From the first link above is a good read. The second link is a setup that you can use with your Megasquirt from what I understand as well. I am going to be going to the junkyard once I collect more information so I can get something going for reading knock on my srt4. The aeroforce gauge I have I am doubting reads knock. I havent heard knock in my car, but with the 3 inch dump under the two front seats and the open wastegate....you cant hear much. I have looked to see if I could find information about how to hook up the stock knock sensor to the megasquirt, but came up with no luck at all. So from the threads above it looks like it can be done with an after market one just fine. Has anyone tried this yet or have there stock srt4 knock sensor hooked up? Having the ability to datalog and see knock is just as important as an egt and a/f gauge IMO.
I emailed the person that makes the boards for the KnockSense device. He said that any two-wire Bosch sensor would work, which the SRT-4 has.
I am going to get one of these before getting the MS to see how they work. Since the KnockSense taps into the sensor, the only concern that I have is if there is any crosstalk/interference between the stock ECU and the KnockSense. I don't want to lose my stock knock control until the MS goes in...
I emailed the person that makes the boards for the KnockSense device. He said that any two-wire Bosch sensor would work, which the SRT-4 has.
I am going to get one of these before getting the MS to see how they work. Since the KnockSense taps into the sensor, the only concern that I have is if there is any crosstalk/interference between the stock ECU and the KnockSense. I don't want to lose my stock knock control until the MS goes in...
xxx_srt
I feel like heading to the junkyard and pulling the sensor and module from a GM vehicle so it can be wired into the MS unit. I can get thos eparts for probably $5 at the junkyard I go to. The knocksense seems like a great choice as well, but $5 < $65. I am wondering though if I can ujst inscrew the knock sensor the car currently has and screw in this GM one or what? I dont want to drill any holes in my motor......if I have to going the GM route I will end up going with the knocksense unit.
In my view, since all the unit does is listen to a certain frequency depending on the bore diameter of the engine, the module from the GM vehicle would not necessarily detect the knock as effectively as you would want.
The advantage with the KnockSense is that Boris tunes the device to match whatever frequency your engine would resonate at upon detonation. The bore diameter for the SRT-4 is 3.445" or 87.5mm.
I own a knocksense knock sensor made by boris and its a nice unit but it doesnt work well with my setup. I have a 1st gen with the 2.4 swapped motor and solid motor mounts. When I say solid I mean theres no rubber at all. ALL METAL and this knocksense doesnt work for me.
Now if you have inserts or stock motor mounts it will work.
If someone wants Ill sell my knocksense unit with 3 knock sensors, teflon cable, red led and knock box.
Like I said before, factory knock sense is very very indepth and good compared to aftermarket ecu's and knock sensing devices.
They are tuned using listening devices, then they factor out engine noise at all rpm ranges which is hard to duplicate(most of the aftermarket stuff will only work at a certain rpm range because of this, so your best off setting it up for around torque peak where knock is most prevalant, which is around 5000rpms for 2.4's). Even if you buy one of these add on/replacement setups you will still need some det cans to interprupt and tune it. So you might as well just tune w/ det cans and not worry about it unless you trying to push the limits or bad gas is concern
Like I said before, factory knock sense is very very indepth and good compared to aftermarket ecu's and knock sensing devices.
They are tuned using listening devices, then they factor out engine noise at all rpm ranges which is hard to duplicate(most of the aftermarket stuff will only work at a certain rpm range because of this, so your best off setting it up for around torque peak where knock is most prevalant, which is around 5000rpms for 2.4's). Even if you buy one of these add on/replacement setups you will still need some det cans to interprupt and tune it. So you might as well just tune w/ det cans and not worry about it unless you trying to push the limits or bad gas is concern
I would love to be able to leave the stock knock sensor in its place and it be able to read knock from it. Just that with the megasquirt it doesnt work unless there is some way to tap into the wires and run it to the megasquirt instead. I have purchased a knock sense kit and havent installed it yet. I need some sort of device to monitor knock....figure knocksense should work....well I hope
thats what I've said and dont feel like its getting to your head.
Basically aftermarket knock stuff at this point sucks, all of it!
Your going to need "det cans" or headphones to mess w/ whatever knock stuff you get, then its only going to be "tuned" for a small rpm range and if its hooked to the computer to pull timing, you'll be hurting b/c the egt's will go to hell when its constantly picking up false knock.
Please dont take this harsh, I'm trying to help.
I tried it w/ my standalone and kept getting false knock(stock sensor), my car is stiff(suspension and motor mounts) it was driving me nuts and if I set it to pull timing it would pull when not in boost and just random
Basically get a safe tune(find out how much timing advance causes knock at a low boost on what gas you run, then back it off a couple deg's), then you can watch your a/f's because knock will show as a lean spike
Put it this way as of now the knock devices are comparable to a narrow band a/f gauge, basically a light show
Last edited by SpeedEuphoria : 11-03-2007 at 12:41 PM.
K well this sucks because I already have the knock sense on the way....I doubt he will let me return it and get a refund. I will just end up eating the money I spent I suppose...$100 and make this since its more reliable. I have started looking for headphones that are cheap I can take apart and begin making this thing. You guys have any links to headphones that can be taken apart like the ones in the instructions?
I got the cheap ones from Lowes for $10 and made mine
K I will go look at those...oh and I emailed the dude from knock sense telling him the issues I have heard. I took some of your posts and showed him what someone was commenting....he said this...
"Interesting. Occasionally I get a car that produces too much mechanical
noise, the spectrum of which falls in the same frequency as knock. If the
racket is loud enough than all bets are off since what is being detected is
basically a sound frequency of a short duration. There is away to take down the overall sensitivity vie external pot. See the attached file.
I take my 740 Volvo to 6200 RPM making 338hp at 18lb of boost and I do not
get false alarms. It is a loose engine too. I suggest the you do not
prejudge based on someone else's experience. The installation is not a
monumental affair. Give it a chance."
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Knock Sensor Choices?
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