Indeed Mr B......I had TBs on my 4/4 together with Librands full sports exhaust system. It gave 156 bhp.. I don’t have the printout anymore otherwise I’d mention the increase in torque ....... or may be not 😉
It certainly sounded very nice.
I once drove a Caterham 7 fitted with a similar engine. IMHO The Sigma engine with TBs really suited that car.