DIY Rom tuning for exhaust pops and backfires W/ romraider

[_gt86_user]

Originally Posted by donthaveoneyet

pretty sure it's safe, i currently have a 92 SC400 with the 1uz V8 and it crackles sometimes when warm simply because the engine runs so rich. it's completely stock by the way with 244k miles, so yea, safe i guess.

Not exactly the same thing that's going on here. Artificial vs. natural.

[eddieflyinv]

well to be honest I dont want to be hitting my gas pedal to make the pops lol
I understand why alot of you guys like it this way, but my personal preference would be for it to happen on its own
especially considering the way I drive in the city and highway as it results in aloooott of very very light throttle application, rarely do I use more than like 10% throttle application on a normal drive (logged it lol i was kinda surprised)
but yes my goal is to create the same effect but without the pedal application, looked into some threads on romraider forums with the sti's and it seems the combination of the above, while also changing the Base Idle Timing (above speed threshold) would do the exact same thing without any effect to low speed drivability. the intensity of the pop resulting from changes in the Idle timing,
Also read that it could improve drivability as far as the lurching/uncomfortable choppiness when coming off throttle fast in low speed driving, it should theoretically smooth out the transition (aka stop and go highway driving using mostly 1st & 2nd where the car lurches alot) and when coming back on I read that I should be aware that tip in enrichment may need modification to further smooth out going back on throttle from overrun

Idn, im going to try it out anyways and see what it does, and I will report back here with what I come up with in case anyone else cares to try it as well
I mean my buddy has a catless 3.8L genesis that backfires like a shotgun from time to time... and no one has bothered him lol mine would be more sublte and at least I can adjust/change the intensity if it is too much

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[Snyperiflex]

Originally Posted by eddieflyinv

well to be honest I dont want to be hitting my gas pedal to make the pops lol
I understand why alot of you guys like it this way, but my personal preference would be for it to happen on its own
especially considering the way I drive in the city and highway as it results in aloooott of very very light throttle application, rarely do I use more than like 10% throttle application on a normal drive (logged it lol i was kinda surprised)
but yes my goal is to create the same effect but without the pedal application, looked into some threads on romraider forums with the sti's and it seems the combination of the above, while also changing the Base Idle Timing (above speed threshold) would do the exact same thing without any effect to low speed drivability. the intensity of the pop resulting from changes in the Idle timing,
Also read that it could improve drivability as far as the lurching/uncomfortable choppiness when coming off throttle fast in low speed driving, it should theoretically smooth out the transition (aka stop and go highway driving using mostly 1st & 2nd where the car lurches alot) and when coming back on I read that I should be aware that tip in enrichment may need modification to further smooth out going back on throttle from overrun

Idn, im going to try it out anyways and see what it does, and I will report back here with what I come up with in case anyone else cares to try it as well
I mean my buddy has a catless 3.8L genesis that backfires like a shotgun from time to time... and no one has bothered him lol mine would be more sublte and at least I can adjust/change the intensity if it is too much

Sent from my LG-H812 using Tapatalk

I'm interested in what you're saying. It would be nice to have the exhaust pops off-throttle, with engine speed's above say 3k rpm.
I don't think it will be annoying, several newer sports cars do this on purpose as well
Jaguar F-type, Porsche Cayman GTS, Mercedes A45 AMG, etc.

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[_gt86_user]

It's possible to do without the "feathering" technique, it's hard to find the sweet spot between popping corn kernels and loud shotgun bangs, also it's hard to get the consistency of the time between pops usually you end up with ppppop-POP OR POP----POP it would just be nice to find that range for a nice refined crackle that happens a relatively quick but I suppose the exhaust setup comes into play as well when trying to tune for a specific sound.

[HoustonM]

I'm still wanting to see somebody come up with rotational idle? Anyone?


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[Kodename47]

Originally Posted by HoustonM

I'm still wanting to see somebody come up with rotational idle? Anyone?

I assume you mean lumpy idle? If so I don't think its been done yet.

[HoustonM]

Originally Posted by Kodename47

I assume you mean lumpy idle? If so I don't think its been done yet.

Yes sir


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[eddieflyinv]

Originally Posted by Snyperiflex

I'm interested in what you're saying. It would be nice to have the exhaust pops off-throttle, with engine speed's above say 3k rpm.
I don't think it will be annoying, several newer sports cars do this on purpose as well
Jaguar F-type, Porsche Cayman GTS, Mercedes A45 AMG, etc.

Sent from my SM-N910T using Tapatalk

well I will update on friday, unfortunately have to wait till then to test it out (day off, no time during the week for logging etc)

I think using just 2 of the tables I mentioned should work (Enrich RPM Delta Activation & Initial Injector Enrichment)
but I did add Kodename47`s additional DEF files to RomRaider, and it changed some related tables, there`s more to the Fueling Cut Counter RPM Threshold table than I thought there was before adding those DEF`s so there may be something else going on that will interfere but I will just have to see when it comes to that...

[rawafoo]

Yea i get that small popcorn pops and if i just hold the peddle right befor the sweet spot and hold it results in a Huge Gunshot sound and a beautifull backfire but it happens mostly on 2nd and 3rd gear on high rpms
so if someone could find out how to make those Loud Gunshot sounds come on more often then that would be cool !
Im running N1 Catback and Tomei Uel header and catless overpipe and frontpipe

[orangespark]

Set my 0.15 to -10 and the overrun fuel to 6000.
I have around 135km on the new ROM. I am getting, a jerky motion when decelerating sometimes but no backfires or engine pops yet.
Dreams shattered

[_gt86_user]

Originally Posted by orangespark

Set my 0.15 to -10 and the overrun fuel to 6000.
I have around 135km on the new ROM. I am getting, a jerky motion when decelerating sometimes but no backfires or engine pops yet.
Dreams shattered

Yeah don't touch the overrun fueling, just he base
Timing B for the feathering technique.

[eddieflyinv]

well looks like I wont be testing this. My OFT crapped out on me. Been trying to work it out all day but she is toast I think

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[Jonathanlim]

Hey guys i'm new and i am really liking this. I don't know how to use rom raider. Can anyone help me on what i need to change for this?

Thanks

[_gt86_user]

Originally Posted by Jonathanlim

Hey guys i'm new and i am really liking this. I don't know how to use rom raider. Can anyone help me on what i need to change for this?
Thanks

Just change Base timing B (from 0 to -15), look back a few pages for a screenshot and use those numbers as a starting point..not going to walk you through it, search for the thread for rom raider DIY's. You will also have to feather the throttle for the effect to happen.