Do you trust your factory knock sensor?

[cyclonekid77]

Im curious as to how accurate/trustworthy the stock knock sensor is. I have tried everything to get rid of my knock and nothing seems to help. If you look at my profile you can see the engine is nowhere near stock. I was reading in a post by cbrfrenzie that the sensor can pick up the sounds of the valves shutting if you have aftermarket springs(wich i do) and I wonder if that might be my problem. What gets me is the knock allways starts around the same rpm(5krpm), no matter if im running 8psi, or 15psi. Wouldnt more boost make the knock start sooner? I have tried changing plugs, nylon washer between the sensor and the block, just barley snugging the sensor in just enough that it wont fall out, changing timing, ect. Any suggestions would be greatly appreciated

 

[toofast82]

I trust my knock sensor in my car. I see it works in a reasonable fashion and seems like it would be as accurate as I guess a knock sensor could be.
My car gets some part throttle knock sometimes when not fully warmed up from what I believe is the "old 1g lifters." They can be sensitive to vibrations, clutch chatter, lifters, etc. Many do swap to 2g knock sensors which are said to be more accurate. I forget if there is any other modifications to do. Im sure its covered on here somewhere

What are you using to tune? You may be getting "rich knock" if you are still on the stock fuel maps.
I was experiencing this, before I hooked up my wideband, my a/f was unfortunately 9.3:1 and the car would pick up knock and even sputter sometimes. Then tuned it out to 10.8-11:1 and knock went away and car ran so much better.
Also 5-6k rpm, is where the 1g stock timing map is at a very aggressive level for pump gas. You shouldn't really have knock on 8psi unless, excessively rich, but 15psi, its possible its because of the timing.
Have you tried to back off the CAS a degree or two, if that helps?

 

[Fejery4491]

I trust it, but phantom knock does happen. It was nice when I was using the evo rom on my 3g you could just go into the knock sensor maps and change them if you were sure it was phantom knock. Haven't had this problem yet with my 2g so I'm not much help there. Hope someone else can give you a better answer

 

[cyclonekid77]

I have a keydiver chip with the a/f set at 11:1. I have the cas set at 2* base timing rite now. I have thought about rich knock, but when you pull the plugs they dont look like its running rich. They are a nice medium brown color. Im kinda stumped I guess.

 

[toofast82]

I have a keydiver chip with the a/f set at 11:1. I have the cas set at 2* base timing rite now. I have thought about rich knock, but when you pull the plugs they dont look like its running rich. They are a nice medium brown color. Im kinda stumped I guess.

I had a hell of a time trying to tune my car last summer on the 1g mas, although I wasn't using a wideband at the time. I had my target a/f set at 11:1 on my chip and I was getting knock on about 15psi.
What are your Intake Air Temps compared to ambient temperature? That seemed to have quite a bit to do with it from what I was seeing.

 

[cyclonekid77]

I do have 9:1 compression too, wich is pretty aggressive. Do alot of people run 9:1's on pump gas?

 

[cyclonekid77]

I had a hell of a time trying to tune my car last summer on the 1g mas, although I wasn't using a wideband at the time. I had my target a/f set at 11:1 on my chip and I was getting knock on about 15psi.
What are your Intake Air Temps compared to ambient temperature? That seemed to have quite a bit to do with it from what I was seeing.

I forgot to add that I have the 2g mas. I dont have a wideband at this point How do you check air intake temps? Sorry, I need to learn ALOT about tuning. Thats why I get on here and ask questions

 

[toofast82]

I do have 9:1 compression too, wich is pretty aggressive. Do alot of people run 9:1's on pump gas?

Yeah, I think you just spilled the most crucial detail
Its probably 99% the cause of your knock as retarding 2* isn't going to be enough for that much compression.
Get on the horn with Jeff and I would get yourself an Evo8 timing map coded in as they run 8.8:1 compression and almost 20psi from factory so that should work pretty good as a baseline

 

[cyclonekid77]

I new I got carried away when i built this thing.... So the 1g timing map may just be too aggressive for my engine and thats why I cant get rid of this knock? I want to get this figured out because I would really hate to blow a hole in a piston after spending all that money on building this thing.

 

[toofast82]

That's the reason! Jeff charges like $20 for a reflash. Tell him you want an evo8 map or even a 2g with a degree or two taken out.
The high compression is good, it has its benefits at cost of a trade-off of timing.

 

[talon187]

Get a good tunning device and you can take the timing out yourself

 

[cyclonekid77]

Looks like i'll be sending that chip back for a re-flash then. Its a good thing he sends the chips really quickly too because this is my dd and it wont get to far without the chip in there .

 

[cyclonekid77]

Get a good tunning device and you can take the timing out yourself

I hope to sometime soon.

 

[toofast82]

Looks like i'll be sending that chip back for a re-flash then. Its a good thing he sends the chips really quickly too because this is my dd and it wont get to far without the chip in there .

I believe he sends it to you and then you send the old one back after you recieve it from him. He's cool like that!
I would begin to look into your own eprom editing using Tunerpro(free). You can get a chip burner for $30-100. There are base files in the DSM-ecu Yahoo forums. You're already socketed. This will give you full timing and fuel control. Research hex editing if you don't know what it is as well.
First Generation DSM EPROM Editing
I'd be happy to give some help if you're willing to do some research about it

Then when you get good at it, you can think about how you saved all this money over Link and all the other parts you bought instead

 

[cyclonekid77]

Do you know a good place to find a burner? That program sounds very interesting and useful

 

[toofast82]

Do you know a good place to find a burner? That program sounds very interesting and useful

I didn't have a clue what hex editing was before I learned about it. I'm just as lost when it comes to burners. I bought a Moates Burn1 for around a $100 with like 5 chips. It is very easy to use!
They sell these Willem burners for around $50 that I see some guys use?
You can just edit the numbers on the most of the stuff instead of having to hex edit on Tunerpro. The stuff like stutterbox, you have to hex edit, but you can create a definition for Tunerpro, where you would have to just edit the rpm for future changes.

 

[cyclonekid77]

When you order the chips from jeff, he asks for your compression. Shouldnt that compensate for it? Just wondered because I got to thinking about it and I remember specifiying that when I ordered the chip.

 

[toofast82]

If you have a logger, which you should, you could verify your timing and throw some numbers out at the given rpms. I'll let you know if it's the stock map or not

 

[JayRolla]

Well if it was Phantom Knock you would get it at idle and before hitting boost. Which makes be believe it could be real knock.

 

[toofast82]

Well if it was Phantom Knock you would get it at idle and before hitting boost. Which makes be believe it could be real knock.

He's got 9:1 on pump and is unsure of the timing maps, so its probably the real deal

 

[wishihadatalon]

If the engine isn't stock, I do not trust the stock ecu to determine what is and what isn't knock. I usually don't rely on them anyway as tuning for knock is far from ideal.

 

[toofast82]

I've read that some of the "big" guys tune for around 15-20cts of knock. This is the point most likely of absolute max power but it is right before the point of max destruction. Not to be done unless you have engine parts sponsors

 

[bling5tatus]

double post... database errors ftl

 

[bling5tatus]

TooFast82 - if you have any info on using a 2g knock sensor let me know... I'm pretty sure I was told that you cannot do it on a 1g because the knock board on the ecu is different and doesn't operate the sensor in the same fashion.

I would recommend Moates.net for burning/emulation devices. The Ostrich is still hands down one of the best purchases I ever made for my car.

 

[toofast82]

TooFast82 - if you have any info on using a 2g knock sensor let me know... I'm pretty sure I was told that you cannot do it on a 1g because the knock board on the ecu is different and doesn't operate the sensor in the same fashion.

I could swear I read somewhere that someone installed some type of resistor of diode or something? I'm not an electronics guy, so i don't know much. I can do electronics wiring, but when it comes to something like setting the sensors at the same frequency or something, i'm useless.