[foggyjames]

Simon,

My advice would be...if you've got an MBC set at 14psi...I think you're gonna be disappointed with £600 of chip.

Yes, it'll alter the *delivery* in a way an MBC just can't, but if its more power you're looking for...you want the ability to squirt and spark at the right time at more like 20psi. Whether a T5 can standard that much boost in terms of internal strength, I don't know.

One of the biggest jokes out there was the 'superchip' for the 740 turbo. £500-600 bought you a £100 chip and a bunch of guys to use an MBC to up the boost (the chip providing the extended fuel and ignition maps).

I would assume that the more modern chips are more advanced than that, and they can probably do 'wilder' versions than most people have (I certainly know Adam has mentioned different 'extremeties' of the same basic chip), but if you're already at 14psi, I think you're already at the 'basic package' most people go for.

I've noticed that MBC's seem to have a bad reputation amoungst the T5 community (not especially on this site) - indeed one of the 'power increase' ebay info-auctions says something like "I won't have you upping the boost and overboosting". As long as you're careful and sensible, an MBC is perfectly safe and provides remarkably stable boost for such a simple device. There are plenty of cars out there with nothing more than a *home made* bleed valve mighty faster than a 'chipped' T5!

cheers

James