ok so car is being remapped next weekend, couple of mods going on before just to get torque up, so will be expecting a return of 400/400 min. im wondering whether or not to use an octane booster, car alweays runs on v-power, and will be still on standard sti internals so i know im just about at the limit of the block, will it be worth my while or am i not going to able to reep the benefits, oh yeh, have been looking at booster with i think 4 point increase, so effectively 103octane.

 

If you get mapped for it then 103 RON should net you some decent power gain over V-Power alone. But you will be 'married' to it i.e. you'll have to use it all the time as the same mapped dosage (or more) everytime you fill up.

As you say, 400/400 is pretty much as far as you want to push OEM STi internals, so I'd just make life easier, and cheaper, for yourself, and get remapped on V-Power only. If you have the correct supp. mods for 400, then V-Power will comfortably do it.... What is your year/model of STi and what are the turbo, IC and injectors?

 

my99 type r, md321h turbo, rcm headers and intake, harvey smith up pipe, fmic, 550cc injectors

 

Yeah, V-Power will get you as near as dammit to 400bhp (could well tip over that) on those mods. The RCM headers and harvey's upipe will help the 321H to do it.

As said, I personally wouldn't bother with OB...

 

cheers