The tyres would be ok but as previous I would really suggest 225 45 17. The best way to sum it up is you'll get an extra 80mm surface contact, which is a lot and esp when you have power through all four corners! Goodyear F1 AS2 are cheap.
Worth double checking fluid levels. Gear oil can make a big difference.
As sav says it def sounds like a linkage refresh is in order whatever.
Some bits worth doing to eliminate worse case which would be the synchro.
Sounds like a good plan. Lots of nice scooby alloys out there to put on.
I know what you mean about the ratios, I'm always looking for 6th lol. £1500 and the rest!
Is it always the same in each gear and is it smooth? Mine boosts higher in 3rd 4th as the load period increases. As long as it's not fluctuating. If it's been mapped then cool.
What's stock boost? 0.9 bar?
I assume the horrific squiggly lines are original?? Making a very quick steady 250bhp with 0.7bar in the mid range?
With mod rising to peak 285bhp as boost steadies down to 0.8ish. Just doesn't look right to me sorry.
I'd be expecting upto1.2ish bar from a performance remap and sort of power your developing? Be interesting to get others in who've had same car remapped