2005 GTP L32 VE tuning ATTN: Bill

[9T8Bird]

I know the topic has been discussed but I have no clear answer on a 2005 GTP with the series 3 3800 L32 engine. Is the VE table used or should I go straight to MAF tuning on this platform? Not much info on the series 3 engine/computers.

[5FDP]

You can't ve tune these car really, it's just not set up to run that way.

Just tune with the maf. But if the car is running good, you'd never need to adjust the maf unless you went with a bigger maf. Easier to adjust fuel in the pe stuff and with timing.

[G_P_K]

You can't ve tune these car really, it's just not set up to run that way.

Just tune with the maf. But if the car is running good, you'd never need to adjust the maf unless you went with a bigger maf. Easier to adjust fuel in the pe stuff and with timing.

it will of course depend on your mods but if your trims throughout the range of the MAF table arent between 0 and -5 you should be tuning the MAF. PE is only for PE and those calculations are directly related to how well the MAF is tuned. In addition, when you are in PE your trims should lock in at 0. if they don't the MAF needs to be tuned. if you want you actual wide band values to match commanded in the PE tables this is the best way to get there on the 3800 platform. if you dont care how far off the PE table has to be to get you to your desired value on your wideband and you dont care about driveability then by all means dont tune the MAF.

[Russ K]

it will of course depend on your mods but if your trims throughout the range of the MAF table arent between 0 and -5 you should be tuning the MAF. PE is only for PE and those calculations are directly related to how well the MAF is tuned. In addition, when you are in PE your trims should lock in at 0. if they don't the MAF needs to be tuned. if you want you actual wide band values to match commanded in the PE tables this is the best way to get there on the 3800 platform. if you dont care how far off the PE table has to be to get you to your desired value on your wideband and you dont care about driveability then by all means dont tune the MAF.

Exactly, and this is how I tune the fueling on the V6 cars;http://www.hptuners.com/forum/showth...1064#post61064

Russ Kemp

[G_P_K]

Exactly, and this is how I tune the fueling on the V6 cars;http://www.hptuners.com/forum/showth...1064#post61064

Russ Kemp

as always russ k thanks for the write up's that you have done. i use them extensively.

[Shane Hewitt]

I remember reading a post years ago from the HPTuner guys saying that the V6's have a parameter in the file that determines whether the VE tables were referenced or not.....can't find it right at the moment. Without having access to that parameter you have no way to know whether your particular car references it or not.

With that in mind I went ahead & did tune the VE tables on my car (cammed, headers, etc on my 99 gtp) & noted a marked improvement in refinement vs the straight MAF tune I had done to it previously. My fuel trims tightened up in the lighter engine load areas as well. Apparently my car is one of the ones that does reference VE.

My suggestion would be to go ahead & tune the VE as well.....it certainly isn't going to hurt. It may not necessarily be referenced with your specific vehicle, but until you try you won't know.

[9T8Bird]

Great info there Russ, I really appreciate it! I do have one more question though in regards to the AFR side of things.
I know gasoline is 14.7:1, and Gasoline with E10 can vary widely from 4-10 percent ethanol around here giving me an average Stoich of around 14.4:1

The question is, do I need to change the target stoich in the Fueling, General tab to this 14.4?
And secondly, in your write-up where in the first part of MAF tune and setting the base AFR to 14.7, do I need to use my 14.4 number since I changed the general one too?
School me on this part if you would.

[Russ K]

Great info there Russ, I really appreciate it! I do have one more question though in regards to the AFR side of things.
I know gasoline is 14.7:1, and Gasoline with E10 can vary widely from 4-10 percent ethanol around here giving me an average Stoich of around 14.4:1

The question is, do I need to change the target stoich in the Fueling, General tab to this 14.4?
And secondly, in your write-up where in the first part of MAF tune and setting the base AFR to 14.7, do I need to use my 14.4 number since I changed the general one too?
School me on this part if you would.

Change your Stoich to 14.4, the open loop AFR to 14.4 (at operating temps) and 0 the open loop AFR adder table

Russ Kemp

[9T8Bird]

Change your Stoich to 14.4, the open loop AFR to 14.4 (at operating temps) and 0 the open loop AFR adder table

Russ Kemp

Ok and is this how I need to leave those tables permanently?

I did try the open loop MAF tune this evening on the 2005 L32. I did the rinse and repeat about three times, after setting things back to original with new MAF curve, I see my fuel trims go very negative at low throttle/idle scenarios (-12 to -15). Would that be because I hadn't changed the Open Loop AFR to the 14.4. (I only had the stoich at 14.4 not the Open loop AFR table tonight.)

[Dr. Nopps]

Keep in mind if you change your Stoich & OL tables to 14.4, you will have to use that as your PE target while MAF tuning/re-tuning your cruise area before the Wide Open Throttle MAF tuning actually begins.