R-Classes News

**Mirek** · 5th Dec 10, 16:14

This is valid only for WRC events, nothing else.

**OldF** · 5th Dec 10, 17:55

Originally Posted by navtheace

From Sullands seperate topic of the FIA document. We have the following structure.

WRC
WRC (2011): 1.6 T engine with WRC kit

1
S2000-Rally: 1.6 T engine

2
S2000-Rally: 2.0 Atmospheric
Group R4

3
Group N car over 2000cc (actual N4)

4
RGT Cars

5
Group A car over 1600cc and up to 2000cc
Super 1600
R2C (over 1600cc and up to 2000cc)
R3C (over 1600cc and up to 2000cc)
R3T (up to 1600cc / nominal)
R3D (up to 2000cc / nominal)

6
Group A car over 1400cc and up to 1600cc
R2B (over 1400cc and up to 1600cc)
kit-car over 1400cc and up to 1600cc

7
Group A car up to 1400cc
kit-car up to 1400cc

8
Group N car over 1600cc and up to 2000cc

9
Group N car over 1400cc and up to 1600cc
R1B (over 1400cc and up to 1600cc)

10
Group N car up to 1400cc
R1A (up to 1400cc)

This could also be put this way.

Class WRC: 1.6T engine + WRC kit
Class 1: S2000 with 1.6T engine
Class 2: R4 and S2000 with 2.0 NA engine
Class 3: N4
Class 4: RGT
Class 5: A7, S1600, R2C, R3C, R3T and R3D
Class 6: A6, R2B and Kit cars >1400 cm3 – 1600 cm3
Class 7: A5 and Kit cars < 1400 cm3
Class 8: N3
Class 9: N2 and R1B
Class 10: N1 and R1A

**navtheace** · 5th Dec 10, 19:31

Yep.

Class WRC: 1.6T engine + WRC kit
Class 1: S2000 with 1.6T engine
Class 2: R4 and S2000 with 2.0 NA engine
Class 3: N4
Class 4: RGT
Class 5: A7, S1600, R2C, R3C, R3T and R3D
Class 6: A6, R2B and Kit cars >1400 cm3 – 1600 cm3
Class 7: A5 and Kit cars < 1400 cm3
Class 8: N3
Class 9: N2 and R1B
Class 10: N1 and R1A

Then to take out the categories that manufacturers are not homologating in anymore and S2000 which is no new homologations after end Dec 2010.
This is what will happen over time (a long time!)

Class WRC: 1.6T engine + WRC kit
Class 1:
Class 2: R4
Class 3:
Class 4: RGT
Class 5: R2C, R3C, R3T and R3D
Class 6: R2B
Class 7:
Class 8:
Class 9: R1B
Class 10: R1A

**morganmilan** · 5th Dec 10, 20:08

Originally Posted by navtheace

Yep.

Then to take out the categories that manufacturers are not homologating in anymore and S2000 which is no new homologations after end Dec 2010.
This is what will happen over time (a long time!)

Class WRC: 1.6T engine + WRC kit
Class 1:
Class 2: R4
Class 3:
Class 4: RGT
Class 5: R2C, R3C, R3T and R3D
Class 6: R2B
Class 7:
Class 8:
Class 9: R1B
Class 10: R1A

Maybe I´m wrong, but AFAIK, s2000 new cars can´t be homologated from 2011 with 2000cc NA engines, but 1.6T can be, so "class 1" would be still ok

**OldF** · 6th Dec 10, 23:47

Originally Posted by dimviii

don t think that brembo monoblock racing calipers/floating 355mm discs are bad brakes at all.Same with ap racing for slowbarus.

I’ve understood that the brake pads for group N can’t be bigger than the original ones and using bigger brake disks won’t change the braking power but there must be some reason for using bigger brake discs. Of course the Brembo and AP Racing brakes used are made for rally use with some heavier usage than standard brakes.

I’ve been trying to compare S2000 and homologated group N break disks, and they seem to be the same size. Rear gravel/tarmac brake discs 300 mm and tarmac front discs 355 mm and gravel front brake discs 300 mm (which are actually smaller than the original ones for both Mitsubishi and Subaru).

I don’t know the brake pads sizes of S2000 cars but maybe the brake pads size of the original for Mitsubishi and Subaru are enough to give enough braking power.

Those who know better can explain this. If the braking powers of the group N brakes were OK with the current brakes then the problem would be to get some weight of from the R4 cars, with reasonable costs.

**Mirek** · 7th Dec 10, 09:11

To brake rotating wheel You need braking torque. The torque is a multiplication of braking force and disc effective radius.

Braking force is normal force multiplied by friction coefficient (changeble with temperature or pad state for example). Normal force on brake pads is caused by hydraulic pressure via brake pistons.

It's not good to compare stock and racing brakes as racing systems doesn't use brake booster to prevent time delay (they use larger brake cylinders) and for better feeling in brake pedal.

Anyway the larger the disc, the bigger brake torque and the better cooling (larger area means more heat exchange). But it also means bigger wheel inertia which negatively affects both acceleration and deceration. Therefore You have to think about ideal dimensions for both axles (each one have different adhesion).

In group N cars the problem is mostly in weight. Very simpliffied: For some decelaration "a" of a weight "m" You need some force "F". If You have same F for both S2000 and gr.N You can easily compare difference in decelartion a=F/m. That's the simplies case when both braking on 100% and have same adhesion (same tyres, suspension, weight ballance etc.) and same cooling, which is another problem.

**OldF** · 7th Dec 10, 21:30

Thanks Mirek.

I dug up and old book that I bought when I was a young boy and did some reading. Now I’m more aware of what you wrote.

You know, the physics haven’t changed at all during these years.

**urabus-denoS2000** · 7th Dec 10, 23:09

It's always fascinating for me to read the conversations of you 2 .... Thanks Mirek and OldF

**morganmilan** · 8th Dec 10, 16:11

Originally Posted by OldF

Thanks Mirek.

I dug up and old book that I bought when I was a young boy and did some reading. Now I’m more aware of what you wrote.

You know, the physics haven’t changed at all during these years.

Newtonian mechanics, at least...

**OldF** · 8th Dec 10, 17:09

Originally Posted by urabus-denoS2000

It's always fascinating for me to read the conversations of you 2 .... Thanks Mirek and OldF

Thanks for the compliment.

We work as a team. I ask the questions and Mirek give the answers.

**Sulland** · 8th Dec 10, 18:55

Originally Posted by OldF

Thanks for the compliment.

We work as a team. I ask the questions and Mirek give the answers.

And the rest of us learn - thats the beauty of internet and Forums like this one !

**cali** · 8th Dec 10, 19:50

Originally Posted by Sulland

And the rest of us learn - thats the beauty of internet and Forums like this one !

Yes indeed !

I'm reading and learning all the time

**navtheace** · 9th Dec 10, 14:41

It would be excellent to see Audi come in with the S3 for an R4 car.

However, it's one of those where Audi will not want to have their cars be second rate to a Fiesta, MINI and DS3 on rallies.

**morganmilan** · 9th Dec 10, 14:56

Originally Posted by OldF

This could also be put this way.

Class WRC: 1.6T engine + WRC kit
Class 1: S2000 with 1.6T engine
Class 2: R4 and S2000 with 2.0 NA engine
Class 3: N4
Class 4: RGT
Class 5: A7, S1600, R2C, R3C, R3T and R3D
Class 6: A6, R2B and Kit cars >1400 cm3 – 1600 cm3
Class 7: A5 and Kit cars < 1400 cm3
Class 8: N3
Class 9: N2 and R1B
Class 10: N1 and R1A

It´s one of most useful way of grouping classes I´ve ever seen. Thnx OldF

**navtheace** · 9th Dec 10, 15:31

Here is a car to rival VW if they come in with their Scirroco as 2 litre turbo FWD.

http://uk.autoblog.com/2010/12/08/re...llying-megane/

Is it 32mm restrictor for this category? Has somenoe got the link to the FIA PDF which has the rally categories explained showing the restrictor sizes? I think I saw it posted on here earlier?

**OldF** · 9th Dec 10, 15:55

Originally Posted by navtheace

Here is a car to rival VW if they come in with their Scirroco as 2 litre turbo FWD.

http://uk.autoblog.com/2010/12/08/re...llying-megane/

Is it 32mm restrictor for this category? Has somenoe got the link to the FIA PDF which has the rally categories explained showing the restrictor sizes? I think I saw it posted on here earlier?

It’s 33 mm from beginning of 2010. Renault is little down with power compared to other N4 but it’s only FWD so 266 bhp is probably enough.

Here. http://www.fia.com/en-GB/sport/regul...tingCodeA.aspx

Click on “Appendix J (2010) to the International Sporting Code” or this direct link.

Appendix J (2010) to the International Sporting Code

Article 254 group N, Article 260 group R etc.