actual bhp

[Frosty]

Quote: Originally posted by Rich-D on 19 November 2003

Quote: Originally posted by jonnyboy on 19 November 2003

Just to add my two penneth. I think that all 172s have near enough 172 BHP. (Due to miniscule manufacturing tolerances etc) Its far more likely that there are loads of dodgy rolling roads that are ill maintained and not callibrated properly. Rolling rodes when you think about it are quite a crude way of determining output from and engine which is many many moving parts removed from it (ie a big margin for error throughout the process)

So what if several 172s & Cups are all tested on the same rolling road on the same day and they all varied, some by quite a bit?!

Becuase this has happened in the past... at RE in fact...

This is pefectly normal.

Tyre pressures alone make a huge difference between cars, and theres bound to be a few inconsistencies there.

Another factor is coolant temperature - again, will vary with most cars.

Yet another is the temperature of the gearbox oil. This will warm when the car moves, and the warmer it is - the thinner it will get, thus altering run-down figures.

Rolling roads are very useful for mapping, and to see approximate benefits of modifications, but cannot really be used to compare different cars.