Those of you who have self-tuned 2-Bar Speed Density with FMU

_l_DeViL_l_ · 09-15-2009, 08:18 PM

Whether it be using EFILive, HPTuners, or whatever other program you've used to tune, can you screenshot your VE table for me? I just want to see what it looks like. Mine looks like it has been chopped down when I hit the boost region (105 kpa-200kpa), and it just seems a little odd to me. Right now I'm just doing part boost and part throttle, haven't gone WOT yet. Frankly the way it looks is making me nervous about going WOT. I look at tunes on the HPTuners forum and they are a straight linear progression all the way through, which is making me wonder if the FMU has something to do with all this.

I've tuned the VE table in the non-boosted region and all the cells mostly hit -3 with only a few in the higher regions (95-100kpa) hitting -4, so really those aren't in bad shape at all.

Originally when I first setup the 2-Bar VE Table it looked like a smooth linear progression, but when any boost my Open Loop fueling would hit 10.9 A/F ratio when I'm commanding 11.7 through the PE Table. Since Open Loop fueling references the VE Table and PE Table, I lowered the values in the VE table in an attempt to lean out the A/F mixture a bit. And it did work. Now at around 1-3 psi I get about 12.2 A/F and 4-6 psi I get about 11.4 A/F. I haven't gone any further than that as by the time I would hit 10psi I'm going way too fast on the road.

So basically the VE table is working how it should work, you hit Power Enrichment mode, the computer goes in to Open Loop zero'ing out the LTFT and STFT's and referencing the VE Table and PE Table for fueling. Still though, its weirding me out that my table looks like this and I have yet to see anyone else's table look like mine. The second picture shows best what I'm talking about. As you can see it looks chopped downward. I dunno am I just worrying over nothing or does anyone know if I'm just doing this wrong?

http://img5.imageshack.us/img5/4696/vetable1.png
http://img21.imageshack.us/img21/8486/vetable2.png

the SS show · 09-16-2009, 11:18 AM

that is a very odd looking table. i dont personally use a fmu but i have helped tune cars for a couple of friends that had them. their tables looked pretty wierd also. an fmu is not very precise at all and tend to have swing in the a/f. you never said if you are using a wideband or not but i would assume that if you were tuning wot that you would. i would keep a sharp eye on the wideband.

_l_DeViL_l_ · 09-16-2009, 08:11 PM

Yeah I use an Innovate LM-1. Originally I tuned the truck on 1bar, stock computer system, and strictly using the FMU for adjusting A/F ratio. Truck ran fine but I wanted to fine tune it so I bought the 2bar map sensor and ordered HPTuners. The FMU isn't really as bad as its made out to be, at least not in Virginia weather. I have two settings I use, one for summer and one for the rest of the year and the A/F is pretty stable.

You said you have tuned other's who used an FMU, what was weird looking about their tables? Any similarities?

Also, I know there are a few people on here who have done 2bar with an FMU so how have you guys adjusted the trucks

the SS show · 09-18-2009, 11:51 AM

the two i have worked on were done two different ways. one the ve table was mapped with the engine na. then when the turbo was added the fuel tables and maf transfer functions were the only things changed. it ran alot better than the other one but it took weeks to get the tune right. the other was done like you are doing and it ran ok. they were different setups and that will account for some of the difference in the trucks performance. the one modeled like you are doing had tables that looked like 3d models of the rocky mountains haha... hptuners has a tune repository on thier website and can saye you tons of time.

_l_DeViL_l_ · 09-19-2009, 10:09 PM

The more I think about it, I bet my table would actually be a bit more linear if I got the LTFT and STFT's damn near perfect (+-1% difference). Right now I'm at -3% for the majority of the non-boost region and I figured that is good enough, but I bet I could take that entire table from 0 to 105 kpa and say decrease it by -2 or -3 and it would be fairly close to perfect. On top of that it would look linear instead of chopped at 110kpa. I'll have to play with that later. For now I'm going to continue experimenting with the boosted region. So long as the fuel trims are negative both STFT and LTFT go to 0 when you hit Open Loop so it doesn't matter too much what they are at. I'll keep this thread open to report my results in tuning. Thanks for your help.

09-15-2009, 08:18 PM	#1
_l_DeViL_l_ Registered User Join Date: Sep 2007 Posts: 100 Location: User is: OffLine	Those of you who have self-tuned 2-Bar Speed Density with FMU Whether it be using EFILive, HPTuners, or whatever other program you've used to tune, can you screenshot your VE table for me? I just want to see what it looks like. Mine looks like it has been chopped down when I hit the boost region (105 kpa-200kpa), and it just seems a little odd to me. Right now I'm just doing part boost and part throttle, haven't gone WOT yet. Frankly the way it looks is making me nervous about going WOT. I look at tunes on the HPTuners forum and they are a straight linear progression all the way through, which is making me wonder if the FMU has something to do with all this. I've tuned the VE table in the non-boosted region and all the cells mostly hit -3 with only a few in the higher regions (95-100kpa) hitting -4, so really those aren't in bad shape at all. Originally when I first setup the 2-Bar VE Table it looked like a smooth linear progression, but when any boost my Open Loop fueling would hit 10.9 A/F ratio when I'm commanding 11.7 through the PE Table. Since Open Loop fueling references the VE Table and PE Table, I lowered the values in the VE table in an attempt to lean out the A/F mixture a bit. And it did work. Now at around 1-3 psi I get about 12.2 A/F and 4-6 psi I get about 11.4 A/F. I haven't gone any further than that as by the time I would hit 10psi I'm going way too fast on the road. So basically the VE table is working how it should work, you hit Power Enrichment mode, the computer goes in to Open Loop zero'ing out the LTFT and STFT's and referencing the VE Table and PE Table for fueling. Still though, its weirding me out that my table looks like this and I have yet to see anyone else's table look like mine. The second picture shows best what I'm talking about. As you can see it looks chopped downward. I dunno am I just worrying over nothing or does anyone know if I'm just doing this wrong? http://img5.imageshack.us/img5/4696/vetable1.png http://img21.imageshack.us/img21/8486/vetable2.png
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09-16-2009, 11:18 AM	#2
the SS show SVT this... Join Date: Aug 2008 Posts: 31 Location: palestine tx User is: OffLine	Re: Those of you who have self-tuned 2-Bar Speed Density with FMU that is a very odd looking table. i dont personally use a fmu but i have helped tune cars for a couple of friends that had them. their tables looked pretty wierd also. an fmu is not very precise at all and tend to have swing in the a/f. you never said if you are using a wideband or not but i would assume that if you were tuning wot that you would. i would keep a sharp eye on the wideband.
	[Reply w/Quote]

09-16-2009, 08:11 PM	#3
_l_DeViL_l_ Registered User Join Date: Sep 2007 Posts: 100 Location: User is: OffLine	Re: Those of you who have self-tuned 2-Bar Speed Density with FMU Yeah I use an Innovate LM-1. Originally I tuned the truck on 1bar, stock computer system, and strictly using the FMU for adjusting A/F ratio. Truck ran fine but I wanted to fine tune it so I bought the 2bar map sensor and ordered HPTuners. The FMU isn't really as bad as its made out to be, at least not in Virginia weather. I have two settings I use, one for summer and one for the rest of the year and the A/F is pretty stable. You said you have tuned other's who used an FMU, what was weird looking about their tables? Any similarities? Also, I know there are a few people on here who have done 2bar with an FMU so how have you guys adjusted the trucks
	[Reply w/Quote]

09-18-2009, 11:51 AM	#4
the SS show SVT this... Join Date: Aug 2008 Posts: 31 Location: palestine tx User is: OffLine	Re: Those of you who have self-tuned 2-Bar Speed Density with FMU the two i have worked on were done two different ways. one the ve table was mapped with the engine na. then when the turbo was added the fuel tables and maf transfer functions were the only things changed. it ran alot better than the other one but it took weeks to get the tune right. the other was done like you are doing and it ran ok. they were different setups and that will account for some of the difference in the trucks performance. the one modeled like you are doing had tables that looked like 3d models of the rocky mountains haha... hptuners has a tune repository on thier website and can saye you tons of time.
	[Reply w/Quote]

09-19-2009, 10:09 PM	#5
_l_DeViL_l_ Registered User Join Date: Sep 2007 Posts: 100 Location: User is: OffLine	Re: Those of you who have self-tuned 2-Bar Speed Density with FMU The more I think about it, I bet my table would actually be a bit more linear if I got the LTFT and STFT's damn near perfect (+-1% difference). Right now I'm at -3% for the majority of the non-boost region and I figured that is good enough, but I bet I could take that entire table from 0 to 105 kpa and say decrease it by -2 or -3 and it would be fairly close to perfect. On top of that it would look linear instead of chopped at 110kpa. I'll have to play with that later. For now I'm going to continue experimenting with the boosted region. So long as the fuel trims are negative both STFT and LTFT go to 0 when you hit Open Loop so it doesn't matter too much what they are at. I'll keep this thread open to report my results in tuning. Thanks for your help.
	[Reply w/Quote]