my last few knocks @ 15PSI before I pulled my car apart to rebuild the turbo...
#6
Nordschleife Master
I do it using MaxTune and and Ostrich 2, you can also order chips with the timing retarded... I would recommend you get chips for the boost level, or get some tuning software and a setup like the ostrich... I can pull timing add fuel and burn the chip image with the car running and see instant results... I have gotten 5 tunes and runs in a half hour...
DONT change the belt.. it will change the valve timing, not just the ignition timing.. and that could be BAD...
DONT change the belt.. it will change the valve timing, not just the ignition timing.. and that could be BAD...
#7
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What AFR is your target @ WOT?
Also, the FQS switch pulls nearly 3degrees of timing, not 3%.
And Changing the belt won't effect ignition timing...
-Rogue
Also, the FQS switch pulls nearly 3degrees of timing, not 3%.
And Changing the belt won't effect ignition timing...
-Rogue
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#8
Nordschleife Master
He already has FQS set -3/0... I stand corrected, the FQS pulls 3 degrees not 3%... now I know, and knowing is half the battle....GOOOOOO JOE..sorry, I blew out my back today and am on drugs now...
#9
Thought I'd start a fact finding thread here for those using a knock counter (Curtis or other) or for anyone interested in this. I've been playing with 91 and 100 octane gas and boost levels trying to minimize the number of occurrences I get under WOT.
EDIT: I also changed the FQS to -3 timing / 0 fuel
Hopefully we can compare these recordings with some constant variables related to car set-up, octane and boost levels and get some kind of consensus as to what's acceptable.
Here's what I've recorded on 91 octane running 15-16# boost. First off, under spirited driving conditions I get absolutely no knocks through all gears shifting at approx. 5500rpm. When I get a little more aggressive with running the shift rpm's up to about 6000 I get:
no knocks 1st and 2nd
1-3 knocks 2nd to 3rd
2-4 knocks 3rd to 4th
4-6 knocks 4th to 5th.
At WOT it ticks up...
no knocks in 1st to 2nd
1-3 knocks 2nd to 3rd
4-6 knocks 3rd to 4th
6-8 knocks 4th to 5th.
I've been trying to tune the WOT knocks down by making very small changes +/- in my A/F mixtures with little success.
Running 100 octane at 18# boost those numbers are basically cut in half. Would love to run 100 oct all the time...but at $9 a gallon.
I would be interested in knowing how you guys are eliminating these knocks if at all...or is it impossible to tune these knocks out of a modded car?
Please post your results.
Thanks
EDIT: I also changed the FQS to -3 timing / 0 fuel
Hopefully we can compare these recordings with some constant variables related to car set-up, octane and boost levels and get some kind of consensus as to what's acceptable.
Here's what I've recorded on 91 octane running 15-16# boost. First off, under spirited driving conditions I get absolutely no knocks through all gears shifting at approx. 5500rpm. When I get a little more aggressive with running the shift rpm's up to about 6000 I get:
no knocks 1st and 2nd
1-3 knocks 2nd to 3rd
2-4 knocks 3rd to 4th
4-6 knocks 4th to 5th.
At WOT it ticks up...
no knocks in 1st to 2nd
1-3 knocks 2nd to 3rd
4-6 knocks 3rd to 4th
6-8 knocks 4th to 5th.
I've been trying to tune the WOT knocks down by making very small changes +/- in my A/F mixtures with little success.
Running 100 octane at 18# boost those numbers are basically cut in half. Would love to run 100 oct all the time...but at $9 a gallon.
I would be interested in knowing how you guys are eliminating these knocks if at all...or is it impossible to tune these knocks out of a modded car?
Please post your results.
Thanks
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#11
Nordschleife Master
but that is a trivial discussion as it is NOT advised to change the timing of the cam to the crank as that is what leads to valves hitting pistons... Only extreme performance cars need to be playing with the cam timing at the pulley using an adjustable pulley...
TO THE OP.. for this application the values of the DME timing table need to be changed, not the timing belt cam pulley.. DO NOT PLAY WITH YOUR TIMING BELT PULLEYS... get the chips changed... or just lower your boost...
#12
Three Wheelin'
Thread Starter
John - if only I had the tuning software/ability to change the timing and burn the e-prom myself, that would be a perfect scenario. Unfortunately I'm using a piggyback system for tuning, which at best is limited. One of the things I was considering, is doing a few dyno runs to get some graphed info., then taking that info. to someone who can program the chip to work with my set-up at a desired boost level.
Sound like a viable way to go? Not having the ability to correct this with my current tuning capabilities.
Rogue - my target A/F is low 12's @ WOT
eniac - though I haven't looked, not sure E85 is available here in So. Cal.
Edit: ok, California does have E85, the closet station is 50 miles away.
Sound like a viable way to go? Not having the ability to correct this with my current tuning capabilities.
Rogue - my target A/F is low 12's @ WOT
eniac - though I haven't looked, not sure E85 is available here in So. Cal.
Edit: ok, California does have E85, the closet station is 50 miles away.
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The timing will only change if you move the rotor so far out that it is igniting the incorrect cylinder.
The rotor is fairly wide, to allow a large range of timing advance commanded by the DME.
This is not a small-block chevy, rotating the distributer does not alter ignition timing. I implore you to hook up a timing light if you don't believe me.
-Rogue
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#15
Nordschleife Master
John - if only I had the tuning software/ability to change the timing and burn the e-prom myself, that would be a perfect scenario. Unfortunately I'm using a piggyback system for tuning, which at best is limited. One of the things I was considering, is doing a few dyno runs to get some graphed info., then taking that info. to someone who can program the chip to work with my set-up at a desired boost level.
Sound like a viable way to go? Not having the ability to correct this with my current tuning capabilities.
Rogue - my target A/F is low 12's @ WOT
eniac - though I haven't looked, not sure E85 is available here in So. Cal.
Sound like a viable way to go? Not having the ability to correct this with my current tuning capabilities.
Rogue - my target A/F is low 12's @ WOT
eniac - though I haven't looked, not sure E85 is available here in So. Cal.
Russel berry (MaxHPKit.com) can do this for you... not sure if authority or Vitesse can do the same, but I imagine so... Russel can also work just off the BIN file if you can have it pulled of your existing chips... call the dyno shop and ask if they can pull the BIN file off your EPROMs... that can then be e-mailed to Russel with your desired changes, he can then burn them to a new set of chips and send the chips to you.. granted for a charge of course...
You MIGHT be able to find locally to you a tuning shop that has the capability to work with your DME files, but there aren't any in my state much less close enough for me to take the car too, hence I bought a chip reader/burner, the ostrich and MaxTune SW.. I do it for myself, and once the car is back together will be investing in some dyno time to maximize the HP while eliminating the knock, and get the car tuned to run perfectly at 15 or so PSI..until I do a full rebuild this winter and get a bigger turbo... new exhaust..etc..etc..etc..