VersaTune User Forum

Hi all!

I have a 2006 Mazda 6 MPS with a custom tune, CST4, fmic, catless downpipe, and all the other supporting mods.

I ran the car with my custom tune for a year, and my car only pops sometimes when letting off throttle because I have a vta bov.
Now I have been trying to customize my tune to add some pops n crackles to my tastes. I disabled decel fuel cut, and adjusted the two ignition max tables (2 rows on top) and last I had to do was adjusting the Volumetric efficiency table. I basically copied the values of the OTS pops and crackle tune to my custom tune.

However.. my car doesn't pop, crackle or do anything like it with the adjustments. Normally it popped a bit when letting of throttle because of the bov. Now it doesn't even do that anymore.

Can anyone tell me what's wrong and why it's not working on my car? I attached a datalog

Help would be highly appreciated!

Kind regards,

Colin

Looking at your logs it seems you're getting about 5 degrees, if that, of ignition timing on deceleration. Generally speaking, I'm pretty sure you have to be targeting around -10 or -20 or so to get some decent pops out. What have you set the max ignition too, and are you still running stock cats?

xbrandino wrote: ↑August 27th, 2023, 2:29 pm Looking at your logs it seems you're getting about 5 degrees, if that, of ignition timing on deceleration. Generally speaking, I'm pretty sure you have to be targeting around -10 or -20 or so to get some decent pops out. What have you set the max ignition too, and are you still running stock cats?

Thank you for looking at it. My car is catless. I've set it at -20. I have a feeling it might be load related

You've set it to -20 BUT the timing you are getting is like 5 and the load does not go below 0.22 under decel (or if it does it comes back up quickly).
Also in your log you have some useless parameters such as fuel injection amount and catalyst temperature (on a catless car!!) but no AFR/Lambda, desired and actual as well would be really useful. Also you should add acceleration pedal position as well so that we can figure out which part of that almost 2000 lines log should be about pops&bangs and which lines we can ignore.

mituc wrote: ↑August 28th, 2023, 1:46 am You've set it to -20 BUT the timing you are getting is like 5 and the load does not go below 0.22 under decel (or if it does it comes back up quickly).
Also in your log you have some useless parameters such as fuel injection amount and catalyst temperature (on a catless car!!) but no AFR/Lambda, desired and actual as well would be really useful. Also you should add acceleration pedal position as well so that we can figure out which part of that almost 2000 lines log should be about pops&bangs and which lines we can ignore.

Thanks for your response!

Uhh yes there were some random parameter in there from another logging session. I will be out logging tonight or tomorrow morning with the parameters you ask me to log. Will post them here when I have the logs. I adjusted some timing because I don't need big bangs but just burbles, so Ignition is at -5 in both tables. I don't use the Disabled fuel cut option but tend to go for the option with engine braking. So I adjusted the decel fuel treshold.

Will be back with a log ASAP

Kind regards,

Colin

mituc wrote: ↑August 28th, 2023, 1:46 am You've set it to -20 BUT the timing you are getting is like 5 and the load does not go below 0.22 under decel (or if it does it comes back up quickly).
Also in your log you have some useless parameters such as fuel injection amount and catalyst temperature (on a catless car!!) but no AFR/Lambda, desired and actual as well would be really useful. Also you should add acceleration pedal position as well so that we can figure out which part of that almost 2000 lines log should be about pops&bangs and which lines we can ignore.

Made a new log with some normal driving.

I've read all your posts but it's still unclear to me:
- what you want to achieve (expected result);
- what you actually get (the actual result);
Posting your tune (+engine mods list) along with mentioning clearly the things above may help.

mituc wrote: ↑August 28th, 2023, 3:14 pm I've read all your posts but it's still unclear to me:
- what you want to achieve (expected result);
- what you actually get (the actual result);
Posting your tune (+engine mods list) along with mentioning clearly the things above may help.

Hi Mituc,

So what I want is: Lift burble, each time I step off the gas pedal I want some burbling sound like in this video: https://www.youtube.com/shorts/FcdS8pncMbM

What I actually get: No lift of burble or pops, just nothing. only thing I've noticed is when I play a bit with the gas pedal on decel sometimes I can get a big bang out of the exhaust. But if I don't touch the accelerator pedal nothing happens.

What have I tried: I tried the method with disabling the fuel cut on deceleration (no engine braking) adjusting the CL and OP, and Volumetric Efficiency tables.
And I also tried the method with engine braking and not clicking the fuel cut disabling button. Extra thing here is that I had to adjust the Decel fuel cut requested treshold.
I also tried to play around with the ignition in both tables, but -20 or 5 doesn't make a difference. For now I written the tune with -5 on ignition since I understood that burbling mostly happens between 0 or -5

My modlist: Mazda 6 mps, Stock block, CST4, stage 2 stock diam CS intake, CS Catless downpipe, CS ebcs, VTCS delete, 3,5 bar cs map sensor, CS hpfp, CS FMIC, OCC setup, GFB blow of valve (100%vta)

I attached my tune to this message,

- Colin