A RR will not give you your exact BHP figure, if you want that take the engine out and bench dyno it. It will give you a good comparison for before and after mods though if used on the same dyno i.e. a rr gives you 210 stock and 230bhp after remap = 20bhp increase so good gain (although, again, not necessarily accurate) All RR gives different readouts and the amount of variables involved (temp, petrol, mileage etc etc) will never give you a 100% acurate reading.
The point is though you are happy with the increase and feel of the car! Thats what makes the spend worth it, the BHP figure is just something to brag about down the pub! Start chasing BHP figures and you will lose alot of £££, as long as you enjoy it then it doesn't matter whether you get an extra 5bhp or 50bhp

Now if its as sunny as it is here i hope your out using it!!!
