| Slant Six Forum https://www.slantsix.org/forum/ |
|
| Megasquirt with knock sensor https://www.slantsix.org/forum/viewtopic.php?t=51344 |
Page 1 of 1 |
| Author: | Turbo Toad [ Sat Mar 09, 2013 11:16 am ] |
| Post subject: | Megasquirt with knock sensor |
I'm in the process of building a megasquirt for the valiant and was wondering if anyone has built the knock sensor circuit on there megasquirt? If so where on the block are you installing the sensor? I just got the launch control circuit built, next is boost control, then the knock sensor circuit Thanks all Aaron |
|
| Author: | Turbo Toad [ Tue Mar 12, 2013 5:01 am ] |
| Post subject: | |
Anyone Lou, matt???? |
|
| Author: | Dart270 [ Tue Mar 12, 2013 5:22 am ] |
| Post subject: | |
I bought a standalone knock sensor circuit, but it will not integrate into my MSI system. I have not hooked it up yet. Sitting in trunk of turbo car in Vegas... This is what I bought: http://www.viatrack.ca/ Lou |
|
| Author: | Matt Cramer [ Tue Mar 12, 2013 7:31 am ] |
| Post subject: | |
The MS1/Extra knock circuit is a pretty crude one - I'd rather have a microphone clipped to the block and a set of headphones for tuning. The MS3 add on module is a lot more sophisticated. Not quite up there with, say, the factory LS1 setup, but we didn't have the luxury of a budget large enough to blow up a half dozen engines on the dyno to develop it. |
|
| Author: | DadTruck [ Tue Mar 12, 2013 7:53 am ] |
| Post subject: | |
Quote: knock sensor circuit on there megasquirt
I though mechanical valve clatter would confound a knock sensor, has the technology improved, or are you running a hydraulic cam..?I am putting a knock sensor on the 83 D-150 (hyd cam) ,, I plan to mount the sensor in the water jacket drain plug. |
|
| Author: | emsvitil [ Tue Mar 12, 2013 2:16 pm ] |
| Post subject: | |
Quote:
I though mechanical valve clatter would confound a knock sensor, has the technology improved, or are you running a hydraulic cam..?
And so will forged pistons because of greater tolerances......This is for toyota engines, but gives you a basic idea of where to mount one. http://www.lcengineering.com/LCTechPages/engtech14.html |
|
| Author: | Turbo Toad [ Wed Mar 13, 2013 4:53 am ] |
| Post subject: | |
Well the plan is to build the circuit from the msextra manual for when I get my long rod motor together and after I get the bugs worked out or the car and install the knock sensor in the new motor. But with the fuel upgrades I made this winter donation shouldn't be much of a problem enless my tune is just way off.... Thanks always. Org Aaron |
|
| Author: | Charrlie_S [ Thu Mar 14, 2013 4:04 pm ] |
| Post subject: | |
Quote: Quote:
I though mechanical valve clatter would confound a knock sensor, has the technology improved, or are you running a hydraulic cam..?
And so will forged pistons because of greater tolerances......This is for toyota engines, but gives you a basic idea of where to mount one. http://www.lcengineering.com/LCTechPages/engtech14.html |
|
| Author: | Dart270 [ Thu Mar 14, 2013 8:16 pm ] |
| Post subject: | |
I think those are basically myths propogated because of difficulties some people have had. There are plenty of examples where these work with solid cams and loose pistons... Yes, you may have to play with thresholds more or do some control tests to be sure you are distinguishing knock from other things. Lou |
|
| Author: | DusterIdiot [ Thu Mar 14, 2013 8:33 pm ] |
| Post subject: | But... |
Quote: I think those are basically myths propogated because of difficulties some people have had.
I have a couple of friends that are SAE mechanics for "the other brands" and are gear heads and they have stated that in the older vehicles (90's) the knock sensor was dialed into a specific set of frequencies to detect knock (probably checked by a piezo on an oscilloscope while running the test engine on an engine stand in detonation), and not cause a false alarm (say a ride down an improved fire road with lots of rocks nailing the underside of the oil pan and block-would not be good if after 10 seconds the engine management system yards out all the advance save the base timing or goes to limp mode because of it).I also have heard that the industry has shifted to ion sensing for knock detection since for emissions purposes the manufacturer has to monitor the vehicle to keep it within govt. specs. These sensors look for a specific ion signature in the exhaust that would occur if the mixture didn't combust properly then adjust the timing accordingly. A quick search of the internet shows an interesting post by Delphi, and some traffic on the topic at DYIEFI.org on that topic (looks like Delphi goes hand in hand with coil at the plug DIS). FYI, -D.Idiot |
|
| Author: | Dart270 [ Mon Mar 18, 2013 4:49 am ] |
| Post subject: | |
Yes, you may need to limit frequency range to get knock and not other stuff. I think some (all?) of these circuits do this. Also, the threshold adjustment will be critical. You will need to induce knock (briefly) and hear it and get the sensor to pick it up, then adjust accordingly and dial the engine back in to normal operating. WOT and light throttle at the same RPM should not both produce knock, so that can help separate knock from purely mechanical sources. Lou |
|
| Page 1 of 1 | All times are UTC-07:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|