Can a S/C FF be chipped or boosted to give out more Bhp instead of the current 396bhp.

I'd recommend a phone call to JE Engineering. if it can be done they'd be the ones to know as they work with Land Rover on engine development.

http://www.jeengineering.co.uk/index.htm Discovery 4 HSE
1998 110 TUM HS FFR Hard Top XD WOLF
1982 Series 3 Hard Top

*Gone:L462 D5 HSE LUX, L663 Defender 110 HSE, Discovery 3 HSE, 2014MY Range Rover Sport 5.0 Supercharged AB Dynamic; L405 Exec Vogue SE 4.4, 5.0 Supercharged Autobiography, Defender TDCi XS CSW, Defender TD5 HT, Vogue SE TDV8, Vogue TD6, RRSport SC 4.2V8, Classic 3.9 Vogue Auto, Land Rover Series 3 SWB

or you could add some more simple mods like;

K&N Filter
New Supercharger pulley
New Exhaust

Should give about an extra 40 bhp  ---------------------------------------------
Current - 2015 RR & Lumma CLR GT 558

Previous

RRS HSE now Gone
SC FFRR Gone

as the supercharger is a menchanical device, you cant just up the boost like turbo car so there's not easy gains to be had. To increase boost pressure you need to change the gearing on the supercharger pulley, ie fit a bigger pulley but you'll find that the supercharger is working at pretty much optimum speed from the factory anyway so you'll need to consider fitting an uprated supercharger for decent gains. I think Arden have started doing a 550 bhp kit but it isnt likely to be cheap

You'll only get 5-10 bhp max from just a chip. '14.5 SDV8 Nara Bronze for sale
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'95 Volvo 850R modified to 400hp
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Been looking into something down the same lines. Chipping petrol engines has never been very good, all the claims of various companies’ "superchips" are optimistic at best.
To get real buck for the money I would suggest taking the heads off and getting them worked on and gas flowed incl mating intakes. while this is done send the supercharger to the states to Eurotoydltd.com for a complete makeover incl. porting and smaller pulley of the SC itself.(increasing the speed of the SC without opening up the ports will only result in increased internal temperatures and little power gains.)
This and a free flowing filter naturally then require a chip or re-mapping of the ECU and you end up with gains in the 60 - 75 Bhp area. All nice reliable power from a well tuned engine..

Not done it myself....YET I think I will wait a year or a bit longer before I take it apart maybe next winter.. 2006 Full Size 4.2 V8 SC. Bonatti Grey - Ivory/Aspen.

However, modding a petrol engine in the RR is not going to bring as much Torque to the party as getting a TDV8 and having JE look at it. They reckon after fettling the engine puts out 800nm of Torque!

Thats the stuff of tractor pulling and tree stump wrenching ability....awesome!  Discovery 4 HSE
1998 110 TUM HS FFR Hard Top XD WOLF
1982 Series 3 Hard Top

*Gone:L462 D5 HSE LUX, L663 Defender 110 HSE, Discovery 3 HSE, 2014MY Range Rover Sport 5.0 Supercharged AB Dynamic; L405 Exec Vogue SE 4.4, 5.0 Supercharged Autobiography, Defender TDCi XS CSW, Defender TD5 HT, Vogue SE TDV8, Vogue TD6, RRSport SC 4.2V8, Classic 3.9 Vogue Auto, Land Rover Series 3 SWB