When considering AE vs Delta TPS:

What's the time period over which the ECM calculates the delta?

That is, if I take 30 seconds to go from TPS=0% to TPS=50%, does the ECM register that as a 50% delta? Or is it thinking there are multiple 10% deltas on the way up to 50%? Does the 50% delta need to occur in say .5 seconds to register as a 50% delta?

Hopefully I'm being clear about my question...


Also, I notice the $EE does not have any AE function. Did GM roll that algorithm into the VE? If any engine needs AE, I would think the LT1/LT4's do, with that short runner manifold.

 

What ecm/mask are you currently using? The TPS AE logic varies quite a bit from mask to mask.

 

On $ee $eeb going forward to new Modern PCMS the VE table provides the Reference for an AE Function.

As for how long to consider a Delta AE event. If the pdeal position changes over X amount of time that creates the Delta.

So if the pedal moves at a rate of 5% per second you will not Get AE, but if it moves %50 in 0.1 Seconds you'll Get a %50 I'm Not sure ive ever had to play with those constants but you can if you'd like. the TPS Delta filtering rate is the one your After.

to answer your ogriginal Question it is entirely possable to have a long duration AE event if the pedal travel at the correct rate. if the TPS was traveling at a rate of %10 per 0.10 seconds you could indefinately keep the Delta event going. but it would be a %10 delta AE event. i do not belive there is a cummulative Ae function but i could be wrong about that,

 

Dimented, I'm running a $8D.


Funstick, what's this TPS Delta filtering rate? I use Tunercat so it's probably not there. Is there a location in the Hex I can look for? Has any one messed with this constant? Any observed benefits/detriments to doing so?

 

I think this is what you're wanting to know.

**
*DIFF TPS ACCEL ENRICH TABLES & PARAMS
**
L852E: FCB 3 13.5% TPS MIN FOR ACCEL ENRICH PROP TO BASE PW
L852F: FCB 1 ; 1 INJ IN FUEL LIMITING
L8530: FCB 12 ; ACCEL ENR LASTS 12 REF PULSES
L8531: FCB 128 ; 50% TPD DIFF FOR V6 ACCEL ENR CALC
L8532: FDB 454 ; 6.92 MSEC MAX ACCEL ENR PW LIMIT
L8534: FCB 32 ; 0.125 MULT FOR 12.5 Msec TPS Accel Enr
L8535: FCB 32 ; 0.125 MULT FOR DIFF TPS * 32

The decay rate sets how it lasts, so you can have indefinite AE.

 

Got a snippet of code to show how that works?.

It'd be interesting to see how a VE table is used in a timed base situation.

 

Uh, yeahhhhhh..... Grumpy, could you translate some of those parameters into english for a layman like me?

 

TunerCat possibly will add the TPS Delta Filtering rate if you ask them too. They are good about doing that.

 

I can't add anything that hasn't already be said about the logic but I can tell you that the engines that need the most AE are those with the largest surface area between the air throttling device and combustion chamber. I'd say the Lt1's probably need very little AE vs most LTR setups.

 

At a glance the actual TPS AE calculation appears to work by first starting with a scaled TPS term. If the TPS is rising or steady, the TPS is then filtered and saved as an old TPS term. The filter coefficient is based on RPMs.

As long as your opening the throttle and not closing it, this filtered TPS term is filtered and subtracted from the current TPS to get a delta TPS.

IOW, there is basically a TPS term thats lagged and takes some time to catch up with the current TPS. Once you move the throttle to some new position, the filtered TPS term wont be able to reach the current TPS reading since its lag filtered. This generates a delta TPS and as long as that filtered term is still catching up, the delta TPS will be non-zero. If the delta TPS is sufficient, there will be some form of AE.

Basically you can imagine the current TPS as a skinny kid and the lag filtered accel enrich TPS as a big fat kid and theyre both running in a race. The skinny kid moves real fast but the fat kid is slow and takes some time to catch up. The distance between the two will be a delta, or in this case the delta TPS.

 

I'm not really sure of how to discribe them. This gets back to making small changes, and noting the results. There's some stuff that seems to react to some cars, in a definte way, and others you'd hardly notice. So it's a matter of just playing with things until you see if they work or not for you.

 

Funstick claims to have the related code, but just repeats that claim without actually trying to clarifiy things.

 

and as stated a multiture of tiimes a wide band allows you the ability to watch in real time and values the transition into - out of AE and the onset of PE if you are into pedal.

as a side note it also shows enleanment if the event is inadequate. that plus seat of pants meter make it all real.

 

I think one of the things thats needed is a fully commented hac for the $8D. Maybe something to be added to the $8D wishlist? I know comments like PWENR 3-DRP DECENL .125% DELTA ENR MULT dont mean jack **** to me Someone needs to go through that and put it in plain people speak. The code on the 7730 is short enough that someone could jump in there and get something presentable in a year or two.

Its alot easier to change things if you know what theyre supposed to be doing. Making small changes to random things and noting results can just lead to incorrect assumptions.

Even for something like the TPS AE knowing that the delta AE can be represented as a mathematical series could save you alot of time. You could just whip out a calculator and see what need to be changed in the table instead of having to use exhaustive testing. My cars so crappy that it breaks down before I even get done tuning it so knowing how to use applied theory rather then exhaustive tuning is worth its wieght in gold, or in this case cast iron and steel.

 

Its getting better by the day.
the latest "stock" AUJP is Moates site. AUJP_JP2

 

I'm sure he doesn't have the proof we desire but it's been said before elsewhere on the internet that AE and DE are disabled... http://www.lt1edit.com/pipermail/lt1...04/008481.html
If what is said is truth then I can't explain why DE was seemingly working for me and my buddy! There was also no apparent AE issues and the MAF was in the trunk . Maybe it's a rumor, maybe not, so far I've personally seen no proof with data to back up the claim that AE and DE are defunked when in SD mode.

 

Really?, maybe if the note taking is poor, or there is some other problem, but the most all of the Programming 101 was done with making changes, and documenting the results. BTW, there should be no assumptions, while there was an error in 101, for what we did, when we did it, I think the work was well done.

 

I also would like to see how the EE & EEB VE table effects AE. I've been tuning with the MAF table exclusively and have'nt touched the VE table cause I always figured it wasn't reference as long as the PCM was running in Mass Air mode. Am I wrong?? Can I really tweek AE by tinkering with VE tables? This would be huge news to the EE,EEB LT1 world.

Sorry for hijacking the thread.

Steve

 

What some folks will do is throw a bunch of VE in up at high MAP / relatively low RPM. This tends to act like an AE fuel adder. Not puritanical, but it works. A little better with Auto vs Manual just due to the dynamic there.

 

While it will make-up for a slight leaness, it ain't AE. If we're going to start making up terms as a matter of whim, we might as all start speaking in foreign languages. AE is temporary fuel enrichment based on TPS, or load sensing. It has it's own terms.
A VE table is VE table, if you want to correct an AE/ PE problem, with it, fine, by all means do so, but in using the VE table to fix other problems, doesn't change the fact that it's still a VE table.

Now if someone has some code that uses the VE table in some way as a correction for AE, that would be interesting. While someone's alleged that, they haven't been able to support that claim.

 

Intuitively, I would think richening up the higher MAP VE's would be to compensate for a delayed PE. AE appears to be a very quick shot of fuel for a given quick delta TPS rather than a prolonged enrichment period like a PE.

 

8D has async Delta TPS AE and sync Delta MAP AE.
dT map is added to the normal PW calc. dT TPS is done between normal injector firings. I believe this means the injectors will fire between DRP's. But I haven't verified this myself. Both terms have a temp table mult. factor too IIRC.
There is also the %TPS mult table that is all 1.0 in aujp.
I need to look at the code to see just what TPS value it uses for that look up.

PE is used to run at an AFR of say 12.8 at WOT or above the PE trigger setpoint. Non PE is used to run on the CAT and at 14.7.

 

If you have too much lag before you're in PE, then you need to look at that.

The lenght of AE is set by it's decay rate. You can have an infinite amount of AE.

As mentioned TPS AE is *normally* done in Asynch mode, ie right now, with your delta MAP/MAF AEs done with the next synch pulse calc..

IMO, the stock AE tables need some revision, so that you get to a given delta TPS, the AE begins to decrease so that as the synch AE is added you don't get too rich.

It can at times take alot of work to get it right, especially with a marginal ignition system... Since you can wind up going rich, in order to keep the firing voltage requirement down, so that you don't have a *miss* (however slight). Not to mention blending the two AEs, vs actual load, vs RPM.