Knock sensor Teflon tape

[roachjuice]

How much is too much Teflon? I got 3 rounds on it. Runs great!

[minigts]

I don't understand. Why the tape on the knock sensor?

[turbovanman²]

You do realize your reducing its effectiveness, or is that your purpose?

[zin]

He's trying to lessen the sensitivity of the sensor, three rounds of typical teflon tape is not a real big deal. I'm pretty sure they would have had some kind of tape/sealer from the factory anyway, if for no other reason than to prevent galling...

I would do the "tap" test (tapping the intake next to the sensor, while watching the timing light or scan tool) to be sure the sensor still functions when "real" detonation occurs.

Mike

[roachjuice]

You do realize your reducing its effectiveness, or is that your purpose?

Yes. It's being dumb. The SAME tune that I tuned out the knock with was getting knock with nothing else changed. So I lowered timing more. Still got knock. Honestly if it were knocking as bad as it said it was according to my cel then I wouldn't have an engine. Knock just driving down the highway at 3k and 20in of vac? Lol yea right. So since no one can tell me what acceptable timing would be on the advancefullthrottle table I'll just take it into my own hands. I'll check the plugs for detonation. Hell I ran my old 2.2 u2 engine for 2 years with the dam knock light going off because I didn't know about the timing slope thing. Never busted a piston.

[roachjuice]

He's trying to lessen the sensitivity of the sensor, three rounds of typical teflon tape is not a real big deal. I'm pretty sure they would have had some kind of tape/sealer from the factory anyway, if for no other reason than to prevent galling...

I would do the "tap" test (tapping the intake next to the sensor, while watching the timing light or scan tool) to be sure the sensor still functions when "real" detonation occurs.

Mike

Yea I'll try that tomorrow. It just seemed way too sensitive. But it hauls way more --- now! Lol. I have solid motor mounts and I think it picking up noise from that.

[cordes]

If you have a scanner you can take down the RPM vs. knock volts and then adjust the actual table. That's the best way to go about it in general IMO.

[roachjuice]

Teflon tape. No tuning required. No headache.

[roachjuice]

Did you guys know there are at least two types of knock sensors. I found 2 different ones in my tool box. One with a tapered end that goes in the manifold. And the other sensor had a flat end. The flat end one is in there now. Didn't know if they were different or something.

[turbovanman²]

Did you guys know there are at least two types of knock sensors. I found 2 different ones in my tool box. One with a tapered end that goes in the manifold. And the other sensor had a flat end. The flat end one is in there now. Didn't know if they were different or something.

Hmmmm, did not know that, it could be a production change.

[trannybuster]

IMO I would make sure the knock sensor worked as designed.

[roachjuice]

IMO I would make sure the knock sensor worked as designed.

Yea be so sensitive that it picks up dumb ---- in vacuum on the highway

[turbovanman²]

Yea be so sensitive that it picks up dumb ---- in vacuum on the highway

Hmmmm, tuning by Simon, works for me, hehehehe.

Seriously though, something isn't right, my old TIII with stupid piston clearance wouldn't set it off until around 3000 rpm, :(

[johnl]

Maybe try testing/comparing the signal strength of both of them with a volt meter?

[cordes]

Maybe try testing/comparing the signal strength of both of them with a volt meter?

I don't think you can read the output of the knock sensor with a volt meter, but I may be wrong.

I would certainly try a different knock sensor if it's causing problems in vac. You may as well have it disconnected at this point.

[roachjuice]

http://img.photobucket.com/albums/v515/mobite/61b09aac.jpg

I'm running the rusty one now. I was running the clean one. I took it out and the Teflon tape pushed all the way up top. So Teflon was only covering the top threads. Re did it and took it for a spin. Did a heavy load in 4th. Like 3000rpm it knocked a little then went away. Before it wouldn't go away. Again. Same tune. Same boost. Only changed knock sensor.

[BadAssPerformance]

Just looks like the same part made by different manufacturers, are you sure they are both Mopar or maybe one is aftermarket?

I am slightly confused by trying to reduce the knock sensor effectiveness, if it always knocks, just unplug it and run conservative timing and good fuel and keep the WB-O2 11.5:1 under WOT?

[roachjuice]

Just looks like the same part made by different manufacturers, are you sure they are both Mopar or maybe one is aftermarket?

I am slightly confused by trying to reduce the knock sensor effectiveness, if it always knocks, just unplug it and run conservative timing and good fuel and keep the WB-O2 11.5:1 under WOT?

Exactly. I know the old one is a mopar unit. I don't know about the newer one. Ok. What is conservative timing for a 2.5 and a 50 trim at 20psi? I haven't had a straight answer. I'm at -20 at 20 now. Fuel is 11:1. And I always run race gas 91 through it lol.

[roachjuice]

No one knows?!? No one tunes?

[turbovanman²]

No one knows?!? No one tunes?

Hard to say, every setup is slightly different. I would pull the timing down after 15 psi, maybe 5 deg total, then you know your safe.

[roachjuice]

Well that's good to know. Me and rob m are going past that. He is at like -27 at 18psi. I'm at -20

[cordes]

Pull out just enough so it doesn't knock anymore.

[trannybuster]

-20 at 18psi sounds high(too much timing), when running timing right at the edge it doesnt always act consitent due to variuos loads on the engine, outside temp blah blah. I could run aggresive timing if I went through the gears at dead stop, put if I did a 3rd gear pull the turbo was at 100% asap and it knocked some. Yeah I know pulling timing sucks!

[roachjuice]

Pull out just enough so it doesn't knock anymore.

I'm not gonna keep fighting this crap. I'm not gonna think "oh it's not knocking let's leave it alone" then a few days later the mother----er knocks. Then I'm back on the forum asking the same question that I still have YET to get and answer too. Im not gonna drag the crap out of my brakes down the highway. Thats more load than the engine will see and by would I tune for that? It still doesn't make sense to me. This tune was perfect and all of a sudden this crap. I'm not gonna run 20psi through a ----ing 50 trim and a 2.5 and run 15's. I can just leave the car bone stock to run that. 104 trap speed and I should pull more timing? and loose more power. That 104 trap puts me at 210whp. Really? Doesn't make since.

[roachjuice]

and tell me how i was able to run 14.0@104 @ 20psi of boost and no knock and pump gas. timing was -19 the WHOLE night. 20-25psi on the highway later that night too. if -20 is too much then i would think my engine would have ---- out by now or i would have broke some serious stuff. tell me how gary and gus ran STOCK tunes which didnt adjust timing past 14.7psi at 20+psi of boost on s60 turbos? come on. im really gonna take out -25+ deg of timing? it REALLY doesnt make sense to me. this isnt my daily anymore so im thinking about just putting half 112 octane fuel in there since its just a weekend car now. just to make sure i dont break anything. i dont mind adjusting things but when i dont get knock i assume im tuned. then out of nowhere i get knock. just driving down the road. ill upload a video.

[zin]

Sometimes these things are just too sensitive, or maybe more accurately too indiscriminate and pull timing due to valvetrain noise or piston slap, etc. The tape is an old school way of desensitizing it when your options have run out.

Ideally, it should be able to know where a sound came from (chamber vs valvetrain, etc) ,and disregard sounds that cannot be detonation, while modern engine management can, ours not so much.

So long as it still functions when real or significant detonation occurs, which would save the engine, what's the big deal?

Mike

[roachjuice]

Exactly. Hell it started to go off when I hit the two step. It NEVER did that before.

[turbovanman²]

Im not gonna drag the crap out of my brakes down the highway. Thats more load than the engine will see and by would I tune for that?

Why do you refuse to do something that helps is beyond me. :confused: And your partially right, at the drag strip with slicks, you will see that load, hence why you do it but if you still for some reason refuse to do it, then you can't come on here complaining your tune is never right. I tuned my van like that a few weeks ago, it was so close, some minor tweaking at the track, unlike years before where I don't brake load it and end up adjusting everything all night, :banghead:

[roachjuice]

Why do you refuse to do something that helps is beyond me. :confused: And your partially right, at the drag strip with slicks, you will see that load, hence why you do it but if you still for some reason refuse to do it, then you can't come on here complaining your tune is never right. I tuned my van like that a few weeks ago, it was so close, some minor tweaking at the track, unlike years before where I don't brake load it and end up adjusting everything all night, :banghead: yes. im gonna hit my brakes at the track. i tried that and it wouldnt go past 10psi. so ---- didnt work. im just gonna do what im doing. :thumb: plus i dont have slicks.

[turbovanman²]

Your name suits you, and your stubborn, lol.

[roachjuice]

im more than willing to try something. but when something doesnt work like people say it should then i take ---- into my own hands. hence what im doing now. ive tried the brake thing. it didnt work. trying something over and over again and getting the same results is crazy. so if SOMEONE can tell me WTF TIMING TO START OUT AT WITH A STOCK 2.5 ADVANCEFULLTHROTTLE @ 20PSI ID BE MORE THAN HAPPY TO TRY IT. I GET NO ANSWERS WHEN I START THESE THREADS. SOMEONE HAS HAD TO HAVE TUNED A STOCK 2.5 BEFORE. ITS BACK TO THE OLD DAYS WHERE NO ONE SHARED ANYTHING. /end rant.

[ShelGame]

This tune was perfect and all of a sudden this crap.

What changed?

[DodgeZ]

google SRT4 and knock sensors.

[roachjuice]

What changed? it started knocking out of nowhere. the only thing i changed is the hep and the coil wire. thats it.

---------- Post added at 03:26 PM ---------- Previous post was at 03:26 PM ----------


google SRT4 and knock sensors. will do when i get home.

[roachjuice]

what am i looking for kevin? i found a thread about it and it doesnt show anything. just something about the tq specs.

---------- Post added at 04:12 PM ---------- Previous post was at 04:11 PM ----------

http://www.srtforums.com/forums/f74/srt4-knock-sensor-information-17020/

[glhs0426]

Exactly, torque specs. How tight is the knock sensor in your 2.5?

[roachjuice]

Hell I don't know lol. I didn't know there were tq specs to a knock sensor. Its tight enough where I can break it loose with the valve cover and fuel rail all on with a crescent wrench.

[roachjuice]

The newer one was tight in there. This one is a little less tight.

[DodgeZ]

what am i looking for kevin? i found a thread about it and it doesnt show anything. just something about the tq specs.

---------- Post added at 04:12 PM ---------- Previous post was at 04:11 PM ----------

http://www.srtforums.com/forums/f74/srt4-knock-sensor-information-17020/

TQ specs and also the Knock sensor threshold when programming a DSP. Another things that falsely set the sensor off. Force Fed Mopar had a thread about knock light problems. He went through a bunch of used sensors trying to get rid of. I had a local guy asking about tuning his car last weekend.... I'll quote "I don't do any tuning on a car unless it has a wideband. It really should have a new knock sensor (Mopar). "

[roachjuice]

im more than willing to try something. but when something doesnt work like people say it should then i take ---- into my own hands. hence what im doing now. ive tried the brake thing. it didnt work. trying something over and over again and getting the same results is crazy. so if SOMEONE can tell me WTF TIMING TO START OUT AT WITH A STOCK 2.5 ADVANCEFULLTHROTTLE @ 20PSI ID BE MORE THAN HAPPY TO TRY IT. I GET NO ANSWERS WHEN I START THESE THREADS. SOMEONE HAS HAD TO HAVE TUNED A STOCK 2.5 BEFORE. ITS BACK TO THE OLD DAYS WHERE NO ONE SHARED ANYTHING. /end rant.
Bump.

[DodgeZ]

Bump.

with the amount of different combos we have it is hard to say. What is your build?

http://www.turbo-mopar.com/forums/forumdisplay.php?85-ECU-Code-Repository&s=&pp=20&daysprune=-1&sort=lastpost&order=desc

[roachjuice]

with the amount of different combos we have it is hard to say. What is your build?

http://www.turbo-mopar.com/forums/forumdisplay.php?85-ECU-Code-Repository&s=&pp=20&daysprune=-1&sort=lastpost&order=desc stock 89 2.5 with balance shafts removed. +40's 50 trim turbo .63 ar stage 2 turbine wheel. big fmic. stock manifolds. stock cam. back cut valves. cleaned up ports. not ported. 555 trans. no cat no muff. the pump eff table was pretty close to stock. had to bump it up a little 3500+ i just need to know what is acceptable on timing with that high of boost 20 psi+ because the advancefullthrottle table just flatens out at -16 degrees 2 14.7+psi

---------- Post added at 08:37 AM ---------- Previous post was at 08:35 AM ----------

i have it at -23 degrees @ 20psi. -33 @ 29psi i changed it yesterday from -19 to -23 since i teflon tapped the knock sensor just to be safe because i assume that is safe. it kinda hits flat spots in the rpm band now and picks back up. pulls a little funny.

[ShelGame]

stock 89 2.5 with balance shafts removed. +40's 50 trim turbo .63 ar stage 2 turbine wheel. big fmic. stock manifolds. stock cam. back cut valves. cleaned up ports. not ported. 555 trans. no cat no muff. the pump eff table was pretty close to stock. had to bump it up a little 3500+ i just need to know what is acceptable on timing with that high of boost 20 psi+ because the advancefullthrottle table just flatens out at -16 degrees 2 14.7+psi

---------- Post added at 08:37 AM ---------- Previous post was at 08:35 AM ----------

i have it at -23 degrees @ 20psi. -33 @ 29psi i changed it yesterday from -19 to -23 since i teflon tapped the knock sensor just to be safe because i assume that is safe. it kinda hits flat spots in the rpm band now and picks back up. pulls a little funny.

Can you post screenshots of the 3 timing curves? WOT, P/T from MAP and RPM?

[DodgeZ]

stock 89 2.5 with balance shafts removed. +40's 50 trim turbo .63 ar stage 2 turbine wheel. big fmic. stock manifolds. stock cam. back cut valves. cleaned up ports. not ported. 555 trans. no cat no muff. the pump eff table was pretty close to stock. had to bump it up a little 3500+ i just need to know what is acceptable on timing with that high of boost 20 psi+ because the advancefullthrottle table just flatens out at -16 degrees 2 14.7+psi

What head, is it shaved?
Stock cam. roller-slider?
Square tooth or round tooth?
What kind of fuel?
AFR are you targeting?

The problem is our cars have to many combos. It isn't like an SRT where all the stuff is the same, we have alllllll kinds of different stuff. You'll be able to run more timing then an auto van for example. Some of these things you have to figure out on your own with track or dyno tuning. Go through that link I sent and download other people's tunes. You'll get an idea of where you want to start your timing out at.

As for people not wanting to help. Really I think that good tuners have spent years and years learning and trail and errors on cars. Even expensive training, http://www.efi101.com/ . I know I have spent a bunch of time reading and messing around with with the stuff. I even bought these AEM videos http://www.youtube.com/watch?v=u5LgJMuqEaM . I feel that I am not good enough to tell someone how to do their tune, too much risk. "DodgeZ told me to put my timing up and it cracked one of my pistons"..... The good guys charge for their skills and rightfully so. The hobbyist prolly just don't want steer you wrong and or don't know.

[roachjuice]

Swirl head. Shaved. No. It's hairy.
91 fuel with 10% eth. Usual crap
Round tooth.
88 tbi cam roller.
Target afr. 11.1-11.5 is fine by me. Afr is good now.
I was just asking what's a good starting point on wot timing. I'm not asking for a full tune lol.

[Force Fed Mopar]

For the record, I'm at -13.3 @ 10 psi, -18.82 @ 20 psi, and -22.34 @ 29 psi.

[DodgeZ]

maybe take a look at this cal
http://www.turbo-mopar.com/forums/showthread.php?16492-LM-1987-2.5L-8V-3-Bar-40-G-Head-and-Swirl&daysprune=-1

I can't open it right now but I am sure that would be a good starting point.

[roachjuice]

hell yea. thanks. ill try that. even though its old.

[roachjuice]

http://img.photobucket.com/albums/v515/mobite/cb98cdef.jpg
Dark blue is the bb60. Green is 2.5 atx v12.5
Light blue is what I'm running now.

[roachjuice]

http://img.photobucket.com/albums/v515/mobite/d322abfc.jpg
Same. But fuel map.

[DodgeZ]

hell yea. thanks. ill try that. even though its old.

looks through that whole sub forums. there are a bunch of tunes in there.

---------- Post added at 11:51 AM ---------- Previous post was at 11:48 AM ----------


http://img.photobucket.com/albums/v515/mobite/cb98cdef.jpg
Dark blue is the bb60. Green is 2.5 atx v12.5
Light blue is what I'm running now.

Most timing curves I see don't drop off sharp after 15psi. They seem to level out and slightly go down. Like the dark blue

[roachjuice]

Really? I didn't know that. So mine slopes way too much?

[roachjuice]

No wonder my car is ----ing slow lol. I bet that's why it was glowing under the car while I was racing that s2000.

[Force Fed Mopar]

Yeah I'd say you are retarding it too much in high boost. Try setting the last point (29 psi) at -26 and see how it does.

[roachjuice]

Lol ok I'm matching the bb60 tune right now and it says -9 deg advancefullthrottle table. Are you sure this is gonna work?

[Force Fed Mopar]

Btw you need to be looking at the Ypt, not the Y ;)

[trannybuster]

Is ti possible your bov is venting on you, or your waste gate spring isnt up to the task, your boost is rock steady? I dont remember reading you wideband numbers....?..although your feuling looks 'okay',,,yeah your timing table drops pretty hard, it might be your knock is comin on earlier than you think and your adjusting all the tables when you only need a point or two, dont get crazy 1deg could do it or couple psi to the left or right would fix it as well.---------- Post added at 12:08 PM ---------- Previous post was at 12:03 PM ----------BTW make sure it isnt part throttle table thats screwing you up, ensure your actually in wot pedal mode!

[roachjuice]

So start from -16? That's what I'm trying to get at. The tunes Kevin posted up are -10 at 20 psi. Ok ---- that. I know ---- will blow up. I had another idea. It may not work. But. Adjust only the advancefromrpmmax table. For racing only. Because in my theory it wouldn't go past that point no matter what the others are set at.

[roachjuice]

The turbonator v12 cal Atx timing is at -6 advancefullthrottle!!!! Doesn't drop off!

[ShelGame]

The dark blue line above appears closer to what I usually put in for 29psi. The light blue line is taking out way too much timing. When you add the advance from RPM to that, basically you will get 0 advance.

[cordes]

Brandon, could you post up the advance from rpms, and the max advance tables too? I'll make some of the comparison spreadsheets with info you give me if you would like. It's much easier to see what's really going on that way.

Also, are you logging the temp and weather conditions while you are tuning? A cool night at the track can allow for more timing that a hot day on the streets.

[trannybuster]

^^And dont ask too much of 91 octane, Im sure youve heard horror stories about gas stations dumping 87-89 octane in 90+ tanks, whos gonna know?? ....

[cordes]

^^And dont ask too much of 91 octane, Im sure youve heard horror stories about gas stations dumping 87-89 octane in 90+ tanks, whos gonna know?? ....

That's a great point too. the difference between 91 and 93 is quite a lot.

[roachjuice]

The dark blue line above appears closer to what I usually put in for 29psi. The light blue line is taking out way too much timing. When you add the advance from RPM to that, basically you will get 0 advance.

Holy crap!! Ok I'll change it. I matched the other tables to the atx file. I'll change this one. I ran a new SS with headers exhaust and intake and was dead even with him. No knock. I wonder what would happen with the correct timing!! Hell I ran the 14.0@104 on that tune!

[roachjuice]

I'll post em up. I love this remote desktop crap lol

[roachjuice]

http://img.photobucket.com/albums/v515/mobite/b7c1fd32.jpg
http://img.photobucket.com/albums/v515/mobite/213febd5.jpg
http://img.photobucket.com/albums/v515/mobite/bd5542b6.jpg

Light blue is current tune. Green is stock atx 2.5

[ShelGame]

http://img.photobucket.com/albums/v515/mobite/b7c1fd32.jpg
http://img.photobucket.com/albums/v515/mobite/213febd5.jpg
http://img.photobucket.com/albums/v515/mobite/bd5542b6.jpg

Light blue is current tune. Green is stock atx 2.5

The RPM curve is fine. Those are the same for all intents and purposes.

The WOT timing though, it looks like ~-30deg at 30psi and that is way too little timing. I would use something like -24deg at the lowest; maybe as high as -20deg. And, I would match the green table with all the other points.

[roachjuice]

Alright. That's great info. I'll try that. Maybe a degree or two out since I'm running a 50 trim. So how do you explain the knock at -19? Lol. Just false?

[roachjuice]

How do I post up my actual tune?

[zin]

I'm curious if there is a "rule of thumb" for ignition retard per pound of boost? Something akin to the 1.5-2* retard per 50HP of nitrous injected...

Too bad we can't read the cylinder pressure in relation to crank angle, that would be the most accurate way to adjust timing, then it's just a matter of setting the target angle to build peak pressure and then let the computer handle it!

In the mean time a rule of thumb would be better than nothing!

Mike

[roachjuice]

I'm curious if there is a "rule of thumb" for ignition retard per pound of boost? Something akin to the 1.5-2* retard per 50HP of nitrous injected...

Too bad we can't read the cylinder pressure in relation to crank angle, that would be the most accurate way to adjust timing, then it's just a matter of setting the target angle to build peak pressure and then let the computer handle it!

In the mean time a rule of thumb would be better than nothing!

Mike

So like 1.5 degrees per 5psi? That would be roughly 50hp.

[cordes]

So like 1.5 degrees per 5psi? That would be roughly 50hp.

I seem to recall Stephan posting that he was pulling around 1.8*/lb when he was still running a swirl head.

I actually would like it if you could post your cal. That way I can make a detailed timing file for you and also a few others to compare.

[roachjuice]

How do I do that? I'm on my phone now but I have remote desktop so I can email it from my desktop from my phone lol

[ShelGame]

How do I post up my actual tune? put it in a .zip file...

[roachjuice]

Just a bin file? Or everything that goes with it?

[ShelGame]

I'm curious if there is a "rule of thumb" for ignition retard per pound of boost? Something akin to the 1.5-2* retard per 50HP of nitrous injected...

Too bad we can't read the cylinder pressure in relation to crank angle, that would be the most accurate way to adjust timing, then it's just a matter of setting the target angle to build peak pressure and then let the computer handle it!

In the mean time a rule of thumb would be better than nothing!

Mike

Not that I know of. I just know what usually works for me. You should also always check what your total timing would be at an RPM you will see a lot of and make sure it makes sense.

---------- Post added at 06:58 PM ---------- Previous post was at 06:56 PM ----------


Just a bin file? Or everything that goes with it?

Well, if you want someone to check it out, the .bin +.tbl (ot .mpt if it's from MPT2) at the minimum. The .vxx or .tpl would also help.

---------- Post added at 06:59 PM ---------- Previous post was at 06:58 PM ----------


Alright. That's great info. I'll try that. Maybe a degree or two out since I'm running a 50 trim. So how do you explain the knock at -19? Lol. Just false?

-19deg? At what boost was the -19 set to? And what boost did you get knock? If you set it to -19 at 30psi boost, and got knock at 20psi boost, then I would add or move a point to the 20psi mark and drop the timing some there.

[Aries_Turbo]

can you post your KnockFromRPM table (should be something like that for the name)....

Brian

[roachjuice]

try this. took me a min to make the zip file lol.:D

33542

[roachjuice]

dunno if i did that right or not? anyway. its -19@20psi of boost. iirc.

[cordes]

It worked, but I couldn't open it with MPT2. I don't have d-cal or Chem on here any longer so I can't view it unless someone has some suggestions.

[roachjuice]

Works in mpt1

[roachjuice]

try this

[cordes]

try this

That'll do it. Are there any files which you would like me to make comparisons of? I'll really just be posting the screen shots of the files, but it should be helpful to folks I think.

[roachjuice]

Just what ever you think I need to change with mine. It drives pretty decent the way is. Afr is right where I want it. I just need to work out the timing at wot.

[roachjuice]

And what ever can help anyone else out. Or a starting point.

[roachjuice]

That'll do it. Are there any files which you would like me to make comparisons of? I'll really just be posting the screen shots of the files, but it should be helpful to folks I think.

Everything look ok in the tune? Except the wot timing?

[cordes]

Everything look ok in the tune? Except the wot timing?

I haven't looked at it except to see that it would open yet. To be honest, I change very few tables in the cal.

[roachjuice]

I haven't looked at it except to see that it would open yet. To be honest, I change very few tables in the cal.

I've heard that too.

[cordes]

89' MPTII just because it's what I had the sheet saved as first.

http://www.turbo-mopar.com/forums/photopost/showfull.php?photo=16159

ETA: For some reason it isn't showing up for me, but when I open the broken pic in a new window it works well.

[cordes]

Here's your cal

http://www.turbo-mopar.com/forums/photopost/showfull.php?photo=16160

[cordes]

Note that this is the 89' MP 2.5 TI cal and the spreadsheet doesn't reflect the multiplier. I need to revisit Rob's posts on the matter to see what I need to do with the values.

http://www.turbo-mopar.com/forums/photopost/showfull.php?photo=16162


Here is what I do to the cals for gas mileage. I believe this is what 5digits was speaking of when referencing the step in timing for emissions purposes.

http://www.turbo-mopar.com/forums/photopost/data/858/partgasmileage.gif

[Aries_Turbo]

i looked at the cal.

there doesnt look to be anything in there tablewise that would cause the car to knock alot.

you need to get a scanner (borrow?) and see how much timing it is pulling and what the intake temps are and stuff like that.

i compared it to that old BB60 that i used to run in my car that had a 2.5L swirl head. i used to get a touch of knock sometimes in 4th gear or after the car heatsoaked and i got on it too quick before the intake temps came down. but the most it ever pulled timing wise was like 3 deg in cyl 3 or 4 and most of the time if the light came on, it pulled 1 deg and then as the rpm's rose, it would stop pulling timing and the light would go out.

most of the time, it would happen at around 4400 rpms so i took a degree out there and then the light came on alot less and it was only for 1 deg pulled and it was only when the car was really hot. i was fine with that.

you could also make a detonation tube setup (metal tubing, 1/2 or 3/4" copper with a hose attached to it run into the cabin and Y'ed off to a pair of hearing protection earmuffs with a hole drilled in each one) and listen to see if there is any actual knock.

then get some other sensors and use the scanner that you borrow to see how many volts they are outputting at various points of operation to see if yours is out of control.

brian

---------- Post added at 11:55 PM ---------- Previous post was at 11:49 PM ----------

even if the sensor is a little sensitive, you can put some racegas (or torco accelerator) in the tank (to ensure no knock) and go out with the scanner and hold the car at various rpm's in boost (again with with brakes) while looking at the knock voltage produced.

write down these values and take a reading for 2000rpm, 3000, 4000, 5000 and 6000 rpm and write the value down. verify that you dont have knock with the detonation tube earmuff setup.

then go to KnockSensorVoltageForKnock FromRpm and add 5-10% to each of the voltage values that you wrote down and put them in the table for the rpm points.

that way your KnockSensorVoltageForKnock FromRpm is calibrated for your exact engine and boost level. more boost makes the block ring louder because more power is produced.

Brian

[turbovanman²]

[/COLOR]even if the sensor is a little sensitive, you can put some racegas (or torco accelerator) in the tank (to ensure no knock) and go out with the scanner and hold the car at various rpm's in boost (again with with brakes) while looking at the knock voltage produced.

write down these values and take a reading for 2000rpm, 3000, 4000, 5000 and 6000 rpm and write the value down. verify that you dont have knock with the detonation tube earmuff setup.

then go to KnockSensorVoltageForKnock FromRpm and add 5-10% to each of the voltage values that you wrote down and put them in the table for the rpm points.

that way your KnockSensorVoltageForKnock FromRpm is calibrated for your exact engine and boost level. more boost makes the block ring louder because more power is produced.

Brian

He doesn't approve of the brake/torque method, lol.

[Force Fed Mopar]

...more boost makes the block ring louder.

Aha! :)

[Aries_Turbo]

He doesn't approve of the brake/torque method, lol.

i dont care if he approves. :) its a technique that works. its a technique that the folks that MADE our cars used and recommend. its a technique that slows down the rpm changes and allows more samples of a given RPM range for a scanner that doesnt output very fast.


Aha! :)

the block isnt ringing much in vacuum and low boost where he said that he is getting knock.

Brian

[Force Fed Mopar]

No but it would explain the knock I seem to get between 3k and 4k when the power hits. I tried everything to get rid of it, from dropping the rpm timing to retarding it from map so much it would miss.

Btw I have my knock voltage table matched to the MP smec table and still get a knock flash sometimes on decel.I just changed the front motor mount today and reset the preload on the bobble strut, so we'll see if that cures that.

[trannybuster]

^^I thought I had the same issue,but in reality it was partthrottle timing tables I had to adjust. WHen your looking at gages, road and everything else that foot can betray you. FYI...

[Force Fed Mopar]

This was with my foot on floor or part throttle. However I just found my tps to be bad a day or so ago, replace it and so far so good. So that may have been part of the issue. However my part throttle was pretty much the same as wot after 10 psi,so...

[ShelGame]

No but it would explain the knock I seem to get between 3k and 4k when the power hits. I tried everything to get rid of it, from dropping the rpm timing to retarding it from map so much it would miss.

Btw I have my knock voltage table matched to the MP smec table and still get a knock flash sometimes on decel.I just changed the front motor mount today and reset the preload on the bobble strut, so we'll see if that cures that.

You get knock on decel? That's not really likely, I think. Maybe piston slap? What pistons do you run?

[roachjuice]

Tested 3 knock sensors today. All used. With volt meter and knocking on manifold with wrench. It read knock with all three. At idle. Voltage jumped from .02 to .039 haven't ran the car yet with the upped timing and matched knock voltage table.

[Aries_Turbo]

you cant use a volt meter on the knock sensor itself. it outputs an AC wave that is too fast to read with a slow volt meter. an oscilloscope, yes. a volt meter, no.

besides, the LM has a very specific circuit that takes that AC wave and transforms it to a 0-5v DC voltage that the LM can read with its analog/digital converter.

to measure the voltage that the LM is seeing, you HAVE to datalog the LM with either a USB/Serial datalogging cable setup, or a scanner.

you cant just put a meter on the knock sensor itself. it wont translate into valid data that you can quantify against anything other than "yup, its putting something out..... what frequency, dunno, what amplitude, dunno....."

brian

[trannybuster]

Well you can get the rpms up and tap on them and see which one is 'touchy'....I dont know what rpm needs to be before it pulls timing??

[cordes]

you cant use a volt meter on the knock sensor itself. it outputs an AC wave that is too fast to read with a slow volt meter. an oscilloscope, yes. a volt meter, no.

besides, the LM has a very specific circuit that takes that AC wave and transforms it to a 0-5v DC voltage that the LM can read with its analog/digital converter.

to measure the voltage that the LM is seeing, you HAVE to datalog the LM with either a USB/Serial datalogging cable setup, or a scanner.

you cant just put a meter on the knock sensor itself. it wont translate into valid data that you can quantify against anything other than "yup, its putting something out..... what frequency, dunno, what amplitude, dunno....."

brian

Thanks for confirming that Brian.

[Aries_Turbo]

you're welcome.

here is that circuit.

i dug through a few LM's and some chrysler patent docs to figure out what those transistors were but i found them. :)

http://www.squirrelpf.com/bucar/ecu%20stuff/85_86_87_detonation_diag-values.gif

Brian

[roachjuice]

Atleast I know now that they all work. Lol

[cordes]

Nice work. That piece of paper which says EE on it is really paying off. Thanks again.

[roachjuice]

drove it this morning. breaking up on the topend. like 4500+

[roachjuice]

Oh I forgot to add. It sounds like it's missing now. Maybe a plug. I just changed them yesterday. Or it could be a wire. I didtnt look because I was already frustrated with the car.

[roachjuice]

Afr was good. Low 11's.

[roachjuice]

I think I'm really just sick of this ----. Thought about going back to a stock tune just scaled for 40's and 3 bar. I'm really done. I don't give a ---- about timing or fuel or the car ----ing knocking RANDOMLY anymore.

[DodgeZ]

I'll give you 500 bucks for the car.

[roachjuice]

I'll give you 500 bucks for the car.

Lol no.

[roachjuice]

hopefully i just fouled a plug or a wire is grounding out. its missing just driving down the road. at idle it sounds a little different. not much though. i would think if i would have messed up a piston that it would make some noise. i checked the plugs. all look ok except #4. it was a little black.

---------- Post added at 11:40 AM ---------- Previous post was at 11:36 AM ----------

its not like a hardcore miss. just slight. noticable though. in boost it seems to act normal. word of advice for anyone else "tuning" or what i like to call now "guessing" a 2.5. -19@20psi advancefullthrottle seems to work out pretty well. ---- that -11 ----. when it was breaking up it was -13@20psi. so i think im just gonna stick with that. call me stubborn but the ---- just plain doesnt work @-11. take out dam near 1 degree per psi. i honestly dont see how peoples engines last running timing like that on some pump 91-93.

[roachjuice]

So I changed plug wires and plugs. Still missing. Think I burnt a hole in a piston. Pulled the valve cover to see if there was a rocker off and smoke came out. :( So. Word to the wise. -19 deg works great. -13 not so great on a 2.5. I dont care what anyone says.

[Force Fed Mopar]

You get knock on decel? That's not really likely, I think. Maybe piston slap? What pistons do you run?

Hypereutectic Seal Powers, .030. Engine has about 40-45k on it, complete proper rebuild (bored and honed to match the pistons, etc). I think it's just vibrations from the engine maybe. It has some vibration at idle and again around 3-4k rpm. It's an '88 T2 engine, stock rods, crank's turned .030". I'm sure balancing the rotating assembly would do wonders. I also still have one bad mount. Also, it is better since I replaced the tps sensor.

It usually seems to trip the light around 2500 on decel when it does it. Knock voltage table is matched to the '89 MP cal.

[trannybuster]

Cracked ring land for sure! Burnt hole and you'd have oil everywhere, I guarantee cracked piston, been there, done that, went forged no longer an issue.

---------- Post added at 09:04 PM ---------- Previous post was at 08:55 PM ----------

BTW I had knock so bad earlier in year I took out a cometic hg and cracked the ceramic on both plugs, pistons looked brand new!

[Force Fed Mopar]

I've burnt a hole in a piston one time, went through 4 quarts a day for like 2 weeks :p I dunno about a cracked piston, it runs pretty good and doesn't use oil really. I had the pistons out last year and they were fine, Knock light was on more then than it is now. Still, I'll keep it in mind.

[trannybuster]

Well a compression test will tell all, it can be a real tear jerker..LOL..

[roachjuice]

Luckily I found another complete 2.5 near me for dirt cheap. I'm gonna sell my 50 trim and just go back with a stock Garrett for awhile.

[DodgeZ]

just pull the head and slap a new piston in it. 3-4 hours worth of work.

[Force Fed Mopar]

just pull the head and slap a new piston in it. 3-4 hours worth of work.

This ^^

[tryingbe]

Tune at 10psi and work you way up by 1psi... don't start at 20psi and mess with timing

[roachjuice]

just pull the head and slap a new piston in it. 3-4 hours worth of work. problem is that oreilly offers 2 different pistons. hyper and hyper cast. is there a major difference?

---------- Post added at 08:34 AM ---------- Previous post was at 08:34 AM ----------


Tune at 10psi and work you way up by 1psi... don't start at 20psi and mess with timing i did and when i was told i was pulling to much timing to add some then this happens.

[Force Fed Mopar]

I'm running hypers. Not sure if the cast may be stronger.

[roachjuice]

thinking about doing a ported exhaust manifold while i have it apart.

http://www.oreillyauto.com/site/c/detail/SEA0/WH579P.oap?year=1989&make=Dodge&model=Caravan&vi=1077072&ck=Search_piston_03384_1077072_830&keyword=piston&pt=03384&ppt=C0365
:D

[DodgeZ]

hmmmmm. reuse the rings? its only 40 bux for a new piston.... another thing. ive never broke a piston before. i assume i should look for damage on the cylinder wall. what else?

---------- Post added at 08:43 AM ---------- Previous post was at 08:39 AM ----------

thinking about doing a ported exhaust manifold while i have it apart.

I'd buy that 2.5 you were talking about and just use the pistons out of it. Block should be fine if don't run it.

[roachjuice]

I'd buy that 2.5 you were talking about and just use the pistons out of it. Block should be fine if don't run it.all i did was drive it home. yea that can be a plan too. your just FULL of ideas! lol thanks. guy said the engine turns free. but who knows what the hell its been through. i picked my current one up for around the same price. didnt touch the bottom end. just removed balance shafts.

[DodgeZ]

i did and when i was told i was pulling to much timing to add some then this happens.

If you are spark knocking enough to crack pistons you should clearly be able to hear it. When you hear the spark knock clack you have to let off NOW not later. When you take it apart check your rod bearings. Spark knock puts a hurting on rod bearings. People love to tell you forged pistons will take the abuse and they do but your bearings get beat up and if left unchecked it will kill your crank. 91º gas is pretty shitty. Do you have e85 around your area? You may want to convert if it is.

[roachjuice]

Yea but its in bfe. I have 112 at a pump like 5 miles from my house. I get it back together I'm gonna put 112 in it constantly. So this ---- doesn't happen. I found a formula thingy.
http://www.wallaceracing.com/octane-mix-calc.php
Luckily I just bought another car and this isn't my daily. But my wife is pissed that i ----ed it up lol. It won't be my daily. Just a toy and I can afford to put some 112 in it

[tryingbe]

Have you run a compression test yet?

[roachjuice]

Have you run a compression test yet?

Nope. I just know what happened. It's #4 defiantly. But I'll do one before tearing it down.

[Aries_Turbo]

there must be something about your combo that cant take the timing.... shaved head, hotspots, etc.

when it comes apart, CC your combustion chambers.

Brian

[roachjuice]

when it comes apart, CC your combustion chambers.

Brian que??

[Force Fed Mopar]

Means measure the combustion chamber volume.

[roachjuice]

here rob m

[trannybuster]

You have other issues, which is causing you grief with timing, IDK could be alot of things. Best bet is get back to stock everything, timing, cal and boost settings(Id keep the turbo). Be easier to slap in a piston, Ive got some nice 2.5 stock mahles you can have for 30.00 shipped, all four have rings no cracks, pretty decent really.....Ive never had to pull timing like that, not even close, nor it sounds like have any others. Isnt there any 93octane anywhere???, I run 1/3tank e85 and rest 93 at 22-23psi with a felpro, so far so good. Someones gonna have some good used forgings for sale sooner or later,,

[roachjuice]

Means measure the combustion chamber volume.
im not really bout bout wit dat. lol. so where can i get this done at? how much is this gonna dent my pocket book?:D

---------- Post added at 11:36 AM ---------- Previous post was at 11:33 AM ----------


You have other issues, which is causing you grief with timing, IDK could be alot of things. Best bet is get back to stock everything, timing, cal and boost settings(Id keep the turbo). Be easier to slap in a piston, Ive got some nice 2.5 stock mahles you can have for 30.00 shipped, all four have rings no cracks, pretty decent really.....Ive never had to pull timing like that, not even close, nor it sounds like have any others. Isnt there any 93octane anywhere???, I run 1/3tank e85 and rest 93 at 22-23psi with a felpro, so far so good. Someones gonna have some good used forgings for sale sooner or later,,hell that sounds like a deal! nope. these ----ing dicks around here took all the 93 away. even though our main export here in oklahoma is oil and aerospace stuff. so we got 91 with 10%eth. but i do have a track near my house that has 104&112 octane. 112 is cheaper than 104? the 112 is 7.00 a gallon and 104 is 7.50. doesnt make sense but i know its real ---- because i can smell it. plus its pretty purple color. slap a few gallons in there should be good to go. i dont mind because i dont plan on driving it everyday.

[DodgeZ]

http://www.google.com/search?q=how+to+cc+a+head&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

[roachjuice]

http://www.google.com/search?q=how+to+cc+a+head&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a dam thats a bad --- idea. to get the liquid out i assume you just open the valve lol.

---------- Post added at 11:42 AM ---------- Previous post was at 11:40 AM ----------

so what are the stock cc numbers for a swirl head? mine is just a cleaned up swirl with back cut valves.

[Force Fed Mopar]

You have other issues, which is causing you grief with timing, IDK could be alot of things. Best bet is get back to stock everything, timing, cal and boost settings(Id keep the turbo). Be easier to slap in a piston, Ive got some nice 2.5 stock mahles you can have for 30.00 shipped, all four have rings no cracks, pretty decent really.....Ive never had to pull timing like that, not even close, nor it sounds like have any others. Isnt there any 93octane anywhere???, I run 1/3tank e85 and rest 93 at 22-23psi with a felpro, so far so good. Someones gonna have some good used forgings for sale sooner or later,,

So what timing are you running?

[roachjuice]

So what timing are you running? bump. i want someone with a 2.5 to try out my timing fix tune i posted up. see if anything is wrong.

[roachjuice]

come on. no one wants to give my tune a try?

[Aries_Turbo]

all my stuff is apart still. may have my trans back on the motor soon.

Brian

[turbovanman²]

come on. no one wants to give my tune a try?

I would but i don't have an LM to try anything with and the customers is a stock engine, don't want to harm it, lol, I have enough issues with my own stuff.

---------- Post added at 09:58 AM ---------- Previous post was at 09:52 AM ----------

I use some clear plexi glass, grease and a 50ml syringe, you don't need to open the valves to drain??? You use some grease to seal the glass, I drill 2 holes-one to fill, one to vent the air as it fills up and fill so there are no air bubbles, that's your chamber cc's, do the pistons and then use this this calculator to figure out your compression-

http://www.wheelspin.net/calc/calc2.html


If you are spark knocking enough to crack pistons you should clearly be able to hear it. When you hear the spark knock clack you have to let off NOW not later. When you take it apart check your rod bearings. Spark knock puts a hurting on rod bearings. People love to tell you forged pistons will take the abuse and they do but your bearings get beat up and if left unchecked it will kill your crank. 91º gas is pretty shitty. Do you have e85 around your area? You may want to convert if it is.

What he said. If the copper is showing on the top bearing in the center, you had real detonation issues.