Welcome to the North American Subaru Impreza Owners Club Tuesday September 23, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC General > Proven Power Bragging

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 02-08-2009, 07:08 PM   #1
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default Speed Density Tuning with the Accessport on an 08 STI

Cobb Tuning now offers AccessTuner software and companion AccessPORT firmware which enables speed density based tuning for certain drive by wire Subaru applications. This major new feature has been implemented to satisfy the growing demand within the Subaru community for a highly reliable and cost effective motor sports grade engine management solution. ( See the press release here: http://forums.nasioc.com/forums/show....php?t=1694627 )

The new "speed density" operating modes redirects the ECU to calculate load by using temperature and manifold absolute pressure (MAP). The software allows the engine to operate in pure speed density, pure mass air flow (MAF) mode, or a hybrid of both speed density and MAF modes.
High horsepower applications often saturate the stock MAF sensor and oversized MAF housings designed to extend the effective range of the MAF sensor seriously compromise its sensitivity and thus degrade drive-ability at lower air flow levels.

The availability of this new AccessPORT feature means that these high horsepower projects do not rely on the MAF sensor for precise engine control. These high horsepower vehicles that otherwise would require the use of expensive and comparatively unreliable stand alone ECU's can now look to the reliability and consistency of the stock ECU partnered
with Cobb Tuning's increasingly capable AccessPORT and our network of experienced tuners.

This new speed density based tuning relies on a host of controls, logic, and tables that are novel to stock ECU tuning. Here we present the results of a dyno tune for an 08 Sti as a way to demonstrate these exciting new tuning tools from Cobb Tuning in action.

As part of the development process, Surgeline Tuning built and testing speed density calibration in a number of different configuration. One of these configurations is the Stage 1 2008 STI presented here.

We started with a Stage 1 STI running a Cobb Accessport and a Surgeline Tuning Protuned map. Based on this map we developed the speed density tables in an effort get identical power and air fuel delivery. As you can see from the chart below, the Speed Density tune is nearly identical to the MAF based one. With the proper calibration of these speed density tables the tune can be made to run as effectively in either speed density or MAF.



Technical Details of the Speed Density Implementation

With the stock ECU, airflow measured by the MAF sensor is used as the basis for calculating fueling and timing, as well as other load based systems. In order to convert this system to not require the MAF sensor, you need to provide an alternative method of calculating effective engine load.

Given the large number of tables in the ECU that use calculated load, it is most effective to intercept the load calculation during its calculation. The Cobb Speed Density system provides that intercept.

When running in Speed Density mode the calculated load is based on an airflow reading that is pulled from an Assumed Airflow table. This table represent the effective airflow based on rpm and manifold pressure. By using this table, a tuner can adjust the airflow to correctly represent the VE of the motor, and provide for a seamless air fuel and timing adjustments.

Here is a look at a sample Assumed Airflow Table



You can see the RPM and Manifold Pressure axis, and the Z-value is the airflow at that load point. Weighted interpolation is used inter-cell, and the axis variables are editable to allow fine tuning and greater resolution in critical areas of the map.

Once this assumed airflow lookup is made, a further adjustment is applied based on intake air temperature and coolant temperature. Since both intake air and coolant temperature sensors calibration can be adjusted, you can also use aftermarket sensors.





With this final calculated load available fueling, timing, AVCS, and other engine parameters are calculated. By providing this seamless integration other complex ECU algorithms are not affected. Cold start, hot restart, and safety enrichments are all left intact.

An additional feature of the speed density system is the ‘hybrid SD/MAF’ mode. This allows you to keep the factory MAF control for certain conditions, but switch over to a speed density mode based on engine parameters (see screenshot of switching and hysteresis variables below). This feature can be used to switch to Speed Density only under a given manifold pressure boost or based on RPM or load. This makes it possible to keep a stock sized MAF on a high power car and switch to the speed density at high load. Stock sized MAF translates to great street drivability.



Jeff Sponaugle/Tim Bailey
Callibrators, Surgeline Tuning
* Registered users of the site do not see these ads.

Last edited by Cobb Tuning; 02-09-2009 at 01:24 AM.
Cobb Tuning is offline   Reply With Quote
Old 02-08-2009, 07:20 PM   #2
Token-Negro
Scooby Specialist
 
Member#: 81659
Join Date: Feb 2005
Chapter/Region: NWIC
Location: Sammamish
Vehicle:
2010 Fozzy XT
Ice Silver Metallic

Default

Nice work Surgeline/Cobb on this one.
Token-Negro is offline   Reply With Quote
Old 02-08-2009, 07:25 PM   #3
wrspeed
Scooby Newbie
 
Member#: 40110
Join Date: Jul 2003
Chapter/Region: Tri-State
Location: Who said you Cant Rev to 9K
Vehicle:
04 STI
131 MPH 4th gear Madness

Default

Sick...
no more you need a Big Maf.
wrspeed is offline   Reply With Quote
Old 02-08-2009, 07:28 PM   #4
apexslider
Scooby Specialist
 
Member#: 168101
Join Date: Jan 2008
Chapter/Region: NWIC
Vehicle:
15 STi LE
WRB

Default

I heard this was coming, sounds like the best of both worlds.

Last edited by apexslider; 02-08-2009 at 10:49 PM.
apexslider is offline   Reply With Quote
Old 02-08-2009, 07:59 PM   #5
Token-Negro
Scooby Specialist
 
Member#: 81659
Join Date: Feb 2005
Chapter/Region: NWIC
Location: Sammamish
Vehicle:
2010 Fozzy XT
Ice Silver Metallic

Default

So Surgeline with this setup, is there any preferred MAF locations for the FULL SD setup? What is the Maf now used for in the FULL SD role, or is it eliminated?
Token-Negro is offline   Reply With Quote
Old 02-08-2009, 08:20 PM   #6
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by Token-Negro View Post
So Surgeline with this setup, is there any preferred MAF locations for the FULL SD setup? What is the Maf now used for in the FULL SD role, or is it eliminated?
There are a couple of options. If you want to do a hybrid setup with the MAF operating part of the time, it would be a MAF in the normal location (before the turbo).

If you went to a full SD mode, you would not need a MAF at all. However the MAF also contains the intake air temp sensor. You could leave the MAF sensor in the intake stream, or alternativly use an aftermarket AIT sensor (and the required changes to the calibration for that sensor).

Since the Accessport allows recalibration of the IAT Sensor, it would be possible to switch to something like a GM IAT.

Jeff
Cobb Tuning is offline   Reply With Quote
Old 02-08-2009, 08:35 PM   #7
Token-Negro
Scooby Specialist
 
Member#: 81659
Join Date: Feb 2005
Chapter/Region: NWIC
Location: Sammamish
Vehicle:
2010 Fozzy XT
Ice Silver Metallic

Default

Quote:
Originally Posted by Surgeline Tuning View Post
There are a couple of options. If you want to do a hybrid setup with the MAF operating part of the time, it would be a MAF in the normal location (before the turbo).

If you went to a full SD mode, you would not need a MAF at all. However the MAF also contains the intake air temp sensor. You could leave the MAF sensor in the intake stream, or alternativly use an aftermarket AIT sensor (and the required changes to the calibration for that sensor).

Since the Accessport allows recalibration of the IAT Sensor, it would be possible to switch to something like a GM IAT.

Jeff
What do you recommend Closed or Open Element Sensors?
Token-Negro is offline   Reply With Quote
Old 02-08-2009, 09:31 PM   #8
PikkaGTR
Scooby Newbie
 
Member#: 179940
Join Date: May 2008
Location: SJ
Vehicle:
2007 Sti
SWP

Default

how does this affect blow thru setups with the maf on the cold side?
can I just remove it completely and run SD and retune
thanks
PikkaGTR is offline   Reply With Quote
Old 02-08-2009, 10:03 PM   #9
turboge
Scooby Specialist
 
Member#: 35076
Join Date: Apr 2003
Chapter/Region: TXIC
Location: Austin/Round Rock
Vehicle:
2004 507whp Wagon
Silver

Default

Will this be available for RaceTuner use or only ProTuner?
turboge is offline   Reply With Quote
Old 02-08-2009, 10:10 PM   #10
mxpunk
Scooby Specialist
 
Member#: 132130
Join Date: Nov 2006
Chapter/Region: TXIC
Location: Austin, Texas
Vehicle:
2002 Ford F-150
Graphite Gray

Default

Is this only for the 08+ cars??

I'd be very interested in this along with alot of others if this was available to 02-07 cars.
mxpunk is offline   Reply With Quote
Old 02-08-2009, 10:31 PM   #11
saab-on-the-cobb
Scooby Specialist
 
Member#: 116330
Join Date: May 2006
Chapter/Region: South East
Location: 132&Bush I got em at gunpoint
Vehicle:
2005 Ram SRT-10
Sex Silver

Default Sticky!

I got sticky reading this, and I vote sticky!

THIS is a huge upgrade to an already awesome tool.

Now we can datalog, tune, and run FULL SD or hybrid?! Wow.

Glad I kept the AP.

Surgeline & COBB FTW.

Quote:
Originally Posted by mxpunk View Post
Is this only for the 08+ cars??

I'd be very interested in this along with alot of others if this was available to 02-07 cars.
READ the first sentence. "...for drive-by-wire Subaru applications."

My guess is, that means all STis, 04+, 2006+ WRX, and 2.5L turbo Forester, Baja, etc.

sotc
saab-on-the-cobb is offline   Reply With Quote
Old 02-08-2009, 11:51 PM   #12
mxpunk
Scooby Specialist
 
Member#: 132130
Join Date: Nov 2006
Chapter/Region: TXIC
Location: Austin, Texas
Vehicle:
2002 Ford F-150
Graphite Gray

Default

^^ my bad. im exhausted!

those guys are lucky then..i want SD for my car
mxpunk is offline   Reply With Quote
Old 02-09-2009, 12:04 AM   #13
cpturbo
Scooby Specialist
 
Member#: 49175
Join Date: Nov 2003
Vehicle:
2004 STI
WRB

Default

Would this only work on the Acess Port Version 2 or will version 1 also work?
cpturbo is offline   Reply With Quote
Old 02-09-2009, 12:17 AM   #14
alcoolaid
Scooby Guru
 
Member#: 134949
Join Date: Dec 2006
Chapter/Region: VIC
Location: Vancouver, BC
Vehicle:
'07 SWP STi
Instagram | arthurlam89

Default

Awesome. Can't wait to use it.
alcoolaid is offline   Reply With Quote
Old 02-09-2009, 12:31 AM   #15
PolarisSnT
Scooby Specialist
 
Member#: 85905
Join Date: Apr 2005
Chapter/Region: Tri-State
Location: Staten Island
Vehicle:
2004 WRX

Default

Quote:
Originally Posted by mxpunk View Post
^^ my bad. im exhausted!

those guys are lucky then..i want SD for my car
RomRaider + UTEC
PolarisSnT is offline   Reply With Quote
Old 02-09-2009, 01:14 AM   #16
atomicfire
Scooby Specialist
 
Member#: 136296
Join Date: Dec 2006
Chapter/Region: TXIC
Location: Midtown, Houston, TX
Vehicle:
2005 STi
OBP

Default

Can we request MAP based maps from your online ordering form?
atomicfire is offline   Reply With Quote
Old 02-09-2009, 01:19 AM   #17
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by PikkaGTR View Post
how does this affect blow thru setups with the maf on the cold side?
can I just remove it completely and run SD and retune
thanks
You could do several things.. you could run complete SD and just ignore the MAF, or you could run a hybrid and use the MAF for cruise and idle only. Blow thru or pull thru makes no difference in the SD mode, and the hybrid mode allows you to mix as you see fit.

Quote:
Originally Posted by turboge View Post
Will this be available for RaceTuner use or only ProTuner?
This is currently only a Protuner feature, and it will need some development time for the protuners to get this feature to its full potential. It is more difficult to do an SD tune ( imagine tuning the MAF curve in 3D). To get the cruise and transistions right, you need a lot more dyno time. Think like a standalone mixed with the stock ECU.

Quote:
Originally Posted by mxpunk View Post
Is this only for the 08+ cars??
I'd be very interested in this along with alot of others if this was available to 02-07 cars.
This is for DBW cars only, so 04+ STI, etc. This iteration is just the STIs, but other DBW cars are the same software changes. It is unlikly to get this for the 16 bit ECUs due to ram constraints.

Quote:
Originally Posted by cpturbo View Post
Would this only work on the Acess Port Version 2 or will version 1 also work?
Hmm.. Good question. I will have to find out...

Jeff Sponaugle
Cobb Tuning is offline   Reply With Quote
Old 02-09-2009, 01:22 AM   #18
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by atomicfire View Post
Can we request MAP based maps from your online ordering form?
No, SD is available for dyno tuning only. There are a lot more variables in an SD tune. With a MAF, small changes to VE are measured by the MAF. With SD, everything has to be worked into the SD tables. This is a feature intended for the more serious motorsports guys, or people with larger power requirements. (Large boost, > 450g/sec air flow, etc)

Jeff Sponaugle
Cobb Tuning is offline   Reply With Quote
Old 02-09-2009, 01:26 AM   #19
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by Token-Negro View Post
What do you recommend Closed or Open Element Sensors?
Good question, but I don't have an answer yet. I would have to experiment with each. While the idea of the fast reacting open element sensor sounds good, my experience has been that you generally want to air temperature trims to be dampend. Once I get some experience with each in this application I can provide a more educated opinion.

Jeff Sponaugle
Cobb Tuning is offline   Reply With Quote
Old 02-09-2009, 02:06 AM   #20
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by cpturbo View Post
Would this only work on the Acess Port Version 2 or will version 1 also work?
This is for version 2 accessports.
Regards
Tim
Cobb Tuning is offline   Reply With Quote
Old 02-09-2009, 08:01 AM   #21
mxpunk
Scooby Specialist
 
Member#: 132130
Join Date: Nov 2006
Chapter/Region: TXIC
Location: Austin, Texas
Vehicle:
2002 Ford F-150
Graphite Gray

Default

Quote:
Originally Posted by PolarisSnT View Post
RomRaider + UTEC
i know, but a stock ecu based one would be even sick'r
mxpunk is offline   Reply With Quote
Old 02-09-2009, 08:30 AM   #22
tekfoc
Scooby Specialist
 
Member#: 21392
Join Date: Jul 2002
Chapter/Region: Tri-State
Location: NEW YORK CITY
Vehicle:
2014 45 AMG MB
WHITE /07 STI IS SOLD

Default

This is incredible , I have had dreams about this for years.
Now it's come true. The power patential and reliabilty with
This will be fantastic.
Cobb will be the killer of the world in ecu tuning .
I can't fanthem what tommorrow brings.

Last edited by tekfoc; 02-09-2009 at 12:46 PM.
tekfoc is online now   Reply With Quote
Old 02-09-2009, 10:20 AM   #23
PerformanceAutoSolutions
Former Vendor
 
Member#: 853
Join Date: Feb 2000
Chapter/Region: Tri-State
Location: Deer Park, NY, USA
Vehicle:
2011 STI Sedan
Satin White Pearl

Default

great news guys thanks to everyone who got this done

dave/mspt
PerformanceAutoSolutions is offline   Reply With Quote
Old 02-09-2009, 12:14 PM   #24
Gixx6
Scooby Newbie
 
Member#: 134563
Join Date: Dec 2006
Default

I just may have to go back to Cobb now.

Any tests of this being done on a high HP application car? Say going from Hydra to a tune with Cobb SD?
Gixx6 is offline   Reply With Quote
Old 02-09-2009, 12:29 PM   #25
Phatron
Scooby Guru
 
Member#: 36033
Join Date: Apr 2003
Chapter/Region: SCIC
Location: Tuning Lab
Vehicle:
CEO PhatBottiTuning
2006 STi GTX3582 + Meth

Default

Quote:
Originally Posted by Gixx6 View Post
Any tests of this being done on a high HP application car? Say going from Hydra to a tune with Cobb SD?
Im pretty sure you wont see any hp/tq differences in WOT dyno pulls. I mean if the car was just tuned in 4th gear with a hydra and then tuned in 4th gear with the SD AP the #'s should be almost exactly the same....as they were in the dyno plot in post 1 with MAF vs SD.

Switching an ECU, AP, UTEC, Ecutek, etc dont cause changes in power....the engine can only work with the air its provided from the turbo and the fuel from the fueling system. Same air, same fuel = same power.

Where the benefits come in is the resolution and "correctness" of the mass air flow. If this SD system adds resolution or causes the MAF estimation to be more correct in more situations, then the daily drivability and consistency of the car will be better.

But looking at the afr on the plot in post 1, neither seems to be any more consistent.....but 1 WOT pull doesnt show much to daily drivability/consistency.

But switching to SD wont give +20whp.

After seeing all the new fueling maps uncovered in romraider these last couple revs, it really makes me uneasy moving more and more away from stock. There were recently 18-20 fueling maps defined in the romraider def's. So its been 8+ years and these things are just being seen. Per injector compensations, startup compensation algorithms, etc.

Last edited by Phatron; 02-09-2009 at 12:37 PM.
Phatron is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
05-07 STi BBS wheels fit on an 08 STi? criz Tire & Wheel 9 10-31-2008 10:23 PM
400 lb-ft on an 08 STI Stage 2! sponaugle Proven Power Bragging 123 05-17-2008 08:20 PM
WTB 08 STI BBS wheels or any 18x8.5 wheels with proper offset for an 08 STI. HRCboy VIC Private Classifieds 3 01-28-2008 05:06 PM
Just installed an MBC with the utec on my 2005 STi.. CBRDSpeedfactory Factory 2.5L Turbo Powertrain 1 11-05-2004 06:44 AM
Tuning with Delta Dash on an Ecutek Reflash Tuned Factory 2.0L Turbo Powertrain 12 10-04-2004 08:43 PM


All times are GMT -4. The time now is 08:54 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.