The Road Cars of Touring Car Racing: BMW 320si

This is the third article in the series “The Road Cars of Touring Car Racing”. Last time we featured the Volvo 240 Turbo Evo, this week it is time for the BMW 320si, one of the newest homologation specials. The car was introduced in 2006 when BMW introduced the new 3-series model called E90. Why has it been so successful in WTCC? What are the special features of it?

The BMW 320si E90 replaced the BMW 320i E46 for the 2006 FIA World Touring Car Championship season.

The road car series, only sold in Europe, is limited to 2.600 units and features some interesting features brought from the race version of the car.

The 320si model marked the change from 6 cylinders, which BMW used in the E46, to four cylinders. The engine of the 320si (N45) is different to the standard 320i engine (N46).

The engine is hand built at the BMW Landshut factory. A lot of changes has been made to the engine to reduce weight and increase durability. The cam cover is made of carbon fiber which saves 10 kilos.

The valvetronic system has been removed in order to reduce the number of moving parts and increases precision of the valve control at high rpm.

The maximum rev limit has been increased to 7.300 rpm and the engine power is 173 bhp compared to the standard 320i which features 150 bhp. The race specification engine puts out approximately 280 bhp with a rev limit at 8.500 rpm, as required per the S2000 rules.

While 173 bhp isn’t a lot in a road car in these days, car magazines are thrilled with the engine and the way it delivers the power. As written in the car magazine EVO:

“Power may be up by just 22bhp over a standard 320i, but the way the screaming four-pot delivers is very different. The noise is fantastic, too, a tight metallic timbre that’s bursting with aggression.”

It is not only the noise that is fantastic of the car, the results of the race version are one of a kind. The car has secured two World Touring Car Championship titles in the hands of the Brit Andy Priaulx, the two last privateer WTCC titles have been taken by drivers of a BMW 320si and BMW has taken the constructors championship two years in a row, 2007 and 2008.

But the success has not been limited to the WTCC. The car is hugely popular in the various national championships around the World.

Fredrik Ekblom and Richard Göransson clinched the Swedish Touring Car Championship titles in 2007 and 2008 respectively, both driving BMW 320si, for example.

For the 2009 season a new aero kit is going to be introduced for the racing version of the BMW 320si E90 based on the recently face lifted BMW E90-series. If it continues to be successful on the race tracks remains to be seen!

The Road cars of Touring Car Racing next week: BMW M3 Sports Evo E30. The article series continues with another BMW, the BMW M3 Sport Evo E30. The road car version of the legendary M3 is extremely rare and apprechiated among collectors. Read everything about it and its successful years on the race tracks in our next edition of The Road Cars of Touring Car Racing!