I need FLAMES out of the exhaust (lots of them) can someone help me

[nsogiba]

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 replying, I am still working through this.

Part of the issue what that graph was that I had Idle Timing tables that differed. Specifically, they didn't have much timing retard (if any), whereas the main spark tables did.





So I made some changes to retard timing above 3000 rpm at cylinder airmass values in the Idle tables (both in gear and in park, whatever that means since this is a 6 speed manual C5) to match - now I can get a really steady and angry crackle on decel. However, this only occurs with a tiny bit of throttle input on decel (don't recall exactly how much, but only a few % I'd say). I wonder if this has something to do with the "Tumble Flap Closed" values, which by the description decides when the PCM disables main spark tables (what does it start using then? Idle tables?)



My settings seem to have the main spark tables permanently disabled since I'll never go above 250 mph - but going above 1.2% will also do something - so I wonder if that overrides that max speed requirement. Is it one or the other, or must both values be satisfied to enable that effect? Also, does it use Idle Tables when it's not using main spark?

Finally, the last thing I'm looking for is to retard timing DURING a shift (only while No Lift Shifting using N2MB WOTBOX). Is there some sort of condition in which the g/cyl or cylinder airmass changes during a no-lift shift that I can take advantage of to fool the PCM into retarding timing?

I will work on posting up a log during some No lift shift events

[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