PE And Boost VE {A0009}

[Mort]

I have a problem with Commanded AFR vs Actual AFR. It seems I am running 2 points richer at WOT than Commanded.

I was wondering what the relationship is between PE and Boost VE.

I have PE set to {B3613} = 110, {B3610} = 0, {B3616} = 50 all RPM, {B3606} = 10.446. As far as I know it is going into PE. Max PE AFR is 11.56 @ 5600RPM which is my shift RPM.

I am running some meth as well but it never caused this big a divergence before. My MAP indicates values close to 1.00 at 105 Kpa and down to 0.75 - 0.80 at 145 Kpa to 195 Kpa. The truck is bogging very badly at ~ 4000 rpm and I have to lift to get it to go any higher.

Is PE independent from Boost VE or do I need to decrease the VE some to get the WOT AFR in line?

[johnv]

When PE is entered, commanded AFR will be the richer of either B3647 or B3618.

If commanded does not = actual your VE tables must be off, have you done the auto VE on the normal and boost VE tables.

[Mort]

I have done and am working on the Main VE, after installing new injectors, but have not done much with the Boost VE. I see a very select number of cells and I am running PE so I did not bother but I will have a look at it because the cells I do see are very rich above 145 Kpa. I had a feeling the Boost VE was contributing to the AFR commanded in PE.

Well I'll try the Boost VE and see how it goes.

Thanks.

[johnv]

If the boost VE table isn't dialed in commanded won't = actual afr, probably easiest to auto tune the boost VE table with PE disabled, just set the last columb of B3647 to your desired AFR at WOT, around 11.8 for a boosted car. then re enable PE after Boost VE is done if you wish.

[Mort]

Thanks John, I was thinking something along those lines. I have B3647 set to 12.5 at 105 Kpa above 4800 rpm. I run PE and keep the B3647 a little on the leaner side on the theory of improving throttle response by not getting too rich too early.

Try and try again!

[johnv]

On my turbo setup I have B3647 last columb set to 12.2 above 1600rpm (i start making boost from 1500 rpm in higher gears)

Then have PE coming in at 125 kpa about 4psi boost and set to 11.8 just seems to help with transition into boost and not getting a big hit of fuel all in one go. Lower the PE rpm and throttle position enablers so PE comes in as soon as you hit 4 psi boost.

Also make sure the 105 columbs of both main VE and boost VE have the same values.

[aaronr]

On my turbo setup I have B3647 last columb set to 12.2 above 1600rpm (i start making boost from 1500 rpm in higher gears)

Then have PE coming in at 125 kpa about 4psi boost and set to 11.8 just seems to help with transition into boost and not getting a big hit of fuel all in one go. Lower the PE rpm and throttle position enablers so PE comes in as soon as you hit 4 psi boost.

Also make sure the 105 columbs of both main VE and boost VE have the same values.

What do you have your PE rpm and throttle position enablers set to.
So do you have to meet throttle position and rpm to get the enrichment to start.

[Mort]

PE mode is activated by Throttle position {B3616} at given rpms (mine for example is 50% all rpms). Some people like to set them lower depending on when they see boost. I was not seeing any KR so I thought it was just a waste of fuel to go any lower. If I set my TPS any lower my AFR always seems to be rich on the highway.
Then you need to determine when you what PE mode to start based on boost. With the MAF still in place I set mine to 95 kPa or just before entering boost. You set this value in {B3613}.
Now I am running COS3 I will set it like John does at 125 kPa or so to get ~11.5 AFR. If I get the Boost VE tuned so I am comfortable with it I may not run PE at all. I am not running it now trying to tune the Boost VE A0009.
Yes you have to meet both the Normal PE Mode Enable {B3616} and PE Map Threshold {B3613}. Also be sure to set Delay before entering PE Mode {B3608} to zero. Mine was set to 60 seconds in my stock tune.:doh2:
There are a few other settings. Just make sure they are reasonable.

[aaronr]

PE mode is activated by Throttle position {B3616} at given rpms (mine for example is 50% all rpms). Some people like to set them lower depending on when they see boost. I was not seeing any KR so I thought it was just a waste of fuel to go any lower. If I set my TPS any lower my AFR always seems to be rich on the highway.
Then you need to determine when you what PE mode to start based on boost. With the MAF still in place I set mine to 95 kPa or just before entering boost. You set this value in {B3613}.
Now I am running COS3 I will set it like John does at 125 kPa or so to get ~11.5 AFR. If I get the Boost VE tuned so I am comfortable with it I may not run PE at all. I am not running it now trying to tune the Boost VE A0009.
Yes you have to meet both the Normal PE Mode Enable {B3616} and PE Map Threshold {B3613}. Also be sure to set Delay before entering PE Mode {B3608} to zero. Mine was set to 60 seconds in my stock tune.:doh2:
There are a few other settings. Just make sure they are reasonable.

So you and John are running open loop then?? I'm running cos3 and sem-closed loop and have mine set at 115kpa. I was just looking into this to see if this would help me being lean at 95kpa to 114kpa. It stays in closed loop intill 115kpa. I think i will move the enrichment to 95kpa.

[johnv]

My B3616

40.000000
40.000000
40.000000
40.000000
40.000000
40.000000
36.660156
33.339844
30.000000
26.660156
23.339844
20.000000
20.000000
20.000000
20.000000
20.000000
20.000000
20.000000
20.000000

Sounds like you need to look at B3647


mine is 13.6 afr at 85 kpa
12.87 90
12.65 95
12.4 - 12.2 100

must learn how to post a screen shot lol.

[aaronr]

O.k John i got your screen shot.
May be you didn't read my fist post about asking you if you were running open loop or sem-closed loop. When I’m in open loop my command a/f follow table b3647 to a T. Now that I’m running sem-closed my command a/f doesn't change in till I get 115kpa. So I was trying to find out if I messing with b3616 would help rich it up before I get to 115kpa. Yes in table b3613 I have set to 115kpa. So I was just going to lower b3613 to 95kpa to go in to enrichment sooner. Here is a log file.
Thanks for the help.
http://i241.photobucket.com/albums/ff48/russell1978/b3647.jpg
http://i241.photobucket.com/albums/ff48/russell1978/b3616.jpg

[johnv]

I am open loop, but semi closed loop should work the same.

Try lowering the values in the 85,90 and 95 kpa columbs in B3647 to similar values as mine.

Then log and see what commanded and actual AFRs are doing up to 115 kpa when PE comes in.