modding order

[curtpank]

thanks. I have used the Table Modifier Thingy for my VE, MAF and spark tuning, and I had things dialed in pretty well for what I had before the TB and manifolds.

I always filter out the lines where PE was active during the scan (by including only cells with a/f ratio of 14.7:1 in the adjustment calculations). I have PE set to activate at 60% throttle because there is sometimes a delay before a/f actually richens to the PE level.

VE was the one I knew the least about and only did 2 rounds of it before moving on to MAF.

given the new TB, I will scan tonight and see what extent of VE table adjustments are suggested by the Table Modifier Thingy. I'll use 40% of the LTFT ave. to ensure that I don't over correct.

by the way, are you saying that the MAF table is still being consulted by the pcm during PE? I thought that the PE a/f kicks in and only changes based on the PE a/f vs. time table. When I tune the MAF table, I only include lines where a/f is 14.7:1. Should I do a MAF tune that includes when I'm in PE?

[AaronGTR]

Originally Posted by curtpank

thanks. I have used the Table Modifier Thingy for my VE, MAF and spark tuning, and I had things dialed in pretty well for what I had before the TB and manifolds.

I always filter out the lines where PE was active during the scan (by including only cells with a/f ratio of 14.7:1 in the adjustment calculations). I have PE set to activate at 60% throttle because there is sometimes a delay before a/f actually richens to the PE level.

VE was the one I knew the least about and only did 2 rounds of it before moving on to MAF.

given the new TB, I will scan tonight and see what extent of VE table adjustments are suggested by the Table Modifier Thingy. I'll use 40% of the LTFT ave. to ensure that I don't over correct.

by the way, are you saying that the MAF table is still being consulted by the pcm during PE? I thought that the PE a/f kicks in and only changes based on the PE a/f vs. time table. When I tune the MAF table, I only include lines where a/f is 14.7:1. Should I do a MAF tune that includes when I'm in PE?

I usually keep 60% or more for the adjustment value until I start getting within 2 of 0 LTFT. But anyway, yes the MAF table is still being consulted in PE mode. It's ALWAYS being consulted. It's the most important basic table for fuel enrichment that the pcm uses. It's the point from which all the other fuel modifiers work from. That's why we always said it was so retarded that RSM's supercharger kit deleted the MAF.

[curtpank]

Originally Posted by AaronGTR

I usually keep 60% or more for the adjustment value until I start getting within 2 of 0 LTFT. But anyway, yes the MAF table is still being consulted in PE mode. It's ALWAYS being consulted. It's the most important basic table for fuel enrichment that the pcm uses. It's the point from which all the other fuel modifiers work from. That's why we always said it was so retarded that RSM's supercharger kit deleted the MAF.

I have my trims between -1 and 0 pretty much all the time. I use the filter in the Thingy to prevent adjustments to cells where the ave LTFT is between -1 and 0.

I will do a round of VE, then, and follow that with a MAF tune that will include all lines of scan data including those in PE. Finally, a round or two of WOT (where the new TB actually comes into play)

then I should be getting close to maxing the benefit from the new mods.

half the reason I love getting new mods is because I get to tune for them!

[MMGT1]

Problem with HP is the V6's don't have support for Idle tuning. There are tables in there that we cannot access. For V6's HP Tuners recommends that you MAF tune these cars only. In some Grand Prix's you need to fail the MAF and VE tune due to it being referenced even with MAF in place, but in the Grand Am it was recommended to me to not touch it. The only time VE is used is if our MAF fails is what I was told.

[AaronGTR]

Originally Posted by MMGT1

Problem with HP is the V6's don't have support for Idle tuning. There are tables in there that we cannot access. For V6's HP Tuners recommends that you MAF tune these cars only. In some Grand Prix's you need to fail the MAF and VE tune due to it being referenced even with MAF in place, but in the Grand Am it was recommended to me to not touch it. The only time VE is used is if our MAF fails is what I was told.

What do you mean? They don't have access to the VE table available? I don't understand what you mean by support for idle tuning. You mean you can't adjust your base idle rpm? As far as LTFT it doesn't matter if the car is at idle, part throttle, mid throttle... there are different fuel trim cells for those ranges but the VE table is based on MAP and RPM so if you can access the VE table, you can adjust your fueling at idle or any other rpm point.

And as for the grand prix's... no idea what you are talking about with those either. Yes, the VE table is still referenced even with the MAF in place. It is on grand ams too. It is on every car. That doesn't mean you have to take the MAF out to VE tune. The MAF gives the PCM the primary fuel enrichment needed based on how much air is coming in. The VE table tells the pcm how much fuel it should need based on rpm and MAP pressure. It uses both in it's base calculation and then makes adjustments based on O2 readings. If you've improved your volumetric efficiency, your fuel needs are going to be different so your case calculation will be off and the O2 will see that and increase LTFT to compensate. That's the whole basis of VE tuning. If you improve the VE table, the fuel trims will get closer to 0 so the O2 sensor doesn't have to make as much adjustment. I've seen it work on my car and my fuel trims are greatly improved from VE tuning and I never unplugged my MAF. What you were told was wrong, the car runs off only VE if the MAF fails but even with the MAF working it still always references VE.Or maybe they don't have the ability to do that with HPT? Which if thats the case I'd say HPT sucks.

[MMGT1]

My info on HP comes from Greg Banish. He's the guy that does the base tuning for the big 3 when they develop a car. He teaches tuning across the US for mechanics. Met him on the HP Tuners site and used his book to get into this stuff. HP Tuners is really ment for LS motors if you ask me. RTT Tuning and Idle tuning is only available to those plants. Yes, unless you have a LS1 or something in your driveway, Id re-consider owning HP for a V6. Have not really been on the HP site in some time either so they may ave this done by now, don't know bud. We can tune the VE if we fail the MAF, but that is the only way we can access it right now that Im aware of. The only reason I tried to get into VE tuning was a slight lean spike between Cruise and PE. In the end, I ended by placing my TPS PE to 55% and I no longer have the spike. My VE table is stock and with my mods the trims are excellent in both cruise and PE. I also use a NTK/AFX WB to tune it.

[AleroB888]

The Tables we are missing in the calibrations are related to the fuel injectors. I mentioned that on here before somewhere....

[curtpank]

I use DHP, not HP tuner. As I understand it, either one will serve the needs of people with basic mods like mine. I will do the VE tune as Aaron suggests in an effort to account for the change in throttle range (and thus MAP) that may come with the larger TB.

in summary, then, MAF table is still referenced during PE, but VE table is not. Is that right?

[AaronGTR]

No, MAF table and VE table are both always referenced. During PE the pcm just stops using the O2 sensor and making fuel trim adjustments.

[curtpank]

Originally Posted by AaronGTR

No, MAF table and VE table are both always referenced. During PE the pcm just stops using the O2 sensor and making fuel trim adjustments.

okay - that makes sense now. This why you want fuel trims to 'lock in' at 0 during PE. But when a tune isn't perfect yet, and LTFT locks in at, say, 0.78, does that mean that the pcm is constantly adding that fuel adjustment throughout the time in PE?

[MMGT1]

yes

[AleroB888]

Originally Posted by curtpank

okay - that makes sense now. This why you want fuel trims to 'lock in' at 0 during PE. But when a tune isn't perfect yet, and LTFT locks in at, say, 0.78, does that mean that the pcm is constantly adding that fuel adjustment throughout the time in PE?

Compare the INJ(msec) and Injector Duty Cycle logs from different scans with
LTFT's locked in at zero in one and locked in at -5 or +5 in the other

[curtpank]

okay - did a scan yesterday, then used the Modifier Thingy to make adjustments to the VE table. It seems to be leaning the cell values out (lowering them). Actually, it didn't increase any cell values, just lowered them.

I was running a little bit rich after some MAF adjustments I made after installing the new TB and manifolds. I hope that the adjustments to the VE table will help address some of the more throttle-position-sensitive changes.

I've let the trims learn for a day and now I'm going to scan again. I'm thinking a MAF tune now. I'll update you on how the trims are looking after the VE adjustments

[curtpank]

I did a full VE tune (without disconnecting the MAF). Then I topped that with a MAF tune. Things are looking very good now. The trims are as much in line as I had them before installing the manifolds and TB.

so, to summarize, going from a 56mm to 65mm TB and porting the UIM and LIM, the trims went about 2% leaner. Probably not a problem since the PCM obviously makes adjustments and in stock form the trims adjustments are often larger than that anyway. But to get the utmost from the mods, a round or two of VE and MAF table tuning is appropriate.