the 960's 3.0 responds to snuggling and cheap romance novels
yes, I use scented oils for murrr power.
Seriously though:
Even in N/A form, there are many limiting factors on the stock b6304:
Manifoils are crap
Front pipe W/ cat is CRAP (pipe in pipe, tiny diametre!)
Also, the cat robs some power (but this I have to have on my current car).
The b6304 is also limited in the ECU, since Volvo wanted the 960 to be a "mercedes like car".
I never tried chipping the b6304, but with new exhaust from the OEM manifoils, down to 3" N/A JT Superflow exhaust (and cat removal) I got 242Hp on the dyno.
Ironically enough, the engine resided in a Volvo 242.
This was running on regular fuel.. The b6304 is also not mapped for premium fuel, from factory.
Powerchip amongst others (also frpe82) offers tuning for the software too.
Ps. I also had a conical filter, but this does not give a gain
I just had to have it, due to space limitations in my engine compartment.
Read the file I posted above, it's about turbocharging with unleaded 95 octane (european standard, the best octane here is 98), it also tests M85 (E85) on the lower displacement engine b6254. 200Kw was easy, they say.
I've read some nice posts lately, where some board members here have figured out that bmw m50/m52 manifoils fit, with a little custom work.. This means you can have headers for the b6304 too, with just modding the flange (klracing sells flanges for b6304).
If I cant get the "PCP" engine approved, which I have, I'll either go for the B6304 N/A w/ the earlier cams (204hp version) and tune it, or I'll go for a T5 engine.
An N/A engine with power, is very fun to drive.. it responds much faster than a turbo lagged car. (ps. that is comparing the b6304 vs the b230ft, both cars auto and ~~same weight, as well as ~~same power levels).
If you where to turbocharge the b6304 w/ lower comp. you would easy attain 400++nm and 200++Kw on NON PREMIUM fuel :O That must be a loco drive..
Volvo tested this on the 760, 1560kg.. 0-100 km/h (0-60mph) 6.8 seconds. With traction control: 6.5 and with perfect grip, even lower (6.25 or so).
I hope this gives you some inspiration/goals/ideas.
N/A tuning for the b6304 wont be very expensive and it will give your engine a nice ROAR, like a sportscar.