Never heard of this before! Any truth in it?

[Brett]

Bear in mind that in recent years the gentlemans agreement of 276-280bhp has been stuck to in name only.  A standard R34 was dyno\'d at over 320bhp when it was imported back in the late 90\'s.  
 It may be that the internals can handle more boost with a reprogrammed ECU and the relevant controllers.  Has anybody over here dyno\'d a std Spirit R?

[bnaellis]

Bear in mind that in recent years the gentlemans agreement of 276-280bhp has been stuck to in name only.  A standard R34 was dyno\'d at over 320bhp when it was imported back in the late 90\'s.  
 It may be that the internals can handle more boost with a reprogrammed ECU and the relevant controllers.  Has anybody over here dyno\'d a std Spirit R?

Correct they are many cars in Japan as standard that produce 300+bhp
but for politically correctness they are advertised as 280.

[BlitzBoy]

Also, the standard ecu does not ACTIVELY control boost.

Yes, it opens and closes a solenoid to vent boost. But there is nothing in the ECU that says "When I see 14PSI of Boost, I must open the solenoid more"

There is a Boost sensor, the MAP ( Manifold Absolute Sensor) , but that ECU only uses that to put in the correct amount of fuel.

Yes correct Martin, but the ECU does control the duty cycle of the boost Solenoid, so a lot of custom chips out there hike up the duty cycle to increase boost levels.
Just happens the Mazda Engineers increased the duty cycle on the ECU for 99 spec and onwards. Remember they upgraded the turbos to deal with the extra 2psi being run for reliabilty.