S4 Newbie questions

[kozmos]

I'm into my 4th week of owning my S4 and I cannot be more pleased with my purchase. But coming from a E36 M3, I've noticed a few shortcomings on the S4, namely, the brakes, and suspension. The brakes are way too soggy for my liking and the suspension is very floaty. I've done some research and although my choices are limited living in Singapore, I'm determined to get this corrected once and for all. I also have a few questions which hopefully this board can advise me on:

1) H&R sport/Bilstein sport combo or H&R street coilovers?
2) MTM or APR or GIAC stage 1 chip?
3) Average fuel consumption on the o/b computer does not
tally with the actual consumption. On 2 seperate
occasions, I ran the tank all the way until the fuel
symbol appeared and after I topped up the tank, both
occassions around 48litres and total distance covered,
345km. This works out to 13.9L/100KM or 20.2mpg. But
the o/b computer reads 12.5L/100KM AVERAGE. How is this
possible and I thought the tank is 62litres? You mean
there is a 14litre reserve?

Many Thanks in advance

[Dippy]

Hi, my opinion FWIW is as follows:

1) I know F-all about suspension other than I find my H&R coil-overs fantastic. I know it doesn't help with your choice, but at least there's 1 satisfied customer for one of your options.

2) MTM are known to map for high overboost but restrict it at the top end. So peak torque is great but peak power a bit down. APR have have more of a balance between peak torque and power. I don't know much about GIAC except that they do 3 types of chip. IMO the X-chip raises the boost to a level where it might be too bad on long-term reliability.

As you're in Singapore, I would actually recommend you select the chip based on what best support you can get. I.e. if something goes wrong, the tuner you take the car to knows the chip and so can give you good service. Also don't forget the weak points on the car (TBB, DVs, f-hose if fitted, and other hose fixings) - increasing boost pressure increases the chance of failure so get them fixed/upgraded.

3) I have been looking into this too and have just started tracking my fuel efficiency because I've been refilling the car at fewer miles than my DIS suggests. Early results seem to be that the DIS mpg is 1-2 more than reality. I think this is because it is based on a rolling average rather than a 'how many km did you do for the last X litres of fuel'. So if you give the car some welly and the mpg takes a dive, the DIS is still averaging over a period so it will be a bit higher.

I reset my DIS after refuelling. I am going to check this for a few more weeks and then I will run it for a few weeks without resetting to see if the average DIS mpg over several tanks seems to approach the real mpg averaged over several tanks.

P.S. The tank on the A4 is 62 litres. On the S4 and RS4 it is 60 litres.

[DavidT]

I have the H&R street coilovers as well and I agree with Dippy. They are a huge upgrade from standard suspension but very usable on the road (so long as you don't go too low).

I think you can use vag-com to correct the mpg. I seem to remember reading (probably on audiworld) that the standard seting is about 2.5% optimistic.