Title says it all, 4.2 SC 2006. it seems to run out of omph after 90mph. Is that normal ie its 400bhp moving a lot of weight or should it fly to the limiter?

Cheerd

The first thought is "why are you accelerating through 90mph?"

The aerodynamics start to play a big part in progress at those speeds so even with 390bhp, it'll not be as quick to add speed. At 90mph, you're going to be using over 50bhp just to overcome the drag. As power absorbed by drag increases with the cube of the speed, you get a very fast tailing off of acceleration once you get up towards 3 figure speeds. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Haha its just something I noticed... On a private road ofc. Just wanted to make sure it's not a performance issue but rather just standard performance

Can't see this as being normal, my 3.6TDV8 goes into 3 figures effortlessly, almost turbine like.

Even before new turbos and exhaust manifolds it did not want to slow down.

Dave 2010 3.6 TDV8 HSE (Gone)
2011 Discovery 4 Commercial SDV6 (Gone)
1980 OBLIC 4.0ltr Range Rover (went a long time ago)

That sure is not normal.
As mentioned above it should smoothly and happily get into 3 figures.  Malaysia Boleh!
4.2SC Chawton White, Stormers
Tasmod's Sills, Wind Deflectors, LR Sills
Clear Side Repeaters, Towbar
Larini Sports Exhaust, K&N Air Filter
______________________________
WINNER - 2008 'Tech-Head Of The Year' Award
WINNER - 2009 Outstanding Contribution
WINNER - 2009 'Tech-Head Of The Year' Award

the engine as standard should easily pull into 3 figures

hmmm this is one of those things i can't test myself. i'll get it to a rolling road when i get a chance

It does sound off.

My 2005 SC will accelerate past 90mph effortlessly. Only did it once and then I ran out of guts, not the car!!!  2016 RRS SVR Estoril Blue
2005 4.2L Supercharged Java Black - gone but was my first love.
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If we all point our RR's in the same direction and accelerate at the same time can we turn back time?

In my frequent trips down south to Singapore I do touch 200 kph (more than 120 mph) on some stretches!  Malaysia Boleh!
4.2SC Chawton White, Stormers
Tasmod's Sills, Wind Deflectors, LR Sills
Clear Side Repeaters, Towbar
Larini Sports Exhaust, K&N Air Filter
______________________________
WINNER - 2008 'Tech-Head Of The Year' Award
WINNER - 2009 Outstanding Contribution
WINNER - 2009 'Tech-Head Of The Year' Award

ill be getting the lpg fixed soon. ill check how it performs there incase its a fuelling issue. but it certainly doesnt feel like a fuelling issue