[TurboQueef]

I am trying to tune my 05 STi with StreetTUNER and I just hit a roadblock with the intake calibration table. This table will not accept more than 500 gps values... I am running an FP Red and a RAW build engine. At 21psi I am hitting 458 gps at 4.54 volts (KS Tech 83mm intake). I want more headroom so I can run race fuel and turn up the boost...

My specific question: How can I unlock StreetTUNER to accept values greater than 500 gps?

Thanks,

Jeff B

[EQ Tuning]

You can't. That's an internal ECU cap on that value. There's a workaround for this, however. Hit me up and can point you in the right direction.

[jays05]

300g/s workaround - 'hacked' MAF up to 600g/sec or 1200g/sec - NASIOC


I have actually seen one well-known tuner hack up their maps with this methodology, presumably just to make it harder to copy the map onto other cars.

[fullerton]

I believe Jorge from P&L Motorsports offers his intake calibrations to the public. Myabe you can use this for a base.

P&L Motorsports - Downloads

[Merchgod]

Originally Posted by EQ Tuning

You can't. That's an internal ECU cap on that value. There's a workaround for this, however. Hit me up and can point you in the right direction.

That's incorrect. The 32-bit ECU (which pertains to all USDM STis) can represent any value you want in the maf scaling table. A cell could be 1,000,000 g/s if you wanted it to be. If the ST software limits it to 500 g/s, then that is a limitation of ST software not the ECU in question (likely some arbitrary limit they placed in there). There is a separate parameter that caps airflow at 300 g/s, but this can also be raised to whatever you want (that is, the maf scaling table has no effective limit, but the final airflow will be limited by this parameter, but it is easily raised).

The link that was posted refers to the limitation of the 16-bit ECU (ex. 02-05 WRX) which cannot represent airflow greater than 300 g/s (except for select JDM ECUs). This does not apply to the vehicle in question.

[TurboQueef]

Originally Posted by EQ Tuning

You can't. That's an internal ECU cap on that value. There's a workaround for this, however. Hit me up and can point you in the right direction.

Thanks Ed...

[TurboQueef]

Originally Posted by jays05

300g/s workaround - 'hacked' MAF up to 600g/sec or 1200g/sec - NASIOC


I have actually seen one well-known tuner hack up their maps with this methodology, presumably just to make it harder to copy the map onto other cars.

Hi Jay,

Good lead... thanks

Jeff B

[Merchgod]

I guess you ignored my post. Ed's statement is false. You can tune with RomRaider/Ecuflash and enter any value you want for maf scaling for your ECU. Using the airflow hack in the link mentioned is completely unnecessary and a bad idea, but I guess might be your only option if you ECU is locked due to a ver. 2 AP (I would at least report the issue to Cobb so they can fix it). If you have a ver. 1 AP, then I would suggest you pick up a tactrix table and modify maf scaling with RomRaider/Ecuflash even if you are going to continue to use ST.

[TurboQueef]

Originally Posted by Merchgod

I guess you ignored my post. Ed's statement is false. You can tune with RomRaider/Ecuflash and enter any value you want for maf scaling for your ECU. Using the airflow hack in the link mentioned is completely unnecessary and a bad idea, but I guess might be your only option if you ECU is locked due to a ver. 2 AP (I would at least report the issue to Cobb so they can fix it). If you have a ver. 1 AP, then I would suggest you pick up a tactrix table and modify maf scaling with RomRaider/Ecuflash even if you are going to continue to use ST.

Currently I use RomRaider & ECUFlash for base.. I understand that I can input values higher than 500 there. I don't like to do my fine tuning using the base map / ROM adjustments so I use StreetTUNER for the real time adjustments. I use the tactrix cable to adjust both ROM and StreetTUNER. If I could use some other program to adjust the "real time" tables I would consider it..

[EQ Tuning]

Originally Posted by Merchgod

That's incorrect. The 32-bit ECU (which pertains to all USDM STis) can represent any value you want in the maf scaling table. A cell could be 1,000,000 g/s if you wanted it to be. If the ST software limits it to 500 g/s, then that is a limitation of ST software not the ECU in question (likely some arbitrary limit they placed in there). There is a separate parameter that caps airflow at 300 g/s, but this can also be raised to whatever you want (that is, the maf scaling table has no effective limit, but the final airflow will be limited by this parameter, but it is easily raised).

The link that was posted refers to the limitation of the 16-bit ECU (ex. 02-05 WRX) which cannot represent airflow greater than 300 g/s (except for select JDM ECUs). This does not apply to the vehicle in question.

On first examination it looks like you're right. Romraider definitions will allow you to enter any value you want for flow, but this doesn't mean that the ECU will understand them. Have you actually successfully references values higher than 500g/s and logged them?

Thanks
-- Ed

[Merchgod]

Originally Posted by EQ Tuning

On first examination it looks like you're right. Romraider definitions will allow you to enter any value you want for flow, but this doesn't mean that the ECU will understand them. Have you actually successfully references values higher than 500g/s and logged them?

Thanks
-- Ed

I'm not experimenting with values in a piece of software or doing any kind of black box testing, which would be subject to error. I know this from reverse engineering these ROMs in IDA and this is such a simplistic determination that it isn't up for any debate (airflow data type is 32-bit float for this ECU). As I mentioned, there is a threshold that caps airflow at 300 g/s with the factory ROM for this ECU, but this can also raised to any value you want in RomRaider (and I imagine the other software packages), so you have no effective limit.

[P&L Motorsports]

Maybe this is a limitation on Cobb's part.. maybe it isn't. But, I'll add this.

Yes, you can raise the AccessTuner vaule above 360g/s, but all the testing I've done showed that at 360g/s you hit a brick wall and simply stop registering above that point.

FWIW

-Jorge

[Merchgod]

Originally Posted by P&L Motorsports

Maybe this is a limitation on Cobb's part.. maybe it isn't. But, I'll add this.

If you understand how the ECU stores this value (32-bit float), there is NO doubt that there is no effective limit. It can represent 500 g/s, 1,000,000 g/s, 10,000,000 g/s, whatever up to about the number of stars in the known universe. This is not probably-maybe type deal. This absolute fact not up for debate. Of course, as already mentioned there is a separate threshold that caps airflow at 300 g/s with the factory value, but again, you can raise this to whatever you want. If you didn't touch this threshold, you would still be able to change airflow in the maf scaling table to any large value you wanted, just that the final airflow value would be capped at this threshold as used by the ECU.

Cobb undoubtedly knows this, so it is either a bug in their software that they are not aware of, or they deliberately did this for whatever reason.

[Tgui]

Originally Posted by Merchgod

If you understand how the ECU stores this value (32-bit float), there is NO doubt that there is no effective limit. It can represent 500 g/s, 1,000,000 g/s, 10,000,000 g/s, whatever up to about the number of stars in the known universe. This is not probably-maybe type deal. This absolute fact not up for debate. Of course, as already mentioned there is a separate threshold that caps airflow at 300 g/s with the factory value, but again, you can raise this to whatever you want. If you didn't touch this threshold, you would still be able to change airflow in the maf scaling table to any large value you wanted, just that the final airflow value would be capped at this threshold as used by the ECU.

Cobb undoubtedly knows this, so it is either a bug in their software that they are not aware of, or they deliberately did this for whatever reason.

Just for my education, I'm only aware of 1 table in my ROM to change the g/s limit within RR. Where is this other cap?

[12SecSTI]

I know the ecu values are capable of over 500 g/s but like they said do they understand what to do after an assumed "cap"

Originally Posted by P&L Motorsports

Yes, you can raise the AccessTuner vaule above 360g/s, but all the testing I've done showed that at 360g/s you hit a brick wall and simply stop registering above that point.



-Jorge

Brick wall? i dont understand, the vehicle goes lean im guessing? I haven't had any issues as all my GT30R cars dip easily into the mid 400s', plus i dont like using the primary fuel tables to remove or add a substantial amount of fuel, i would rather set it at actual Air/fuel desired and have the car perform to what i indicated, thats just the way I learned.. that way load, maf, and fuel all agree with logs. Also cutting the scaling in half isn't really anything I would do just because then load tables do not agree either, kind of a last resort. I would suggest to Queef to go blow through meter.