If you have a DAM or 12, you're not getting full timing advance because the ECU determined that it was experiencing knock. If you want the old 16 value to happen at a DAM of 12, you'd need to set your timing advance to be (max timing without knock - base timing)*16/12.

However... why you would want something below a DAM of 16 is beyond me. Since it lowers with a knock condition, you would be forcing your car to knock regularly. This is not something I would want to do to my car, especially at full boost. You may lose a degree or two of advance, but I think it's well worth the compromise.

 

corrrect. I think you may have misunderstood what i was trying to say. Or maybe i didnt say it clearly.

Im trying to get the ECU to run MORE timing beyond the scope of the off the shelf cobb stg 2 DAM value of 16. I am currently at 16, but lets say when i re-tune the ignition values that i am getting as much advance at DAM of 12, that i am now, at 16. Then shouldnt the ECU advance as much as it feels it can (possibly up to 16 again if possible).

Im new to tuning timing and whatnot, so im trying figure out how i can safely run more ignition advance. I know im in the clear now, so i would think i could advance it 1 degree at a time. I just dont know what table to start changing first.

 

DAM has nothing to do with tuning ignition other than if it is never 16 something is wrong.You tune the base ignition map and when you log if the DAM changes you might want to note at what rpm and load,then pull timing from that area.

 

That brings up a good question then (since I want to learn more about it): How exactly do you go about tuning ignition timing?

I've read about the timing methods Subaru uses with base timing, advance, and a multiplier, but not the theory behind actually tuning it. If you have a DAM of 16, you're at full advance, correct? 0 DAM gives you base timing. Tuning the base map instead of increasing advance prevents large swings due to dynamic advance, etc...

Donkey, would you mind giving a brief rundown of your methods to reach an 'optimal' tune? I know it would certainly help me (and others) to get a better understanding with Subaru tuning and maybe we could then just refer back to this post instead of fielding similar questions.

 

I also would appreciate that. I feel a little overwhelmed right now trying to figure out how to advance my timing safely.

 

I actually plan on using RomRaider since I want to do the tuning myself (once I have my car paid off next year).

My tuning experience is limited to N/A engines with an intake restrictor and a stand-alone ECU. However, this was more of a 'get it good enough to drive' and then hand it off to someone with real experience so as not to waste their time otherwise.

Turbo cars that run well to begin with are a different story for me. I'd like to make my own stage 1 and work up to 2 using other people's maps as reference. I assume xsnapshot is in the same position here. I can work theory well, I just lack experience. Anyway...that's where I'm coming from... and where I hope to go...

 

Romraider has a neat little tool called "learning view".It allows you to see where timing has been pulled and your fueling trims. RomRaider • View topic - Learning View tool

Basiclly for timing I just watch my IAM/DAM and Knock Correction.Unfortunaly with turbocharged cars at some point you will see knock and more than once.Knock isn't the same as predetonation.Knock isn't always severe or damaging.There is also "false knock" that is caused by loose/vibrating parts,exhausts knocking,bad gas and general road noise that the knock sensor detects as knock.Also using a knock lite or det cans help dermine false knock from real knock durring tuning.Best thing to do is just grab a six pack and spend some time going through the RomRaider Tuning forum weeding around in the threads.Also spend some time learningto use the logging program and playing around with the ECU editor before tuning your car.Saves time and less mistakes.Plus it's fun just to log a baseline of your car and make sure no problems are evident before you start.

 

ya im basically in the same situation as you (falconflyer). Ive been reading up on tuning lately, and i think im going to leave timing values set for now. (stock timing tables for cobbs stage 2 91 octane)

Instead i will just focus on boost and fueling. Right now in third im hitting 18psi, so thats about all im gonna get for boost.

I want start modifying fuel tables, but the load sites are confusing me. Load sites for fuel only go up to 1.98, and WOT im seeing loads of 2.6 or more. Right now fuel for load's 1.98 (and greater im assuming) is really rich. Ending at 10.3:1 the last 1kRPM, im gonna try leaning it out .1 AFR at a time.

One question though, how can i tell when my ECU starts to pull timing? Will the DAM always go down? Im not sure how to look at the ignition/fuel/knock correction tables that the ECU hides.

 

I want start modifying fuel tables, but the load sites are confusing me. Load sites for fuel only go up to 1.98, and WOT im seeing loads of 2.6 or more. Right now fuel for load's 1.98 (and greater im assuming) is really rich. Ending at 10.3:1 the last 1kRPM, im gonna try leaning it out .1 AFR at a time.

Now that you have recognized you are basiclly "over running" the factory mapping you can understand why people tell everyone you cannot just turn up the boost without tuning You need to rescale the load colum.This is done by changing the actual column #'s and plugging in the new values for the cells.If you don't the ECU will just basiclly go off the last value scaled for.And as for tuning up the boost and fuel,you need to be watching your IDC's (injector duty cycle).Once you are getting into the 90's you are starting to get close to going "static" aka- maxing out the injectorsRemeber that come winter,colder air is denser and will require more fuel.My IDC's always go up in winter so you have to make sure you have enough injector headroom to compensate for this.For AFR's I run 11.25:1 AFR at redline and around 12.5:1 at max torque.

One question though, how can i tell when my ECU starts to pull timing? Will the DAM always go down? Im not sure how to look at the ignition/fuel/knock correction tables that the ECU hides.

If you use Romraider you can use the "learning view" tool like I mentioned before or log DAM/IAM,"fine learning knock correction" and "feedback knock correction" with the rest of your logging parameters.What I did before that tool and more sophisticated logging programs was make my knock correction map all "10's" (known as a flattened knock correction map) and changed the values in my base timing map to reflect the same overall timing with the KC map + base ignition map added together.So if I see a change in knock correction I know the ECU is pulling timing and how much.DAM changing is significant.KC will change before DAM does usually.DAM is the real safety net.Also for the both of you these are some great books on tuning theory and such:
Amazon.com: How to Tune and Modify Engine Management Systems (Motorbooks Workshop): Jeff Hartman: Books
Amazon.com: Engine Management: Advanced Tuning: Greg Banish: Books

 

It's funny you mentioned those books because I bought them both about 3 months ago. I started into them and then was told I was needed to go back and forth to Seattle and Philadelphia for work until last week. I guess now's the time to get back into them :tongue:

Another question while you're looking...
How do you know when you reach the limits of a turbo in terms of flow and boost? I've seen the compressor maps for the td04 so I know about the pressure ratios and efficiency ranges. With a stock exhaust and full TBE, what lets you know you're at the point of diminishing returns?

 

It's funny you mentioned those books because I bought them both about 3 months ago. I started into them and then was told I was needed to go back and forth to Seattle and Philadelphia for work until last week. I guess now's the time to get back into them :tongue:

Another question while you're looking...
How do you know when you reach the limits of a turbo in terms of flow and boost? I've seen the compressor maps for the td04 so I know about the pressure ratios and efficiency ranges. With a stock exhaust and full TBE, what lets you know you're at the point of diminishing returns?

Like Xsnapshot said,when you stop flowing more air.Air is measure from the MAF in g/s (grams per second).If you increase boost and your g/s are not increasing then you are at the turbos limit.I honestly don't try to tune to that limit,especially on a stock turbo.

"factory mapping"? Im basing my tuning off of cobb's map. So that shouldnt be factory.....i mean wouldn't they scale values for the different loads?

Also let me make sure im getting my load values correct. Im just using plain old v2 AP live data to monitor the loads under WOT conditions. (it just says calculated load....)

Not always do they rescale,but they should have.I thought their stage 2 maps ran 16.5psi?What year WRX do you have?I assumed a 2.0L (02-05) since you mentioned a DAM of 16.The 16bit ECU's have a max initial advance multiplier of "16".The 06+ WRX's,which are 32 bit ECU's (like the 04+ STi and LGT's) have a max of "1".So Falconflyer912,you would want to see a value of 1 for your DAM/IAM

Donkey how much boost are you running? Its probably not going to relate very well due to your mods....but just curious what your take on TD04 boosting is?

I run around 20psi in the midrange and taper down to 13.5psi by redline.My IDC's get high in the winter.I have already bumped my fuel pressure up once and might have to again for more head room.With more fuel I think I could run 15psi at redline safely but would not raise my max boost.I have seen people run 22-24psi on the stock turbo in the midrange and that is pushing the turbo.Some do it on pump gas,some do it on meth or 100+ octane.

 

"factory mapping"? Im basing my tuning off of cobb's map. So that shouldnt be factory.....i mean wouldn't they scale values for the different loads?

Also let me make sure im getting my load values correct. Im just using plain old v2 AP live data to monitor the loads under WOT conditions. (it just says calculated load....)

Oh and falconflyer, theres a method you can use that factors in mass air flow rate. bascially at some point you will turn up the boost and you will not see a corrisponding jump in the mass air flow. I believe on my car around 18 psi falling off to around 13.5 is pushin it pretty good.

Donkey how much boost are you running? Its probably not going to relate very well due to your mods....but just curious what your take on TD04 boosting is?

 

yep cobbs boost was only 16.5. I never saw that until 3rd gear either. Ive made some adjustments (including turning the WGA twice) and raising WGDC so that i hit 16.7 in 1st, 17.4 in 3rd, and 18 in 3rd. I still have a little headroom when it comes to WGDC as im only at 91% right now. I could probably push another PSI out of it, whic i may do....

I figure that's a pretty safe boost level. Its definitely faster than it was stock.

When i start to lean it out, i basically only need to modify two areas of the fuel tables. I was going to modify the area with loads .6-1.3 which takes care of the loads i see when cruising, and then anything higher than a load of 1.9 i was going to modify as well. Perhaps changing two values in the table. One for a load of 2.4, and then another one for when im seriously pushing the motor hard, like load 2.7 or greater.

Question (i feel like im interrogating you :sadwave
So after leaning it out, there will be less fuel to burn, so less advance is needed, but at what point do you see better power with leaving it a little rich and more advanced, or leaner and less advance?

BTW how does the car with its factory "wideband" able to determine if its getting 10.3 at redline anyway? I thought it only read down to 11.1 and only accurately to like 12.1 or so?

 

When i start to lean it out, i basically only need to modify two areas of the fuel tables. I was going to modify the area with loads .6-1.3 which takes care of the loads i see when cruising, and then anything higher than a load of 1.9 i was going to modify as well. Perhaps changing two values in the table. One for a load of 2.4, and then another one for when im seriously pushing the motor hard, like load 2.7 or greater.BTW how does the car with its factory "wideband" able to determine if its getting 10.3 at redline anyway? I thought it only read down to 11.1 and only accurately to like 12.1 or so?

The fueling map is for Openloop only.When your crusing,your generally in closedloop,which means the ECU is using O2 sensor feedback and trying to target a 14.7:1 AFR.In Openloop you are relying on the MAF sensor to be close to correctly scaled.Another reason why tuning for an intake(if need) is so crucial.Even the stock box can use some retweaking of the MAF scale.I have rescaled my MAF on the stock box using the MAF scaling tool in RomRaider.Most of the tweaking that was needed was suprisingly in the lower range.

So after leaning it out, there will be less fuel to burn, so less advance is needed, but at what point do you see better power with leaving it a little rich and more advanced, or leaner and less advance?

Yes and no.Maybe if the vehicle was already in a high state of tune,but from the factory it's not (and even with Cobb's maps).Both the factory mapping and Cobb's OTS maps are somewhat conservative.If your running lots of fuel and not alot of advance in the first place then there is lots of room for improvement Especially when you start slapping on a bigger TMIC,EL header,turbo inlet......

 

on a bit of a random note...i found out my IDC's were about 107% at WOT (~6,800RPM). So thats just dandy. Its targeting 10.28:1.....i wonder what it actually is????? Whatever it is must not be enough to cause knock....(high 10's?)

How comfortable would you guys be tuning without a true wideband O2 sensor? Cause i don't have one....and.....ya. Not really wanting to push things very far until i get one.

BTW according to cobbs accessport i did my first sub-14 second 1/4 mile tonight. 13.92 @ 105.7 mph (stock speedo would be off by what?....3 or 4 mph at that speed?). That's a definite improvement from the 14.4 second that i ran when i was using the OTS un-tweaked map. So i must be gaining HP somewhere

 

How comfortable would you guys be tuning without a true wideband O2 sensor? Cause i don't have one....and.....ya. Not really wanting to push things very far until i get one.

I wouldn't - you really should be using a WBO2

 

I wouldn't be willing to tune without a real wideband either.

Again, I'm just getting ready to dive into the WRX, but the stand alone's I've used had native support for a wideband. Do people with WRXs replace the 1st O2 sensor with something like the LC-1 and use the narrowband emulator to run to the car or do you tap a second O2 sensor in addition to the stock 1st O2?

i found out my IDC's were about 107% at WOT (~6,800RPM).

I'm wondering how this is even possible...:screwy:

 

Again, I'm just getting ready to dive into the WRX, but the stand alone's I've used had native support for a wideband. Do people with WRXs replace the 1st O2 sensor with something like the LC-1 and use the narrowband emulator to run to the car or do you tap a second O2 sensor in addition to the stock 1st O2?

You tap the DP right past the turbo - before any catalytic converter (if any)

 

I'm wondering how this is even possible...

I honestly couldnt tell ya. I know its possible. Not that your actually getting that much fuel...but the ECU is calling for that much i believe. I'll probably have to raise my fuel pressure to get more headroom.

Any preferences/recommendations for WBO2? Preferably not mega $. I would think as long as it could read between 16.1 and 10.1 accurately it would be enough. guess its time to do a little research.

That would be nice to get the ECU to read off the wideband O2.....i would think that would make tuning a map much easier.

 

I honestly couldnt tell ya. I know its possible. Not that your actually getting that much fuel...but the ECU is calling for that much i believe. I'll probably have to raise my fuel pressure to get more headroom.

Any preferences/recommendations for WBO2? Preferably not mega $. I would think as long as it could read between 16.1 and 10.1 accurately it would be enough. guess its time to do a little research.

That would be nice to get the ECU to read off the wideband O2.....i would think that would make tuning a map much easier.

Injector duty cycle % is not a true representation of a 100% scale.Pulsewidth is the actual measurement and injector duty cycle is calculated from it using RPM x PW / 1200 = %DC

Stealth 316 - Injector Duty Cycle Calculation

LC-1 is a good choice and is supported by RomRaider and Cobb Street Tuner

 

Any preferences/recommendations for WBO2? Preferably not mega $. I would think as long as it could read between 16.1 and 10.1 accurately it would be enough. guess its time to do a little research.

LC-1 Lambda Cable with 02 Sensor : Wideband Controller Cable for Dyno, ECU, Data Acquisition, or Gauge Applications

That's what I would say the "standard" WBO2 cable is

DB Gauges: Air Fuel Ratio Guage

That one comes with the LC-1 and a nice 52mm gauge

 

regarding knock and Learning View

Learning View is a great tool. I don't think you ever want to see what I saw tonight though:

:whoa::whoa::whoa::whoa::whoa::whoa::whoa:

I too am running the Cobb Stage 2 map 91oct...

 

Your A/F Correction percentages seem really high to me. Have you done anything to the intake that isn't on Cobb's recommended hardware list?

Also, even though you are certainly experiencing knock, your IAM is at 15, so it's not terrible.

 

Well, I have the snorkus thingy delete...like the vent and the elbow, that's it... I figured that was safe? I cleaned my MAF the other day too, just for fun... and then this -4.22 knock happened :whoa: