Stage 4 Tuning.
135 with full boltons, meth kit and VP MS019 unleaded race fuel.
My car made 296.1 rwkw (397 rwhp) with PROcede, full boltons, Vishnu methanol kit (dual D04 nozzles) running on VP MS109 race unleaded.
Recap:
Stock 187.9 rwkw
Stage 1: Computer 234.1 rwkw (+46.2 rwkw)
Stage 2: Computer + boltons 259.0 rwkw (+71.1 rwkw)
Stage 3: Computer + boltons + meth 291.3 rwkw (+103.4 rwkw)
Stage 4: Computer + boltons + dual meth + race fuel 296.1 rwkw (+108.2 rwkw)
The race unleaded allowed some additional timing and another 1-2 psi in boost and gained 4.8 rwkw (~7 rwhp) over the same setup with pump unleaded (98 RON) but with a single larger meth nozzle over the dual nozzles.
Examining the dyno sheets in a bit more detail, the car picked up a useful amount of torque with race fuel over the pump fuel, however the peak horsepower number was a marginal gain (~1.6% increase).
In conclusion 98 RON pump unleaded plus methanol is convenient and makes 99% as much power as race unleaded plus methanol. Why would you bother? VP MS109 is expensive, you need a race licence to buy it and you've got to store it somewhere. I won't be using VP MS 109 going forward but it's good to find out the results for yourself.
I also suspect that a dyno run with race unleaded/ no methanol might show a large improvement over pump/ no methanol. What I mean is that race fuel is worth it if you take methanol out of the picture.
But a Vishnu methanol kit plus regular pump unleaded is a massive improvement and well worth the price.