I'm trying to know how to disable DFCO and get lots of flames with no luck. what other things should I do other than disabling DFCO?can you show me a before and after files?
Thank you in advance
I'm trying to know how to disable DFCO and get lots of flames with no luck. what other things should I do other than disabling DFCO?can you show me a before and after files?
Thank you in advance
Retard ignition in decel areas, make sure you have no cat converters and a good straight through exhaust... lol
lolQuote:
I NEED flames
This is something I have been playing around with on a few vehicles. Try setting all idle tables to 0 degrees above 2000 rpm, in addition to tweaking DFCO. With DFCO you can try leaving it on and setting the timing to 0 degrees or something negative, or you can turn DFCO off.
Is there any risk of damage retarding timing every time you decel? I am hesitant to do go below 0 degrees. I'm going to hypothesize that it is safe, can anyone else provide input here?
From my understanding, if you turn DFCO off your exhaust needs to be hot enough to ignite the unburnt fuel left in the exhaust gas, you also need enough air left in the exhaust stream to allow the fuel to burn. Heat wrapping the exhaust will help with this.
I would like to find a reliable combination to setup a vehicle to shoot flames during decel or between gear... a way to ensure that it happens on almost every wot up shift.
Don't know if anyone cares but I seem to have found the trick, make sure to set timing to 0 degrees or very low during closed throttle at higher rpms and set DFCO timing to 0 degrees. I assume setting the timing negative would yield even a greater result. In addition to this. running rich right before redline makes a big difference. Also I would like to note that I was able to produce the desired effect with repetition and never had to go below 0 degrees of timing.
If you have catalytic converters I wouldn't bother even trying this.
If you have chambered mufflers it will still pop, but will be less likely to create a flame. (One of the test vehicles I used was still able to produce a flame between WOT shifts even with a chambered muffler)
As far as this being safe, it should be as long as you don't make so much heat that the head gets too hot. The quick burn between gears shouldn't add that much more heat to the exhaust valve and head than normal.
I will try this thing on my turbo montecarlo men thanks.for sharing men .....i do care LOL
Well i wasn't TRYING to get this but when my target and actual AFR at 6200-7000 once hit ~10.0 AFR it shot flames pretty well. I wasn't going for that lean on purpose so I adjusted it back. You'll lose power up top and quite a bit on a FI setup going that rich.
There certainly is a power loss from running too rich, but you can set it up to run rich during decel and the transition to decel and leave wot alone, or if you're power falls off after a certain rpm set the rev limiter a little higher, after you would normally shift, and run it rich up there.
^ your speaking of wetting the valves for decel?
there is no table per say that controls fuel at decel, you can run the car in OL and disable DFCO some timing adjustments and should be good to go!
There actually is a table that controls Transient Fueling impact ratio between accel and decel. I remember skewing some transient changes more toward accel. I believe a "1" in this table makes the impact the same, <1 impacts decel settings less and >1 increases transient during decel more.Quote:
Originally Posted by SultanHassanMasTuning
big bump here, 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).Quote:
Originally Posted by VodeAn
Shutting DFCO completely off doesn't seem hard, but where can I find the table to retard timing in the "closed throttle" (idle?) area for certain RPMs?
Thanks in advance.
I sent you a PM. Can you post your technique here so others can learn from it as well?Quote:
Originally Posted by Ihab
Bump. Is turning off DFCO as simple as raising the activation temperature to above 286*F or whatever the max enable temp is?
^yes
you can also log DFCO PID to see on or off
Having trouble finding the DFCO PID. What's the ID tag? What section is it under? Don't see it under Fuel...
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.
https://farm5.staticflickr.com/4539/...1eb1f9b1_o.png
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!
Files attached
So with the new videos of the zr1 shooting flames, supposedly a video released by GM, how are they doing this. I know for a fact they would not be running the car without cats, so they have got to be doing something to provide fuel in the exhaust to burn?
The white flame from the ZR1 is different than the backfire we are looking for between shifts, when rpm drops.
If you look at the video Ihab posted and compare that to GM's video of the ZR1 you'll spot the difference in flame appearance.
The new zr1 "flame" is mostly a 'clean' hot flame (white flame, no orange as you get further from the exhaust tip)
They are not injecting fuel directly into into the exhaust or anything like that. You can see this flame on other vehicles as well, a lot of FI cars with undersized exhaust exhibit this effect (I am not suggesting the ZR1 exhaust is undersized, I'm sure they engineered it to be as big as needed to meet their many requirements) For example, a S480 turbo on a ls motor with a single 3" exhaust out the back will often show a blue/white flame under wot.
We aren't looking for a a visible flame under load, we are looking for a flame between shifts or on decel.
nsogiba, try running less timing, maybe 0 degree or even -5 degrees. Even on bone stock vehicles timing can go negative during TM events. Additionally, to the right of your highlighted point timing increases and then ramps down, you need to look at your timing tables and get it to hold the lower timing, not go from WOT timing to 5 degrees then back up to 20ish and slowly back down like it does in the log. Look at the idle spark tables, not just the main spark tables.
Thanks for the info, do you think a car with stock cats can get the kind of flame we are looking for?