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Force Fed Mopar
12-19-2010, 08:04 PM
Is there a way to check the knock sensor to see if it's working? Can you read the voltage from it some way? I have the CEL Flash mod checked on my cal but I've never seen the light flash, even when I heard knock.

Is there a way to test if the CEL Flash mod is working? We've tried the "tap w/ a hammer" method and haven't seen any difference, and no flash.

shelbymonster
12-19-2010, 08:48 PM
tap the intake with small metal object

Force Fed Mopar
12-19-2010, 11:24 PM
tap the intake with small metal object

Is this a verified method? Will the engine change tune when you do it? If so then mine is bad, cause we whacked the shyte out of it right next to the knock sensor and it didn't change anything. Wonder what would cause a knock sensor to go bad? I 've never seen it much, but I guess most of them are 20+ years old now.

DodgeZ
12-19-2010, 11:29 PM
If so then mine is bad,

prolly would explain why the check engine light randomly comes on.

Force Fed Mopar
12-19-2010, 11:34 PM
Yeah but it doesn't flash though, is what gets me. Isn't it suppose to rapidly flash? Mine just comes on for like 3 secs, then goes out.

Stupid PITA car :mad: lol

turbovanman²
12-20-2010, 02:49 AM
Yeah but it doesn't flash though, is what gets me. Isn't it suppose to rapidly flash? Mine just comes on for like 3 secs, then goes out.

Stupid PITA car :mad: lol

When it see's knock, the light comes on solid, then when the knock goes away, it turns off.

Force Fed Mopar
12-20-2010, 08:53 AM
Ah okay, I though it blinked. So maybe it is a hosed-up knock sensor.

ShadowFromHell
12-20-2010, 10:51 PM
I dont know what causes it, but the one in my NY went south. Cost me a HG when I upped the boost and kept adding timing with the log motor. I was watching the scanner, but nothing ever showed up.

Force Fed Mopar
12-22-2010, 01:19 AM
Well I changed mine out, haven't seen any light yet (would randomly come on before) so we'll see.

ShelGame
12-22-2010, 09:12 AM
It comes on whenever there is knock retard. Technically, it does flash. It typically just happens so fast that you can't see the individual flashes. If the knock level is really low, you might see the flashing, but probably the light will just seem dimmer.

It does not flash the same way the codes flash out. Maybe that's what you were thinking it would do?

Force Fed Mopar
12-22-2010, 11:17 AM
No, I just thought it would be a rapid blinking that I could see whenever it knocked. Like, maybe a flash every 1/4 sec or something. I guess similar to the code flash yeah, just a lot faster and only when it knocked.

Turboomni
12-22-2010, 12:36 PM
Years ago I had my knock sensor trip my Cal power loss light for no good reason. I had a bunch of old knock sensors on hand. I tested them out of the car with a voltmeter [digi} on AC . I then tapped them with a small screw driver to see the voltage. I was surprised to see the voltages sent out with me trying to tap them all close to the same way would vary abit from sensor to sensor. I then tested the knock sensor in my car and found it was hyper sensitive to the same tapping. A good bit higher the the others.
I averaged out the outputs of all the sensors I tested and put in the one that was in the middle output wise. Problem gone.
Basically the knock sensor is a Piezo type microphone and some put out more than others because of manufacture tolerances and age and they put out alternating current.

Force Fed Mopar
01-30-2011, 01:01 AM
tap the intake with small metal object


Is this a verified method? Will the engine change tune when you do it? If so then mine is bad, cause we whacked the shyte out of it right next to the knock sensor and it didn't change anything. Wonder what would cause a knock sensor to go bad? I 've never seen it much, but I guess most of them are 20+ years old now.


prolly would explain why the check engine light randomly comes on.

Okay, so I replaced the knock sensor w/ another used one, light does not randomly come on anymore. However, it also does not light up when I tap on the intake next to it. Another bad one maybe? One extreme to another? Is tapping on the intake on sensor really a good way to test, or is it only supposed to work on a certain frequency? Need to get this working right before I crank the timing up too much more :)

shackwrrr
01-30-2011, 11:36 AM
Okay, so I replaced the knock sensor w/ another used one, light does not randomly come on anymore. However, it also does not light up when I tap on the intake next to it. Another bad one maybe? One extreme to another? Is tapping on the intake on sensor really a good way to test, or is it only supposed to work on a certain frequency? Need to get this working right before I crank the timing up too much more :)

Doesn't the computer have a certain threshold of knock at different rpms? I would think the knock threshold is pretty high at idle. I would get a scan tool and actually look at the voltage it is producing. The computer may even ignore all knock at idle with the stock slider cam and all.

Force Fed Mopar
01-30-2011, 12:09 PM
Hmm, quite possible. I'll see if I can hook it to the scanner this week. I have an OTC here at the house, but it only goes back to '89 :(

risen
01-30-2011, 02:26 PM
Doesn't the computer have a certain threshold of knock at different rpms? I would think the knock threshold is pretty high at idle. I would get a scan tool and actually look at the voltage it is producing. The computer may even ignore all knock at idle with the stock slider cam and all.

Give this man a cookie! You have to take it off idle for the sensor to have an active role in retard. I did the hammer test on mine, but I held it @ 2500 for a few secs while I tapped the intake lightly with a ball peen. I could hear the change in the engine when the retard came on and the light came on. There is a table for the volts vs rpm and a cutoff constant in the lm code. So the rpm has to be above the rpm constant and above the voltage level in the table in order to trigger the retard and light your cel.

Force Fed Mopar
01-30-2011, 02:43 PM
Give this man a cookie! You have to take it off idle for the sensor to have an active role in retard. I did the hammer test on mine, but I held it @ 2500 for a few secs while I tapped the intake lightly with a ball peen. I could hear the change in the engine when the retard came on and the light came on. There is a table for the volts vs rpm and a cutoff constant in the lm code. So the rpm has to be above the rpm constant and above the voltage level in the table in order to trigger the retard and light your cel.

This is exactly what I needed to know, thanks!

Force Fed Mopar
02-21-2011, 05:45 PM
Well I switched out my knock sensor again, as I was 99% positive I was hearing pinging under boost and no CEL flashing going on. The old sensor came apart when I unplugged it, in about 4 pieces :) I put another one in, and now the CEL is coming almost anytime I get on the gas. I am running 87 oct as I'm working on a tune for that, but it still seems pretty extreme. It pretty much just stays on anything over 1-2"Hg of vacuum. And it takes a second for the light to go out too when I lift, probably almost 2 secs. I am running bone stock T2 timing curves. In fact, the whole tune is stock other than scaling for 3-bar and +40s and turning the CEL Flash mod on. I dunno if I just have an over active sensor or what. I swear this stupid car is trying to drive me crazy :)

moparman76_69
02-21-2011, 06:04 PM
I have a "hyper sensitive" knock sensor in the van, either that or a loud lifter tap. I had to adjust the knock sensor voltage table in the cal. The CEL would flash anytime I was out of boost or cruising over 2500 rpm even when I put straight CAM2 in it.

Try some higher octane to rule out actual knock and adjust the sensor voltage table to compensate.

DodgeZ
02-21-2011, 06:10 PM
Well I switched out my knock sensor again, as I was 99% positive I was hearing pinging under boost and no CEL flashing going on. The old sensor came apart when I unplugged it, in about 4 pieces :) I put another one in, and now the CEL is coming almost anytime I get on the gas. I am running 87 oct as I'm working on a tune for that, but it still seems pretty extreme. It pretty much just stays on anything over 1-2"Hg of vacuum. And it takes a second for the light to go out too when I lift, probably almost 2 secs. I am running bone stock T2 timing curves. In fact, the whole tune is stock other than scaling for 3-bar and +40s and turning the CEL Flash mod on. I dunno if I just have an over active sensor or what. I swear this stupid car is trying to drive me crazy :)
stock 87 or StageII? try to pull some timing out. Maybe it is time to buy a new knock sensor.

turbovanman²
02-21-2011, 06:38 PM
Well I switched out my knock sensor again, as I was 99% positive I was hearing pinging under boost and no CEL flashing going on. The old sensor came apart when I unplugged it, in about 4 pieces :) I put another one in, and now the CEL is coming almost anytime I get on the gas. I am running 87 oct as I'm working on a tune for that, but it still seems pretty extreme. It pretty much just stays on anything over 1-2"Hg of vacuum. And it takes a second for the light to go out too when I lift, probably almost 2 secs. I am running bone stock T2 timing curves. In fact, the whole tune is stock other than scaling for 3-bar and +40s and turning the CEL Flash mod on. I dunno if I just have an over active sensor or what. I swear this stupid car is trying to drive me crazy :)

Rig up a listening device, some tubing and a stethoscope.

cordes
02-21-2011, 06:47 PM
Why not just log the knock voltage with a scanner while cruising? Then adjust your table accordingly while adding 10% to get your real knock value. That's what was suggested at SDAC 18.

turbovanman²
02-21-2011, 08:17 PM
Why not just log the knock voltage with a scanner while cruising? Then adjust your table accordingly while adding 10% to get your real knock value. That's what was suggested at SDAC 18.

Interesting.

ShadowFromHell
02-21-2011, 10:25 PM
Well I switched out my knock sensor again, as I was 99% positive I was hearing pinging under boost and no CEL flashing going on. The old sensor came apart when I unplugged it, in about 4 pieces :) I put another one in, and now the CEL is coming almost anytime I get on the gas. I am running 87 oct as I'm working on a tune for that, but it still seems pretty extreme. It pretty much just stays on anything over 1-2"Hg of vacuum. And it takes a second for the light to go out too when I lift, probably almost 2 secs. I am running bone stock T2 timing curves. In fact, the whole tune is stock other than scaling for 3-bar and +40s and turning the CEL Flash mod on. I dunno if I just have an over active sensor or what. I swear this stupid car is trying to drive me crazy :)

So your running a cal designed for premium, and cant figure out why it is knocking on 87? Seems pretty simple to me. Start using premium, or adjust the spark curves accordingly.

risen
02-21-2011, 10:27 PM
Well I switched out my knock sensor again, as I was 99% positive I was hearing pinging under boost and no CEL flashing going on. The old sensor came apart when I unplugged it, in about 4 pieces :) I put another one in, and now the CEL is coming almost anytime I get on the gas. I am running 87 oct as I'm working on a tune for that, but it still seems pretty extreme. It pretty much just stays on anything over 1-2"Hg of vacuum. And it takes a second for the light to go out too when I lift, probably almost 2 secs. I am running bone stock T2 timing curves. In fact, the whole tune is stock other than scaling for 3-bar and +40s and turning the CEL Flash mod on. I dunno if I just have an over active sensor or what. I swear this stupid car is trying to drive me crazy :)

I'm pretty sure the light stays on as long as there is timing being pulled. That's the reason the light stays on for a little while after you get out of it the ecu doesn't go back to full advance for some time after it detects knock.

Force Fed Mopar
02-21-2011, 10:45 PM
stock 87 or StageII? try to pull some timing out. Maybe it is time to buy a new knock sensor.

Stock 87. I may buy a new one here soon, trying to decide where to get one. Advance has a BWD for 46 bucks, AutoZone has a Duralast that is made by Wells for 37. The BWD sensor is supposed to be an improved design or something:


BWD knock sensors are designed to respond to knock frequencies up to 1000 Hz accommodating shifts in engine knock frequency, making it a more flexible sensor that responds to help correct engine knock over a broad range of vehicle conditions.

Duralast


Duralast products are engineered and manufactured by Wells Manufacturing, a leading global supplier of advanced vehicle electronics solutions for original equipment and replacement applications. Every component either matches or improves on the OE design to ensure fast, easy installation, superior performance and reliability. Wells offers extensive application information and technical support via its Tech Line at 1-800-558-9770, as well as in-depth product and repair videos at www.wellsVE.com and through the “Wellstech” channel at www.YouTube.com .

turbovanman²
02-22-2011, 03:29 AM
So your running a cal designed for premium, and cant figure out why it is knocking on 87? Seems pretty simple to me. Start using premium, or adjust the spark curves accordingly.

He is working on the cal.

Force Fed Mopar
02-22-2011, 10:32 AM
I'm pretty sure the light stays on as long as there is timing being pulled. That's the reason the light stays on for a little while after you get out of it the ecu doesn't go back to full advance for some time after it detects knock.

Ah, so the light isn't really triggered by the knock sensor then? Only comes on when the computer retards the timing?

---------- Post added at 09:32 AM ---------- Previous post was at 09:28 AM ----------


So your running a cal designed for premium, and cant figure out why it is knocking on 87? Seems pretty simple to me. Start using premium, or adjust the spark curves accordingly.


He is working on the cal.

Exactly. And I can't work on it properly unless I know exactly what it is doing.

I was going to ask, are all the turbo cals set for premium? What about like a T1 auto or something, still set for premium?

BTW Kevin, I compared the stock T2 to the 93 oct tune you built me... the stock T2 has more timing lol. Did you say you based that on a Stage II cal?

DodgeZ
02-22-2011, 10:47 AM
BTW Kevin, I compared the stock T2 to the 93 oct tune you built me... the stock T2 has more timing lol. Did you say you based that on a Stage II cal?
I'd have to look at the file again. I have done so many different tunes of you now I don't remember. What was the name of the file?

shackwrrr
02-22-2011, 01:03 PM
last time I looked at a stage II it had more timing (1-2 degrees) across the board. And right at 12-15 psi its actually a little bit leaner.

Force Fed Mopar
02-22-2011, 10:07 PM
I'd have to look at the file again. I have done so many different tunes of you now I don't remember. What was the name of the file?

I don't remember, Rob_22_3bar_40s or something like that. I'm not at my computer right now.

risen
02-22-2011, 10:29 PM
Ah, so the light isn't really triggered by the knock sensor then? Only comes on when the computer retards the timing?


If you think about it you can't really represent the sensor value, which is analog, with a light, which is a single, digital, bit for all intents and purposes. There has to be some decision made about at which voltage it is deemed that the engine has knocked. And the ECU determines knock based upon the knock threshold table and voltage read from the sensor. It's as good as you're going to get unless you want to drive around and attempt to read an oscilloscope to watch for knock. Reading a scope is hard enough to do standing still with all your mental facilities dedicated to it, or at least for me it is.

Force Fed Mopar
02-23-2011, 08:47 AM
If you think about it you can't really represent the sensor value, which is analog, with a light, which is a single, digital, bit for all intents and purposes. There has to be some decision made about at which voltage it is deemed that the engine has knocked. And the ECU determines knock based upon the knock threshold table and voltage read from the sensor. It's as good as you're going to get unless you want to drive around and attempt to read an oscilloscope to watch for knock. Reading a scope is hard enough to do standing still with all your mental facilities dedicated to it, or at least for me it is.

Okay, so is the computer still "seeing" knock after I lift? Do this mean that I do indeed have a hyper-sensitive knock sensor and need to adjust the knock table(s)?

cordes
02-23-2011, 06:40 PM
Okay, so is the computer still "seeing" knock after I lift? Do this mean that I do indeed have a hyper-sensitive knock sensor and need to adjust the knock table(s)?

do you have access to a scanner?

Force Fed Mopar
02-23-2011, 08:19 PM
do you have access to a scanner?

Yeah I do.

Watching it today, it's even coming on here and there on decel, 22" of vacuum and no throttle applied, 2200ish rpm. I'm just gonna go buy a new sensor and see what it does. I pulled 4 degrees of timing out of the cal in boost, still comes on.

cordes
02-23-2011, 08:24 PM
Yeah I do.

Watching it today, it's even coming on here and there on decel, 22" of vacuum and no throttle applied, 2200ish rpm. I'm just gonna go buy a new sensor and see what it does. I pulled 4 degrees of timing out of the cal in boost, still comes on.


That's probably a bum sensor then.

Force Fed Mopar
02-23-2011, 08:54 PM
That's probably a bum sensor then.

Kinda what I was thinking, they've all been used ones so far.

Force Fed Mopar
02-27-2011, 11:58 AM
Well, I bought a brand new BWD sensor, and it still lights up all the time in boost. Maybe I just have a noisy engine :) This is on stock timing curves and 93 oct too. Are you supposed to put teflon tape on the threads?

---------- Post added at 10:58 AM ---------- Previous post was at 10:56 AM ----------


I'd have to look at the file again. I have done so many different tunes of you now I don't remember. What was the name of the file?

Nvm, I think it was one of mine that was named similar :p

cordes
02-27-2011, 04:32 PM
Well, I bought a brand new BWD sensor, and it still lights up all the time in boost. Maybe I just have a noisy engine :) This is on stock timing curves and 93 oct too. Are you supposed to put teflon tape on the threads?

---------- Post added at 10:58 AM ---------- Previous post was at 10:56 AM ----------



Nvm, I think it was one of mine that was named similar :p

I believe you should install them without any sealer or tape on them. I would adjust the knock table at this point if it were me.

Force Fed Mopar
02-27-2011, 05:16 PM
I believe you should install them without any sealer or tape on them. I would adjust the knock table at this point if it were me.

Well, I don't see a table for adjusting the threshold, not in MPTuner anyway.

cordes
02-27-2011, 05:45 PM
Well, I don't see a table for adjusting the threshold, not in MPTuner anyway.

I see a table called KnockSensorVoltageForKnockFromRpm Unless I'm sorely mistaken this table is what you need to reset. Take readings of your knock voltage every 500 RPMs and add 10%. Then plot those values in the table.

Force Fed Mopar
02-27-2011, 08:23 PM
I see a table called KnockSensorVoltageForKnockFromRpm Unless I'm sorely mistaken this table is what you need to reset. Take readings of your knock voltage every 500 RPMs and add 10%. Then plot those values in the table.

I don't see that table under Knock Retard. What cal are you using? Mine is based on the A171 Stock T2 template.

cordes
02-27-2011, 09:38 PM
I don't see that table under Knock Retard. What cal are you using? Mine is based on the A171 Stock T2 template.

I am viewing TLM. It is under spark-knock retard and then that table.

Force Fed Mopar
02-27-2011, 10:20 PM
This is what I see:

cordes
02-27-2011, 10:25 PM
It's probably knock from rpms. It should look like this.

http://www.turbo-mopar.com/forums/photopost/data/858/knockretardtable.GIF

Force Fed Mopar
02-28-2011, 08:53 AM
Ah yeah, you are right. Silly me :p Here is the table, should I move it up across the board?

DodgeZ
02-28-2011, 09:00 AM
Ah yeah, you are right. Silly me :p Here is the table, should I move it up across the board?

id say just that last point

---------- Post added at 07:00 AM ---------- Previous post was at 06:56 AM ----------

does the voltage go up or down when there is knock?

shackwrrr
02-28-2011, 09:17 AM
id say just that last point

---------- Post added at 07:00 AM ---------- Previous post was at 06:56 AM ----------

does the voltage go up or down when there is knock?


Up, its a piezoelectric crystal that translates pressure to voltage.

I would find out where and when it goes crazy and then adjust there.

Also to build a baseline read the scan tool knock voltage at each rpm point with no load, then adjust from there. You just need to make sure there is absolutely no knock when you adjust it.

cordes
02-28-2011, 02:53 PM
Up, its a piezoelectric crystal that translates pressure to voltage.

I would find out where and when it goes crazy and then adjust there.

Also to build a baseline read the scan tool knock voltage at each rpm point with no load, then adjust from there. You just need to make sure there is absolutely no knock when you adjust it.

Agreed. Since he has a scanner it will be easy to dial in the table perfectly for that engine/sensor combination.

zin
02-28-2011, 05:51 PM
Give this man a cookie! You have to take it off idle for the sensor to have an active role in retard. I did the hammer test on mine, but I held it @ 2500 for a few secs while I tapped the intake lightly with a ball peen. I could hear the change in the engine when the retard came on and the light came on. There is a table for the volts vs rpm and a cutoff constant in the lm code. So the rpm has to be above the rpm constant and above the voltage level in the table in order to trigger the retard and light your cel.

Do our ECUs have the ability to "look" for a certain frequency in order to ignore "false positives"? If so, maybe that could be used to isolate the true knock signal vs a noisy lifter or mechanical cam?

Mike

PS Now that I've written this, I'm not sure if you could do this with just one sensor, maybe two like the LSx engines...

risen
02-28-2011, 11:27 PM
Do our ECUs have the ability to "look" for a certain frequency in order to ignore "false positives"? If so, maybe that could be used to isolate the true knock signal vs a noisy lifter or mechanical cam?

Mike

PS Now that I've written this, I'm not sure if you could do this with just one sensor, maybe two like the LSx engines...

No, not currently. Bucar, Frank, and I are working on an external black box that does exactly this. It uses a DSP chip to filter for a certain set of frequencies, only monitors for knock in a set window (@ a start crank angle, for a set number of degrees), and holds the output until next ignition event. It works well on the bench, but the winter has hampered in-car testing. I'd look for something preliminary by the fall of '11. You'd basically use a wideband type sensor (though our normal sensors would likely work, too), hook the output of our box to where your normal sensor sits, and away you'd go. There's still dev work to be done, but it's coming along nicely, as far as I'm concerned.

zin
03-01-2011, 05:16 PM
You'd basically use a wideband type sensor (though our normal sensors would likely work, too), hook the output of our box to where your normal sensor sits, and away you'd go. There's still dev work to be done, but it's coming along nicely, as far as I'm concerned.

I'm curious as to what constitutes a "wide-band" knock sensor? I do understand the literal meaning of it, but I'm curious as to the technical differences...

Also, would the output of the sensor make an intelligible sound if it was hooked up to an amp and played over a speaker? Seems possible as it is an analog signal (AFAIK anyway)... I'm wondering if we could use it like the old-school knock sensors used on dynos, basically a stethoscope hooked up to the intake. They allowed one to discern actual knock from mechanical noise, I think it would be neat, and possibly helpful to do the same an electronically.

Mike

risen
03-09-2011, 11:47 PM
I'm curious as to what constitutes a "wide-band" knock sensor? I do understand the literal meaning of it, but I'm curious as to the technical differences...

Also, would the output of the sensor make an intelligible sound if it was hooked up to an amp and played over a speaker? Seems possible as it is an analog signal (AFAIK anyway)... I'm wondering if we could use it like the old-school knock sensors used on dynos, basically a stethoscope hooked up to the intake. They allowed one to discern actual knock from mechanical noise, I think it would be neat, and possibly helpful to do the same an electronically.

Mike

Sorry it took me so long to get to this. Though, my answer isn't great since all I have to back it up are 2nd and 3rd hand references. I think the difference between the 2 sensors has to do with response frequency. I believe our sensors are designed to physically respond more effectively to the frequencies that our engines knock at. I've been told that the knock frequency of an engine is directly related to it's bore size (the exact formula is posted around here, somewhere), so designing the sensor to respond less to any frequency other than the one you're looking for would be a worthy design goal. The wideband sensor, it's my understanding, more accurately transmits all the sound it picks up from the engine and lets the electronics do the filtering (e.g. DSP). In any case, the chip we're playing with has all sorts of cool features like adjustable center frequency, adjustable gain and we can window the sensing period to only check say 10 or 20 degrees of the crank revolution. All of those things added up should make for a much better detection of knock than whatever we currently have. I'd bet we're throwing more computing capacity at this problem than the LM has as a whole if you take the MCU and the DSP together.

Anyone who knows how these things *ACUTALLY* work and can explain the whole theory of why exactly the sound is related to the bore (resonance?), what design choices have to be made to make sensors respond in different ways, or anything that gives a much greater level of knowledge than what's above is more than welcome to enlighten me, or all of us for that matter. It'll need to be better than stating that a knock sensor "is just a microphone" or "produces an A/C waveform" though, since I think everyone already knows that.

Force Fed Mopar
03-12-2011, 07:25 PM
I was going to ask, are all the turbo cals set for premium? What about like a T1 auto or something, still set for premium?



Bump for this, anybody know?

cordes
03-12-2011, 08:47 PM
Bump for this, anybody know?

All of the turbo cars recommend premium The MP cals are obviously set for premium. In my experience, you can run stock 2.5 TI timing with regular up to 6-7PSI. I just DD the car now, so I haven't pushed it farther than that. It's a no AC 90' Shadow ES so I don't know what you could get away with in a heavier car.

I actually upped the timing in vac to better my gas mileage too.

Force Fed Mopar
03-16-2011, 12:49 AM
So do you guys think that with the mods in my sig, should I be seeing any knock at all up to 15 psi on stock timing curves? Or are my mods enough to have to change the curves? On a bone stock cal scaled for 3bar and 40's, CE Flash Mod turned on and with a brand new knock sensor, I get CE flash all the time even running 93 oct. Is it possible that it is picking up injector noise or something?

Force Fed Mopar
03-16-2011, 03:33 PM
Bump...

cordes
03-16-2011, 08:19 PM
I wouldn't think you should get any knock. How much if any has the head or block been milled? Cam timing dead on? ign. timing didn't get bumped out etc? I'm sure you've double checked all that, and if you have I don't know what to say.

Force Fed Mopar
03-16-2011, 09:36 PM
I wouldn't think you should get any knock. How much if any has the head or block been milled? Cam timing dead on? ign. timing didn't get bumped out etc? I'm sure you've double checked all that, and if you have I don't know what to say.

IIRC the head was milled .008". I don't think the block got decked much if at all, I can't remember. Let's just say .002", that would make a combined .010".

Cam timing is right, ignition timing is at 12*, or should be, AFAIK it hasn't been moved. Need to check again to be sure. I did pick a dizzy that seemed to have a solidly mounted shutter wheel also (no broken or loose plastic rivets), however, the mark does seem to move around a little bit when trying to set the timing. Normal? It kinda flickers a bit around the 12 mark. Always has done this, not sure if it has to do with spark scatter or if something is wrong.

bakes
03-16-2011, 09:42 PM
So do you guys think that with the mods in my sig, should I be seeing any knock at all up to 15 psi on stock timing curves? Or are my mods enough to have to change the curves? On a bone stock cal scaled for 3bar and 40's, CE Flash Mod turned on and with a brand new knock sensor, I get CE flash all the time even running 93 oct. Is it possible that it is picking up injector noise or something?

Yes is posible to pick up non knock sounds I had my valves on my last motor in my LS set the cel off and back timing out.

cordes
03-16-2011, 11:33 PM
I've had many distributors which have fluttered a bit with no ill effects. Did you ever map the knock volts and adjust your table accordingly?

Force Fed Mopar
03-17-2011, 01:23 PM
Not yet, I have had time to spend driving it around w/ the computer on it, always seem to have more pressing matters when I'm at the shop. I have played around with the knock voltage table a good bit and it still flashes over 5-psi. It doesn't go off at any rpm out of boost though (ran it up to 5k in 1st and 2nd with no boost, does not flash the light).

I'm wondering if my mods have increased the efficiency of the engine or something. I seem to remember reading somewhere that the more efficient the charge burns, the less timing is needed. Like, more timing is needed in vacuum because the charge is leaner and is harder to light. Something along those lines. I never really considered mymods as being that much, but maybe they are.

DodgeZ
03-17-2011, 01:41 PM
does it do it with e85?

Force Fed Mopar
03-17-2011, 01:45 PM
I don't remember. Don't know if I had it turned on then or not. Also had the old sensor in then.

cordes
03-17-2011, 07:49 PM
Not yet, I have had time to spend driving it around w/ the computer on it, always seem to have more pressing matters when I'm at the shop. I have played around with the knock voltage table a good bit and it still flashes over 5-psi. It doesn't go off at any rpm out of boost though (ran it up to 5k in 1st and 2nd with no boost, does not flash the light).

I'm wondering if my mods have increased the efficiency of the engine or something. I seem to remember reading somewhere that the more efficient the charge burns, the less timing is needed. Like, more timing is needed in vacuum because the charge is leaner and is harder to light. Something along those lines. I never really considered mymods as being that much, but maybe they are.

I don't think your mods should be enough for the problem you are having at the boost level you are having it at. IIRC your knock volts were way out of line compared to the table. I would make a table of that with no load first. I'm afraid you may be chasing your tail on this one.

Force Fed Mopar
03-17-2011, 08:03 PM
Yeah, checked the timing today, apparently I'm retarded or something cause it was nearly at 15 degrees. Also listened close and could hear the lifters a bit still when I revved it, and I think this is probably setting it off too. I drove around with the computer on it today, I could free rev it (no load, just push the clutch in going down the road and rev it) and get .4 on the knock sensor, and it would flash the light every time too (this is after I reset the timing and on stock knock voltage table). Under boost around 4k I got anywhere from .6 to .8, couldn't tell if it set the light off or not, can only do so many things at one time while driving fast and holding a scanner in one hand :D

So I reset the timing to 12* (for real this time :) ), and my next step is to add another washer under each lifter and see if I can get rid of that noise. I am running PT lifters already.

Force Fed Mopar
03-17-2011, 09:07 PM
Just ran back out to the store, and couldn't get it to flash at all unless I went in and out of WOT and PT. Bit cooler out now though. So must be pretty close.