I have a UKMY99 simtek ecu vf29 fmic ect making about 340 bhp, thinking of having 2nd map set for methanol, whats the best way to go mix or injection kit

 

I would have thought in with the petrol and either run it all the time or summer/winter,the problem would be at changeover, being sure you had the correct mix with the methanol.
The injection systems use water or water/meth and are more about reducing air charge temps rather than raising fuel octane.
Trev

 

I run 25% on the second map but remember you will be limited to what % you can run depending on injector size, you need to flow more fuel when running meth, when i just had standard 440's i just ran 10% mapped by Andy F. mix in the tank is best imo and it dosent need to be exact, 44 litre of v power means 11 litres of meth and thats the tank full. its easy to work out using your gauge..