Stage block Knock sensor

Discussion in 'Stage II Tech' started by dank GN, Nov 11, 2017.

  1. dank GN

    dank GN
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    hey guys I had a quick question . I don’t have a spot for the stock style knock sensor . I’m sure I could drill and tap a spot on the block to make it happen my question is where should I place it ? Do you run a knock sensor with your stage block? There is acouple aftermarket setups that look nice that you can program the sensor so it would ignore false knock . .
     
  2. Boost231

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    Lots of people don't run them no need to imop. Once you start with aftermarket heads, valve train, gear drives etc they don't like to act right. Just make sure your tune is on check plugs and go.

    Sent from my SM-G935T using Tapatalk
     
  3. NY Twin Turbo

    NY Twin Turbo
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    Funny you brought this up.

    I'm using an off center stage block. It had provisions for a knock sensor. So I used one.

    Years ago, before the stage motor, I used a Casper's audible knock detection alarm. This of course, ties into the factory knock sensor circuit and is supposed to let you know that if the computer is hearing knock.....you hear it also. But the knock detector can do some weird unpredictable things from time to time. Even when there is no knock being herd by the sensor or even being observed by the XFI. I've noticed that other board members have also had some issues with them as well. Sometimes it gets stuck on alarm mode and I have to key the car off and on to get it to stop. Probably due to some voltage anomaly or something. It's not often and not worth the trouble to diagnose. But still, this has nothing to do with the actual observed knock detection by the XFI. So, on with the knock sensor itself........

    J. Cotton urged me not to bother with a knock sensor or the alarm. He claimed the alarm will "sound off" for all kinds of silly reasons and sooner or later drive me crazy. He also explained that when the sensor hears those same noises the XFI will pull timing unnecessary. He told me I would have to zero-out the timing retard on the XFI's ESC Parameters table, so then why bother? As explained above, a stage motor that is "built to the hilt" will just make way too much noise for a knock sensor to be considered even somewhat accurate.

    But I didn't listen, and I chose to use it anyway. Due to it's intended street use, I figured any warning of knock should be cause for suspect and checked out before I dismiss it as false. So now it's been more than 10 years.

    And this is what I have found......

    The damn thing drives me F*CKING CRAZY!!!! :mad:

    In the beginning, I couldn't help to ignore it. So I relentlessly played with timing and fuel forever trying to get it to go away. I thought it could be.....and then I said no way. Then I started checking the engine compartment for witness marks on component hits. I found a few suspected areas and began to make corrections over time. Then kept taking timing out. Then adding it back. Then turned down the boost. Then turned it back up. Then added alky. Then backed it out. Then added race fuel. Then used pump gas. And this went on and on. But I wasn't confident in my tuning abilities and just wasn't sure if I should ignore it. I noticed that even when I commanded massive timing retard in the XFI it still wouldn't alleviate the problem. But again...I left the damned thing in place. I guess I'm just a glutton for punishment.

    Over time, I began to noticed that the knock began to happen much more seldom. I began to think that maybe there was some actual noise at some point in the beginning. But whatever it was, my constant tinkering with the hardware and software finally began to make a difference. However, it never went away. It still happens and I still have the alarm and sensor in place. I slowly became completely confident that everything was OK a long time ago. Then I finally zero'd out the XFI's ESC Parameters.

    Today, with my set-up, It seems that at certain conditions the knock sensor will hear noise no matter what. Usually around 0-boost up to about 3 pounds on light throttle (22.5 degrees of timing and 12.1 AF and the alky coming on light as soon as it crosses the 1 lb threshold). Also, sometimes on down shifts, and sometimes randomly for no reason at all. Lately this summer, it started acting up again more often. But the tune hasn't changed and everything was checked well. I threw in the only 5 gallons of C-16 I have bought in years just to verify it, but I didn't need to.

    My stage motor has never been apart. It has been flawlessly perfect, street driven every year and occasionally driven to the track and raced since the day it went in over 10 years ago. Not next summer, but the one following, I may pull it to take a look see.
     
    #3 NY Twin Turbo, Nov 12, 2017
    Last edited: Nov 12, 2017
  4. dank GN

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    Intresting . I will be runing without one . I am runing a gear drive and would hate to just hear it go off for every time for what it thinks is knock . I will however look into a aftermarket setup that is user friendly . My only issue is the place to mount it as my oncenter block does not have a provision for one .
     
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  5. NY Twin Turbo

    NY Twin Turbo
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    I guess you cant go wrong with the factory location. It seems like the most logical place. Are you sure there is no provision for it? If you have a late 153 block the bung is already cast into the design. All you have to do is drill it out. It won't get in the way of anything there. Otherwise, you could drill it out there anyway. Nothing structural to worry about back there.
     
  6. dank GN

    dank GN
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    Here is a pic of the rear of my block . 4119DFC3-01C1-4590-A452-994C76E540F8.jpeg
     
  7. NY Twin Turbo

    NY Twin Turbo
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    Funny, I would think the hole goes smack in the middle of the turbo 6.
     
  8. dank GN

    dank GN
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  9. NY Twin Turbo

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    Wow. That looks pretty fancy!

    I would like to here more about it from some of the guys I trust. But it seems like a good idea. I see that the cost is in euros. How much in American dollars?

    If it's expensive, the cost may make it only worth it for full time tuners to be used on engine dynos.
     
  10. Pronto

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    Plex makes an aftermarket knock sensing device. It uses 2 donut style sensors. I'm sure you could find some spot to mount them. Some manufacturers have the sensor mounted on the intake. Maybe that's an option or on each side of the block down near the pan rail. Knock link makes a visual style unit that uses just one sensor.
     
  11. rag231

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    That gear drive will drive a knock sensor crazy.
     
  12. NY Twin Turbo

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    ^^^ DEFINITELY THIS ^^^

    I still twitch in my sleep thinking about knock. You want the name of a good shrink? You'll need one.:)
     
  13. dank GN

    dank GN
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    My gear drive isn’t bad Imo . I’ll be firing her up real soon I’ll get a video and I can decide for your self
     

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