Jump to content

MoTeC knock control


JohnReed
 Share

Recommended Posts

First, mods if this is the wrong section let me know and/or move it. It pertains mostly to TT Gallardos at the moment but is available for TT Murci, Diablo, etc (anyone running or wanting a MoTeC ECU system). More and more of the Gallardo guys are going MoTeC for good reasons, and below describes one VERY good reason.

 

MoTeC recently released their knock control for the M400/600/800 series ECUs and they have raised the bar for what is available to those of us outside of a Formula 1 team. The ever infamous UGR Nera has been fitted with this system and more Gallardos are being fitted/tuned as well. For anyone wanting to run maximum power on pump gas, it provides a level of safety and control not usually found in the aftermarket. The below log snapshots are from a Viper because that is what I had handy on this computer (but the Nera logs look similar, though less ambient noise due to an engine that is much quieter mechanically by design).

 

The SKM (standalone knock module) can be used with any M400/600/800 ECU and any knock sensor (though some sensors work better than others and I can make recommendations based on your application). Tuning is fairly complex, and should only be done by properly trained MoTeC dealers.

 

The SKM has definable "center frequency", meaning the frequency band it focuses on when looking for knock. This frequency band varies engine to engine, and build to build. If you change your rods/pistons, add iron sleeves for instance, or bolt turbos on, you just changed the frequency that knock will "ring" through your block/engine assembly at. Think of a glass of water, change the volume or mass inside and the frequency changes when you tap it. The MoTeC ECU also generates a programmable knock "window" which narrows the window it is looking at the knock sensor to a certain number of crankshaft degrees. So once we set it all up correctly (a fair bit of work), we are now targeting a specific frequency band and a specific window of time per cylinder to look for knock. This makes the end result very effective.

 

Since the MoTeC knows our firing order and cylinder count, it also knows which cylinder just fired (as it is then looking for knock on that cylinder). This allows us to not only do individual cylinder knock retard, but we can also log knock sensor activity by cylinder. Tuning this way also allows setting up the individual cylinder timing trims to take some of the burden off the knock control (engine is tuned properly, knock control is there for unusual conditions).

 

Below are a couple of log snapshots from a Viper. The first shows normal knock sensor noise, along with my defined threshold (above that I have determined to be knock, and corrective timing action will be taken. The second snapshot shows a forced "ping" on a couple of cylinders (done under carefully controlled conditions this poses zero risk to the engine).

 

skmlog1.jpg

 

skmlog2.jpg

 

Let me know if you guys have any questions! MoTeC is tough to beat once you start factoring in safety and control such as we have above, along with traction control, boost by gear, etc etc

Share this post


Link to post
Share on other sites

Hey John, a couple of questions. I'm assuming the Gallardo has factory knock sensors, correct? Is there not a way to take control of the OEM sensors? And can any additional knock sensing be accomplished via the AEM as opposed to the Motec? Thanks!

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...