DIY Rom tuning for exhaust pops and backfires W/ romraider

[CFutGwai]

Originally Posted by guybo

Are you guys catless? Because even at -5 I got gunshots sometimes. Hell at -9.96 I got AK47 gunfire!

I went back and re-did my tune (changed FFS and LC too) and I changed the B table some and I'm popping again. not a lot of burbling though (my new Works axleback really changes the sound from when I had a Berk dual exit). It sounds good now.

Between 2800-4000 RPM I advanced the timing because in that range it gets obnoxious

Just curious, what is your overrun rpm delta set to?

Also, were the changes immediate or did it take time for the car to adjust?

[guybo]

Originally Posted by CFutGwai

Just curious, what is your overrun rpm delta set to?

Also, were the changes immediate or did it take time for the car to adjust?

I never changed the overrun rpm delta. I don't even know what that is TBH. The changes were immediate after I flashed the tune. Even cold my car popped just changing the B table you see above.

[CFutGwai]

Originally Posted by guybo

I never changed the overrun rpm delta. I don't even know what that is TBH. The changes were immediate after I flashed the tune. Even cold my car popped just changing the B table you see above.

Hmm interesting.. i guess there's more to the 17',s then.. I can't seem to get any results..

[guybo]

Are you catless? My 2016 is catless and the Works Muffler is fairly loud too.

[CFutGwai]

Originally Posted by guybo

Are you catless? My 2016 is catless and the Works Muffler is fairly loud too.

Not fully catless.. still got oem FP.

[wasabiseaweed]

Originally Posted by guybo

Are you guys catless? Because even at -5 I got gunshots sometimes. Hell at -9.96 I got AK47 gunfire!

I went back and re-did my tune (changed FFS and LC too) and I changed the B table some and I'm popping again. not a lot of burbling though (my new Works axleback really changes the sound from when I had a Berk dual exit). It sounds good now.

Between 2800-4000 RPM I advanced the timing because in that range it gets obnoxious

I think I’ve figured it out now. The trick is to floor it, start decelerating, and lightly feather. The harder you floor it, the louder the pops when you’re feathering. Exhaust temp also has a lot to do with it. The harder you’ve been driving, the louder the shots. I took a couple of vids, I’ll see if I can get them posted.

EDIT:

[CFutGwai]

Originally Posted by wasabiseaweed

I think I’ve figured it out now. The trick is to floor it, start decelerating, and lightly feather. The harder you floor it, the louder the pops when you’re feathering. Exhaust temp also has a lot to do with it. The harder you’ve been driving, the louder the shots. I took a couple of vids, I’ll see if I can get them posted.

EDIT:

What kind of numbers are you using?

[wasabiseaweed]

Originally Posted by CFutGwai

What kind of numbers are you using?

The same numbers as someone with a yellow FRS in here. Should be -15 in the .15 column and -6 in the .20 column. I also made it so that I get no pops under 3k rpm since it can get kind of loud in parking garages or when I’m downshifting next to a cop 😅.

[Evangelion]

Ok so I can't figure this out. I have the same charts on my 2017 86 but it still cant produce any popping. I have an n1, Tomei UEL, and invidia FP fully catless. Can anyone clue me in? I'm starting to believe that it's because it's an automatic that it doesn't work.

[CFutGwai]

Originally Posted by wasabiseaweed

The same numbers as someone with a yellow FRS in here. Should be -15 in the .15 column and -6 in the .20 column. I also made it so that I get no pops under 3k rpm since it can get kind of loud in parking garages or when I’m downshifting next to a cop 😅.

This did the trick for me.. now I can get the car to pop on command.. Time to fine tune and dial in the pops to something a little more acceptable

Originally Posted by Evangelion

Ok so I can't figure this out. I have the same charts on my 2017 86 but it still cant produce any popping. I have an n1, Tomei UEL, and invidia FP fully catless. Can anyone clue me in? I'm starting to believe that it's because it's an automatic that it doesn't work.

There was some people saying that you have to use it in the manual mode. Not sure if this applies for your car but I also changed the .20 column and that did the trick.

[Evangelion]

In paddle shifter mode? And does it pop only when downshifting? And what do you mean .20 column?

[guybo]

@steve99 Do you think or have experience with the pop & backfire tune modification damaging an engine? I think it'd damage cats over time (unburnt fuel is known to damage cats) but in an engine with no cats at all, can this tune do any damage?

I hear differing opinions and first hand experiences. I haven't read or heard about anyone with this tune actually doing damage, I have read about people running this tune just fine for a year or more. But I value your opinion over most- do you think it's safe?

[steve99]

Originally Posted by guybo

@steve99 Do you think or have experience with the pop & backfire tune modification damaging an engine? I think it'd damage cats over time (unburnt fuel is known to damage cats) but in an engine with no cats at all, can this tune do any damage?

I hear differing opinions and first hand experiences. I haven't read or heard about anyone with this tune actually doing damage, I have read about people running this tune just fine for a year or more. But I value your opinion over most- do you think it's safe?

Ive been doing these tunes for people for two or more years. I dont do it on turbos only NA and i dont add fuel, i do ignition retard only.

Ive not had anyone complain or come back, except for more pops usually.

Its just doesnt work if you have stock catted header, doesnt rearly work with catted headers at all.

Works ok with catless header and stock catred front pipe and a catback.

As i dont add extra fuel just retard the fuel will be burnt late hence the pops.

The pops obviously cause pressure spikes so its possible it could damage stock ceramic cats but had no one to date with an issue. Its also possible it could dislodge muffler packing material, but again not had any conplaints, must have done 30 plus people myself pluss suppied lots of tunes to people.

Unlikely it would damage the aftermarket metalised cats.

I always tell people it possible, but it does seem unlikely given the number of people doing tgis mod and the time frame of over two years.

The stock tunes on these cars run extremly rich 10.7 afr at high rpm this we assume is to cool cats and extend their life or more likely their efficiency over time. Most tunes run about 12 afr so cats will likey get hotter than stock this is probably more likey tgis will reduce their efficiecy at converting gasses as well.

[Evangelion]

Originally Posted by steve99

Ive been doing these tunes for people for two or more years. I dont do it on turbos only NA and i dont add fuel, i do ignition retard only.

Ive not had anyone complain or come back, except for more pops usually.

Its just doesnt work if you have stock catted header, doesnt rearly work with catted headers at all.

Works ok with catless header and stock catred front pipe and a catback.

As i dont add extra fuel just retard the fuel will be burnt late hence the pops.

The pops obviously cause pressure spikes so its possible it could damage stock ceramic cats but had no one to date with an issue. Its also possible it could dislodge muffler packing material, but again not had any conplaints, must have done 30 plus people myself pluss suppied lots of tunes to people.

Unlikely it would damage the aftermarket metalised cats.

I always tell people it possible, but it does seem unlikely given the number of people doing tgis mod and the time frame of over two years.

The stock tunes on these cars run extremly rich 10.7 afr at high rpm this we assume is to cool cats and extend their life or more likely their efficiency over time. Most tunes run about 12 afr so cats will likey get hotter than stock this is probably more likey tgis will reduce their efficiecy at converting gasses as well.

Would you by chance able to do backfire tunes on the 2017 86 models? If so I would be interested in buying considering I can't figure out why it won't work for me.