I have been thinking of the tubby as being soooo much faster than my na
You are thinking correctly, for general road driving the turbo blows the NA out of the water in performance and grin factor
- the key here is torque, the turbo has buckets of it
- from what you've said a turbo is right up your street, go for a Rev3 version as these can be taken to a higher power level for minimum effort, trust me, you'll love it.
Granted, on a track there is very little between them
- but you have to remember on a track the main goal is to
*retain* speed rather than acquire it, this is done via handling rather than acceleration
- the handling of the tubby
& NA are near enough identical.
If you test drive one, make sure it's from an enthusiast who maintains it and runs it on decent fuel, not some back street car dealer running it on supermarket low octane fuel
(with the ECU in limp mode) or your experience will be blighted somewhat!
I'm starting to think I will need upwards of 280bhp to really feel satisfied with accelleration power and that would need quite a bit of tweaking on a tubby
Not so,
£100 worth of mods will reach 280bhp easily in a rev3, remember they are
~245bhp out of the box with bags of torque to boot, a simple ball&spring valve and a Fuel Cut Defender will get the gains you want.
(Be warned, it's a slippery slope, as Lauren says you'll always want more, when I first got my tubby I said
"It's plenty powerful enough, I doubt I'll modify it", then I bought the spring valve.
.
.then the FCD.
.
.and it snowballed from there, including busting the engine
)
Horsepower sells cars.
.
.torque wins races.
.
.
(on the drag strip)
) 
