MS on NA 90-97 Miata: Knock sensor/correction? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 04-19-2011, 01:31 PM   #1
Newb
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 17
Total Cats: 0
Default MS on NA 90-97 Miata: Knock sensor/correction?

Hello there!

I picked up a 1990 Miata not too long ago, that I eventually plan on boosting. I have a bit of a tuning background (mostly piggybacks & flash-based tuning, mainly on turbo Subaru's, with a few other platforms here and there), but am new to this platform and EM solution (Megasquirt). I haven't picked one up yet, but from what I gather, the MS seems like a fairly intuitive interface that seems like it will work just fine for boosting my Miata eventually.

To be clear, I would plan on running the Miata N/A for a while, and likely building a 1.8L block in the meantime, but from what I understand the NA chassis Miata's don't have knock sensors stock.... so, my question is, will the MSPnP accept a knock sensor? If so, does it have the ability to apply knock correction (i.e. timing retard under knock)?

From what I understand, the NB Miata's have factory knock sensors, and I was considering picking up a 1999-2000 1.8L block to start with (might as well pickup the higher flowing head while I'm at it). However, I'm not sure what, if any modifications would be necessary to the MSPnP's wiring harness in order to accommodate the newer 1.8L longblock.

Is it common for most people to add a knock sensor when tuning the 90-97 Miata's, or do most people just tune them on a dyno with a set of det cans or something to that effect? If so, where are people mounting knock sensors on the older blocks?

Please excuse my ignorance, I'm new to this platform, but very eager to learn.

Either way, thanks in advance!

-Brandon
roninsoldier83 is offline   Reply With Quote
Old 04-19-2011, 01:48 PM   #2
Newb
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 17
Total Cats: 0
Default

Looks like I found a knock sensor that will allegedly interface with the MS:
http://www.viatrack.ca/

^^^I'm assuming running that bugger through the MS, I should be able to log knock count? Or am I mistaken?

From what I understand, on these cars, apparently most of them seem to hit MBT prior to reaching the knock threshold (someone correct me if I'm mistaken), but I'm just a bit wary, as I'm as 5200 ft elevation running on 91 octane **** water (i.e. turbo's have to spin harder/higher IAT's up here than sea level + 91 octane = more likely to det than at sea level on 93).

Actually, long-term I would be considering running E85 (ran it for ~1.5 years on my old STI, approx. 105 octane & latent heat of 310 BTU's/LB FTW!), so det likely wouldn't be an issue (couldn't get my STI to knock on E85 no matter how much boost/timing advance I threw at it, MBT was well below the knock threshold), but just curious about what people are doing with these cars as far as knock/knock correction are concerned.
roninsoldier83 is offline   Reply With Quote
Old 04-19-2011, 02:49 PM   #3
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,266
Total Cats: 51
Default

Yep, we designed the MSPNP to work with the KnockSenesMS. Its output doesn't allow for specific knock counts like Subaru flash tuning does, but it will let the MS pull timing.

We don't use a knock sensor on our own project cars, though - we just tune them with a set of det cans on the dyno (had a homemade set at first, but ended up buying a really nice Phormula setup a couple years ago) to make sure the map isn't close to knocking.
Matt Cramer is offline   Reply With Quote
Old 04-19-2011, 03:19 PM   #4
Newb
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 17
Total Cats: 0
Default

Quote:
Originally Posted by Matt Cramer View Post
Yep, we designed the MSPNP to work with the KnockSenesMS. Its output doesn't allow for specific knock counts like Subaru flash tuning does, but it will let the MS pull timing.

We don't use a knock sensor on our own project cars, though - we just tune them with a set of det cans on the dyno (had a homemade set at first, but ended up buying a really nice Phormula setup a couple years ago) to make sure the map isn't close to knocking.
Nice!

Fair enough, thanks for the reply, it's appreciated.

In the past, I've done a good amount of my tuning on the road, and cleaned it up a bit on a load bearing dyno, which is why I was wondering about logging knock (for road tuning where it's harder to utilize a set of det cans while making a pull, although I have seen some interesting solutions running through in-car stereo systems haha, but it doesn't help much if I'm looking at CSV logs).

Thanks for the clarification.
roninsoldier83 is offline   Reply With Quote
Old 04-21-2011, 07:11 PM   #5
Senior Member
iTrader: (9)
 
Join Date: Oct 2006
Location: Lexington SC
Posts: 1,003
Total Cats: 14
Default

I recently installed a 1.8 in my 91 and am running it NA till I get the MS details worked out. I installed a Knocksense MS with the Bosch sensor two weeks ago. I tuned it using a detcan to accurately identify knock. I know most people tune with the Detcans and I will too, but I have the Knocksense to take care of the off normal situations that could kill the engine. A bad tank of gas, high temps or other issues that can cause knock, even on a great tune. The knock sense is rediculously easy to set up as well. Make sure you mount the sensor in the right location or you will end up picking up noise.
Rallas is offline   Reply With Quote
Old 04-22-2011, 02:24 PM   #6
Junior Member
 
Join Date: Jan 2010
Location: Atlanta GA
Posts: 167
Total Cats: 0
Default

I made these electric det cans:

http://www.d-series.org/forums/diy-f...5-dollars.html

I wired up a harness and left the clip permanently installed right next to the bosch knock sensor. This way I can just unplug them and throw the unit in the glove box when not in use and I don't have to worry about doing anything under the hood when I want to have a listen.

They helped a ton when tuning the knocksense as well.
D.dutton9512 is offline   Reply With Quote
Old 04-25-2011, 04:59 PM   #7
Newb
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 17
Total Cats: 0
Default

Thanks for the insight guys, I appreciate it!

Where are you guys mounting them at?
roninsoldier83 is offline   Reply With Quote
Old 04-25-2011, 05:12 PM   #8
Junior Member
 
Join Date: Jan 2010
Location: Atlanta GA
Posts: 167
Total Cats: 0
Default

Get this mount

http://www.flyinmiata.com/index.php?...umber=07-36901

It bolts into the existing engine mount hole (on the passenger side) and you can screw the knock sensor into it.
D.dutton9512 is offline   Reply With Quote
Old 04-25-2011, 05:21 PM   #9
Newb
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 17
Total Cats: 0
Default

Quote:
Originally Posted by D.dutton9512 View Post
Get this mount

http://www.flyinmiata.com/index.php?...umber=07-36901

It bolts into the existing engine mount hole (on the passenger side) and you can screw the knock sensor into it.
Will do
roninsoldier83 is offline   Reply With Quote
Old 04-25-2011, 05:30 PM   #10
Elite Member
iTrader: (10)
 
soviet's Avatar
 
Join Date: Jan 2010
Location: VA
Posts: 3,517
Total Cats: 257
Default

Quote:
However, I'm not sure what, if any modifications would be necessary to the MSPnP's wiring harness in order to accommodate the newer 1.8L longblock.
You won't need to change the MSPnP harness, but you'll need to wire in some of the 1.8L sensors into the 1.6 harness.
soviet is offline   Reply With Quote
Old 04-25-2011, 05:32 PM   #11
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,440
Total Cats: 198
Default

Note: I've mounted a knock sensor on a 93 to the suggested engine mount, and used the sensor with my Knock Analyzer Pro. Results were awful. Definitely not recommended.
Reverant is online now   Reply With Quote
Old 04-25-2011, 05:46 PM   #12
Junior Member
 
Join Date: Jan 2010
Location: Atlanta GA
Posts: 167
Total Cats: 0
Default

I believe the factory sensor is mounted right at the cyl. 2&3 wall below the head, I don't know if this location will work for NA's though, I havent checked to see if there was a threaded hole there.

My biggest problem with knocksense is that it's relatively "narrowband" IMO. If I tune it for high RPM knock there could easily be lower (and quieter) RPM knock that's below the threshold. If I tune it for knock between 1 and 4K then it's just a glowing light after 5K. Without something that factors in RPM noise it's not really possible to have it cover the whole range.
D.dutton9512 is offline   Reply With Quote
Old 05-09-2011, 12:37 PM   #13
Newb
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 17
Total Cats: 0
Default

Quote:
Originally Posted by Reverant View Post
Note: I've mounted a knock sensor on a 93 to the suggested engine mount, and used the sensor with my Knock Analyzer Pro. Results were awful. Definitely not recommended.
Quote:
Originally Posted by D.dutton9512 View Post
I believe the factory sensor is mounted right at the cyl. 2&3 wall below the head, I don't know if this location will work for NA's though, I havent checked to see if there was a threaded hole there.

My biggest problem with knocksense is that it's relatively "narrowband" IMO. If I tune it for high RPM knock there could easily be lower (and quieter) RPM knock that's below the threshold. If I tune it for knock between 1 and 4K then it's just a glowing light after 5K. Without something that factors in RPM noise it's not really possible to have it cover the whole range.
Interesting to hear. I suppose I might tune it with a set of detcans on the dyno and skip the knock sensor...

Actually I've been toying around with the idea of picking up a set of DW 800cc injectors on a mild turbo setup, and just tuning the car on E85, which would alleviate a large majority of my fear of knock.

Thanks for all the feedback.
roninsoldier83 is offline   Reply With Quote
Old 05-09-2011, 02:36 PM   #14
Junior Member
 
Join Date: Apr 2010
Posts: 107
Total Cats: 0
Default

Anybody have experience using a TurboXS knocklite on a Miata with a Megasquirt setup? It's relatively cheap and I've heard good things about their knock detection sensitivity on other cars. I've been thinking of picking up one of the FM sensor mounts and putting it on when I get around to replacing my engine mounts. I haven't been enthused by anything I've heard about the KnocksenseMS, though.
bearda is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
LucaCarMods's Boosted Dutch Miata Build! LucaCarMods Build Threads 11 02-14-2016 07:13 AM
VW is responsible for rolling global coal warming? skidude Insert BS here 150 11-25-2015 03:42 PM
Replacement clutch disc for FM1, or something else altogether? matthewdesigns Suspension, Brakes, Drivetrain 1 10-10-2015 03:07 AM
Flush mount headlight kit 90-97 miata DonPlatt Miata parts for sale/trade 3 09-19-2015 11:23 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 06:19 AM.