APP Translation : Speed Comp

[djuosnteisn]

Has nothing really to do with Actual Pedal Position, or throttle at all really. Judging from the axis of the table, it's more of a Speed based Boost compensation.

Here's the helpfile snippet:

APP Translation : Speed Comp. Table Description – This table represents the amount of compensation, or correction, made to the APP Translation system values based on current vehicle speed. The table is referenced by vehicle speed on the x-axis. Table values are the percentage change made to the APP Translation values. A value of 1.00 will allow the ECU to run 100% of what it was calculating in order to achieve its target, which is effectively no change. A value of 0.90 will have the ECU run 90% of what it was going to run for that gear, and a value of 1.10 will have the ECU run 110% of what it was going to run for those conditions. Barometric pressure decreases as altitude increases. This means as you climb up into the mountains, barometric (air) pressure decreases. Sea Level barometric pressure is normally around 100 kilopascal (kPa), or 14.5 psi if you have Standard units selected. Tuning Tips – These table values are set to 1.00 or are effectively not used.

LOL at how it starts talking about baro stuff, when this table has nothing to do with baro. Also in the tuning tips, it says this table is set to all 1's and effectively not used, but um... my table isn't 1's at all:

0.00	1.88	3.77	5.65	7.54	9.42	11.30	13.19	15.07	16.96
1.30	1.30	1.30	1.20	1.10	1.00	1.00	1.00	1.00	1.00

This could possibly contribute to some peoples difference in the way boost builds, depending on speed?

Maybe not, just thought this table looked a lil whacky.

[fjames]

I just happened to be looking at that last night. There is a baro table, and it is all 1s, but, err, I dunno. The thing that melts my brain a little is the speed numbers. After FFF's flirtation with that boost comp table, I just added it to the growing pile of stuff I don't need to know lol.

[djuosnteisn]

Hahahahaha. I guess thank for at least not calling me crazy, lol. Our poor poor ecu's. Tuning them is more like being a multiple personality psychologist than a car enthusiast.

[SSinstaller]

Originally Posted by djuosnteisn This could possibly contribute to some peoples difference in the way boost builds, depending on speed? Maybe not, just thought this table looked a lil whacky.

That sounds logical to me. It wouldn't be too hard for you to test though.

You guys keep figuring out more and more shit with the AP, I might just have to ditch my SB.. Has anyone with an BT made good power with the AP yet ??

[djuosnteisn]

Once real time is spent on a dyno adjusting things like VVT and timing with real feed back, i'm sure the gains are definitely there. And considering the recent success with 18psiguy's upgraded stocker & the ap, i'm sure a big turbo would only be better. It's also RR tuning method of choice as well, and even with some of their "secrets", they certainly made it to 400hp pretty quick.

[jahman]

I never understood this table. What do the numbers on the x-axis mean anyway, mph?? Whats VSS? Vehicle speed sensor?

[smakdown61]

Originally Posted by jahman I never understood this table. What do the numbers on the x-axis mean anyway, mph?? Whats VSS? Vehicle speed sensor?

Must be VSS voltage. I'd be curious to see the effects of putting 1's in the whole table.

[djuosnteisn]

yup, vehicle speed sensor. None of it really makes sense, but if someone is willing to put 1's in there, it would be pretty cool. I don't use ecu boost control, and my car is down right now, so i can't really test anything out.

[Frequentflyer]

I'll try it and flash it tomorrow morning before I leave for work. I can report back midday or so once I get enough miles on it. I had 1's in mine from 9.42 on up. Below, I had 1.3, 1.3, 1.2, and 1.1, just like above.

[LBV]

I think that the term "Boost Compensation" shown as a label on the bottom of that table shouldn't be there at all and is an error on Cobb's part.

My hunch is that this table alters the sensitivity of the throttle based on the speed the car is going. My table is just like DJ's above and I suspect the sensitivity is decreased as the speed goes up (ie. you move right along the table).

[djuosnteisn]

It's likely something like that. Table seems odd ball, and description is even worse when it starts talking about baro stuff, lol.

Let us know your impressions frequentflyer.

[Frequentflyer]

Well, I put all 1.00's in there, reflashed, drove about 45 miles this morning and couldn't feel any difference in how the car drove, so I'm not sure if this table is even used or if it does anything significant. It'd be nice to know the voltage to speed correlation since we have no idea what 3.77 volts means in vehicle speed, or do we? I'll drive it more and see if I notice anything different.

[djuosnteisn]

AFAIK we don't have a VSS sensor, that information is inferred from the ABS system.


I guess drive it for a while, and see if you notice anything at all, like lower boost or lethargic pedal response. Maybe you have to mash it quite a bit more to get the same umph as before. 30% difference should be noticeable IMO.

If nothing, then it's prob not used, lol. Thanks for doin this!

[btstarcher]

Another thread revival! I don't know if anyone is curious about this, but I'm gonna try something. My wheel speed sensors are indicating 0mph at all times, probably due to wheel bearings pressed in with the magnet on the wrong side. So I'm changing the tables to 1 across the board. It was set at 1.3 while at 0mph.