S2000 technical thread

[OldF]

I opened a new thread because my question is off topic. The original thread was: “Ypres Westhoek Rally 2008”.

Mirek Fric [Cze] wrote:

Josti: You're not right completely. They missed top speed agains Peugeots only. Fiats go on short gearbox practicaly everywhere. It is because weak engine of Fiat (which is weaker than VW, that was confirmed by Loix and Czopik last year). Even last year in Finland Alén was going on short gearbox with a top speed of 168 km/h!

Compared to that Peugeots usualy uses medium gearbox. We compared that also on rally Hustopeče in Czech champ. where there Béreš's Fiat was evidently weaker than Kopecký's Peugeot (even by sight). From GPS top speed we know that Kopecký was on medium and Béreš on short gearbox. Even though Peugeot was much beter in slow corners and handbrake turns.

Mirek, as far as I know it’s not possible to make handbrake turns if the centre differential has a mechanical lock. When the rules changed few years ago for the WRC cars, one argument for retaining the active centre differential was the ability to make handbrake turns. So, my question is: Do you know if the S2000 cars are using the mechanical lock in the centre differential?

[Mirek]

All S2000 cars have mechanical central diffenrential but I think the handbrake release must be possible by some kind of clutch or any other way. Anyway S2000 cars can do handbrake turn and they do it.

I was also told that 207 doesn't have central differential at all. It seems to be strange to me as I remeber only some gr.B cars without it (Quattro A2 for example) but they also didn't use handbrake. I'll try to ask about 207, how is it actualy.

[HaCo]

I'm not absolutely sure, but I thought that the VW only recieved a handbrake on the end of last year. GTA will defenatly know more about it.

Funny to mention I think: Voullioz didn't want to use his handbrake any more in Ypres on the second day. Everything time he used something went wrong (he also was in a ditch for a minute during day 1).

There is something about direct injection mentioned on the Skoda thread. Is it allowed or not, what advantage could it bring? Anyone?

[Mirek]

Dirrect injection is allowed if used on production base engine.

[oreixa]

I'm not absolutely sure, but I thought that the VW only recieved a handbrake on the end of last year.

Yes, you are right.

[dimviii]

just my 2 cents...
in my evo viii according to manual,you can use the handbrake without problems with the centre diff.
same for evo 9.
evolutions have mechanical centre differentials.
they have an switch under the handbrake lever,and as you use the handbrake a signal goes to the centre diff ecu and releases the centre diff via a electrohydraulic clutch.

[OldF]

the centre diff ecu and releases the centre diff via a electrohydraulic clutch.

The locking mechanism (the clutch discs) is mechanical but it’s controlled by the ECU. Evo 9 has a same type of central differential than the WRC cars. A purely mechanical limited slip differential is also “controlled” mechanically. Here are a couple good sites that explain how they work.

http://www.gordon-glasgow.org/lsdtech.html

http://icpcitation.com/variloc_theory.htm

[OldF]

There is something about direct injection mentioned on the Skoda thread. Is it allowed or not, what advantage could it bring? Anyone?

Higher power and cmpression ratio, better fuel efficiency, peak torque on lower revs etc.

http://en.wikipedia.org/wiki/Gasoline_direct_injection

http://www.mitsubishi-motors.com/cor...ent/e/gdi.html

I found an article from a Finnish motor magazine from 1997 about the Mitsubishi Carisma 1,8 GDI. The GDI had it’s peak torque (174 Nm) @ 3750 rpm compared for the MPI that had the peak torque @ 4500 rpm.

I compared a 2-litre Audi with MPI and GDI

MPI: compression ratio 10,3:1; 131 hp @ 5700 rpm; 195 Nm @ 3300 rpm
GDI: compression ratio 11,5:1; 150 hp @ 6000 rpm; 200 Nm @ 3500 rpm

[RS]

Higher power and cmpression ratio, better fuel efficiency, peak torque on lower revs etc.

http://en.wikipedia.org/wiki/Gasoline_direct_injection

http://www.mitsubishi-motors.com/cor...ent/e/gdi.html

I found an article from a Finnish motor magazine from 1997 about the Mitsubishi Carisma 1,8 GDI. The GDI had it’s peak torque (174 Nm) @ 3750 rpm compared for the MPI that had the peak torque @ 4500 rpm.

I compared a 2-litre Audi with MPI and GDI

MPI: compression ratio 10,3:1; 131 hp @ 5700 rpm; 195 Nm @ 3300 rpm
GDI: compression ratio 11,5:1; 150 hp @ 6000 rpm; 200 Nm @ 3500 rpm

The latter of those two engines is the base unit Skoda are using in the Fabia.

[wwbroe]

I'm not absolutely sure, but I thought that the VW only recieved a handbrake on the end of last year. GTA will defenatly know more about it.

Funny to mention I think: Voullioz didn't want to use his handbrake any more in Ypres on the second day. Everything time he used something went wrong (he also was in a ditch for a minute during day 1).

Haco, not that it is that important, but Voullioz wasn't in a ditch on day 1 but on day two at Watou stage. He could use handbrake, but as a matter of fact he didn't want to use it any more at end of day 2, because of two spins using the handbrake. (but i think we are off-topic).
Concerning the Polo, they had handbrake all the time, but couldn't use it to make turns. It was indeed only at the end of last year's season that the handbrake could be used to take hairpins for example. But Loix had the same problems with handbrake with the Punto that he used in IRC last year. It was only the Pug that didn't have any problems using the handbrake.