New engine regulations introduced by the FIA for 2007 are designed put a block on development in an effort to increase value for money and keep a check on speeds. As a first step all suppliers had to lodge a two-race engine with the FIA at the end of last season. In the case of Toyota, the engine handed over was that used by Jarno Trulli through the Japanese and Brazilian GP weekends.
As part of the rule change, all engines are now limited by the FIA to a maximum of 19,000rpm, whereas previously some competitors could run as high as the 20,000rpm range for short periods, such as in qualifying.
Teams were allowed to make adjustments in certain areas in order to optimise the engine spec they had already handed over for this lower rev limit. Details and drawings of any changes were lodged in December, and in early March teams will hand over a complete engine with the approved modifications. These definitive 2007 engines will then form the basis of what each teams will use for the next four seasons, although there is some flexibility in terms of resolving reliability issues.
Luca Marmorini, Senior General Manager Engine, explains: “On 15 December we had to provide drawings to the FIA. We had to have it fully clear in our minds what this engine would look like. After Brazil mostly we could work on car installation details, auxiliary layout, those sort of areas.
“There is some re-tuning allowed, due to the fact that this engine now can only rev to 19,000rpm. So there was some work on port geometry, the valve and the valve lift profile, the combustion chamber, the piston shape, and to a degree we could work with the oil flow in the engine, to adapt this for reliability reasons.
“It seems like there was a lot of freedom, but there wasn’t really. We couldn’t redesign a block, for example. So a lot of main parameters we fixed when the engine went into the car in Japan last year could not be touched any longer.”Source Toyota Pictures of the new TF107:
http://www.f1technical.net/gallery/v/To ... 07/Launch/