32bit ROM - Throttle duty cycles

User topics relating to software that provides a tuning UI to alter ECU code and data

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32bit ROM - Throttle duty cycles

Postby twg » Thu Oct 12, 2006 8:23 am

Hey Guys,
I have a 2004 USDM Forester XT, the block is identical to the STI, except for the up-pipe, headers, turbo and intercooler. I've changed the up-pipe turbo and intercooler to that of the STI, so right now I'm at stage 2 STI, I've dyno'd around 300hp to the wheels on a clayton dyno and everything looks good..

I'm starting to play with the maps to tweak the settings.. I've noticed that the throttle activator maps on the FXT only go up to 80%, so at 100% throttle input, the throttle activator duty cycles are only at 80%... whereas on the 2004 USDM STI, they go up to 100%... I know the intake manifold is exactly the same between the USDM STI and the FXT, and I suspect the throttlebody is the same too, but can't confirm...

My Q is: is the fact that the duty cycle only going up to 80% means that the throttle plate isn't opening up all the way ? Could this be limited the airflow ?

If I increase this to 100%, is there any downside ?

thanks,
Wayne
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Re: 32bit ROM - Throttle duty cycles

Postby Jon [in CT] » Thu Oct 12, 2006 9:17 am

twg wrote:If I increase this to 100%, is there any downside ?
Since we don't yet have access to the Electronic Throttle Control subprocessor ROM, there might be a problem.
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Postby twg » Thu Oct 12, 2006 9:37 am

thanks for bringing that point up, I'll leave these values the way they are for now.
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Postby 05GarnetLGT » Thu Oct 12, 2006 4:00 pm

check the part numbers, but I suspect they are the same part as well.
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Postby Hawk296 » Thu Oct 12, 2006 7:03 pm

You probably are getting 100% throttle at full throttle. My logs prove this to be on my baja T even though on the maps it only goes to 80%. I think it just interpolates the rest. Youll notice the FXT (much like the baja T) is much more linear on the throttle mapping. 10% accelerator = 10% throttle opening and so on. THe sti "tricks" you more by opening to somehting like 30% when you press the pedal 10%

Ive changed mine to STi settings a few times now with no ill effects, just a different feel.
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Postby Freon » Thu Oct 12, 2006 7:38 pm

You might try logging. There are two logger values, one for your foot pedal, one for the actual butterfly valve in the throttle body.
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Postby twg » Fri Oct 13, 2006 5:56 am

Ya, I was doing some logging last night, and the throttle plate does indeed open up 100% when I mash the throttle plate...

thanks for the responses guys!
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Postby Cabal » Fri Oct 13, 2006 6:13 am

I'm really enjoying using an STi-style throttle map, it gives a more aggressive feel in non-WOT conditions. Out of curiosity, do we know if Cobb or Ecutek are adjusting these maps (often, ever)?
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Postby twg » Fri Oct 13, 2006 6:30 am

ECUtek tunes would depend on the tuner... I've seen ECUTek tunes where these were left alone...

I can't speak for Cobb...
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