Use MAF for off boost/2 Bar SD when in boost

[Earl H]

Guys,

I have a TT all bore '03 Z06. It currently runs high 9's at 144+mph. I want to get a bit more aggressive (i.e. turn up the boost). My car is currently tuned with the MAF. My tuner is responsible for the progress thus far. I have tuned my car in the past and I am slowly getting back into the swing of things. Now, I have just recently loaded in the COS. I have a 2 bar map sensor on order and will be installing it asap. I am getting my tune ready for 2 bar tuning(see attachment). My question is, can I use the current MAF tune for 105kpa and below and the 2 bar SD tune above that? If so, could I get some advice on how to set it up?

I am currently reading as much as i can while awaiting responses to this thread. Thanks in advance for the help.

[diynoob]

Earl,

I'm putting COS5/2bar on my car ASAP. Just reading a little more before taking the plunge. 2bar sensor is sitting here in front of me so it's really just a matter of me finding the right COS5 for my 12593358 PCM :)

JMHO, and there are other experts here that I am sure will chime in soon, but I think you really want to tune the car "completely", e.g., not rely on VE data from a tune that depended on the MAF (unless you know for sure that Phil tuned VE with the MAF disabled at some point). Anyway, to tune your boost table you have to log the same PIDs as you'd need to tune your main VE table so you might as well go over the whole thing and make sure both of them are nice and clean. Plus I would imagine things could get ugly transitioning from one VE table to the other if you didn't do a fresh AutoVE for both together.
:cheers:

[hquick]

I adjusted the Boost VE table to what I believe the tutorial says it should be.
50% though instead of 300.

[5.7ute]

As diynoob states the ve table will be incorrect with the help of the boost so it will need to be remapped.
As for running off the maf & then SD this will not work. If the maf fails over 105 kpa It will use the 1bar ve table only. If the maf fail is before 105 kpa it will transition into the 2 bar table but will not reenable the maf until the engine is switched on & off & the pcm runs through its tests. If you are going to be going over the 512g/sec limit of the maf just tune in SD. Otherwise tune both ve tables & then recheck your maf tune.

[trudynosports]

With the 03 OS you shouldn't have to worry about retuning the 105kpa and below if the original MAF included tune was mapped correctly. The VE should have already been mapped independent of the MAF and the MAF independent of the MAP. This would result in you being able to copy the tables from the MAF tune over to the new COS. At that point you should really only have to fine tune the below 105kpa and then tune boost pressure tables. What kind of boost pressure is your setup running?

[Earl H]

Update: decided to go ahead and spend the time to do a full SD tune. I have been working for about a week re-learning the software and re-learning some old tuning procedures and learning many new ones. My BENs are almost all in the .99 to 1.01 range for the cells that matter (i.e. not decel and other parts of the map that aren't really used).

I will be tuning WOT at the track this friday. My baseline runs on the street show that the vehicle is tracking pretty well to what is being commanded at 105+kPA range.

[hquick]

Has the AutoVE tutorial been changed yet regarding the 'setting the commanded AFR to 14.7' which allows LTFT's to operate?

[vatman02]

i have a question how can this car be running with the maf enabled i am only seeing 6# of boost and that is setting off a maf frequency fail i am running sd anyway just curious

[Earl H]

Has the AutoVE tutorial been changed yet regarding the 'setting the commanded AFR to 14.7' which allows LTFT's to operate?

Please elaborate..I thought commanded was supposed to be 14.63 (stoic)?

[joecar]

Any cells in B3647 that are set to AFR 14.63 will cause the PCM to run in "semi-closed loop" mode...
for those cells, the PCM uses NBO2 feedback and applies STFT; you can't do AVE like this.

[vatman02]

i believe that if you command stoich it allows the LTFT to become active thus throwing off your auto ve
yea what he said

[hquick]

Correct me if I'm wrong Joecar....after we went through this stuff a while back with my autoVE wasn't it understood that even commanding 14.70 is no good as that equals EQ 1.00?
Mine is set to 1.0059 EQ. which equates to around 14.58 AFR.

[joecar]

Howard,

Good point...

that was because your B3601 was set to 14.68... showthread.php?t=5144 (http://forum.efilive.com/showthread.php?t=5144)

(that's why it's better to use EQ units instead of AFR units).

[Earl H]

Howard,

Good point...

that was because your B3601 was set to 14.68... showthread.php?t=5144 (http://forum.efilive.com/showthread.php?t=5144)

(that's why it's better to use EQ units instead of AFR units).

So 3601 and 3647 must be different to prevent the pcm from slipping into semi close loop?

[5.7ute]

As Redhardsupra points out elsewhere, the commanding stoich & disabling pe step is no longer necessary when using a wideband. These steps are only an offshoot of using trims to tune.

[joecar]

So 3601 and 3647 must be different to prevent the pcm from slipping into semi close loop?That's correct.

[Earl H]

So what should we set it up to command 14.7 or 14.5? Once BENs are at ~ 1.0, then what?

[joecar]

If you command 3% under or over, it should be fine.

When BEN's are close enough to 1.00, then you can command stoich if you so wish...
but do keep the high MAP columns of B3647 rich (12.6 or what you want at heavy load).

[joecar]

Here's what semi-open loop looks like (look at AFR_WBOS1)...

http://img262.imageshack.us/img262/4484/semiopenloopng8.png

[Earl H]

Can you guys tell me what you think of these two files? BENS close enough. Commanded is at 14.6 on these passes. I haven't had a chance to adjust.

[joecar]

Can you guys tell me what you think of these two files? BENS close enough. Commanded is at 14.6 on these passes. I haven't had a chance to adjust.I'll hve to look after I get home tonite.

[5.7ute]

There is a lot of crud in them logs that you cant easily filter out. When decellerating during a log you should back your foot right off the pedal quickly so you can filter out the rich spikes that are caused. By letting your foot off slowly you can accumulate richer readings in your log file which will throw your BENS out.

[joecar]

I agree with 5.7ute...

The rest of the BEN's look good.

Are you using then LC-1 to simulate HO2S11...?
You might try to program the high voltage higher by 0.050V and the low voltage lower by 0.150V to bring it closer to HO2S21.

[purrvert]

LTFT has to be turned off in order to get BENs in line. Somebody correct me if I'm wrong!

[joecar]

LTFT has to be turned off in order to get BENs in line. Somebody correct me if I'm wrong!That's correct... and a few other things also.

[Earl H]

Why not just disable trims? {B3801} and {B4108}

[joecar]

Why not just disable trims? {B3801} and {B4108}It will still go into semi-open loop mode (for stoich cells in B3647)... or at least mine seems to.