DIY Rom tuning for exhaust pops and backfires W/ romraider

[wasabiseaweed]

So I ran this tune for a while but got annoyed with the jerkiness when when getting on throttle. Anyone know if you can have this limited to specific gears?

[Vin]

You can limited to certain rpm range, not gear. I toned it down a lot and been driving with it for a while (6 months). Can't live without. I went for slight pops and burbles

[steve99]

Originally Posted by wasabiseaweed

So I ran this tune for a while but got annoyed with the jerkiness when when getting on throttle. Anyone know if you can have this limited to specific gears?

don't start the ignition retard till about 2500 rpm (or even 3000) will be a lot smoother and if you drive below the threshold it wont pop

[guybo]

E85 tune was too jerky when I tried this. I went very conservative and got very little extra sound but all the jerkiness.

Is there any other way?

[wasabiseaweed]

Originally Posted by steve99

don't start the ignition retard till about 2500 rpm (or even 3000) will be a lot smoother and if you drive below the threshold it wont pop

Yeah, I had mine set to 3000- not an issue when I’m cruising around, only during spirited driving. If I’m going around a bend with steady throttle at higher rpm the car starts to jerk. Can be somewhat unsettling at higher speeds.

[jerryzilla]

Anyone's gas mileage decrease tremendously after this tune? Have set to -8 from 3k to 5.7k

Went from almost 28mpg city to almost 17 mpg lol

[guybo]

Mine got a lot worse when I ran this tune on 93

[AbductedCasper]

I saw on some post that some people were able to have the crackles without needing to feather the gas. What am I suppose to edit to achieve that?

[stefodrom]

Hi, its me again.
its getting warmer here in Austria and i started playing around again with the settings.
I still try to get the off throttle Version to work, but something is completely messing up when im at about 3k rpm or higher and doing an downshift.

Is someone from you guys driving an AT and got the off throttle methode to work without the shift issues?

Please help me out, its driving me nuts

[hestekinj]

I started playing around with the off throttle version that eddieflyinv suggested (Thank you!!) and i'm getting some nice pops which I know will wake up even more once I get a catback (currently only have uel header).

My question is, what values would I adjust (also what is a safe range for those values) to achieve more burbles instead of pops? I'm looking to get a sound that's closer to a

(Not sure if I'm allowed to post links here, but look on youtube for 'slawterch' and click on any of his videos for good examples).

I know I won't be able to completely replicate it, but it would be cool to get closer.

Thanks!

[jerryzilla]

[ame="https://www.youtube.com/watch?v=V7yzl2kISd8"]March 18, 2018 - YouTube[/ame]


and

Stage 2 UEL 91 oct tune.
0.15 engine load changed to -15
0.20 engine load changed to -6

[hestekinj]

That sounds good! Ideally I would like to get a similar sound using the 'off throttle' method instead of having to feather the throttle... but I may end up going this route since it sounds good.

Not sure if @eddieflyinveddieflyinv is still around this thread, but in an earlier post i think he mentioned something about increasing the initial enrichment would result in more of a 'burble' sound. what is a safe range for that value? Any other suggestions for getting a burble on off throttle?

Thanks!

[randomthoughts]

Will this also work with my ETune file I have for my SBD turbo?

[eddieflyinv]

Originally Posted by hestekinj

That sounds good! Ideally I would like to get a similar sound using the 'off throttle' method instead of having to feather the throttle... but I may end up going this route since it sounds good.

Not sure if @eddieflyinveddieflyinv is still around this thread, but in an earlier post i think he mentioned something about increasing the initial enrichment would result in more of a 'burble' sound. what is a safe range for that value? Any other suggestions for getting a burble on off throttle?

Thanks!

Lol im kind of around, once in a blue moon. Reading more than posting however and I always get tied up doing something rather than responding to this thread.

Anyways, I am not an expert by any means, but i just played around and read a lot about this and I settled on a few things while experimenting that I think about when I am trying to decide on what I want to change and at what point in the rpm range I want to change it.
some of these points are rather obvious to those that know a thing or 2 about tuning things, or those who have already toyed around with this stuff. Anyways here goes.

1. More aggressive ignition retard = lower positive numbers or higher negatives(eg. +5 to -15) and Less aggressive ignition retard = higher positive numbers (eg. +20 to +5)
2. The noises resulting from your changes in the base timing idle table, will be rpm dependent (eg. +5 at 3000rpm may burble, but +5 @ 6500rpm may crackle)
3. As the above points out, less ignition retard is required in higher rpms to produce crackling
4. and you guessed it, more aggressive ignition retard is generally required in lower rpms to produce crackling
5. The more the ignition is retarded, the more violently the car will crackle, and if you pay attention while driving you will literally feel it happening beneath you (especially singular high rpm ones, theyre like a cannon being fired off beneath you)
6. I found that Initial enrichement tends to display its effects more so in how long the car burbles for, or how many times it crackles after you let off the throttle.
7. * I believe the Initial enrichment values influence how rich or lean the mixture in the exhaust will be when it ignites and that it can have a distinct effect on the sound produced (higher pitched snap/crack or a deeper sounding bang/gunshot)
8. Initial enrichment wastes fuel every time you let off the throttle, keep that in mind if you care about fuel economy, and as @steve99 mentioned some time ago it isnt actually necessary. he was producing crackles etc without any initial enrichment at all (i never thought to try that but plan to the next time I mess around with this)
9. Producing these effects will be done somewhat differently for every car. Some people have used my exact settings and gotten nothing, its kind of up to the user to play around and figure out what does and doesnt work for their particular car & exhaust
*10. Probably the most important part to the control over when or how this is going to happen, is to make sure you rescale the rpm axis in the base timing idle table, and experiment with the rpm values you choose on the table axis. As I mentioned ages ago, leave yourself some of the stock ones, just move then over to the left to give yourself more room to play on the right.
*11. If you have a base timing idle value of -5 @ 4500rpm and -10 @ 5600rpm it is my understanding that @ 5000rpm the timing is going to be somewhere in between those numbers, it will not be -5 until 5600rpm. (Again my understanding based on the ecu interpolating the numbers in between)
So consider the gaps between the numbers on your rpm axis and how those gaps might affect what you are trying to accomplish. You could keep lower rpm gaps tighter and then jump from 4000 to 6500 and have the last column control what happens at all rpms above 6500rpm. Or space them relatively evenly according to how you want to ramp up how aggresive you are towards the higher rpms. Entirely up to you.

I havent touched my OFT aside from logging in quite a while, but I will be messing around with this again sometime soon, and hopefully I can elaborate on the above with some pictures of my tables as examples to indicate x change = x result and so on for those who have trouble grasping the concept or my blurb up there.

Anyways, hope that rambling helped someone :/ lol

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