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-   -   Good Knock Sensor for KnockSenseMS? (https://www.miataturbo.net/megasquirt-18/good-knock-sensor-knocksensems-98730/)

NASSEX 12-07-2018 05:39 PM

Good Knock Sensor for KnockSenseMS?
 
I purchased a KnockSenseMS for my 94 1.8l 0.02" overbored. it's a oem rebuild. Running MS2PNP + TunerStudio.
I wish to mount the knock senser in the threads of the factory oil pressure sender location on the intake manifold side of the block.
Good or Bad idea? Is this dooable? Any suggestions on which knock sensor to get for such a setup? Thanks in advance. I've procrastinated a long while before being able to ask this question!

curly 12-07-2018 05:58 PM

It’s not a terrible idea, but you’d have to find a knock sensor with a flat surface for a crush washer on the back to seal the oil passage. That and they may not like the heat (would it even be hotter?) and they’re sensitive to torque, and the correct torque may not seal the hole. There’s plenty of options in that area, the oil pressure port is the last I’d consider.

borka 12-07-2018 07:08 PM

Why not stick it in the nb stock location right above the oil pressure sender?

NASSEX 12-07-2018 07:28 PM

Thanks guys. Idk why I hadn't thought of the fact that pressurized oil comes from that hole lol. So I think my idea will be something along the lines of using a short bracket to hold the knock sensor facing to the block cylinder head gasket, the bracket holds the sensor and it has a arm welded to threads which screw into the oil pressure sender threads. That way it plugs the oil and holds itself. Bright idea? The BEST IDEA?

I haven't seen any pics of how the NB does it from the factory. I'd replicate that if it is the best way to go. Any suggestions on a specific part number that's known to be a working sensor for Miatas? That's really what I need, is to make an order on a sensor and then I can start to finalize the mount/idea.

I think the knock sensor I buy has to be compatible with KnockSenseMS since I'm using Megasquirt 2 PNP. I ordered it from EnjukuRacing.com. I think it's the DIY Auto tune version since stickers came in the package. lol

borka 12-07-2018 08:00 PM

again, i reiterate. why reinvent the wheel?

stock nb location, above the oil sender. (NA blocks, have the same threaded hole already there)

https://cimg6.ibsrv.net/gimg/www.mia...f970df1c8b.jpg

NASSEX 12-07-2018 08:36 PM


Originally Posted by borka (Post 1513970)
again, i reiterate. why reinvent the wheel?

stock nb location, above the oil sender. (NA blocks, have the same threaded hole already there)

https://cimg6.ibsrv.net/gimg/www.mia...f970df1c8b.jpg


I'm pretty sure what you're saying is, that I can just buy a '99 knock sensor and it threads right into my '94 block?? Why haven't people done this before? Why do people bother with buying aftermarket mounting hardware if they could just do this? o.O

NASSEX 12-07-2018 08:43 PM

I really didn't know this existed in the 94 Block. I always assumed it was replaced with the oil pressure sender hole. But this works even better! I appreciate you!

borka 12-07-2018 08:50 PM

I am running a 94 block in my nb2 and this hole exists for the stock nb knock sensor in the 94 block.

im running an NB2 car, 94 NA block, stock nb2 knock sensor in stock location, which goes to my MS3 basic.

so you can use a stock nb knock sensor if your ms2 has knock sensor capabilities, or use an aftermarket sensor with knocksenseMS.

but either way, the threaded hole is there in the block.

andym 12-07-2018 08:59 PM

For what it is worth, if you are planning to run both a real oil pressure sender and the knock sensor, you might need to get an extended line for the oil pressure sender. It would seem that the real sender is a bit fat and would try to occupy some of the same space as the knock sensor. Note, I haven't done this myself yet or verified it for myself yet. That is just information that I have gathered from this forum. I am in a similar situation trying to figure out how to keep my real oil pressure sender and run an nb knock sensor on my 1.6 with my ms3.

Savington 12-08-2018 01:08 AM

Has anyone mentioned how useless the KnocksenseMS is yet?

shuiend 12-08-2018 07:28 AM


Originally Posted by Savington (Post 1513996)
Has anyone mentioned how useless the KnocksenseMS is yet?

No, but you are correct that it is useless.

To the OP. Using stock NB knock sensor on a NA block is common practice.

ryansmoneypit 12-08-2018 09:08 AM

I thought I read in older threads, that the NB sensor is kinda poopy and that some other model (Volvo?) Was a better option. Is this untrue?

shuiend 12-08-2018 09:29 AM


Originally Posted by ryansmoneypit (Post 1514011)
I thought I read in older threads, that the NB sensor is kinda poopy and that some other model (Volvo?) Was a better option. Is this untrue?

I am not positive on this. I know different know sensors can read different hertz differently and that needs to match the engine harmonics. I know all knock control for MS south of a MS3 is crap and just about worthless. I think Mazda engineers know enough about the BP motors to have hopefully picked a knock sensor that works. There may be better ones out there, but I am not sure how you would test and verify all that as an individual without the engineering lab that an OEM has.

curly 12-08-2018 11:01 AM

Every NB with over 50k comes into my work with literally a melted knock sensor, and never a knock sensor code.

If I use the NB sensor, it operates in the 0-.05v range, with 0.1v probably being knock.

I don't usually use a knock sensor, but when I have, I used this Saturn sensor. It operates in true 0-5v range, seems more usable and tunable in my limited experience.
https://www.carparts.com/details/Sat...E&gclsrc=aw.ds

Cheap, easy to find pigtail, all you need is an adapter, like so: (except with the proper Saturn/Miata threads)

NASSEX 12-08-2018 01:31 PM

Dang so knocksenseMS is useless? :| ..was a 100$ :/


At work right now, on the clock. When i get home later tonight, i can reply to a lot of the other posts

Are there any pros and cons of the knocksenseMS unit?

Savington 12-08-2018 07:51 PM

The filtering is nowhere near complex enough. With no crank window filtering, and no cylinder identification based on crank position, and no RPM-based noise filtration, it's actually less than worthless. If you set it up to identify knock in the mid-range, where knock is most likely, it will false-trigger at higher RPM. If you set it up to not false trigger at high RPM, it won't pick up knock in the mid-range, which gives you a false sense of security.

I had one 10 years ago, they are junk. If you want or need knock detection, you need an MS3

NASSEX 12-11-2018 09:24 PM


Originally Posted by Savington (Post 1514075)
The filtering is nowhere near complex enough. With no crank window filtering, and no cylinder identification based on crank position, and no RPM-based noise filtration, it's actually less than worthless. If you set it up to identify knock in the mid-range, where knock is most likely, it will false-trigger at higher RPM. If you set it up to not false trigger at high RPM, it won't pick up knock in the mid-range, which gives you a false sense of security.

I had one 10 years ago, they are junk. If you want or need knock detection, you need an MS3

Thanks. That pretty much sums up the jist of it lol


Originally Posted by Savington (Post 1514075)
If you set it up to identify knock in the mid-range, where knock is most likely, it will false-trigger at higher RPM. If you set it up to not false trigger at high RPM, it won't pick up knock in the mid-range, which gives you a false sense of security.

Based on from what you said, technically, would I be able to set it up to identify knock in the mid-range while I focus on tuning mid-range? Then set it up to not false trigger at high RPM, so that I can use it to help me identify knock while tuning the highs?
/me *PRAYS*
If I can use it with that kind of method, then it will honestly suit my fundamental need from it and not of wasted that money at all.

I'm basically wondering if there is any kind of way to use it for just a dyno day when tuning the spark map rather than a knock detection safety net since it obviously is no good for that with megasquirt 2 :(


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