Xsi engine upgrades (need advice)

[Niall]

I've seen the variation dyno's can produce. A lot of it is down to the company wanting people to go away pleased, as many will not trust the figure if its lower than they want! I wont take my car near a dyno as I'm afraid it will have the best part of 150bhp

Yeah its very easy for a dyno operator to falsify figures. Its not just as simple as strap her down and put your foot through the floor. Tbh BHP figures are all just willy waving figures anyway. Theres no use in having 400hp if its only making 150 until 8k!

So really it would be a waste of time

Personally if your chasing more power and want to do it easily, fit a 6 engine. If you want more power and have a bit more time/effort/money, then there is loads of ways to skin a cat!