Speed density, stalling out, sick of it.

Grinder34

Track Monkey
are-you-wizard.jpg


seriously, you just know everything. :bow:
 

STI 2NR

New member
Okay Oren. I went out for some tuning today. One thing that has never happened to me before happened today. Once I get the VE table setup right and the car pulls like a banshee I noticed my engine load being maxed out at 4.00. What do tuners normally do at this point? Do I increase the engine load max to say 5.00 or 6.00 or do I raise my sd constant and drop the ve table so the engine load stays below 4.00??

Thoughts??
 

Td_d

Commander In Chief
Just raise the engine load limit A to something much higher, 7 or 8 - no ill effect. Leaving it at 4 is dangerous - you'll lean out as it caps at 4 g/s.
 
I would have shit my pants if i came across that stutter at 2min in that vid and backed off right away...i dont know how you still kept it on the floor...
 

IGOTASTi

System Operator
Staff member
I would have shit my pants if i came across that stutter at 2min in that vid and backed off right away...i dont know how you still kept it on the floor...

Agreed.

My question is do you think that would cause any damage to the motor.
 

STI 2NR

New member
Really not a big deal. I needed data to diagnose the issue.

I am running very mild timing and it does not knock at all. My egt's were nowhere near fatal.

I will figure out the entire issue on Friday when I have more time to tune.
 

STI 2NR

New member
Things I checked/fixed:

Installed new fuel injector clips, old ones were a mess.
Checked spark plug gaps, all were .028.

I did get a good datalog today of the event. I did a 17 psi wot pull and it started to stutter again. It continued to stutter when I let off the throttle. I am guessing one of my coil packs is producing a weak spark and is on its way out. The only time the stutter happens is at peak torque/boost around 4500-5k rpm. It will run rich while this is occurring which leads me in the direction of an ignition issue. It gets more pronounced as I add boost. I ordered a set of coil packs as well as a new set of laser iridiums to try and tackle this issue.

I do recall this happening once or twice on the old stock motor but not as frequently as it is occurring now which also points to a coil pack going bad.

Anyone else ever have this type of a misfire happen??
 

prestonztt

New member
Things I checked/fixed:

Installed new fuel injector clips, old ones were a mess.
Checked spark plug gaps, all were .028.

I did get a good datalog today of the event. I did a 17 psi wot pull and it started to stutter again. It continued to stutter when I let off the throttle. I am guessing one of my coil packs is producing a weak spark and is on its way out. The only time the stutter happens is at peak torque/boost around 4500-5k rpm. It will run rich while this is occurring which leads me in the direction of an ignition issue. It gets more pronounced as I add boost. I ordered a set of coil packs as well as a new set of laser iridiums to try and tackle this issue.

I do recall this happening once or twice on the old stock motor but not as frequently as it is occurring now which also points to a coil pack going bad.

Anyone else ever have this type of a misfire happen??

What fuel are you using again? or did I miss that somewhere in this thread? Lol

Is it a lean studder or is it rich when it does it? Any boost leaks? Are all the grounds hooked up?

I would try tightening up the gap on the plugs to around .022. Coilpacks would be a good thing to swap out aswell.
 

Spamby

Meat Product Toy
Yes, I had this issue on my wife's Porsche. All eight coil packs were toast, plastic falling off. (Known issue on first gen CTT's) was getting a host of misfire and lean condition codes. Rough idle and some hesitation when on throttle and general lackluster performance. Though, I didn't experience what you had when hitting full boost or part boost.
But again, mine were lean codes?
I know it's a different car but still.
 

STI 2NR

New member
On a sidenote, I believe Oren is out partying this weekend so I am wondering if anyone has the tau tables defined for their 2005 sti?? I need to cut and paste that into my rom xml so I can see the actual changes he gave me on a map he tweaked.
 

Td_d

Commander In Chief
Woohoo, party! Yeah... not so much when you have a kid ;)

Code:
[COLOR=#ffffff]    <table name="Tau Input A Falling Load Activation A" address="c6746">        
<table name="Coolant Temperature" address="c60f4"/>
    </table>


    <table name="Tau Input B Activation (Engine Load)" address="c6828">
        <table name="Engine Load" address="c67fc"/>
    </table>


    <table name="Tau Input A Rising Load Activation" address="c7db8">
        <table name="Coolant Temperature" address="c60f4"/>
        <table name="Engine Load" address="c7dac"/>
    </table>[/COLOR]
 
Last edited:

STI 2NR

New member
Woohoo, party! Yeah... not so much when you have a kid ;)

Code:
[COLOR=#ffffff]    <table name="Tau Input A Falling Load Activation A" address="c6746">        
<table name="Coolant Temperature" address="c60f4"/>
    </table>


    <table name="Tau Input B Activation (Engine Load)" address="c6828">
        <table name="Engine Load" address="c67fc"/>
    </table>


    <table name="Tau Input A Rising Load Activation" address="c7db8">
        <table name="Coolant Temperature" address="c60f4"/>
        <table name="Engine Load" address="c7dac"/>
    </table>[/COLOR]
I am still unable to see the tau tables. I cut and pasted this into my rom just like the other stuff you gave me. It looks like you are missing "type= level= scaling=" :) Still waiting on parts so I can fix my misfire issue. NO tuning until then. :(
 

Td_d

Commander In Chief
That means you are not running the latest 32bitbase.xml.

Paste this into the 32bitbase.xml :

<!-- Transient Fueling (Tau) Tables
RomRaider discussion thread:
http://www.romraider.com/forum/viewtopic.php?f=25&t=7442
-->
<scaling name="Tau" units="Enrichment Adder Multiplier" toexpr="x*0.00048828125" frexpr="x/0.00048828125" format="%.2f" min="0" max="20" inc="0.5" storagetype="uint16" endian="big"/>
<scaling name="TauMrp" units="psi relative (sea level)" toexpr="(x*1.933677)-14.6959452" frexpr="(x+14.6959452)/1.933677" format="%.2f" min="0" max="30" inc="0.5" storagetype="float" endian="big"/>


<table name="Tau Input A Falling Load Activation" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is decreasing.</description>
<table name="Coolant Temperature" type="Y Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
</table>

<table name="Tau Input A Falling Load Activation A" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is decreasing.</description>
<table name="Coolant Temperature" type="Y Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
</table>


<table name="Tau Input A Falling Load Activation B" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is decreasing.</description>
<table name="Coolant Temperature" type="Y Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
</table>

<table name="Tau Input A Falling Load Activation C" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is decreasing.</description>
<table name="Coolant Temperature" type="Y Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
</table>


<table name="Tau Input B Activation" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau B enrichment multiplier.</description>
<table type="Y Axis" elements="11" scaling="TauMrp"/>
</table>


<table name="Tau Input B Activation A" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau B enrichment multiplier.</description>
<table type="Y Axis" elements="11" scaling="TauMrp"/>
</table>


<table name="Tau Input B Activation B" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau B enrichment multiplier.</description>
<table type="Y Axis" elements="11" scaling="TauMrp"/>
</table>

<table name="Tau Input B Activation (Engine Load)" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau B enrichment multiplier.</description>
<table name="Engine Load" type="Y Axis" elements="11" scaling="g/rev"/>
</table>


<table name="Tau Input A Rising Load Activation" category="ALPHA Transient Fueling (Tau)" type="3D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is increasing.</description>
<table name="Coolant Temperature" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
<table name="Engine Load" type="Y Axis" elements="3" scaling="g/rev"/>
</table>

<table name="Tau Input A Rising Load Activation A" category="ALPHA Transient Fueling (Tau)" type="3D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is increasing.</description>
<table name="Coolant Temperature" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
<table name="Manifold Pressure" type="Y Axis" elements="3" scaling="TauMrp"/>
</table>


<table name="Tau Input A Rising Load Activation B" category="ALPHA Transient Fueling (Tau)" type="3D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is increasing.</description>
<table name="Coolant Temperature" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
<table name="Manifold Pressure" type="Y Axis" elements="3" scaling="TauMrp"/>
</table>


<table name="Tau Input A Rising Load Activation C" category="ALPHA Transient Fueling (Tau)" type="3D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is increasing.</description>
<table name="Coolant Temperature" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
<table name="Manifold Pressure" type="Y Axis" elements="3" scaling="TauMrp"/>
</table>
 

STI 2NR

New member
That means you are not running the latest 32bitbase.xml.

Paste this into the 32bitbase.xml :

<!-- Transient Fueling (Tau) Tables
RomRaider discussion thread:
http://www.romraider.com/forum/viewtopic.php?f=25&t=7442
-->
<scaling name="Tau" units="Enrichment Adder Multiplier" toexpr="x*0.00048828125" frexpr="x/0.00048828125" format="%.2f" min="0" max="20" inc="0.5" storagetype="uint16" endian="big"/>
<scaling name="TauMrp" units="psi relative (sea level)" toexpr="(x*1.933677)-14.6959452" frexpr="(x+14.6959452)/1.933677" format="%.2f" min="0" max="30" inc="0.5" storagetype="float" endian="big"/>


<table name="Tau Input A Falling Load Activation" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is decreasing.</description>
<table name="Coolant Temperature" type="Y Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
</table>

<table name="Tau Input A Falling Load Activation A" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is decreasing.</description>
<table name="Coolant Temperature" type="Y Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
</table>


<table name="Tau Input A Falling Load Activation B" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is decreasing.</description>
<table name="Coolant Temperature" type="Y Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
</table>

<table name="Tau Input A Falling Load Activation C" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is decreasing.</description>
<table name="Coolant Temperature" type="Y Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
</table>


<table name="Tau Input B Activation" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau B enrichment multiplier.</description>
<table type="Y Axis" elements="11" scaling="TauMrp"/>
</table>


<table name="Tau Input B Activation A" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau B enrichment multiplier.</description>
<table type="Y Axis" elements="11" scaling="TauMrp"/>
</table>


<table name="Tau Input B Activation B" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau B enrichment multiplier.</description>
<table type="Y Axis" elements="11" scaling="TauMrp"/>
</table>

<table name="Tau Input B Activation (Engine Load)" category="ALPHA Transient Fueling (Tau)" type="2D" level="1" scaling="Tau">
<description>This table determines the Tau B enrichment multiplier.</description>
<table name="Engine Load" type="Y Axis" elements="11" scaling="g/rev"/>
</table>


<table name="Tau Input A Rising Load Activation" category="ALPHA Transient Fueling (Tau)" type="3D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is increasing.</description>
<table name="Coolant Temperature" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
<table name="Engine Load" type="Y Axis" elements="3" scaling="g/rev"/>
</table>

<table name="Tau Input A Rising Load Activation A" category="ALPHA Transient Fueling (Tau)" type="3D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is increasing.</description>
<table name="Coolant Temperature" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
<table name="Manifold Pressure" type="Y Axis" elements="3" scaling="TauMrp"/>
</table>


<table name="Tau Input A Rising Load Activation B" category="ALPHA Transient Fueling (Tau)" type="3D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is increasing.</description>
<table name="Coolant Temperature" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
<table name="Manifold Pressure" type="Y Axis" elements="3" scaling="TauMrp"/>
</table>


<table name="Tau Input A Rising Load Activation C" category="ALPHA Transient Fueling (Tau)" type="3D" level="1" scaling="Tau">
<description>This table determines the Tau A enrichment multiplier when engine load is increasing.</description>
<table name="Coolant Temperature" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
<table name="Manifold Pressure" type="Y Axis" elements="3" scaling="TauMrp"/>
</table>

I finally kinda sorta figured out how to use the merp github site. I grabbed the most recent 32bitbase.xml and am amazed by all the craziness that showed up when I opened a rom. :-O
 

STI 2NR

New member
Hey Oren, I fixed it!! I totally forgot about the ecu in my STI. When I flash a map it never resets the ecu like all the other subie ones. I think only a couple of the 2005 roms do this. My baja does not exhibit the same behavior. Anyhow, I used learning view to reset and then flashed the ecu. No more stutter. I believe the 30+ roms I flashed without resetting the ecu overwrote something that the motor did not like.

I made a video. I will post it when it is done. The last pull I do in the video is awesome. Car is running like it should.

The tau tables are awesome, no more rich dip when I dump the throttle. So much easier to tune sd this way. Fuel trims are all looking within -+.3 afr.

I am stoked.

I dialed in a 20 psi map for tonight cops versus drag racers beat the heat event. Should be fun. :) Thanks for putting up with my ocd tuning issues Oren! :)
 

Td_d

Commander In Chief
Great stuff! Yes, it's a quirk with only some of the 2005 and 2006 model, all the others reset when you flash the rom.
 
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