To VAG-Com users, FATS times database for the Euro S4s

[CliveH]

Doesn't seem right, does it. I'll speak with Mihnea.

[S2tuner]

Some cars take more timing than some others, I do think Paul's is a very good car that takes lots of timing and is happy with it, Clive's is running as much timing as it can so there isn't much more that can be had out of it IMHO...

HTH,

Mihnea

[CliveH]

Thanks for the explanation Mihnea

What is it that causes such a difference in a "very good" car and, well, mine...?

[CliveH]

Last question (Mihnea?) :

Is the inability of my car to run as much timing as Paul's likely to be the main reason for the huge difference in FATs time?

[Paulm]

I will do a run when I get home now it is hotter weather. My best run was around 7c, just to see if it makes any diff.


I expect my car to be slower because of.

Hotter air
Bigger wheels / tyres
Spare wheel now back in.

It will be interesting to see by how much.


As Mihnea says, mine seems fine with that timing. In 6th If I boot it from 2k all the way up the most I ever see in CFs is around 4.5 to 5 on Optimax. On 97 I can see as much as 9 much the same as 95. You got to wonder if 97 is re-badged 95. Fuel does make a big diff.


I also wonder how much diff a catch can will make. Maybe your PLV is knackered and sucking up to much oil out of the breather, that may cause det and the inability to run more timing?

[CliveH]

Thanks Paul.

Was your colder run measured when you were running smaller wheels? You now have same as me right? (18" MTM reps)

Can you please educate me on the meaning of "PLV" and why it might be knackered...

[DavidT]

PLV or wheels make virually no difference to acceleration times.

[CliveH]

Can you please educate me on the meaning of "PLV" and why it might be knackered...

I think I worked it out..."Pressure Limiting Valve"?

Assuming this valves limits the boost pressure, this wouldn't appear to be faulty, looking at my boost readings.

[CliveH]

Right,

Just been out for another run, still 18C out there, and still sitting pretty much on 3/4 tank of fuel.

I got 5.43 this time, but the road was ever so slightly downhill, and I wasn't able to average it out with a return run (as a lorry got in the way!).

I'm not unhappy with that, but I'm still curious to know why I can't run any more timing, particularly as I had understood that removing the precats, and having freer flowing main cats (RS4), would allow better ignition timing...? I was only expecting 10-15bhp from this little upgrade, but it doesn't look like I've got anything like that. In fact, if you use the BHP estimator at the top of this thread ( http://www.vastperformance.com/faq.php ), this indicates 298bhp, although the alternative guesstimator of airflow/0.8 gives 315.

Puzzled...

[Paulm]

PLV or wheels make virually no difference to acceleration times.

Got to disagree on both points ( in the nicest possible way)

PLV, if you are sucking up oil and getting det it will <beep> your ignition and Clive's is 6 degrees lower than mine I bet that is worth 30- 40bhp?

Bigger wheels will make a diff in acceleration, just not sure how much yet.

Clive, the PLV has nothing to do with how much boost you have. It is all to do with oil in the inlet track causing det

[DavidT]

Paul,

What I'm saying is that Clives car is making good boost but the timing is poor.

You'd need to be using a LOT of oil to get a measureable difference in performance, there are 7 litres of oil in the engine (or less) and you use a tank of fuel - 50 litres+ - every 250 miles or so, it's a big difference.

Wheel sizes and weights do make a difference. Turning heavier wheels or ones with a bigger rolling radius will reduce acceleration but overall, these things have a relatively small effect.

6 degrees of timing advance = a big power increase. Fuel is the most likely cause.

[Nige_RS4]

6 degrees of timing advance = a big power increase. Fuel is the most likely cause.

Or the timing belt was not aligned correctly - there seems to be a number of cars around with this problem - my old S4 was out by 6 degrees!

[CliveH]

6 degrees of timing advance = a big power increase. Fuel is the most likely cause.

I'm currently running on Tesco 99, although the tweak in the tuning was done on Tesco 97.

Nige - cambelt setup, interesting thought - it will be changed soon, so we'll see...

[Paulm]

Yeah I see what you are saying Dave.

Nige could well have a point there.

[oliew]

Hey up
Yesterday i went down to MRC tuning to get my boost leak sorted! didnt manage to find anything leaking noticeable but looking at realtime runs the boost was surging high then dropping and then building again on hard WOT, we used a generic remap to test the difference and it would only just make 1 bar of boost, so then we remapped it while driving and now im pulling 1.2bar without surges, also removed fog lights . My timing is less but better boost now and my fats run now is 5.17 seconds. We did a fats run uphill with aircon on and 2 people in the car and got 6.4 which i thought was reasonable, this was on bp 97 too! with 19" wheels.
Clive, its a crazy thing this power to timing to boost levels, im still 60-80mbar short on my logs at the bottom

Engine speed Mass air flow Throttle angle Ign timing
TIME g/s 0-5deg=closed deg
STAMP /min g/s % °BTDC

1222.88 2800 100.22 100 20.3
1223.39 3040 132.06 100 16.5
1223.79 3240 168.17 100 12
1224.21 3480 182.94 99.6 10.5
1224.7 3800 196.89 100 10.5
1225.1 4040 207.14 100 10.5
1225.52 4280 216.61 100 10.5
1226.03 4560 228.22 100 9.8
1226.46 4800 234.47 100 11.3
1226.9 5040 237.89 100 12.8
1227.34 5240 237.06 100 12.8
1227.81 5440 238.36 100 15.8
1228.27 5640 241.33 100 18.8
1228.75 5840 245.36 100 19.5
1229.23 6040 247.89 100 21.8
1229.73 6200 249.08 100 21
1230.24 6400 249.78 100 24.8
1230.74 6560 247.06 100 26.3



BOOST levels.
Engine speed Engine load Spec'd Boost Actual Boost
990-1800 mbar <=1800 mbar
/min % mbar mbar

3600 179.7 2240 2080
3720 185.7 2220 2140
3800 185 2210 2160
3880 185 2200 2160
3960 184.2 2190 2170
4040 183.5 2180 2160
4120 182 2150 2160
4200 180.5 2140 2140
4280 178.9 2120 2120
4400 176.7 2100 2100
4440 175.9 2090 2090
4520 174.4 2080 2080
4600 174.4 2070 2070
4640 173.7 2060 2060
4720 171.4 2050 2040
4800 170.7 2050 2030
4880 168.4 2040 2020
4920 166.9 2040 2000
5000 164.7 2040 1980