Back from a quick afternoon session on the rollers to get the new boost valve mapped. Very happy with the results.
With this being the third engine and still on standard internals which were never intended for forced induction I approached the session with my brain set in "reasonable" mode.
Last year I had my own manual boost valve setup consisting of two independant needle valves which gave an initial overboost of 14psi which then trailed off to a steady 8psi giving a very spikey power delivery which peaked at 317 bhp at the wheels at 5500 rpm. Now with the ecu controlled boost valve set to give a steady 9 - 10 psi over the whole rev range the peak power has droped to 299 bhp at the wheels at 5800 rpm but with a very much smoother delivery although with a similar "area under the curve". Of more importance though is the much kinder environment (relatively) that the engine is now working in - peak coolant temperatures on a fairly warm August day with just a couple of workshop fans peaked at 96șC.
So considering I only managed to melt a piston in the first engine running between 14 - 15 psi with, compared to now, a totally inadequate chargecooler system and a barely adequate engine cooling system I think this setup is fairly conservative and shouldn't present any problems.
If I engaged my " push it a bit further brain" I could probably safely up the boost to 12 psi and gain maybe 30 bhp at the wheels but realisticaly what would be the point? On the road the present power is hardly ever used and the car has only ever lost out to very expensive machinery. On the recent track day my balls wern't big enough to even fully exploit the power when the boost valve wasn't working and the boost was pegged at the 6 psi of the wastegate spring!
O.K. maybe one day soon "old fart mode" will be replaced by "f*ck it, hooligan mode" and the laptop will be plugged in and dialed back to russian roulett 450 bhp!