ULTM8Z

This is for $8D...

I did a lot of experimentation today with my MAT tables and stuff... but I accidentally stumbled on to something with this AE Delta TPS Scale Factor. Not sure what made me want to play around with it (I've seen it a million times before), but I for whatever reason, I wondered "what would this do if I changed it?.... lol...

Any rate, this seems to make the computer react quicker to changes in TPS position. I've had good throttle response already, but after this change the neutral-throttle-blip is much more crisp. Going back into the sticky for AE tuning, I see Funstick's description of it and now it makes sense.

I had never quite been able to completely get rid of a minor delay after a quick blip of the throttle in neutral. I'd tap the throttle, I'd hear a slight woosh and a few milliseconds later the engine would rev up. It always felt like the ECM wasn't reacting fast enough to the TPS change, but I could never overcome that until I set this one parameter to 1 (it is .125 in the factory AUJP/ANHT). The maximum value is 1, so I maxed it out right away just to see what it would do (needless to say I was pleasantly surprised!).

There's another parameter in Tunercat fuel constants called AE Delta TPS PW Scale Factor. It's also .125 from the factory. The engine didn't seem to like much more of this one though... over .2 and I started getting stumbling. It may have something to do with the fact that I'm running $DA3 values for all my AE now... which richens stuff up quite a bit over ANHT.

Driving around I didn't see a huge improvement since my driving throttle response is already pretty dang good. But it's cool to get instantaneous engine response on a throttle blip now.

I emailed Tunercat to see if the $DA3 mask has these two parameter is in it. Curious to see what GM did for the LT1's. If it's the same or close to what I have now, it'll keep proving my theory that the closer I get to the LT1 calibration on my $8D, the better this car runs.

84Elky

Lacking hex addresses for the referenced items, hope I have the right ones because many times the XDF file descriptions are different among varous files.
Both items you referenced apear to be the multipliers that serve different purposes in computing AE TPS PW. Increasing one or both of the multipliers from the factory settings of 0.125 to a higher value increases the final AE TPS PW you receive. So if you went to 1.0 and all is OK, that says you're engine was really, and I mean really, starving for fuel on a throttle punch. Just doubling the factors from factory settings of 0.12 to 0.24 results in the following increases in AE TPS PW (assuming coolant temp of 198*F and pump voltage of 13.5v):
0x534=AE TPS Base PW Multiplier-----0x535=AE TPS 6.25ms TPS Change Multiplier-----Final AE TPS PW
0.12--------------------------------------0.12---------------------------------------------------2.56ms
0.24--------------------------------------0.24---------------------------------------------------4.34ms (+69.5%)
0.24--------------------------------------0.12---------------------------------------------------3.05ms (+19.1%)
0.12--------------------------------------0.24---------------------------------------------------3.90ms (+15.2%)
So a factor of 1 is really flogging in some fuel. You can see the details of the above code simulation results here:
https://www.thirdgen.org/forums/diy-...nrichment.html
Look at simulations 1,4,5.

ULTM8Z

Admittedly I haven't tried anything less than 1 at this point.

Yeah, I'm not sure about the hex addresses either... But with the AE delta TPS PW scale factor, yeah increasing that significantly didn't yield good results. If "felt" rich when I stabbed the throttle after increasing it.

The AE Delta TPS scale factor (the non-PW) one is the one I modified. This one seems like it's more of a lag filter or something... more to do with how fast the TPS AE comes in (as opposed to how much fuel is delivered). If it was dumping in as much fuel as you say, I probably would have noticed a heavy stumble driving around, and in reality I didn't really notice too much difference except for the throttle-blip responsiveness in neutral.

ULTM8Z

Tunercat replied. Apparently $DA3 doesn't include these two scale factors. If that's the case, I can only think that

1.) The PW scale factor is already baked into how much more delta TPS AE is inthe delta TPS AE table. The $DA3 table values are MUCH higher than $8D.

2.) For the non-PW scale factor, the lack of a scale factor within the $DA3 essentially translates to scale factor of 1. So it begs the question of why GM slowed down the TPS response time so much on $8D. With the value set to 1, the throttle is so snappy and responsive, I can't see what advantage there is to slowing it down. Some sort of emissions thing perhaps?

RBob

iTrader: (1)

I'd say both emissions and fuel consumption.

RBob.

MaxpowerTA

I played around with this parameter today and did not have good results. I set
AE Delta TPS Scale Factor to 1 and then engine stalled with light application of throttle. so i changed it to 0.325 and driving around i had a noticeable stumble on throttle application, went back to 0.125 and everything was back to normal crisp throttle response no stumbles. Now admittedly mine is a very unique application as i am running SAUJPv4 on a 1227727 driving a pontiac 455 with a carburetor style intake, but at least on this application it didn't have a positive effect.

ULTM8Z

I took the AE delta TPS PW scale factor and reduced it to .075 and now I'm even seeing some improvement driving around too. The non PW scale factor is still set to 1. Going to keep reducing it and see if it starts to get worse (curious what the tipping point is).

But yeah, the neutral throttle blip response is just sooooo crisp now. Never thought I would get to this point with that. Just freaking schweet!

After I'm done with this and the MAT table settings, I'm going to revise my Miniram start bin.

ULTM8Z

yeah probably has a lot to do with my existing AE settings and the Miniram. I wouldn't expect this would work for everyone.