Transients in HP Tuners - anyone have these figured out? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

cc-rider · 04-04-2016, 01:30 PM

Seems that the transients in the E38 ECU are somewhat of a tough bugger to get right. Been reading a ton over at HP Tuners forum and there are a lot of people who have been playing with these for a long time and still can't seem to get the result they are looking for.

Anyone here mastered the transients? I'm getting the typical lean tip in (and rich tip out) that comes with transients not being set properly. This causes some rather nasty KR sometimes.

These PD superchargers can get into boost pretty damn fast and at low rpms. They need some transient help. The stock LS3 settings aren't even close.

gennro · 04-04-2016, 02:45 PM

Yeah this would be great to have some info on this.

supergt99 · 04-04-2016, 07:36 PM

im with these guys, need info as well.

cc-rider · 04-07-2016, 10:58 PM

No responses. I find that very interesting. Either some of the big hitter tuners don't have this figured out either...or they don't want to give any information.

2012LS3VERT · 04-12-2016, 02:15 AM

The transient settings have more to do with injector spray patterns than anything else. They really shouldn't be used to correct major issues in the tune. Generally, if the VE table is correct, and the injector is spraying at the back of the intake valve, only minor changes are necessary in the transient tables. Most lean/rich spikes are a symptom of running MAF only, whereas when running blended mode the VE table also takesee in filtered MAF data to get the fueling right. Anyone who has tuned/ridden in a Ford lightning/HD truck has seen this in bone stock vehicles (because they are MAF only from the factory). The PD blowers generally just need good VE and MAF data.

2012LS3VERT · 04-12-2016, 02:22 AM

To be specific, they are used to compensate how fast the fuel evaporates off the port wall when transitioning to open the throttle, and how much fuel puddles when the throttle is closing. This is and ECT vs injector function more than anything. As one might imagine, there isn't a lot of fuel puddling and evaporating off the port walls when the injector is pointed correctly at the back of the intake valve, which is why big changes to the settings don't do a lot.

04-04-2016, 01:30 PM	#1
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,179	Transients in HP Tuners - anyone have these figured out? Seems that the transients in the E38 ECU are somewhat of a tough bugger to get right. Been reading a ton over at HP Tuners forum and there are a lot of people who have been playing with these for a long time and still can't seem to get the result they are looking for. Anyone here mastered the transients? I'm getting the typical lean tip in (and rich tip out) that comes with transients not being set properly. This causes some rather nasty KR sometimes. These PD superchargers can get into boost pretty damn fast and at low rpms. They need some transient help. The stock LS3 settings aren't even close.

04-04-2016, 02:45 PM	#2
gennro Drives: 2011 Black 2SS Join Date: Mar 2016 Location: Nevada Posts: 53	Yeah this would be great to have some info on this.

04-04-2016, 07:36 PM	#3
supergt99 Drives: 2013 Camaro SS 1LE Join Date: Oct 2014 Location: earth Posts: 288	im with these guys, need info as well.

04-07-2016, 10:58 PM	#4
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,179	No responses. I find that very interesting. Either some of the big hitter tuners don't have this figured out either...or they don't want to give any information.

04-12-2016, 02:15 AM	#5
2012LS3VERT Drives: 2012 2SSRS Vert, Black w/M6 Join Date: Jan 2013 Location: Montgomery, AL Posts: 1,265	The transient settings have more to do with injector spray patterns than anything else. They really shouldn't be used to correct major issues in the tune. Generally, if the VE table is correct, and the injector is spraying at the back of the intake valve, only minor changes are necessary in the transient tables. Most lean/rich spikes are a symptom of running MAF only, whereas when running blended mode the VE table also takesee in filtered MAF data to get the fueling right. Anyone who has tuned/ridden in a Ford lightning/HD truck has seen this in bone stock vehicles (because they are MAF only from the factory). The PD blowers generally just need good VE and MAF data.

04-12-2016, 02:22 AM	#6
2012LS3VERT Drives: 2012 2SSRS Vert, Black w/M6 Join Date: Jan 2013 Location: Montgomery, AL Posts: 1,265	To be specific, they are used to compensate how fast the fuel evaporates off the port wall when transitioning to open the throttle, and how much fuel puddles when the throttle is closing. This is and ECT vs injector function more than anything. As one might imagine, there isn't a lot of fuel puddling and evaporating off the port walls when the injector is pointed correctly at the back of the intake valve, which is why big changes to the settings don't do a lot.