I am getting my V4 mapped tomorrow. Obviously it will be mapped to run on UK fuel but I am unsure whether adding octane booster previous to mapping will mess things up??
Should I use my NF booster tommorrow when I fill up my tank on the way or make sure the tank is just Vpower and no booster?

 

You can get mapped on whatever you like!

You'll gain a bit more power/torque with the OB added... BUT... you do realise that you will have "wedded" the engine to this fuel combo 'indefinitely' - or until a later remap - to always achieve the mapped power and, importantly, be sure of being safe against det?!

If you don't intend to use OB ALL the time, then I wouldn't bother with it - just get it mapped on the regular fuel of your choice, that you know will ALWAYS go in the tank...

 

Excellent. That was the answer I was looking for. I know before a RR session it is advise to add octane booster but I was unsure about mapping.
My tank is nearly empty so will fill it to the brim with only Vpower. Can't afford bloody NF booster all of the time - not after all of this expense anyway!!

 

V-power and Tesco 99 are close enough not to require a different map.

 

A quick Question, will the Apexi remove the Japanese speed restrictor??

 

Yes.

 

Yeah, 360 also make a good point. Don't matter which brand of fuel you get mapped on, so long as the octane rating is the same.

So if mapped on V-Power, then you are okay to run it on that fuel (obviously)... or the UK's other 99 RON: Tesco 99.

Also, if you can only get to a garage that has 97 RON only, then if you add a 3rd of a bottle of NF to a full tank (50 litres), that will add 2 extra full octane numbers, so you'll have the equivalent of 99 that way. For that potential scenario, prob. worth always having a bottle of NF in your boot, just in case... Unless, of course, you put in only enough 97 to get you home or a Shell/Tesco garage, so that you can run it down quickly off boost lol...