1)Depends if you have a heavy foot or a light foot.

2)Because you are going to suck in more air and tell the TPS if you are WOT or just a tad on the throttle.

3)The % is for the low map while if you go over 50% you go in high map.

4)Yes you should, because for MPG to go up you want to be lightly on the throttle vs WOT the whole time and waste gas. 2 different maps low and high. I think of it as cruising for mpg or fast driving. (But thats why they give you 2 files to choose for afc2)

5)If you want mpg you want to tune during cruising. But if you want to make a better map for spirited driving then tune for WOT. Its because its 2 different modes. Normal and WOT.

Anyone correct me if I am wrong.

I have an s5 n/a, The highest % I have for taking away fuel is -10% I am making more power just by feeling. But afr are the best way to actually tune the engine with the afc.

 

My car is an s4.. and because of that ( having only 1 wide band TPS) the AFC picks up 100% throttle.. about 99% of the time.. there is no cruising at 30% for example.. foot on the gas means 100% throttle. LOL... That said..

1) where should it change over? IMO at 1%.. then theres no reason to mess with the lo- map.. ( except for idle) One map to look at makes it even easier.

2) ... ^

3) ..........^

4) ...............^

5) Shouldn't, in reality, the 2 fuel maps be quite similar.. ( you always hear this: a leaner afr will make your car faster.. AND.... a leaner afr will give you less fuel consumption because its economizing the fuel )

Problem with tuning the afrs to cruising, is that if you ever watch the wideband, WOT AFR's are always lower then cruising afrs.. So if i tune to cruising, and then go WOT.. the wideband shows the AFRs a lot higher then what i want.. almost into dangerous levels.. This is why tuning to WOT makes sense to ME.. that way, i never go over a dangerous AFR #

Funny how dependent the way a person tunes is based on s4 vs s5.. seems to make a huge difference.. But this is all my own logic... so it could be way off.

 

Have you tried doing the 98% low and 99% high? It should NOT be touch throttle and it reads WOT or 100%

 

Im pretty sure thats just how the s4 tps works... if you've ever tried to adjust the tps on an s4.. you'd see that 1/4 turn of the cable linkage puts the tps at fully open. then you can keep turning a whole lot more. Weird, and gay.. but true.

 

ewwwwwwwwwww

 

zany huh? LOL..

 

I will provide a small success story for the SAFC users.

Have an 83 with an 89 n/a engine, full RB long primaries exhaust.
Installed the SAFC-II last fall, finally am driving it enough to get some results. I don't have a wideband so I'm just tuning by feel, and I wired the O2 sensor into the SAFC-II. Points of interest:

Cruising:
I set the low throttle to ~53% as that number is only exceeded on steep hills during cruising. Normal cruising for me is between 35-50%. Pulled out around 20-30% fuel throughout the cruising band (2-5k rpm). Fuel mileage has gone from 24-29 Imperial MPG.

WOT
High throttle maps starts around 65%. Harder to tune with only O2 sensor, really need a wideband. But couple things, can't take away fuel @ 3800 RPM and 5500 RPM.