Rally 3 class

[Rally Power]

Does the engine have to be closely based on a road car engine fitted to that model or can the cylinder capacity be enlarged? If no such changes are allowed then it seems rather short sighted they didn’t do something with the restrictor size. It could be rather limiting if a manufacturer does not have a 1.5/1.6 litre engine fitted to the road going model.

That's a good question. In Rally4/5 they're based on the road car engine and once MSport is apparently using the Fiesta ST 1.5 engine (instead of a 1.6) on its Rally3 car, probably they must still be based in stock engines (it's becoming hard to remember that they were meant to be just a 4wd Rally4 upgrade...).

Btw, another strange reg move is to have all Rally4 cars with the same weight (and restrictor), meaning that 1.0 cars crews will hardly be able to match 1.2 or 1.3 rivals, as they now do. And once Rally5 cars won’t get the 30mm restrictor, probably we’ll end seeing the fastest Rally5 drivers pretty close to Rally4 competitors. Time will tell.

[Sulland]

Which national series have Championship class for Rally3 ?
(I know you can make entry to rally with Rally3 but for points I mean)

Up here i guess they will go in class 4,

Klasse 4

Gr.A, R2C og R3C 1601 - 2000 cm³, Super 1600, R3T (maks. 1600 cm³) og R3D (maks. 2000 cm³)

In Norway, not many have ever started in this class. We had a few S1600 back in the days, and 1 R3T as far as I remember.

[Mirek]

That's a good question. In Rally4/5 they're based on the road car engine and once MSport is apparently using the Fiesta ST 1.5 engine (instead of a 1.6) on its Rally3 car, probably they must still be based in stock engines (it's becoming hard to remember that they were meant to be just a 4wd Rally4 upgrade...).

Btw, another strange reg move is to have all Rally4 cars with the same weight (and restrictor), meaning that 1.0 cars crews will hardly be able to match 1.2 or 1.3 rivals, as they now do. And once Rally5 cars won’t get the 30mm restrictor, probably we’ll end seeing the fastest Rally5 drivers pretty close to Rally4 competitors. Time will tell.

Why do You think that 1.0 with the same restrictor would have less power than 1.2 or 1.3? With the same restrictor the power difference shall be all about the efficiency and that could be actually better with 1.0 (less innertia and friction). The question is whether there won't be issue with the size of valves in the small engine or something else I didn't think about.

P.S. I'm no motoring engineer so I may be wrong. Maybe someone can correct me.

[Rally Power]

Why do You think that 1.0 with the same restrictor would have less power than 1.2 or 1.3? With the same restrictor the power difference shall be all about the efficiency and that could be actually better with 1.0 (less innertia and friction). The question is whether there won't be issue with the size of valves in the small engine or something else I didn't think about.
P.S. I'm no motoring engineer so I may be wrong. Maybe someone can correct me.

Take a closer look mate; in Rally4 case I’ve mentioned the weight regs change as the main doubt on 1.0 cars future speed. Probably, there’s no need to be an engineer to get that the Fiesta and the 208 paces are pretty leveled today, once the Fiesta can compensate its lower CC by having less 80kgs. Without that weight compensation and once they’ll use the same restrictor, is it hard to believe that the Fiesta can be outpaced?

[Mirek]

Take a closer look mate; in Rally4 case I’ve mentioned the weight regs change as the main doubt on 1.0 cars future speed. Probably, there’s no need to be an engineer to get that the Fiesta and the 208 paces are pretty leveled today, once the Fiesta can compensate its lower CC by having less 80kgs. Without that weight compensation and once they’ll use the same restrictor, is it hard to believe that the Fiesta can be outpaced?

That's if you suppose that the cars will have same power ratio as they have now. I wouldn't be sure about that. I mean that the smaller restrictor may affect the larger engine's efficiency more than the smaller one. Let's wait and see.

[br21]

Fiesta min. weight is now 50kg less than 208. Apparently with 30mm restrictor max power/torque should should be almost identical to current ones. Simply turbos and engine volumes are so small that it wont affect that much. OK, probably driveability, power/torque curve can be affected, and theoretically 1,0l should be less affected than 1,2l as it needs less air, but it depends also on airflow throught intake (intercooler, manifold, etc). Second question is reliability, as increasing turbo speed can increase power, but affect turbo life...

[Mirek]

Fiesta min. weight is now 50kg less than 208. Apparently with 30mm restrictor max power/torque should should be almost identical to current ones. Simply turbos and engine volumes are so small that it wont affect that much. OK, probably driveability, power/torque curve can be affected, and theoretically 1,0l should be less affected than 1,2l as it needs less air, but it depends also on airflow throught intake (intercooler, manifold, etc). Second question is reliability, as increasing turbo speed can increase power, but affect turbo life...

Sorry for probably stupid questions

Is the turbo pressure limited by the rules?
If not is the turbo pressure determined purely by reliability (and cost limit) and not by the maximum restrictor flow?

[Rally Power]

Fiesta min. weight is now 50kg less than 208.

Yep, wrong me; still that 50kg advantage will vanish in January and every kg matter in top level rally.

[Alpine-110]

Can this fiesta R3 do testrallies before it is homologation next year ?

[Fast Eddie WRC]

Latest Absolute Rally podcast with a good discussion on Rally3 and if its really going to be worthwhile:

https://www.absoluterally.co.uk/

https://www.podbean.com/eu/pb-cyiv2-f2b69a