Ford Focus ST Forum banner
1 - 19 of 19 Posts

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #1 ·
Anyone willing to send me some decel logs from crackles tune (strat?) id like to see final timing, ltft, stft, afr, cam timing, load... think that’ll suffice. Thank you in advance. It would be great also to be able to compare loud crackles to mild crackles. I’m pretty positive the main change will be in the dfso timing but I’d like to see what other changes are made so I can better understand the logic the pros are using to set this up.
 
  • Like
Reactions: Duece McCracken

·
Premium Member
2013 ST2, AGP BWS turbo, long block
Joined
·
742 Posts
Do you have stock downpipe? If so turn back now.

I can share my crackle tune with you if you have accesstuner. I've been down this path before.

You have to retard Exhaust valves while in cruising VCT mode (have to Schedule retarded Exhaust cam pair during closed throttle decel cruing) I believe its VCT mode 5 or something. watch VCT model while you're driving to figure out when you want this to happen.
Then you have to go to the track distance and schedule a VCT pair with retarded exhaust valve.

Once VCT is correct, schedule retarded spark during this mode. You have to watch the Spark mode to figure out what table is active here.
Once spark is retarded, disable DSFO.

The result is lots of unburnt fuel making its way to/past turbo and then you ignite it and it combusts in your downpipe.
you essentially shift the combustion process to your downpipe. Its a rather destructive idea but it sure sounds cool.
 

·
Premium Member
2013 ST2, AGP BWS turbo, long block
Joined
·
742 Posts


 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #5 ·


3” 100 cell depo dp. Stock catback. It has a nice burble already. I’d love to see the tune man! Also to see what else you’re doing. I have accesstuner yes
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #6 ·
How much are we retarding the exhaust cam? I haven’t gotten much into cam tuning yet, saving that for a rainy day
 

·
Premium Member
2013 ST2, AGP BWS turbo, long block
Joined
·
742 Posts
How much are we retarding the exhaust cam? I haven’t gotten much into cam tuning yet, saving that for a rainy day
I drove to work today with my first successful crackle tune. Sounds pretty cool needs a little refinement as to when it comes on/off.
but when its on it has an absolutely fantastic crackle. The degree of the crackle can be varied with the timing

step 1: Essentially turn off DFSO so that there is extra fuel in the exhaust. this can be done by setting the CCT disable temperature very low (1000°F)

Step 2: Under HDFX configuration, set up a HDFX cam pair that has 0°i / 40°e. I picked HDFX 11 because the tune naturally never uses it? ( I think? COBB OTS3 never seems to use it). HDFX 5 has this pair naturally, but that is used within the driving range so I didn't want to map a crazy timing table to 5. (well I did and it made for a rough ride so I figured out a new method). Enable table 11 for snap to mapping.

Step 3: Set up the optimum stability HDFX track # table so that it picks HDFX table 11 at the right time:
Optimum stability strategy is targeted when load is bellow a certain value such as in the low load case of idle or deceleration.
In the HDFX distance tables, under Optimal Stability, set the mapped points to include HDFX 11. I set 1-6 to HDFX 1 and 7 to HDFX 11.
For the track distance table, leave at HDFX set 1 for anything below 1500 rpm (so that you idle like a normal car) and have it target your track number containing table 11 (used track # 7 in my case) at coolant temperatures above 125°F and rpms above 1500 rpm.

Step 4: retard timing during optimum stability deceleration.
This one I'm still working on and I'll update this thread when I figure it out better.
But I essentially just set Borderline timing table 11 and MBT timing table 11 to very low degrees for very low loads. You don't want to set the whole table low incase you encounter high load while optimum stability mode is on (helps make a smoother transition into the normal driving range when you put the pedal down). But you drop the low load conditions from their 60~70° of advance down to like -4° and it starts to produce negative timing when HDFX table 11 is in use. Make sure your ignition timing lower clip allows whatever you set in the BL and MBT tables. (set mine to -30°)
View attachment 386833
The goal is to make a condition where you're still fueling under deceleration, your timing is sparking late for the power stroke, your exhaust valve is opening early for the exhaust stroke, and the result is combustion in the downpipe.

my timing methodology still needs improvement. I keep seeing timing of -20° when in the BL and MBT tables I only told it to shoot for -4°. I dont think i fully understand how the HDFX weighting picks the timing tables. It must not fully snap to table 11.
Also I need to give some attention to the WGDC during these conditions. all the open exhaust valve makes for a good bit of flow through the turbine.
Update: Map switchable smooth crackles:

It runs much smoother when you don't make a cam pair exactly for crackling, and instead just use cam pair 5 for the optimum stability cam targeting pair.
So from my last post, instead of optimal stability mode track # 7 pointing to a HDFX cam pair 11, it would point to pair 5. then drop the low load timing everywhere.

Instead of of the ignition strategies having a custom table for HDFX 11, just lower the low load timing across all BL, MBT, cylinder pressure, and pre ignition tables. <- note I didn't do anything about cylinder pressure and pre ignition in my last post, this was a mistake. They can not be neglected or the timing decision maker will jump between BL/MBT and Cyl pres./ pre ignition and you'll never really peg steady negative timing.
you barely drive in the sub 0.3 load range anyways.. that's mostly for decelerating. As long as you make the graph smooth enough it works very well. I've actually got all ignition tables set to about 10° at 0.1 load, 15° at 0.2 load then ramping up to the normal 30~40° it expects around 0.3 load. I then use the cobb custom feature 3D timing strategy offset to take away -20° of timing for my crackle slot so that the timing goes negative at 0.1 to 0.2 load range. (want about -5° to -10° for nice crackling. -25° sounds like gun shots even with a 'stock' cat)

The result is map switchable crackles that drive very smoothly and sound awesome. Its nice to be able to map one slot to take away the aforementioned -20° degrees for a crackle slot and then have another tune add +20° back on for near OEM timing. If I see another hotboi car I just flip my crackles on and let him have it.
If any self tuners attempt this, just pay attention to your OAR. remeber if you set the CCF offset to -20° and the OAR is -1, you'll end up adding 20° instead of subtracting
This is about all I wrote. Id have to dig back into it. My crackles were obnoxiously strong hahaha. definitely wake up the neighbors type of loud.

Also consider MonsterTuned's advice:

now imagine what happens after 20k miles of fuel detonating inside the integrated headifold and turbo. Seen plenty of headifold cracks that needed new cylinder heads from loud bang maps.
I will give you my map after work but hold no liability for the results lmaoo. It scraped my stock cat.
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #8 ·
This is about all I wrote. Id have to dig back into it. My crackles were obnoxiously strong hahaha. definitely wake up the neighbors type of loud.

Also consider MonsterTuned's advice:



I will give you my map after work but hold no liability for the results lmaoo. It scraped my stock cat.
All good. I’m seeing 9 on vtc mode. It only seems to toggle 9 10 11. I’ll have to look into the tables and see if I need to decide this further. Does it directly coincide with the vct pair?
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #9 ·
This is about all I wrote. Id have to dig back into it. My crackles were obnoxiously strong hahaha. definitely wake up the neighbors type of loud.

Also consider MonsterTuned's advice:



I will give you my map after work but hold no liability for the results lmaoo. It scraped my stock cat.
Also im building another motor so hopefully I’ll have that changed out before anything breaks lol. Gonna play with it and see what sound I get through stock cat back and 3” dp. Not real worried about the 100 cell cat, it was cheap. Maybe I can blow some of the packing out of my resonator and adjust the sound to my liking with this adjustment lmao
 
  • Like
Reactions: Habriant40

·
Premium Member
2013 ST2, AGP BWS turbo, long block
Joined
·
742 Posts
Pm'd my most recent Crackle tune. I think this one was my most controlled crackle. The one before this literally sounded like gunshots.

Cams:
Since my old post about it I switched from HDFX VCT pair 11 to pair 4.
You can see this under VCT-> VCT advanced -> HDFX Distance Tables -> Optimal Stability -> Mapped points, and Track Distance (compare what I did to stock)

Timing:
Litterally every borderline and MBT timing table I nipped the low load spark advance wayyy down.
I made the tune map switchable by counteracting this in the Cobb 3D spark offset tables. Look at what I did there on the low load conditions vs the low load conditions in the boarderline timing.

This tune allowed me to swap to crackle mode and then swap back per slot selection
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #11 ·
Pm'd my most recent Crackle tune. I think this one was my most controlled crackle. The one before this literally sounded like gunshots.

Cams:
Since my old post about it I switched from HDFX VCT pair 11 to pair 4.
You can see this under VCT-> VCT advanced -> HDFX Distance Tables -> Optimal Stability -> Mapped points, and Track Distance (compare what I did to stock)

Timing:
Litterally every borderline and MBT timing table I nipped the low load spark advance wayyy down.
I made the tune map switchable by counteracting this in the Cobb 3D spark offset tables. Look at what I did there on the low load conditions vs the low load conditions in the boarderline timing.

This tune allowed me to swap to crackle mode and then swap back per slot selection
Awesome thank you
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #12 ·
Quite impressed by your work. Iirc stratified did not have map switching for crackle or no crackle. Maybe that’s changed since I was following that idk. Originally I played with dsfo and low load timing but I didn’t mess with hdfx or mapped points for cams. Looking forward to reviewing your tune
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #13 ·
Pm'd my most recent Crackle tune. I think this one was my most controlled crackle. The one before this literally sounded like gunshots.

Cams:
Since my old post about it I switched from HDFX VCT pair 11 to pair 4.
You can see this under VCT-> VCT advanced -> HDFX Distance Tables -> Optimal Stability -> Mapped points, and Track Distance (compare what I did to stock)

Timing:
Litterally every borderline and MBT timing table I nipped the low load spark advance wayyy down.
I made the tune map switchable by counteracting this in the Cobb 3D spark offset tables. Look at what I did there on the low load conditions vs the low load conditions in the boarderline timing.

This tune allowed me to swap to crackle mode and then swap back per slot selection
Going from pair 11 to pair 4, you’re talking about mapped points correct? If so looking at them, aren’t they advancing the exhaust cam 40 and 30 deg respectively? Or am I looking st this backwards.
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #14 · (Edited)
I get it I think.
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #15 ·
Pm'd my most recent Crackle tune. I think this one was my most controlled crackle. The one before this literally sounded like gunshots.

Cams:
Since my old post about it I switched from HDFX VCT pair 11 to pair 4.
You can see this under VCT-> VCT advanced -> HDFX Distance Tables -> Optimal Stability -> Mapped points, and Track Distance (compare what I did to stock)

Timing:
Litterally every borderline and MBT timing table I nipped the low load spark advance wayyy down.
I made the tune map switchable by counteracting this in the Cobb 3D spark offset tables. Look at what I did there on the low load conditions vs the low load conditions in the boarderline timing.

This tune allowed me to swap to crackle mode and then swap back per slot selection
I set it up today and my cam timing sticks at 20 under 2500 rpm. I was trying to bring it back towards zero there. Also my ignition timing is much lower then what I set hitting the lower clip. I’m setting it up again a little differently. Looking for more burbles then loud pops. With stock cat back I can’t judge how big the explosions are and I need to wait a little longer before destroying my turbo and headifold
 

·
Premium Member
2013 ST2, AGP BWS turbo, long block
Joined
·
742 Posts
I set it up today and my cam timing sticks at 20 under 2500 rpm. I was trying to bring it back towards zero there. Also my ignition timing is much lower then what I set hitting the lower clip. I’m setting it up again a little differently. Looking for more burbles then loud pops. With stock cat back I can’t judge how big the explosions are and I need to wait a little longer before destroying my turbo and headifold
20° exhaust cam timing retard under 2500 is pretty normal for WOT and for accelerating conditions. Its not for Decel and coasting conditions.
You need to force that on the Deccel coast / no throttle condition for crackles. If you can make that happen with the VCT exhaust scheduling and track distance, you're on the right path. Normally it stays at 0° Exh Cam retard during coasting. you need it slightly retarded for burbles. - maybe not 20°. Figuring out the VCT scheduling and track distance allows you to tune the cams in weird Ecoboost conditions. Its not what most people mess with during tuning. Usually the VCT optimum power is all that performance tuners need.

Burbles is going to be a less intense version of what I have done on that tune. You won't need such an extremely late spark... could maybe shoot for 2° to -1° of spark and get a nice burble with retarded cams. If I'm remembering correctly, my tune should be like -5° to -10° which is a full downpipe of unburnt fuel igniting (why it bangs so loud).

(Also, I made that tune pretty much as soon as I got access tuner.. I was very new at the time)
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #17 ·
20° exhaust cam timing retard under 2500 is pretty normal for WOT and for accelerating conditions. Its not for Decel and coasting conditions.
You need to force that on the Deccel coast / no throttle condition for crackles. If you can make that happen with the VCT exhaust scheduling and track distance, you're on the right path. Normally it stays at 0° Exh Cam retard during coasting. you need it slightly retarded for burbles. - maybe not 20°. Figuring out the VCT scheduling and track distance allows you to tune the cams in weird Ecoboost conditions. Its not what most people mess with during tuning. Usually the VCT optimum power is all that performance tuners need.

Burbles is going to be a less intense version of what I have done on that tune. You won't need such an extremely late spark... could maybe shoot for 2° to -1° of spark and get a nice burble with retarded cams. If I'm remembering correctly, my tune should be like -5° to -10° which is a full downpipe of unburnt fuel igniting (why it bangs so loud).

(Also, I made that tune pretty much as soon as I got access tuner.. I was very new at the time)
Ya so here’s the thing, through the stock muffler it’s quieter, much quieter. I’m hitting -15 or so to hear it and I get burbles and the occasional loud pop. You think that’s too much? Think I’m gonna damage something? I’m targeting 20 deg cam retard then 30 in the higher rpm. It’s very controlled sounding through my exhaust. The first try I was hitting -20 timing and it was popping loud a lot
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #18 ·
For anyone else reading, I was successful in getting crackles working with 3” downpipe and stock catback, however to hear it while on the road it had to be pretty aggressive, pulling -15 deg timing or so. At 0 to -5 deg I could hear a little when I revved it and that is probably sufficient if you have exhaust. I was a little more conservative on cam timing, retarding cam 30 deg at higher rpm back to 20 deg below 3000 rpm. Then back to 0 below 2000. Since it weights the hdfx tables the timing gradually ran from 20 to 0 as rpm dropped. I ended up pulling 25 degrees out of my mbt tables at low load conditions which, after corrections got me to 0 to -5, then I took an extra 10 out through 3D offset. This could work really well to turn crackles off if your oar goes positive as well, it would add 10 at +1 instead of taking it away. If you have exhaust this could actually be a decent cue to tell you something isn’t right. Just an idea. Happy tuning
 

·
Registered
2018 ST
Joined
·
92 Posts
Discussion Starter · #19 ·
I’m going to try adding overlap in a different way, advancing the intake slightly and retarding the exhaust slightly. I think there are one or two pairs that I can modify, will require pointing certain hdfx tables to different pairs and isolating at least one pair to use exclusively for decel. Going to start with 3 and 3 degrees and play with some other things along the way to see if I can change the sound to my liking. Will report back
 
1 - 19 of 19 Posts
Top