Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   MEGAsquirt (https://www.miataturbo.net/megasquirt-18/)
-   -   He's knocking on the back door. Should I let him in? How much knocking is okay? (https://www.miataturbo.net/megasquirt-18/hes-knocking-back-door-should-i-let-him-how-much-knocking-okay-94301/)

TorqueZombie 08-17-2017 12:53 PM

He's knocking on the back door. Should I let him in? How much knocking is okay?
 
So I've had my MS3 for a while now. I admit that I still feel like a noob. I'm getting ready to roll the dice and try tuning ignition timing. I have a DIY microphone bolted to the block, Audacity app, bluetooth noise cancel headphones, and laptop bluetoothed to the MS3. Laptop is buetooth 4.1, or 4.2, can't remember. Nat-Asp 1.8 VVT, forged rods and oil pump, factory VVT pistons, and a knock curious relationship.

I watch my datalogs now and I see everywhere from 10% to maybe a spike of 30% knock on the gauges and the datalogs. Is this acceptable noise and chatter in the system? I had a played with a Hydra before and it allowed me to tell it what was general engine noise and anything over that was knock. Using the factory knock sensor and the MS3 when should I be concerned about percentage of knock? Is the a way to calibrate it to ignore noise and tell it a threshold to alert me? I can listen for banging knock noise, but the is the little knocks I may not hear. Pardon my paranoia. I just start to wonder. Is 20% knock a little knock? Just noise from the engine? Be concerned? Don't be concerned until big bangy noises? I'm at a mile high with access to 91oct and would like to learn more is all.

18psi 08-17-2017 12:56 PM

There is no set threshold. (well, there probably is, but I don't think mazda would share it with us, and it would be irrelevant on a built engine anyway)

You do "control" logs that for sure should have zero knock.
You set that as your base noise level.
Anything that significantly deviates or spikes from said base is most likely knock.

Newer ms units definitely have a bunch of settings for this

leboeuf 08-17-2017 01:06 PM

Does reverant put the knock module into his boards (Purpose built IC that communicates over SPI)? There is a lot of integration built into tunerstudio for various settings if he's using the same IC as diyautotune. Oddly the only time I see any kind of knock is on hot days with the A/C on while cruising on the interstate.

TorqueZombie 08-17-2017 01:32 PM

I'm not sure. I'm still running his base ignition map. I think it's fairly close to a stock map, but digging around an looking at other NA tunes there might not be a lot of wiggle room.

I figure I'm not knocking now so I guess I'll make some "control logs" and go from there. It'll be road tuning, but I'm going to try and use the Dyno App to see where it drops off. I know it's not perfect, but it should be a go/no-go for improvements/not.

NordicSaab 08-17-2017 07:56 PM

Timing bad... add boost.

afm 08-17-2017 10:33 PM


Originally Posted by NordicSaab (Post 1434535)
Timing bad... add boost.

Timing bends rods :)


All times are GMT -4. The time now is 12:45 AM.


© 2024 MH Sub I, LLC dba Internet Brands