why does unichip suck?
Guest
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The unichip doesn't really suck, it does what it is suppose to do, it is the fact that the stock ECU is so damn amazing.
What happens is the Unichip has a set of maps (fuel, timing, boost) that change the values coming out of the stock ECU and go into the engine (think of just changing the value by some set value everyone time). The problem is the stock ECU is always adjusting the values of the car. So the stock ECU will see that the car is running leaner then expected because the Unichip told it to run leaner, the stock ECU will start adding fuel. So in the end the car will feel like crap becasue the the stock ECU is trying to fix some unexpected values.
This is why you need to reset the ECU pretty regaruly to have this unichip actually work correctly as this is the point at which the unichip was tuned.
Here is an example
No UNICHIP:
Stock ECU has a value of 10 it is looking for so it sends out the value 10 to the engine for fueling. The engine is running pretty hard and it si cool outside so it is running lean (in comparison to what the stock ECU is looking for) and returns the value 9. So it adjust by sending the value 11 to richen things up a little bit.
With UNICHIP:
Stock ECU has a value of 10 it is looking for so it sends out the value 10 to the engine for fueling. The UNICHIP intercepts the value and changes it to 6 (lowers it 4) to make the car run stronger at leaner conditions so the car returns a value of say 5 because it si cold outside and the car is running hard. The Stock ECU sees this and sends a value of 13 to adjust for the big difference, but now the UNICHIP sees 13 and lowers the value to 8. of course this gets back to the ECU and then has to raise it again to 15, but the unichip lowers it to 11. Then the ECU sees it to rich and lowers it. Neverending cycle for fuel and timing...
That is why it does not work well. The UTEC is pretty similiar to this setup, but allows you to reprogram it and change maps on your own.
Standalone engine management on the other hand does nto face these challenges, but other challenges. Then there is reprogramming the stock ECU, the best option I think so far.
What happens is the Unichip has a set of maps (fuel, timing, boost) that change the values coming out of the stock ECU and go into the engine (think of just changing the value by some set value everyone time). The problem is the stock ECU is always adjusting the values of the car. So the stock ECU will see that the car is running leaner then expected because the Unichip told it to run leaner, the stock ECU will start adding fuel. So in the end the car will feel like crap becasue the the stock ECU is trying to fix some unexpected values.
This is why you need to reset the ECU pretty regaruly to have this unichip actually work correctly as this is the point at which the unichip was tuned.
Here is an example
No UNICHIP:
Stock ECU has a value of 10 it is looking for so it sends out the value 10 to the engine for fueling. The engine is running pretty hard and it si cool outside so it is running lean (in comparison to what the stock ECU is looking for) and returns the value 9. So it adjust by sending the value 11 to richen things up a little bit.
With UNICHIP:
Stock ECU has a value of 10 it is looking for so it sends out the value 10 to the engine for fueling. The UNICHIP intercepts the value and changes it to 6 (lowers it 4) to make the car run stronger at leaner conditions so the car returns a value of say 5 because it si cold outside and the car is running hard. The Stock ECU sees this and sends a value of 13 to adjust for the big difference, but now the UNICHIP sees 13 and lowers the value to 8. of course this gets back to the ECU and then has to raise it again to 15, but the unichip lowers it to 11. Then the ECU sees it to rich and lowers it. Neverending cycle for fuel and timing...
That is why it does not work well. The UTEC is pretty similiar to this setup, but allows you to reprogram it and change maps on your own.
Standalone engine management on the other hand does nto face these challenges, but other challenges. Then there is reprogramming the stock ECU, the best option I think so far.
Registered User
iTrader: (3)
Joined: Nov 2002
Posts: 439
From: Blackhawk, CA
Car Info: 996 Turbo,Gallardo,BMW 335,125cc shifter kart,etc
Limitations of Unichips
1) Didn?t know what one was tuning on top of.
--Couldn?t account for spikes or dips in underlying ignition timing or fuel delivery
2) Didn?t have the resolution commensurate of the underlying maps
--Had to make compromise in one map cell in favor of another
3) No control of open/closed loop transitions
--Partial throttle knock correction/de-tuning
--Unexpected long-term fuel corrections
--Hesitations/EGT problems
4) Poor crank angle signal replication
--Induced misfire CEL
--Induced erratic knock correction activity
--Engine roughness/hard starting
5) Not enough software/hardware flexibility for different tuning approaches
6) No control of stock knock control system
7) No influence over stock closed-loop boost control system
--Eliminated all factory boost compensations and safety margin management
8) No user-programmability to account for car-to-car variance
Cheers,
shiv
________
NO2 VAPORIZER
--Couldn?t account for spikes or dips in underlying ignition timing or fuel delivery
2) Didn?t have the resolution commensurate of the underlying maps
--Had to make compromise in one map cell in favor of another
3) No control of open/closed loop transitions
--Partial throttle knock correction/de-tuning
--Unexpected long-term fuel corrections
--Hesitations/EGT problems
4) Poor crank angle signal replication
--Induced misfire CEL
--Induced erratic knock correction activity
--Engine roughness/hard starting
5) Not enough software/hardware flexibility for different tuning approaches
6) No control of stock knock control system
7) No influence over stock closed-loop boost control system
--Eliminated all factory boost compensations and safety margin management
8) No user-programmability to account for car-to-car variance
Cheers,
shiv
________
NO2 VAPORIZER
Last edited by Vishnu; Mar 7, 2011 at 03:50 AM.
Guest
Posts: n/a
Re: Limitations of Unichips
Originally posted by Vishnu
1) Didn’t know what one was tuning on top of.
--Couldn’t account for spikes or dips in underlying ignition timing or fuel delivery
2) Didn’t have the resolution commensurate of the underlying maps
--Had to make compromise in one map cell in favor of another
3) No control of open/closed loop transitions
--Partial throttle knock correction/de-tuning
--Unexpected long-term fuel corrections
--Hesitations/EGT problems
4) Poor crank angle signal replication
--Induced misfire CEL
--Induced erratic knock correction activity
--Engine roughness/hard starting
5) Not enough software/hardware flexibility for different tuning approaches
6) No control of stock knock control system
7) No influence over stock closed-loop boost control system
--Eliminated all factory boost compensations and safety margin management
8) No user-programmability to account for car-to-car variance
Cheers,
shiv
1) Didn’t know what one was tuning on top of.
--Couldn’t account for spikes or dips in underlying ignition timing or fuel delivery
2) Didn’t have the resolution commensurate of the underlying maps
--Had to make compromise in one map cell in favor of another
3) No control of open/closed loop transitions
--Partial throttle knock correction/de-tuning
--Unexpected long-term fuel corrections
--Hesitations/EGT problems
4) Poor crank angle signal replication
--Induced misfire CEL
--Induced erratic knock correction activity
--Engine roughness/hard starting
5) Not enough software/hardware flexibility for different tuning approaches
6) No control of stock knock control system
7) No influence over stock closed-loop boost control system
--Eliminated all factory boost compensations and safety margin management
8) No user-programmability to account for car-to-car variance
Cheers,
shiv
Right now, I have lost my faith in Piggy Backs. I wonder of Autronic or Motec has come up with a plug and play.
Guest
Posts: n/a
Originally posted by Imprezer
You get what you pay for.
You get what you pay for.
Installed the Unichip temporarily as I need the fuelling to be right as I am running a large turbo. And also, Autronic and Motec do not have anything to replace this OBDII ECU.
Registered User
Joined: Nov 2002
Posts: 221
From: South Carolina
Car Info: 02 WRX
Originally posted by krillz
!?!?!?! my hopes have been smashed, i was gettin a utec
!?!?!?! my hopes have been smashed, i was gettin a utec
the utec runs the injectors and coils it's self at the points that you program it aslo has very good boost control
look at wrxhackers.com for more answers
Autotronic has a pnp board out right now but they are hand build units and do not control acvs witch may or may not matter to you look for EFI-guy's posts ad I think he is a distributior for them or somthing
__________________
Robert
Guest
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Autronic PnP available for '02 WRX
Strader Performance Engineering has MY2002 Autronic PnP boards available for 1,599.00
Check out www.dynospeed.com
-Ben
Check out www.dynospeed.com
-Ben
Registered User
Joined: Nov 2002
Posts: 221
From: South Carolina
Car Info: 02 WRX
I don't really know what the final drive is I guess that it will be 4.111.
I meant the hole drivetrain not just trans. I will need an aftermarket ecu that can support acvs after I do a few mods that will render the Ver 8 ECU not quite compatable. Althought I do plan on driving it as it comes for a while just to see what kind of performace they get std over there.
I meant the hole drivetrain not just trans. I will need an aftermarket ecu that can support acvs after I do a few mods that will render the Ver 8 ECU not quite compatable. Althought I do plan on driving it as it comes for a while just to see what kind of performace they get std over there.
Guest
Posts: n/a
Originally posted by bamfwrx
I don't really know what the final drive is I guess that it will be 4.111.
I meant the hole drivetrain not just trans. I will need an aftermarket ecu that can support acvs after I do a few mods that will render the Ver 8 ECU not quite compatable. Althought I do plan on driving it as it comes for a while just to see what kind of performace they get std over there.
I don't really know what the final drive is I guess that it will be 4.111.
I meant the hole drivetrain not just trans. I will need an aftermarket ecu that can support acvs after I do a few mods that will render the Ver 8 ECU not quite compatable. Althought I do plan on driving it as it comes for a while just to see what kind of performace they get std over there.