Transients and Scaling Pecentage

Covers all sn94/95 mustang v8 ecu's.
Killer95GT302
Posts: 21
Joined: 2021 Dec 29, 08:21
Location: Annapolis, Maryland
Vehicle Information: 1995 Mustang GT U4P0

Single Turbocharged 363

Tuned using Tweecer with Binary Editor

Transients and Scaling Pecentage

Unread post by Killer95GT302 »

Does anyone know which transient fuel functions/scalars are supposed to be scaled when scaling the tune for larger injectors? I have a feeling I'm missing one of these.
decipha
Posts: 5164
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Transients and Scaling Pecentage

Unread post by decipha »

fn1321 the tseif table

its got sp**

all scaling percentage values do
Killer95GT302
Posts: 21
Joined: 2021 Dec 29, 08:21
Location: Annapolis, Maryland
Vehicle Information: 1995 Mustang GT U4P0

Single Turbocharged 363

Tuned using Tweecer with Binary Editor

Re: Transients and Scaling Pecentage

Unread post by Killer95GT302 »

Thanks - do transients end up as part of the calculation for LAMBSE, or is the transient value something calculated and used in the background?

I have a tip-in/out issue I'm trying to figure out if its transients or something else. Right now on a sharp tip-in/out (like quick rev) I can see the LAMBSE go way low, AFR goes rich, then it goes way lean even though LAMBSE is not commanded lean, in fact it stays < 1 until AFR stabilizes.
decipha
Posts: 5164
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Transients and Scaling Pecentage

Unread post by decipha »

background

that could be anything but tip out isnt important enough to matter
Killer95GT302
Posts: 21
Joined: 2021 Dec 29, 08:21
Location: Annapolis, Maryland
Vehicle Information: 1995 Mustang GT U4P0

Single Turbocharged 363

Tuned using Tweecer with Binary Editor

Re: Transients and Scaling Pecentage

Unread post by Killer95GT302 »

Tried messing with this in open loop - So I found that the LAMBSE is commanded based on the calculated PERLOAD. I appear to be hitting a pretty high load when stabbing the throttle (in some cases 70 LOAD between 1000 and 1500 RPM) which is causing it to calculate a richer LAMBSE based on fuel table FN1362 and FN035.

I can mess with values if I want I guess to get that under control, and I did to some extent - what I found that I thought was weird was that when I changed things around to have a LAMBSE closer to 1.0 when stabbing the throttle (instead of .88 before), the amount it went lean afterwards also went down. So less fuel went in when stabbing it, but also the amount it went lean afterwards came down too, by about 2 AFR points.

Is there some voodoo going on in the background with transient functions looking at HEGOs even in open loop that see "hey it didn't go that rich, so we don't need to pull as much fuel" - that's the behavior I'm seeing anyways.
Post Reply