Spraying meth for safety

[wsmith30132]

I have a pro tune stage 2 with a catless long DP and ABE. This fall I replaced my Mid and Y pipe to complete my TBE. I did not change my tune after this adjustment to my exhaust. A couple months later I downloaded Learning View and noticed timing being pulled in the 3200-4000 in the 1.6+ of load.

 

I have a HFS-5 installed and dont like my tune for it so I never run it. Well, I decided to just spray the meth as a failsafe and hope it would take the timing being pulled away on my stage 2 map.

 

After a month or so I checked back and the timing is still being pulled. The only difference is the fueling changes. Is it detrimental to my engine to continue to run like this with the timing issues? Attatched is my rescent learning view and I dont have one saved prior to the meth. Thanks

LearningView_12-26-2009%204%2001%2000%20PM(1).csv

[custom_junky]

i'm not too familiar with tuning subaru's specifically, but i don't think there would be much difference in tuning here...you will need to tune you car properly with at the minimum a wide band o2, using meth alone will not change your ignition timing maps since they are hard coded in the ecu, and the ecu can only adjust so much from set number on the table...

 

in short, get a proper tune, if you are not confident in this, goto a tuner that has a 4 wheel dino, and have them tune it for you...

 

someone else chime in for more detail information about tuning software (again never tuned a subaru, not familiar with the hardware outside of the fact that it is obdii) and correct me if i'm wrong on this...

[wsmith30132]

I know the meth wont change my timing maps but was in hope the added octane and fuel would make it more knock resistant. With the exhaust changes I assumed it would run a litter leaner and I was concerned with winter here.

[Darkness of Death]

meth is used to run higher boost safely are far as i know.

 

i think i was told that the car would run lean if not tuned properly for meth.

 

just out of curiosity.

when does you meth start spraying?

are you running 50/50 or 100%?

how much boost are you tuned for?

[wsmith30132]

Oh man, its been a while but i think it starts at 60% IDC. Im runing 50-50 with M1. I'm tuned for 18.5 psi at 900' ASL. I couldnt get much more gains out of the stock turbo so my meth map isnt worth running. I just figured since i opened up the mid and y pipe it would be a little lean, and spraying meth on my 93 map would be my safety factor. Just looks like by my learning view that the knock is still there. Im still trying to learn the logs and learning view

[iNVAR]

Log some third gear WOT pulls. Your LV only tells you part of the story. All your LV shows is that you have learned knock at that load and range. It's possible that you have knock that hasn't been learned at all. Certain maps, notably the Cobb OTS maps, have knock learning disabled above 2.2 load. Which means that at 2.2+ load, your car is relying on FBKC.

[NSFW]

...someone else chime in for more detail information about tuning software (again never tuned a subaru, not familiar with the hardware outside of the fact that it is obdii) and correct me if i'm wrong on this...

 

There's inexpensive hardware and free software that gives us access to most of the relevant tables in the ECU, and the allows logging in real-time and taking snapshots of the learned parameters (fuel trims and knock correction). If you want to get up to speed on this stuff, here's a good place to start:

 

http://www.romraider.com/forum/forum33.html

[NSFW]

I know the meth wont change my timing maps but was in hope the added octane and fuel would make it more knock resistant. With the exhaust changes I assumed it would run a litter leaner and I was concerned with winter here.

 

Exhaust changes won't affect your AFR. Our ECUs use a mass air flow sensor (MAF), so if your exhaust allows the engine to pump more air in, the MAF sees that, and the ECU adds fuel accordingly.

 

When the knock sensor lights up, and the ECU decides to use learned knock correction, the ECU pulls 1.4 degrees. So all we really know here is that the ECU saw knock (or thought it saw knock) in that RPM/load range once. That's actually not a big deal IMO. This happens even with the stock tune. It's not clear to me whether this is true knock or just noise that was mistaken for knock. When more than 1.4 degrees has been pulled, that's definitely cause for changes to the tune. When 1.4 or less has been pulled, that just needs to be investigated.

 

Also note that the ECU will un-learn that knock correction 0.35 degrees at a time, if you drive in the relevant load/RPM range for a while without knocking again.

 

I suggest the following... if you aren't comfortable reflashing the ECU, just skip to the "Reset the ECU" step and continue from there. The adjustments to the tune are not critical, they're just helpful.

 

* make sure learned knock correction is enabled across the entire load range - as iNVAR said, not all tuners do this, but some of us think it's a good idea. In RomRaider, this is the "Ignition Timing - Knock Control / Fine Correction Range (Load)" table. I've set the top-end values to "enable below = 5.1" and "disable above = 5.2" because I'm sure I won't hit those, probably not even with a GT35.

 

* change the "Fine Correction Columns" to 0.8, 1.4, 2.0, 2.6. This will make Learning View a bit more useful. Right now it lumps everything above 1.6 load into one column, which IMO not ideal.

 

* Reset the ECU to get rid of that learned knock correction.

 

* Log some pulls. More about that here:

http://www.romraider.com/forum/topic5384.html

Use the parameters in the "General purpose log profile" section.

Ideally, log from around 2500 RPM to redline in 3rd gear at full throttle.

But only if you have a safe place for this. Know of some long freeway onramps?

If not, log 2nd gear from 2500-to-redline, plus 3rd gear from 2500-to-whatever-you-feel-is-safe.

 

* After the pulls, save another snapshot with Learning View.

 

* Check the logs, see if the "knock sum" parameter increments in the 3200-4000 RPM range. Or anywhere else, for that matter. Note that it's normal to see some increments at idle and cruise, and with abrupt throttle changes. (The throttle-change stuff can maybe be tuned out, but I'm not ready to give suggestions about that.)

[wsmith30132]

^ Thanks, alot of good info there, I appreciate it! I will study those links and do some logs and see what I can find out. My maps are locked on a APV1 and I am no where comfortable enough to touch them if I could. Thanks again

[LittleBlueGT]

Very good info NSFW.

 

Couple other things:

 

-COBB OTS (and many tuners maps) still have the 2.2 load cap for FLKC, your car may not have been able to unlearn this knock cause of this load cap. I bet everytime you go WOT, you shoot up to 2.5 load, or even more. (in that rpm range)

 

-starting to spray at 60% IDC (assuming stock injectors) is tooooo high. You should start spraying at about 30% or so. Assuming stock turbo and fuel system, 60% IDC will only be exceeded when the engine is making about 70% of its power.

 

-injecting meth w/o leaning out the tune, can cause the car to run too rich, which isn't good for cylinder walls. How much is the M5 nozzle injecting? I think you are probably OK, especially as most 93 tunes target 11.4:1. If not changing the tune at all (which is not the preferred route) I would inject a very small amount of meth only, like 175-225 cc/min.

[NSFW]

^ Thanks, alot of good info there, I appreciate it! I will study those links and do some logs and see what I can find out. My maps are locked on a APV1 and I am no where comfortable enough to touch them if I could. Thanks again

 

You can read and write APV1 maps using a Tactrix cable if/when you feel ready to make improvements.

[wsmith30132]

You can read and write APV1 maps using a Tactrix cable if/when you feel ready to make improvements.

 

Thats trouble!!! Attatched is a log i just took today. Looks like it knocked at rpm 2625.

 

In learning view if I reset the ECU will it effect my RT map?

 

Thanks for the info guys, time to read some threads in RomRaider.

 

I was thinking the meth kicked on at 60% but its been a couple years. I was looking at my trigger pot and its set at the 52-53 minute position on a clock. It starts from 12% to 60% so maybe its triggered at around the 55%???

romraiderlog_20091227_150617.csv

[LittleBlueGT]

Thats trouble!!! Attatched is a log i just took today. Looks like it knocked at rpm 2625.

 

In learning view if I reset the ECU will it effect my RT map?

 

Thanks for the info guys, time to read some threads in RomRaider.

 

I was thinking the meth kicked on at 60% but its been a couple years. I was looking at my trigger pot and its set at the 52-53 minute position on a clock. It starts from 12% to 60% so maybe its triggered at around the 55%???

 

 

I have never had problems reading/flashing my AP#1 map. Like I said in another thread, I haven't even touched my AP in years, I just use my ST software.

 

Whenever I reset the ECU it doesn't affect the RT map.

 

Here is the HFS-5 trigger point diagram:

http://i248.photobucket.com/albums/gg194/littlebluegt/HFS-5trigger.jpg

 

I would guess that you have it set at about 30-34% IDC trigger, which sounds about perfect.

 

That knock event is not a big deal. If you look in the log it is happening just as the turbo is spooling, and the ECU probably did not respond with FLKC, but FBKC.

 

It is extremely hard to completely tune this out, and your meth (which is likely just turning on that point) may or may not help there.

 

Notice how quickly the timing is changing right in the spool-up area? If you only get 1 count of knock occasionally in that area, I would leave it. If you start to get 2 or 3, then I would take out a touch of timing, and possible see what the AFR targets are there. (this is assuming a good MAF scale, and no major resonance in the intake at that point)

[Boostin1657615274]

why don't you just pull a couple degrees of timing to be safe and skip the meth altogether for now? I have no problems with meth, but on a stock turbo?? it's not worth the hassle and additional clutter.

 

Based on that one log it looks like your boost control tuning could use a little work under 4000rpm.

[wsmith30132]

If I was more comfortable or knowedgeable about doing it I would love to just pull some timing. I'm a noob and didnt/dont know any better so i thought I could just spray some meth as a safety factor since it was hooked up and I cant tune.

 

I started my build with an upgraded turbo and fueling being the last step. I want to stick with a TMIC so I was getting everything in place. Now with BNR in house hopefully a 20G, pump and injectors my power mods will be done.

[custom_junky]

There's inexpensive hardware and free software that gives us access to most of the relevant tables in the ECU, and the allows logging in real-time and taking snapshots of the learned parameters (fuel trims and knock correction). If you want to get up to speed on this stuff, here's a good place to start:

 

http://www.romraider.com/forum/forum33.html

thank you...i'll be looking through this for myself

[NSFW]

If I was more comfortable or knowedgeable about doing it I would love to just pull some timing. I'm a noob and didnt/dont know any better so i thought I could just spray some meth as a safety factor since it was hooked up and I cant tune.

 

If you're adding meth, you are tuning.

[Darkness of Death]

you have to tune to run meth!!

[wsmith30132]

yeah i know, i was just looking at it as a patch untill i get something figured out with the tune or until i know its safe. Like you guys said the little bit of knock isnt bad then ill stop the meth; keep logging, get ecu flash, download the rom, pull some timing, and be good to go! NSFW has some awsome threads on romraider ill be reading. Thanks for the info!