Can someone explain the Ramp on Rate parameter to me? Does increasing it or decreasing it make DFSO come on quicker? I'm trying to do a mild burble tune on a 2015 Mustang while still leaving DFSO enabled. I don't want the never-ending popcorn. I just want it to pop a little bit and then hit DFSO when I let off. I reduced the torque ratio clips, but DFSO comes on so fast that it barely pops. Any advice?
It does exactly what it says it does, ramps in fuel cut over the set time. The longer the time, the longer it takes for decel fuel cut to engage.
I've used it for limiting burble before, works pretty well... Though at the factory 1.75s it's good enough for me for the occasional pop/burble.
Perfect! It didn't have a description in VCM Editor so I didn't know if the value I was putting in was 'seconds' or like the torque rate reduction or something. That's exactly what I needed. Mine was set to 0.9 so that explains why it came on so fast. I'm going to set it to 2.0 and see if that does the trick!Originally Posted by Seishuku
Update: This doesn't seem to work. I put 4.5 in there, and I still had no change. 4.5 seconds would be a long transition into DFSO and should in theory lead to a ton of pops. Yet, in my log, I see my spark reduce but then my widebands go to 2.0 Lambda just as quickly as before.
2024-03-22 Short Drive.hpl
Interesting... I know it works on my Ecoboost, because I had it set to 5 seconds once and I was getting annoyed with how much time that actually is for fuel cut to kick in. lol
I don't think it would matter being SD vs MAF, but maybe someone more experienced in 5.0 tuning would know better.
I would suggest maybe trying a full write (assuming you're not already doing so), but I don't think that would help really.
Yeah I'm not sure how a full write would change anything. The Ramp on Rate is part of the Calibration, so I doubt it's that. I'm thinking we either don't understand that variable or maybe there's an additional parameter (or parameters) on the Coyote that affect DFSO entry. Would be nice if HP Tuners actually had a description for that particular variable.
Another interesting thing is that my scanner always says Fuel Cut is off, which isn't correct either. I know because I can watch the widebands go to 2.0 lambda. So, obviously, fuel cut is happening. In my case, it happens about one second after I take my foot off the gas. Not enough time for torque management to ramp down spark and get some pops. I wanted it to just take 2-3 seconds to cut fuel so I could get a couple of pops and bangs before fuel cut takes effect. If anyone from HP sees this, any help would be appreciated. I also have a separate thread for my 2021 F-150 where I can't get the burble logic to work despite it being included on the newer Ford vehicles. Frustrating...
This has been my experience as well. Many of the DFSO parameters don't have any effect. I can either turn it "off" or "on" via speed or RPM limits, but its behavior other than that seems to be a mystery.
Yeah I wish we had some more control. I'm sure there is some way to control it that HP Tuners just hasn't exposed to us via the DFSO parameters. Frustrating. I ended up setting the Ramp on Rate to 50 with seemingly no effect. I did set the Spark Ratio Config for DFSO to 0.050 which is supposed to let 95% of the torque reduction happen by spark reduction. So, that gives me a couple of burbles and usually one or two big pops before DFSO kicks in. But we are talking within the span of 1-2 seconds. I wanted it to last 3 seconds or so before DFSO. Just wish we could mess with that transition time.
FWIW, I have the same issue with the Gen V GM platform. There's seemingly no way on that platform to control the DFCO Entry time like there is on the older Gen 3/4 GM platforms.
The DFSO ramp rate is described differently in competing tuning software. It sounds more like it's a torque ramp off rate. If that's true, then higher would be shorter time. I tried changing mine from 1.2 to .5 this morning and it seems to last longer but I need to drive it more to confirm.
Mine was 0.9. I tried raising it a bunch and I've tried lowering it down to something like 0.2. Neither change seemed to make a difference on my car. I suspected I might have had the concept backwards, but after testing it kind of seems like it doesn't do anything to affect the DFSO entry time. If it's a torque ramp off, a higher value would cause it to reduce torque quicker. Given a fixed DFSO entry time, this would be the direction I would want to head in. The more torque it pulls during that time, the lower the Spark Advance (more pops).
I had to artificially lower my mbt for it to make any appreciable crackles. Also you might need to lower the dfco spark only torque ratio. I think stock is .7, so maybe drop it to 0 and see how it affects it.
Yeah I lowered it to 0.050
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