DIY Rom tuning for exhaust pops and backfires W/ romraider
 

did some testing and changes to achieve a noisier exhaust. no damage to anything so far and barely any changes in gas mileage(.1 L/100km).

with just ignition base timing A modified, no pops produced. ignition base timing B produced some pops, but not as aggressive. i ended changing both ignition base timing maps A and B to -10* timing in the lowest load column(.15g/rev). with the lowest load at negative timing, it kind of made the throttle an on/off switch for the pops. you wouldn't reach that engine load when normally driving or when decelerating. but if you gave it the slightest bit of throttle to that sweet spot, it would spit pops and become obnoxious. but everyone loves it. changing the full decel engine load value to negative timing doesn't produce pops for some reason. but its better to not have pops at full decel because you don't want to constantly become a pack of firecrackers when coming to a stop.

after messing with the ignition maps, i started looking into fueling. with the overrun enrich rpm delta activation set to 6000, the pops were alot more aggressive and rally sounding, as opposed to before where it sounded like you were running over a bunch of pop cans.

trying to achieve flames but i think this is as far as im going. i don't want to break stuff

UPDATE 3/16/2015 wow hard to believe this was a year ago.. just an update
don't mess with fueling or overrun. it was probably more placebo effect than it actually doing anything. just do ignition map B. A is a limp map. read through the whole thread before you attempt this on your own car

UPDATE #2 hahaha seeing this again reminded me of my ricer days. glad alot of you are enjoying this!
dirty clip of when it there was no catback. follow me on ig!

https://www.instagram.com/p/wz5XYVRD...anesespaceship

http://i.imgur.com/zwkqmKe.png

will get some driving videos up. just need a exterior camera mounting solution


exterior video!
[ame="https://www.youtube.com/watch?v=OGMrf382Kx4"]https://www.youtube.com/watch?v=OGMrf382Kx4[/ame]


bored @ a railroad crossing under a roof
[ame]http://youtu.be/ghEAXxeHYcU[/ame]

[ame]http://youtu.be/CMDSWnLG2N0[/ame]

[ame]http://youtu.be/c2VgspN8oBQ[/ame]

awesome.

this is desirable???

so dope. if you could get the pops to sound a tad deeper in tone, that would be perfect.

2nd video sounds like fireworks in the distance. This is it
3rd video it died out?

I don't want to sound like a smartass but what's the point of that ?

because racecar??

the 3rd video was the first map i made. not as loud

yep it's sounds great:thumbup:
also the new mercedes cla 45 amg have the same exhaust pops
[ame="http://youtu.be/zkcoeg4Tyd4"]http://youtu.be/zkcoeg4Tyd4[/ame]

Must be a california thing. Most of the trends out there haven't caught on here yet. Thank god.

Got bored. Tried it. Nothing. But then Again I still have stock over pipe and front pipe and a greddy sp style exhaust. Oh and it wasn't really warmed up so maybe I will hear something after driving it around.

I love the idea. As long as it doesn't hurt any thing to for it.

I don't know why but I love that sound, when it's done right. Options for the OFT @shiv@vishnu? So long as it's safe.

Need some ecutek guru's in here

there is already another thread on this, and Shiv already told that it would be added to OFT :)

@nelsmae @jamesm

Thanks for doing this Andrew, I have a feeling it's not going to work very well on my temporarily stock exhaust setup... or will it?

Update: Works fine after you get the pedal feel right. Popcorn on demand :party0030:

Once my OFT arrives I will be doing this

just did this to mine, i have the Borla UEL header, factory overpipe, factory front pipe, vibrant muffler, factory muffler delete.....

below 4500rpm, it sounds like intermittent popcorn popping in the microwave....above 5000rpm.....yea lol..... it sounds like someone shooting a gun at times....super loud! i will try to take a video one day and have someone following me recording cause it sounds like there would be fireball pops being how loud it pops at times above 5K rpm =)

Hrmm I made the changes and got nothing. I do have a catted header though?

i dont know if this is what your doing but reving the engine in neutral didnt really cause much backfiring, its when i was driving, rpm hovering around said RPM, feathering the gas pedal is what caused the poping

stay on the gas just a bit when letting it rev back down and that will give it the extra fuel. There seems to be a sweet spot that gets the correct fuel in the exhaust. My headers cat has gone missing though.

The next tuning adventure should be to find out if we can get ghost cams at idle...

this........ is such a good.... bad idea...... :)

Does it crackle on gear changes?

[ame="https://www.youtube.com/watch?v=WsUsno-Mv2E"]https://www.youtube.com/watch?v=WsUsno-Mv2E[/ame]

Mine is popping like mad now. Nice tone to it as well.

Prove it!

Haha Yea I should get a video with the GoPro. Went on a rally today so I will see if anyone got some clips.

Proof... did it take a while for the popping to begin? I made the changes in RomRaider and just barely notice it.

Yes it did. In fact it took most of 80 miles for it to even begin. But once it did I can get it to do it on command. Once you find the sweet spot its a little fun. But at the same time you can prevent it as well.

What changes did you guys make? I'm not sure if I want to mess with it myself or wait until Shiv adds it in.

Follow Andrew's instructions in the first post in changing base timing A and B to -10 in the .15g/rev column. Then overrun to 6000.

Sent from my HTC One using Tapatalk

If done right with the throttle, it will soft pop when changing gears...and after I made the changes to the maps, it was pooping like crazy on the first drive down the street!

Reminds me of my MCS with a pulley and 3" exhaust.

[ame="https://www.youtube.com/watch?v=-La15bfvtEs"]Mini Cooper S Rand Webb Exhaust - YouTube[/ame]

Loved that sound on the mid-low speed off throttle. I didn't tune for that sound, it was just created with the extra boost, exhaust and tune I had. I like the sound if made from a FI car...split on if I like the sound just from a tune. Same sound, I know...but different feels behind them.

My 04 MCS did not pop and burble at all until I tuned it in. The 05-06 MCS had it with the updated engine ECU and it was tuned in. The Facelift 2nd gen MINIs have it tuned in when you turn the sport mode on.

I get a chuckle out of it for sure. But there are many who do not. Just another "To each their own" situations right :)

Didn't realize it was a tuning thing. I always thought is was a condition created by the exhaust layout. Good to know.

There was a way to do it on the dual avcs EJ engines, i'll play around with BRZedit a little tomorrow after work when I have some downtime to see if it's doable.

(I still have stock catback though, so it may be hard to hear unless I unbolt the muffler for testing)

This sounds kind of like antilag, not as aggressive though obviously.

[ame="http://www.youtube.com/watch?v=YWTvjhfDgy8&feature=player_detailpage"]Lancia Delta HUGE Anti-Lag Flames & Backfire! - YouTube[/ame]


I wonder how bad this is for the exhaust valves on these cars.

My exhaust is full stock and am running on E85...
I've done the tune. The pops are there, but nearly non noticeable.
Then I got an engine error code, no idea if the error code is due to this particular tune, or if it is because I did not wait enough for the ECU to learn. In any case, I flashed back to standard E85 tune.

Did anybody else try with a stock exhaust? Do the pop get louder over time?

Been doing some reading and it sounds like it's probably not that good. Curious though how the F-type goes about it safely.

srt4,vq35,vq37,ka24 and LS engines all pop with a catless exhaust just to name a few others. my s14 shot fire balls stock ecu, intake and injectors. it just had a cat delete and buddy club spec 2. i later dissasembled it to go turbo and the valves were fine. never burnt oil either so id take it he valve seals were fine with it too