Here is the result from a very skilled-TVR-enthusiast:
“The fastest S6’s were those in late Mk1 Tuscan S’s. I’ve even compared a late Mk1 S against a Sagaris to prove the point (and it was proved – the Tuscan felt, and was, faster). That reliability/driveability was improved in later cars is also frequently stated and I’d concur with that from first-hand experience – but later cars do not feel as fierce as the “good S’s”. The supposition is that they were calmed down to achieve the driveability and reliability is perceived to be a corollary of that work. The best standard Speed Six I’ve measured on an engine dyno under controlled conditions had a BMEP of 184.3. The Speed Six in question was a fresh 4.0 litre with a static compression ratio of 12.2:1 (Red Rose / S). It made 295lb-ft. 184.3psi is on a par with the latest AMG engines – a stout result and nothing to be ashamed of. The engine made 345bhp. I am perfectly happy to accept that there may be engines with greater than 345bhp but I’ve not seen one. Rolling road results of later cars gave similar results to my findings – 320’s to 340’s. EVO magazine tested a press car in 2006 and got a result in this range. A summary of TVR’s claims: 3.6L Mk1: 350 bhp, 290 ft.lb 4.0L Mk1: 360 bhp, 310 ft.lb 4.0L Mk1 Red Rose: 380 bhp, 310 ft.lb 4.0L Mk1 S (pre-2003): 390 bhp, 310 ft.lb 4.0L Mk1 S (post-2003): 400 bhp, 315 ft.lb 4.0L Mk2 (post-2005): 380 bhp, 310 ft.lb 4.0L Mk2 S (post-2005): 400 bhp, 315 ft.lb 4.0L Mk2 Convertible (post-2005): 380 bhp, 310 ft.lb Best actual: 345bhp, 295 ft.lb (184.3psi BMEP) A summary of Wilder results: 3.8 Fury: 380 bhp, 305lb-ft (198.3psi BMEP) 4.1: 380bhp, 320lb-ft (193.9psi BMEP) The racing 3.8 (as supplied to Ceejay in his T350R) has over 400bhp and a BMEP of 208psi. Pushing BMEP up to and beyond 200psi is not the work of a laptop. The standard Wilder hardware is profoundly different to TVR’s (and gets close to 200psi on standard maps with low compression, 10.8:1). The lift to the first iteration of racing spec had hardware changes before the mapping changes. Knowing what’s involved to generate the kind of BMEPs implied by TVR’s claims, and what was in the engines, the claims were optimistic. 200psi BMEPs are rare: Ferrari Enzo is 200; 997GT3RS is 204; BMW CSL is 208. The latest generation Porsche/BMW motors are benchmark sixes. The Mclaren F1 engine, often cited as a relative of the earlier gen M3 sixes, has a BMEP of 195psi.