RomRaider

Good day,

The issue: When blipping the throttle to rev match (clutch in, blip, downshift), the RPM's do not respond like any other year WRX/STI. It's more like a slow climb, rather than an instantaneous response. It seems to rev more freely the less throttle you give it, and when looking at the log I see anywhere from -5 to -15 ignition retard about 2 or 3 lines past the throttle input, and then returns back to following my tables. From my understanding and experience, the reduction in timing is normal behavior, but most cars I see dip into the low single digits, not the deep negatives.

I've tuned quite a few of these 07 STI's (USDM A2UJ000J), and it's the only year I've personally seen do this. It causes significant pops and bangs as you can imagine, as well as the slow climb in RPM's. throttle response is completely normal at idle.

I've read the one or two threads on these cars regarding throttle response below 3k and the other various ticks/issues with this year. None of it seems to pertain to this (from what I can tell).

The car is bone stock with the exception of a Cobb SF Intake. The car drives phenomenal otherwise.

I considered it having something to do with boost error, so I played around and dialed that in a little closer with no change. I also tried the opposite, setting a higher target boost error during a blip, also with no change. There are no tables for this that I can find, and my ignition tables are no where near what I am seeing directly following a rev match.

Any assistance is appreciated.

Note, fueling is pretty close, and there are zero hesitations and fantastic response during driving. Fueling does not appear to be the issue, and given I've seen this on 4 or 5 other 07's, I wouldn't be inclined to look elsewhere.

Hey,

If I had to guess, this will be down to the same logic that can also be found in newer (05-06+) 3.0R ECUs. Its some sort of anti-shock / torque managed spark retard implementation that will pull a considerable amount of spark on large torque desire changes. My recommendation is to try and find the spark low and high clip tables to prevent it that way. Its a much easier approach than finding and tuning the actual tables that control the logic.

If you have low and high spark limit defined its easy, otherwise I've included a screenshot of where I found the low and high clipping tables in my EZ30 Rom to help you potentially find them in your rom. The dashes show the base idle timing tables that basically every rom will already have defined. The low and high clips are just a smidge above those circled in the screenshot.

Best of luck with it.