y8s Hydra Nemesis Parallel Install Thread
09-03-2008 | 05:18 PM
#1
Thread Starter
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
y8s Hydra Nemesis Parallel Install Thread
I'm going to be doing this because I want to pass OBDII plug-in tests.
Don't come in here and tell me why I shouldn't do it. That's not this thread.
I'll start with a list of ECU functions and their pins and if they should be ported back over to the stock ECU.
I already have the male and female harness connectors and pins. I can wire them all up like a boomslang and intercept what's needed and send it off to the hydra.
Most of what I'm looking for is answers to questions that come up about sharing sensors, piggybacking signals, etc.
Next post starts the hard dataz.
Matt
Don't come in here and tell me why I shouldn't do it. That's not this thread.
I'll start with a list of ECU functions and their pins and if they should be ported back over to the stock ECU.
I already have the male and female harness connectors and pins. I can wire them all up like a boomslang and intercept what's needed and send it off to the hydra.
Most of what I'm looking for is answers to questions that come up about sharing sensors, piggybacking signals, etc.
Next post starts the hard dataz.
Matt
Reply
0
0
09-03-2008 | 05:35 PM
#2
Thread Starter
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
Stock ECU functions
These are basically just pasted from my Hydra pinout spreadsheet.
Definitely going to the stock ECU:
Definitely going to the stock ECU:
Code:
HYDRA FUNC MAZDA TRIG DESCRIPTION NOTES
A2 INJ 8 2K>+2C POS Air Con A/C Control (diode anode side)
A3 PWM 10 2R GND Check Engine MIL
A4 PWM 11 3C GND Purge Control
A6 PWM 16 2M+2O GND Primer 1 second Fuel Pump Relay + N/C
A9 PWM 4 2Q GND ISCO IAC (negative)
B1 AUX 3 4F Low A/C Refrigerant Pressure Switch
B5 3T Vehicle Speed
B9 3V SGC (CMP Sensor)
C1 4AF +12V IG Power Supply (Ignition On)
C3 3B GND PCM GND
C5 4V 0-5V Throttle Position Sensor
C12 3O Engine Speed
C14 4W HO2S Front
D1 4AF +12V IG Power Supply (Ignition On)
D4 4L 5V Constant Voltage (Vref)
D5 4M Knock Sensor
D9 4N 0-5V Intake Air Sensor
D14 3Y NE (CKP Sensor)
D16 4P 0-5V Engine Coolant Temp Sensor
F4 PWM 5 3M Generator Field Coil Control
F11 3J HO2S Heater (Front) Control
A9 PWM 4 2Q GND ISCO IAC (negative)
Reply
0
0
09-03-2008 | 05:50 PM
#3
Thread Starter
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
Need to be Shared with Stock ECU:
Code:
A3 PWM 10 2R GND Check Engine MIL (wire in second MIL for Hydra...)
B5 3T Vehicle Speed
C1 4AF +12V IG Power Supply (Ignition On)
C2 3A GND Fuel Injector GND (MAYBE?)
C3 3B GND PCM GND
C5 4V 0-5V Throttle Position Sensor
C11 AUX 4 4I Low Clutch Switch / Launch Control
C12 3O Engine Speed
D1 4AF +12V IG Power Supply (Ignition On)
D2 4A GND Output Device GND
D3 4O GND Analog Sensor GND
D4 4L 5V Constant Voltage (Vref)
D5 4M Knock Sensor
D9 4N 0-5V Intake Air Sensor (dont think hydra even needs this)
D14 3Y NE (CKP Sensor)
D16 4P 0-5V Engine Coolant Temp Sensor
Reply
0
0
09-03-2008 | 05:58 PM
#4
Thread Starter
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
OK So I plan to have the stock ECU do the following functions (you can find them above)
I'm NOT sure the stock ECU will care if the hydra will do these:
Also:
It's a pretty easy task to piggyback a digital signal since they're just pulses, right? Finding bias resistor values or making a voltage follower for the stock water temp sensor will be kind of a pain since the hydra may have an internal bias resistor. Might be easier to just put in a second sensor.
- A/C
- Check Engine (MIL)
- Purge Control
- Fuel Pump Relay
- Idle Control
- A/C Control
- All stock gauges
- Use the Stock O2 sensors
I'm NOT sure the stock ECU will care if the hydra will do these:
- Knock Sensor (believe stock ecu doesn't care)
- VVT
- VTCS (pretty sure it's OK since it's passive)
- Fake out the MAF sensor (have kinda done this before--just need a spare output)
Also:
It's a pretty easy task to piggyback a digital signal since they're just pulses, right? Finding bias resistor values or making a voltage follower for the stock water temp sensor will be kind of a pain since the hydra may have an internal bias resistor. Might be easier to just put in a second sensor.
Reply
0
0
09-03-2008 | 06:26 PM
#5
Definately put in a second coolant sensor. Much easier and less headache.
The VVT is questionable, as the stock ECU will constantly be trying to put that cam in a certain spot buy the HYDRA will put it elsewhere. The stock ECU will never win. That could cause a CEL, but I dunno. Is there a CEL for VVT related problems?
Knock sensor won't matter I do believe. I unplugged mine for a while and the stock ECU never cared.
The MAF sensor you are on your own. That has to be given a signal. If you can fake it out then I guess you'll be fine, but there is a potenital for CEL from this if your fake out plan isn't just right.
Someone needs to build a circuit to show the "A-OK" code for passing OBD2. I know, it's probably not legal, but... It would be simpler.
Also2: where are you gonna put the Hydra? Right next to the stock ECU? I did that with MS2 and hated it. Now that I'm standalone Mine is velcro'd to the carpet behind the passengers seat. Easy to get to and no mess under the dash. You might consider remote mounting it.
The VVT is questionable, as the stock ECU will constantly be trying to put that cam in a certain spot buy the HYDRA will put it elsewhere. The stock ECU will never win. That could cause a CEL, but I dunno. Is there a CEL for VVT related problems?
Knock sensor won't matter I do believe. I unplugged mine for a while and the stock ECU never cared.
The MAF sensor you are on your own. That has to be given a signal. If you can fake it out then I guess you'll be fine, but there is a potenital for CEL from this if your fake out plan isn't just right.
Someone needs to build a circuit to show the "A-OK" code for passing OBD2. I know, it's probably not legal, but... It would be simpler.
Also2: where are you gonna put the Hydra? Right next to the stock ECU? I did that with MS2 and hated it. Now that I'm standalone Mine is velcro'd to the carpet behind the passengers seat. Easy to get to and no mess under the dash. You might consider remote mounting it.
Reply
0
0
09-03-2008 | 06:30 PM
#6
Junior Member
Joined: Oct 2007
Posts: 345
Total Cats: 0
From: AC, NJ
Also, when my knocksense went haywire, stock ecu returned P1609 Powertrain Control Module (ECM CPU) Knock Sensor Circuit or something like that. Not sure if Hydra will do the same. But this says there is a KS MIL
Reply
0
0
09-03-2008 | 08:09 PM
#9
Joined: Sep 2005
Posts: 33,556
Total Cats: 6,933
From: Chicago. (The less-murder part.)
Several, in fact. If the Hydra is controlling VVT, then the ECU will happily throw P0011 and P0012 for timing over-advance and timing over-retard, based upon the fact that it cannot control the cam properly. Additionally, it will throw P0010 simply because the oil control valve is disconnected, as it will detect an OCV undercurrent condition and assume a wiring fault.
Likewise, you've for P1512 and P1518 for VTCS valve stuck (vacuum switch not changing in response to solenoid command) plus P1569 and P1570 for VTCS solenoid undervoltage / overvoltage (solenoid fault).
In other words, leave the damn things connected to the stock ECU.
P0327 and P0328 are knock sensor overvoltage / undervoltage faults. Not sure who you didn't see a problem, as they are both listed as MIL faults.
It is quite specifically illegal, unfortunately. And it's Federal, not California law.
Likewise, you've for P1512 and P1518 for VTCS valve stuck (vacuum switch not changing in response to solenoid command) plus P1569 and P1570 for VTCS solenoid undervoltage / overvoltage (solenoid fault).
In other words, leave the damn things connected to the stock ECU.
Knock sensor won't matter I do believe. I unplugged mine for a while and the stock ECU never cared.
Someone needs to build a circuit to show the "A-OK" code for passing OBD2. I know, it's probably not legal, but... It would be simpler.
Reply
0
0
09-03-2008 | 09:02 PM
#10
Thread Starter
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
thanks joe. I hadn't yet looked at the list of fault codes.
AH wait, now I remember. Tec3 used its own knock sensor.
FYI to all, I did run the Tec3 in parallel. It only ran fuel and spark.
I think the thing that's going to suck is if I can't run VVT externally, I will have to fool the ECU twofold...
1. The AFM needs an input signal somewhat proportional to load and rpm.
2. The AFM and RPM signals drive the VVT settings.
So you can see that if I want to control VVT in parallel with no CEL, I'm going to have to do it in a roundabout way. But I can (sorta?) do it.
AH wait, now I remember. Tec3 used its own knock sensor.
FYI to all, I did run the Tec3 in parallel. It only ran fuel and spark.
I think the thing that's going to suck is if I can't run VVT externally, I will have to fool the ECU twofold...
1. The AFM needs an input signal somewhat proportional to load and rpm.
2. The AFM and RPM signals drive the VVT settings.
So you can see that if I want to control VVT in parallel with no CEL, I'm going to have to do it in a roundabout way. But I can (sorta?) do it.
Reply
0
0
09-03-2008 | 09:52 PM
#13
Joined: Sep 2005
Posts: 33,556
Total Cats: 6,933
From: Chicago. (The less-murder part.)
While I agree, it's not really a fair comparison. These problems are endemic of any parallel install (regardless of which ECU is being used) and are a good illustration of the problems and shortcomings which one often experiences with such a configuration.
And for that:
Assuming that Hydra has the ability to squirt out an analog voltage in proportion to two variables (RPM and MAP), just follow the link in my sig and repeat the process for your Hyrda.
Why are you so dead-set against letting the ECU run the VVT system? You're never going to be able to control VVT directly without throwing codes.
And for that:
I think the thing that's going to suck s if I can't run VVT externally, I will have to fool the ECU twofold...
1. The AFM needs an input signal somewhat proportional to load and rpm.
2. The AFM and RPM signals drive the VVT settings.
1. The AFM needs an input signal somewhat proportional to load and rpm.
2. The AFM and RPM signals drive the VVT settings.
So you can see that if I want to control VVT in parallel with no CEL, I'm going to have to do it in a roundabout way. But I can (sorta?) do it.
Reply
0
0
09-04-2008 | 12:38 AM
#15
Joined: Sep 2005
Posts: 33,556
Total Cats: 6,933
From: Chicago. (The less-murder part.)
For standalones, it's easy- pretty much anything is "better than nothing." But since you're already condemning yourself to a life of parallel operation, why make it even harder than it has to be? Get the MAF-substitution map built and let the ECU do its thing.
Reply
0
0
09-05-2008 | 02:45 AM
#17
Elite Member
Joined: Jul 2005
Posts: 6,420
Total Cats: 84
If you let the factory ECU control VVT, and if VVT advance at different RPMs is a function of airlow, you can therefore modify VVT by diddling your AFM cheat signal. Problem is, other things would be affected too, like EGR.
The other way of doing this is to build a box that fakes the cam sensor signal phase angle by an amount specified by a Hydra output. If the box puts a lag in the signal, the ECU will compensate and advance the cam....
The other way of doing this is to build a box that fakes the cam sensor signal phase angle by an amount specified by a Hydra output. If the box puts a lag in the signal, the ECU will compensate and advance the cam....
Reply
0
0
