From what I gathered on SeatCupra.net's dedicated forum for REVO (moderated by Revo_Kev, Revo_Mitchell and Revo_Richard), Riz just did a pretty good explanation.
I'll only add, to answer specifically to your questions :
- reversing to Stock mode will nevertheless give you the benefit of the latest upgrade from Audi.
ie. if your car was shipped with Audi V.1 program for the motronic ECU, when Revo installs their software, they also install the latest version from Audi. Thus when going back to stock with the SPS device, you may actually be running Audi V.2 or whatever latest version.
- Low boost range (from 0-9):
When the revo software is installed, it's set at Low boost 9. This is the so-called "standard performance".
When set to 0, you get into Valet mode which is something like 0.5bar for the RS4, PLUS a max rev of 5,500 rpm.
(note: feels like my parents A6 V6 2.
. I personnally call it "learning driver mode" (say for the missus [img]images/graemlins/wink.gif[/img])
- High boost range (from 0-9) :
Key point : it overrides any setting in Low boost range so if you first enter Low range 5 then High range 3, you end up with Low range 9 + High range 3.
Second point : High boost range is just incremental to Low boost 9.
Thus High boost 3 could be called Boost 9.3.
Just to give a theoretical example on a car with a stock 1.0bar, and modified with REVO with a peak 1.4bar as standard performance upgrade (ie. Low boost 9) :
Low boost 0 - Valet mode ( 0.5bar )
Low boost 1 - Stock boost (1.0 bar)
Low boost 5 - 1.20 bar
Low boost 6 = 1.25 bar
Low boost 7 = 1.30 bar
Low boost 8 = 1.35 bar
Low boost 9 - 1.40 bar
high boost 1 = 1.42 bar
high boost 3 = 1.46 bar
high boost 5 = 1.50 bar
high boost 7 = 1.54 bar
high boost 9 = 1.58 bar
- Timing : if you over-extend the reality (say put Timing 7 for high-end 98Ron, while actually running on good 95Ron which qualifies for Timing 5 at best), the ECU will detect it and set itself back to a lower mode.
That lower mode has two disadvantges :
+ Disadvantage #1 : a set-back mode is less performant than an exact mode. Thus you'd get more of the car by being precise than by putting all modes to MAX levels and expect the ECU to adjust automatically at lower optimum levels (I hope I'm clear enough [img]images/graemlins/smile.gif[/img])
+ Disadvantage #2 : the so-called "adaptation" feature of the Motronic.
As soon as the Motronic goes into safer mode (for example : the Octane level is not as good as initially declared), it re-positions itself to a lower quality level (same example : usual gas is 95Ron octane).
If say you immediatly empty the tank out of 95Ron and replace it with high-end 98Ron, it will not detect it and re-adjust asap : this "adaptation" process may take a few hundred miles and a few full tanks of 98Ron.
Note : this would be a standard functionnality of the Motronic. So whether you drive a stock RS4, an MTM or a Revo tuned one, every time you put cheaper gas in it, it behaves that way and you'll "suffer" the consequences for a longer time than the next refill with high-end gas.
Hope this helps,
Eric