Want to tune DFCO and timing to blow flames during shift: 2000 C5

[nsogiba]

Newb tuner looking for some info. Trying to blow some flames with my 2000 C5 6 speed, already has the N2MB WOT BOX installed, but only gets a big backfire once in every 20 No Lift Shifts (which cuts spark). I want to make this something I can do "on demand". Above a certain RPM (say, 4000, would be fine).

Shutting DFCO completely off doesn't seem hard, but where can I find the table to retard timing in the "closed throttle" (transition) area for certain RPMs? Is there a way to retard timing as the clutch is pushed in during a shift?

I realize that this may not be everyone's style, so flame suit on. Thanks in advance.

[ericbedd]

I wish I could help, but I have no pointers for this project. I'm in for a video clip if you get it going, I'm sure you're not going to shoot a flame, but an in the pipe light off is doable.

I think you would need to be catless.

Blowing flames would be the spark plug at the exhaust tip trick. I've seen some mean oldies about melt their paint off.

[nsogiba]

Forgot to mention that I'm running full longtubes and a catless x-pipe. No cats anywhere on the car. Stock exhaust for now but has cutouts well before the mufflers.

Not into the old "spark plug flamethrower hot rod" thing.

[nsogiba]

Here's the effect I am going for:

https://www.youtube.com/watch?v=lxksaZf0OpU

https://www.youtube.com/watch?v=yfq3H9DGDNc

@ 0:55 https://www.youtube.com/watch?v=vlnnh8PTEuc

https://www.youtube.com/watch?v=n747dGnTjQc

Currently this is the effect I'm getting.

https://www.youtube.com/watch?v=ErRCBWG6hQg
just a lot of sputtering and gurgling (like it's supposed to during the 2 step).

[nsogiba]

Here's the most current update...spent a couple hours tonight with mixed results.

I started off my turning the DFCO Enable temp to 280F so that it was disabled. I then altered the Main Spark Table (both low and high octane) to 5 degrees of advance under the following conditions:
2000-8000rpm
.08-.16g (Cylinder Airmass, high vacuum condition)

Only while letting off the gas abruptly was I able to get the "burble/crackle" effect I'm going for, and it was only for an instant. I was watching the live Scanner and did indeed see the timing advance drop to 5* before readvancing up to the 20s and 30s (without any throttle input). If my "theory" is right, I should be getting a bunch of crackle in that RPM window when the cylinder airmass drops under .16g.



Ironically when the car decelerates in gear on its own fairly low in the rev range it begins to pull timing on its own (see the jagged timing to the right of the highlighted point) and the crackle effect gets nice, but it's too low in the rev range to sound good.

I am obviously not in the right table OR something else is interfering with the timing reduction command I've entered.

Here are my tune and logs for those who are able to take a look. I feel like I'm so close!

[nsogiba]

2000 FRC ECS Mail Order Tune - DFCO off and minor timing retard.hpt

long run new timing 2.hpl

[nsogiba]

Here is a log from some No Lift Shift events (full throttle, press clutch to floor, quickly perform shift, release clutch. Never let off the gas). You can follow it by watching the TPS stay close to 99.6%, and speed will actually spike (wheelspin) as I left the clutch out, followed by a drop in revs as it regains traction.





Unfortunately there aren't any big airmass changes which at this point is the only control I have over changing timing during an event like this. But, there must be some other parameter I don't know about that's rapidly changing during a NLS (look at the O2 sensors switching as the mixture goes full rich when the spark gets temporarily shut off). I'd love to take advantage of that and use it as a control to retard timing...

The last ditch effort is adding fuel above 5500rpm (which is where NLS occurs) but this will probably kill some power and have negative effects elsewhere so I'd rather not pursue that

[C5Z51]

Did you ever figure this out?

[Varto20]

Intersting not gonna lie wanted to do the same thing on my chevy caprice 13 auto but couldn't figure it out I wanted it to backfire whenever I changed gears in s mode from 1>2>3>4>5 whenever I Rev it over 4200 so basically whenever I raced someone but still didn't get the perfect idea of how to do it I know that I should go to spark retard the timing on vacuum area on wanted rpm so that will be from 4200 until 8000rpm on let's say just about 0.20 amount of air (vacuum area) then go to my maf table to richen those cells but that's basically it whenever I am at the maf table I get lost should i just richen it to 0.20 based on the spark table that i retarded earlier in general i don't know where to richen the maf table and I don't know how to make it only backfire on those certain rpms at s mode only when I shift manually so if I am at D I want nothing to happen but I couldn't figure it out so I just backed off for now until I get it completely figured out it would be nice if someone put us on the right path and thank you guys

[kingtal0n]

fwiw A completely stock 2L turbo would throw fireballs during a shift if you simply installed an atmospheric bypass and removed the re circulation from the maf sensor.

All the computer needs to do is throw a bunch of unnecessary fuel and wash down the cylinder walls, fuel winds up in the exhaust and foom! fireballs

not good for the engine, those motors would lose 30psi of compression over the next 10 to 15 years because of all the washing.