the thread where Savington asks a lot of really, really dumb questions. - Page 6 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 03-09-2010, 05:40 AM   #101
Supporting Vendor
Thread Starter
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,360
Total Cats: 1,323
Default

Quote:
Originally Posted by j_man View Post
This statement most likely is true, but after my theory in the previous post -> the short is by design and is most likely on the daughter board, so he has to fix it there.
This makes perfect sense. Only with PW#9 turned on does it ground the injector out. I tested the harness, there's no continuity between the wire for injector 2 and the wire for the VVT.

Julian, if I opened up the box and snapped a couple photos would you be able to tell me what I need to cut/move?
Savington is online now   Reply With Quote
Old 03-09-2010, 09:26 AM   #102
Elite Member
iTrader: (9)
 
TurboTim's Avatar
 
Join Date: Jun 2006
Location: Chesterfield, NJ
Posts: 6,484
Total Cats: 248
Default

Or instead of taking apart the board/moving jumpers/cutting leads/resoldering/whatever, just use move (physically and software wise) injectors 1 & 2 to 5 & 6, after you've done this check to see if it's the problem.

Quote:
Originally Posted by j_man View Post
So ... my suggestion is test the injector outputs manually to see if you have 9 and 10 in the connector at all or whether those two are connected to pins for 1 and 2 and you either have to move some jumpers on the daughter board to separate them or you may even have to cut some traces on the daughter circuit board and route them to the proper pins.

To do a test:

1. Open AEMPro, go to Options -> Injector screen
and turn off all injector outputs there (so the software temporary doesn't treat them as injectors).

2. Disconnect the plugs from the injectors.

3. Since all our injector outputs are not treated as injectors anymore but as general LS drivers.
In AEMPro, open Options -> Configure Outputs and there manually toggle Fuel 1, 2, 9 and 10 to ON one by one.
Monitor their status in a parameter window (Ctrl-P) and check with a multimeter the pins 2U, 2V, 3O and 3P.

My prediction is that when Fuel 9 is ON, pin 2U will be grounded instead of 3O and when Fuel 10 is ON, pin 2V will be grounded instead of 3P.
So, to make 9 go to 3O and 10 to 3P, you'll either have to move some jumper or do some trace cutting and/or soldering on the daughter board

This is just for Savington's AEM EMS. Jason uses one with a Honda daughterboard so I guess his is fine.
TurboTim is offline   Reply With Quote
Old 03-09-2010, 01:49 PM   #103
Senior Member
 
Join Date: Dec 2007
Posts: 671
Total Cats: 2
Default

Quote:
Originally Posted by TurboTim View Post
Or instead of taking apart the board/moving jumpers/cutting leads/resoldering/whatever, just use move (physically and software wise) injectors 1 & 2 to 5 & 6, after you've done this check to see if it's the problem.
Ah, that's the better idea! I guess my brain was half off that late last nite

What Tim suggests also won't break the box warranty if it is brand new.

Move the OEM injector harness wires from inj 1 & 2 to something like 5 & 6. In the software in "Options->Injector" disable 1 & 2 (disable = uncheck "Active") and enable the two new ones (set them as primary, etc. options there just like 1 & 2 were).

Then open the "Fuel->Advanced Fuel->Injector Phasing" and put the values you have from Inject Tooth #1 & #2 into the two new ones you used.

After this start the engine to make sure you did the switch correct.

Then connect the VVT solenoid to injector 2 (or 1 - whichever the 9 is shorted to)

Last edited by j_man; 03-09-2010 at 02:03 PM.
j_man is offline   Reply With Quote
Old 03-09-2010, 01:53 PM   #104
Senior Member
 
Join Date: Dec 2007
Posts: 671
Total Cats: 2
Default

Quote:
Originally Posted by Savington View Post
Julian, if I opened up the box and snapped a couple photos would you be able to tell me what I need to cut/move?
Jason is the hardware guy - he could give you a much better guidance But I think Tim's idea is much much better because you won't have to mod the ECU at all and all you have to do in hardware is move the 1 & 2 injectors wires to two other pins.
j_man is offline   Reply With Quote
Old 03-09-2010, 09:26 PM   #105
Elite Member
iTrader: (9)
 
TurboTim's Avatar
 
Join Date: Jun 2006
Location: Chesterfield, NJ
Posts: 6,484
Total Cats: 248
Default

Quote:
Originally Posted by j_man View Post
Jason is the hardware guy - he could give you a much better guidance But I think Tim's idea is much much better because you won't have to mod the ECU at all and all you have to do in hardware is move the 1 & 2 injectors wires to two other pins.
It wasn't my idea. Jason posted it first and I thought it made more sense. I just retyped it to make sure Sav tries it.

Quote:
Originally Posted by JasonC SBB View Post
No the phasing just changes when the injector fires.
Just a random check, try inj output #6...............
TurboTim is offline   Reply With Quote
Old 03-10-2010, 04:36 AM   #106
Supporting Vendor
Thread Starter
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,360
Total Cats: 1,323
Default

OK, I moved injectors 1 and 2 over to outputs 7 and 8. Still not totally sure why activating injector 9 as VVT control is grounding out 2/10 but whatever. Hopefully it's solved now. Changed the active injectors and injector phasing and the car fired up fine. I will play around more with VVT tomorrow and see if I can get it to run the circuit without locking an injector open, and then power the solenoid and start zeroing in on some settings.
Savington is online now   Reply With Quote
Old 03-10-2010, 06:16 PM   #107
Supporting Vendor
Thread Starter
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,360
Total Cats: 1,323
Default

It appears to be solved. I can activate PWM9 in the software and the injector stays closed as it should. I'll move on to settings today/tomorrow.

One quick question about knock sensing - I hooked my Bosch sensor up to the AEM and stuck it on the side of the block. I placed the sensor in the OEM location using the FM adapter. I can tap the sensor and get ~1v out of it, but when the car is idling and revving it won't go above .02v. Any ideas?
Savington is online now   Reply With Quote
Old 03-10-2010, 07:41 PM   #108
Elite Member
iTrader: (22)
 
Join Date: Dec 2006
Location: Sunny Spanish speaking Non US Caribbean
Posts: 3,257
Total Cats: 3
Default

Quote:
Originally Posted by Savington View Post

One quick question about knock sensing - I hooked my Bosch sensor up to the AEM and stuck it on the side of the block. I placed the sensor in the OEM location using the FM adapter. I can tap the sensor and get ~1v out of it, but when the car is idling and revving it won't go above .02v. Any ideas?

You may find the answers to this question in this thread: https://www.miataturbo.net/forum/t33781/
Rafa is offline   Reply With Quote
Old 03-10-2010, 07:43 PM   #109
Elite Member
iTrader: (22)
 
Join Date: Dec 2006
Location: Sunny Spanish speaking Non US Caribbean
Posts: 3,257
Total Cats: 3
Default

J_man's answer to that question. Here you go:

Quote:
Originally Posted by stinkonamonkey
You can use a saturn knock sensor for the EMS. Search the AEM forums for details. You have to run a shielded wire to the sensor and mount it to the block using a modified bolt. I've got one installed but I haven't got it working real well yet.


+1. The resonant Saturn sensor is the one he needs.
Flat response sensors won't work.
Rafa is offline   Reply With Quote
Old 03-10-2010, 08:04 PM   #110
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

I posted a bandpass filter and amp for the AEM to be used with the 99 knock sensor.
There was a thread about using said circuit for a Bosch type sensor. I answered there but I don't remember my answer.

The GM resonant sensor center frequency is a bit off from the miata's knock resonant frequency. Those resonant sensors have extremely narrow bands so I don't know how well they would work compared to a flat sensor with a proper bandpass filter.

BTW the Link doesn't have a bandpass filter either based on a schematic I was shown. (Unsure ifi I saw the FM version)
JasonC SBB is offline   Reply With Quote
Old 03-10-2010, 08:35 PM   #111
Supporting Vendor
Thread Starter
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,360
Total Cats: 1,323
Default

I may have a '99 sensor laying around but I know I have a 2002 sensor. Mazdacomp's site is cocked up so I can't check part numbers, but are the 2001+ sensors similar to the 99/00 sensors?
Savington is online now   Reply With Quote
Old 03-10-2010, 09:24 PM   #112
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

I don't see any reason for the 99 sensors being different from 01.
JasonC SBB is offline   Reply With Quote
Old 03-11-2010, 08:42 AM   #113
Elite Member
iTrader: (9)
 
TurboTim's Avatar
 
Join Date: Jun 2006
Location: Chesterfield, NJ
Posts: 6,484
Total Cats: 248
Default

Quote:
Originally Posted by Rafa View Post
Flat response sensors won't work.
Flat response/bosch/wide band knock sensors do work, I use one. It just doesn't work as well as something setup specifically for the miata, or something that outputs up to 5volts like a dedicated filter & amp circuit would.

I can check when I get home Andrew, but I don't think the knock sensor volt moves much when I rev my engine either (using FM supplied bosch sensor from my Link ECU days). But it definitely "spikes" when I get knock. The spike is less than 1 volt but it's still obvious when there's normally a constant 0.x volts. You have my settings to see how much timing it pulls/fuel it adds per volt but obviously there's a bunch of resolution not used when using a bosch sensor wired directly to the box.

EDIT: Sooo a dedicated black box tuned/amplified for use with a Bosch knock sensor will be included in the crank trigger/vvt kit you guys are putting together for us lazy AEM users, right?
TurboTim is offline   Reply With Quote
Old 03-11-2010, 04:56 PM   #114
Senior Member
 
Join Date: Dec 2007
Posts: 671
Total Cats: 2
Default

I had just a Bosch flat response sensor in the past connected to the AEM - it is kinda unusable. It picks the entire frequency range and often there are high level sounds which are not knock frequncy but could fool the ECU.

I currently have the Saturn resonant sensor hooked to the AEM.

Jason says Miata knock frequency is abnormally high - if that's true I'll switch back to the Bosch sensor with his bandpass filter / amp (you have to filter out the proper frequencies and amplify the signal before feeding it to the AEM if using a flat response sensor).

Hey Jason, was your frequency pick based on just that single wav file you posted back then (with a couple of knocks in it)?
Or did you test with a bunch of induced knocking at low, mid and high rpm to confirm that the frequiency is the same over the rpm range at both mild and strong knocking - but you never posted those?


j_man is offline   Reply With Quote
Old 03-11-2010, 04:58 PM   #115
Senior Member
 
Join Date: Dec 2007
Posts: 671
Total Cats: 2
Default

Quote:
Originally Posted by Savington View Post
I may have a '99 sensor laying around but I know I have a 2002 sensor. Mazdacomp's site is cocked up so I can't check part numbers, but are the 2001+ sensors similar to the 99/00 sensors?
Both should be the same since it is a simple flat response sensor - the filtering and amplifying in the OEM case are done in the OEM ecu.
j_man is offline   Reply With Quote
Old 03-11-2010, 05:06 PM   #116
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

I only tested off-idle knock and found 13 kHz to be the best center frequency.
I would appreciate some knock recordings - I can analyze them, and then I can re-adjust the center frequency of my circuit.

13 kHz is not "abnormally high". I tested some GM Saturn sensors and IIRC they were at 12 kHz IIRC.

Last edited by JasonC SBB; 03-11-2010 at 05:25 PM.
JasonC SBB is offline   Reply With Quote
Old 03-11-2010, 05:17 PM   #117
Senior Member
 
Join Date: Dec 2007
Posts: 671
Total Cats: 2
Default

Quote:
Originally Posted by JasonC SBB View Post
I only tested off-idle knock and found 13 kHz to be the best center frequency.
I would appreciate some knock recordings and then I can re-adjust the center frequency of my circuit.

13 kHz is not "abnormally high". I tested some GM Saturn sensors and IIRC they are at 12 kHz.
Yeah, I've tested your wav file too and saw the freqiencies there.

I should've said compared to that GM paper often posted about how to calculate the knock frequency knowing the cylinder bore. Following that formula IIRC the Miata engine knock was somewhere around 8Khz.

With that other thread about the electronic det cans group buy, I hope people post knock recordings too sometime soon


Quote:
Originally Posted by JasonC SBB View Post
13 kHz is not "abnormally high". I tested some GM Saturn sensors and IIRC they are at 12 kHz.
Hmm. John @ J&S posted in the past that the Saturn sensor has lower than 12Khz resonant frequency. No idea whether he tested but IIRC the sensor part info came from him.
j_man is offline   Reply With Quote
Old 03-12-2010, 05:43 PM   #118
Supporting Vendor
Thread Starter
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,360
Total Cats: 1,323
Default

Quote:
Originally Posted by JasonC SBB View Post
Like this.
In this example I set the targets to full retard everywhere.
These settings are what I started with. I can run the duty up to 90% and there's no effect on the solenoid. I raised the output limit to 100% since it was being limited at 48 and it still doesn't want to respond. Idling at a steady 11.8-12.0 cam degrees.
Savington is online now   Reply With Quote
Old 03-12-2010, 07:31 PM   #119
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Post a screenshot of the cam #1 template.

Did you look at the parameter screen to see what duty cycle it's actually outputting?

And, if your "cam start" number is correct, it should idle at ~23* cam degrees if you're outputting zero duty cycle.

Last edited by JasonC SBB; 03-12-2010 at 07:43 PM.
JasonC SBB is offline   Reply With Quote
Old 03-12-2010, 07:32 PM   #120
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

J_Man, a super easy way to find the resonant frequency of a piezo sensor is to use a signal generator with 1V or so of output on it. It will act as a loudspeaker. there is a very narrow range of frequency where it gets loud. I posted this a long time ago on MF.

Here I found my thread

http://forum.miata.net/vb/showthread...ight=resonance

Two piezo sensors with the same part number show 11.6 kHz and 8.5 kHz. I have a feeling the 8.5 kHz one got over-tightened and damaged.

If you listen to the recording, you get a descending note, which I would think is because the piston is moving down the cylinder. Which means that bore diameter is only part of the picture.

Also, 13 kHz is exactly one octave above 6.5 kHz ......
JasonC SBB is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 57 07-19-2017 05:11 PM
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 04:00 PM
Noob to Miataturbo from MA JxPhan Meet and Greet 3 10-02-2015 03:17 AM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 06:09 PM.