So I decided after having my car since I bought it in October there I would like to get it on the rollers to see what power it was putting out. Just for my own piece of mind. So I got the car booked in and it went on the rollers this morning.
To say I got a shock was an understatement. After the first 4 consistent runs it returned a result of 264.2 HP at the fly wheel. Holy

After some trouble shooting there was a vacuum leak detected at the air box intake valve. This was sorted and then another 4 consistent runs were carried out. This time returning the reading of 291.3 HP at the fly wheel.
Very disappointed as I was hoping it would have been running around the mid 300's.
I'm looking for some advise on to why it is so down on power. I have read a bit about the carbon build up on the intake manifold and that it helps to have it cleaned. But is it normal seeing a reading as low as 291.3 HP?
Thanks for all your help.