Rally2 (ex-R5) News

[ictus]

But are there any drawbacks in having a 3 cylinder engine?

fewer valves,
but i think they can be larger, so the overall amount of air getting in the combustion chamber is the same

[dimviii]

also less friction at movement parts,and very near to the ''ideal'' 500cc for each cylinder.
Also less length of engine.

[Sulland]

One difference

Maximum valve lift :
• 11 mm for a 4-cylinder engine
• 13 mm for a 3-cylinder engine
The cam lift must be homologated in VRa2.
The number and diameter of the bearings must be retained.
‘’VVT’’ and “VALVETRONIC” etc. type systems are authorised if original. They may be rendered inoperative.

Check article 261 to see if you can spot other differences:
https://www.fia.com/regulations/search

[becher]

Also generally speaking a engine with more displacement per cylinder is more suitable to regulations with a small restrictor right?

[dimviii]

Also generally speaking a engine with more displacement per cylinder is more suitable to regulations with a small restrictor right?

Imho i dont see any advantage.If you could explain will be usefull.

[Sulland]

Where are all the engineers/ math experts that can explain the tech pros/cons of 3 and 4 cyl 1620 ccm turbos!

[becher]

Imho i dont see any advantage.If you could explain will be usefull.

Well as an example, 1000cm^3 two cylinder motorcycle engines tend to produce more torque earlier in the rev range than 1000cm^3 four cylinder. Given the restrictor formula "forces" engines to be "low reving engines with lots of torque down low" there is a similarity in the power delivery i'd say, if the displacement per cylinder really does make a difference under current rules is another matter.

[Andre Oliveira]

Eurosol, to Simon Wagner

[WRCStan]

Where are all the engineers/ math experts that can explain the tech pros/cons of 3 and 4 cyl 1620 ccm turbos!

Youtube


Inside Toyota's Insanely Powerful 3-Cylinder

[Fast Eddie WRC]

The Fiesta ST switched to a 3-cylinder 1.5 engine with the Mk8 and it makes more power than the old 1.6. It's also used in the Fiesta Rally3 so it's clearly been found to be a good configuration.