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Old 10-15-2009, 08:42 PM   #1
Scooby Specialist
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Join Date: Nov 2007
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Location: Effingham IL (Central IL)
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Default Speed Density - OS 16bit Rom - Discuss Here

Alright guys I'm tired of getting PM's. So here is the thread.. Lets discuss and help each other out..

Here goes.

Purpose of thread is to discuss and learn about the Speed Density Rom for "CERTAIN" 16bit ecu's.
It is KNOWN to work on v7/v8 JDM ECU's and MY02 USDM ECU - THIS IS IT AT THE MOMENT. No others have been confirmed. If you don't see your year/ecu listed above please don't ask if it will work, I don't know - If you have tested it and it works PLEASE let people know.

I have a feeling this will work on all V7/V8 JDM Ecu's (STI and WRX) and MY02/03 USDM ECU's...

Please understand this rom is MUCH MUCH more complicated than your typical MAF based 16bit rom.

So lets start off -

1. Thank you to everyone involved in Romraider and ECU flash - Especially TeaCups (Merchgod) he has been the backbone of the OS community and I for one really really really appreciate his hard work, dedication, and helpfulness with nearly anything he can/can't explain!

Thank you!

Lets go -

This is a Speed Density Style Rom - It does NOT use the Mass Airflow Sensor - but does use it as a reference for you (if you need it for a reference)

Speed density tuning (for fuel) is using Manifold Pressure vs. RPM vs. Intake air temperature to determine load and last but not least to determine final
Injector Pulse Width

Timing is Manifold Pressure based (not load based)

Knock correction exists and works but advance is very limited (4 cells total)

You will have a constant CEL with this rom (Well MY02 USDM ecu's will)

Idle is random (either 1000 rpms or what you set it at..)

Launch control and Anti-lag are an option but not switchable - they are either ON or OFF. No buttons or switches sorry.

Those of you wanting to run this, I hope you have good fuel and a very good sense of tuning as it is NOT easy to get things proper - simply this rom is NOT designed for our ECU's - It works but things are just more complicated.

Per Gear Boost/Wastegate control

More advanced fuel/ignition maps (more cells to tune)

- Here are some other facts.

The map sensor "offset" must be changed to suit your application:
01-05 JDM STI/WRX - -8.005
02+ USDM WRX/STI - -8.005
Late Model Year 2005+ JDM STI - -5.666 (This is what comes on the rom if you don't own a late 2005+ JDM STI or the map sensor off one THIS MUST BE CHANGED)

Front o2 Sensor scaling is improper for USDM applications. You have 2 choices - 1. Rescale for your stock roms o2 scaling 2. Move your front o2 Sensor to the Downpipe.

Knock control is disabled on the OE rom - In order for your to have knock control you must match your stock knock control settings. Very simple. NOW the rom comes with 0* of ignition advance, meaning if you have knock controlled enabled and working it WILL remove timing DURING the knock event but if IAM drops timing will NOT be removed (DANGEROUS). Scaling the advance map to a solid number (IE: 10) and removing 10* of timing everywhere will allow timing to be removed in the case of IAM drop - I have not tried this and don't care. I HAVE forced IAM drop and HAVE seen FBKC but have not seen any FLKC (my map is set up to have knock but my advance map is 0'd - I run E85... So this is not nearly as important to me)

IAT sensor must be scaled to match your stock rom.

Gear speed scaling must be changed to suit your current application.

Codes that need to be removed:

^^ These codes need to be removed when using a NON-JDM ecu..
You will still have a check engine light for P1307 and P1309. At this time **** happens.

IF you have a Utec you CAN run it with this rom but it must be disabled (from my understanding) or bypassed. Hopefully Todd (General) will jump in here and help the guys wanting to use Utec for FFS and LC with this.

Mode Byte - this determines the mode of the ecu - It is THOUGHT that the intercooler autowash button is what is used to change this when the proper car/ecu together. This is not available to us now.
The rom comes with a mode byte of 136 which to my understanding means LC/AL are active but Per Gear boost/wastegate compensation are not.

^ Do yourself a favor and set your mode byte to 0 - This is true antilag/LC once its on its on and the only way to turn it off when enabled is to engine brake below the GPN threshold. Otherwise once the rpms reach the threshold the car stays @ this rpm anti-lagging. Only turning the car off or engine braking it below the threshold turns it off - Not a cool thing really.

Set it to 0 and go on with life.

IF/WHEN the Mode Byte is set to 0 - GROUP N conditions ARE NOT MET - meaning you won't use the Group N fueling map. You will use Base Timing B (I have yet to see my base timing A map run)

Idle is wacky sometimes and likes to hover @ or around 1000 rpms no matter what you have it set to - Sometimes it will idle @ what you want it set to - this almost HAS to be Mode Byte related but is currently not known.

To prevent throttle lift knock - removing all negative timing in the idle timing maps is a must.

Per cylinder timing and fueling are @ 0 on this rom - Do what you feel is best, USDM WRX's use these compensations and it might be good/necessary for you to use these as well.

Alright I'm sure I've left some stuff out and its un-organized (I'm not Unabomber, so piss off! )

If you have questions please refrain from PMing me... My inbox was filled twice yesterday from dozens of PM's. Lets discuss it here.

Guys (Todd - Brocksdad - Bill - Anyone that has successfully used this - Please feel free to add your comments and experiences.)

Yes your car will idle/start/drive MUCH better! A cold air intake of your size is VERY recommended with this setup as this uses air temperature to determine fueling, a Hot air intake (such as mine that is being removed) will make tuning for weather conditions nearly impossibly due to cold weather heat soak and the such...

I will update as time goes on.

JSarv is offline   Reply With Quote

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