RomRaider

Who?
Anyone that wants to run Speed Density on their 16bit 02/03 USDM/JDM/ADM/SADM ecu's.

Why?
Because its Speed Density? Ok because the way in which it determines load is much different and less "vulnerable" such as MAF based load roms.

What Cars (ECU's)?
02-03 USDM WRX
0.5-05.5 JDM STI/WRX
SADM/ADM Has not been confirmed BUT I assume similar years.
More or less if your ecu uses a wrx02 flash method - you can use this rom. < Easy enough? If you don't know what flashmethod your car uses, you need to do more reading.

How Easy?
Its not compared to MAF based. Its actually somewhat complicated if your not a "semi-experienced" tuner. Load is not figured based on MAF/RPMS anymore. YOU determine load based on an additive to base load. I'll get more into that shortly.

How Speed Density Works.
You have to understand the general concept of Speed Density first, I'm not explaining that sorry. I will explain Subaru's method of figuring VE - or Load.

The most simple equation is as follows:
Manifold Absolute Pressure x Speed Density Multiplier - Speed Density offset x Speed Density Load Compensation Table x Speed Density IAT Compensation.

Now an equation: For s*** and giggles we will use 0PSI Relative @ Sea Level - So Manifold Absolute Pressure will be 14.7. We are also assuming that Speed Density Load Comp is @ 10% (VE is 110%) And IAT Comp calls for 10% (VE would technically be 120% in theory)

(14.7*.07644-.00684) < This is BASE LOAD - ALL Manifold Absolute Pressure values will have their own base load.
1.116 G/Rev = Base Load for 14.7PSIA

1.116*1.10*1.10 <This is final Speed Density Load determination.

1.35 G/Rev is the final load value for 14.7PSIA with SDLC of 10% and IAT SDLC of 10%.

RPMS do not effect load, they are only used for reference to the Speed Density Load Comp. table.

So total equation is as follows:
(14.7*.07644*.00684)*1.10*1.10= Current Load

Other Stuff For Fueling?
You probably have noticed you have 2 fuel tables. Table use is based on Group-N mode. These tables work IDENTICALLY to previous MAF based OL Fueling Tables. Unless you plan on setting Group-N Mode it does not need to be used.



Will Add later

I'll post here so you don't feel lonely You should mention that they need to change the FBKC threshold in every post just so we don't have people blowing up their cars because they're careless and didn't know that FLKC and IAM had been disabled.

Andy

Bump just to recognize the work done here. Do you have a link to a rom that is speed density? Thinking about messing around with this for now, but considering more when I go big turbo...

I haven't researched it at all, but are there MAP sensors that can be easily adapted to replace the stocker for when the ~24 psi limit is reached?

Also, has a different IAT sensor been explored (smaller, cheaper, easier to integrate into a custom intake)?

^^I ask those questions simply because I see SD more as something you should go to when the setup isn't conducive to MAF (ie, giant intake) or the logistics of the setup make MAF a pain.

I don't suggest SD to anyone who is not comfortable building a scratch calibration.

hey new to the site but not to tuning
to answer your qustion
althou i use a AEM ecu
i might ber abule to help forIAT you can use the GM tem sensoer
and omni map sensor or aem map

i have seen the evos convert to speed densaty and works very well but hoping to help you guys find a way to do it to the subys

i was thing of spliceing a the maf wires and instaling a map sensor and reconfiguring the maf scaling
do you guys think that will work?

If using the JDM EJ207 with the jdm harness, I think that already has a plenum air temp sensor on the intake manifold and the wiring from it going to the ecu, have a look at the attached schematic.

I got a AEM IAT sensor. i'm going to try and get it wired in next week.

It looks like the IAT is under the TB on the manifold, it’s not on the usdm manifold I have, I would only assume it’s an IAT

On manifolds equipped with an IAT, it is a closed element sensor that does not have a scaling present in the ROM, and is not currently loggable or otherwise used by the ECU except for ecus that came equipped with auto-intercooler wash.

I don't remember what the thread pitch is, but in USDM manifolds that have the 1/8 BSPT fitting in the front/beginning of cylinder 1 runner (used with the black T diaphragm in the USDM evap system) you can tape and thread in 1/8 NPT IAT sensor, such as Haltech/AEM

I recommend ordering them from haltech. the cost is good, shipping is reasonable and timely, and comes with a nice weatherproof DTM connector.