To limit power, all forced induction cars were fitted with a 34 mm diameter air restrictor before the turbocharger inlet, limiting the air flow to about 10 cubic meters per minute. The restriction was intended to limit power output to 300 hp although some WRC engines were believed to produce around 330–340 hp. Engine development did not focus on peak power output but towards producing a very wide powerband (or power curve). Typically, power output in excess of 300 hp was available from 3000 rpm to the 7500 rpm maximum, with a peak of 330–340 hp at around 5500 rpm. At 2000 rpm (the engine idle speed in "stage" mode) power output was slightly above 200 hp.
Rallying is also unique in its choice of where and when to race. Rallies take place on all surfaces and in all conditions: asphalt (tarmac), gravel, or snow and ice, sometimes more than one in a single rally, depending on the course and event. Rallies are also run every month of the year, in every climate from bitter cold to monsoonal rain. As a result of the drivers not knowing exactly what lies ahead, the lower traction available on dirt roads, and the driving characteristics of small cars, the drivers are much less visibly smooth than circuit racers, regularly sending the car literally flying over bumps, and sliding the cars out of corners.
It scored six successive World Rally Championships in its long career, and on the road it punched way above its weight. To drive, Integrales feel unwaveringly surefooted and endlessly poised. But, whereas more modern turbocharged four-wheel drive cars have sacrificed outright fun for grip and numbed precision, the Integrale is always exciting to hustle down a back road.
Two ultra long distance challenges took place at this time. The Peking-Paris of 1907 was not officially a competition, but a "raid", the French term for an expedition or collective endeavour whose promoters, the newspaper "Le Matin", rather optimistically expected participants to help each other; it was 'won' by Prince Scipione Borghese, Luigi Barzini, and Ettore Guizzardi in an Itala. The New York–Paris of the following year, which went via Japan and Siberia, was won by George Schuster and others in a Thomas Flyer. Each event attracted only a handful of adventurous souls, but in both cases the successful drivers exhibited characteristics modern rally drivers would recognise: meticulous preparation, mechanical skill, resourcefulness, perseverance and a certain single-minded ruthlessness. The New York–Seattle race of 1909, if shorter, was no easier. Rather gentler (and more akin to modern rallying) was the Glidden Tour, run by the American Automobile Association between 1902 and 1913, which had timed legs between control points and a marking system to determine the winners.
1968 brought the first of a series of British-organised intercontinental rallies, the Daily Express London-Sydney Marathon, which attracted over 100 crews including a number of works teams and top drivers; it was won by the Hillman Hunter of Andrew Cowan/Brian Coyle/Colin Malkin. Not to be outdone, the rival Daily Mirror sponsored in 1970 the London-Mexico World Cup Rally, linking the stadia of two successive football World Cups, on a route that crossed Europe to Bulgaria and back before shipping out from Lisbon to Rio de Janeiro, after looping around South America, and a run through some of the most frightening sections of Peru's road race, the Caminos del Inca, they wrap it up being shipped to Panama and a final run up Central America. The Ford Escort of Hannu Mikkola and Gunnar Palm won. These were followed in 1974 by the London-Sahara-Munich World Cup Rally, and in 1977 by the Singapore Airlines London-Sydney Rally.