S8 and R8 V10 engines

RS2_Russ · 27-07-2010, 07:42 PM

Does anyone know what the differences are between the S8 V10 and R8 V10?

Looking at the obvious specs they look mighty similar.
From
2009 Audi R8 Spyder specs, specifications, tech specs - 2 door 5.2 litre (5204 cc) V10 525.2 PS, 6 speed manual
and
2005 Audi S8 5.2 FSI quattro specs, specifications, tech specs - 4 door 5.2 litre (5204 cc) V10 450.2 PS, 6 speed automatic

BOTH have the same:
Bore × stroke 84.50 mm × 92.80 mm
3.33 in × 3.65 in
Cylinders V-10 in 90.0° vee
Displacement 5.2 litre 5204 cc (317.568 cu in)
4 valves per cylinder 40 valves in total
Compression ratio 12.50:1
Fuel system direct petrol injection
Bore/stroke ratio 0.91
Unitary capacity 520.4 cc/cylinder

The R8 is dry-sumped and has 525.2 PS (518 bhp) (386.3 kW) @ 8000 rpm
with 530.0 Nm (391 ft·lb) (54 kgm) @ 6500 rpm
The S8 is wet-sumped and has 450.2 PS (444 bhp) (331.1 kW) @ 7000 rpm
with 540.0 Nm (398 ft·lb) (55.1 kgm) @ 3500 rpm

Apart from tuning, anyone know why they're so different?

Tell you what else is amazing if true: The R8 has a Drag coefficient of 0.37 (which is middling), but the S8 has a Drag coefficient of 0.286, which is amazingly low! So low that even with 15% larger frontal area it has a 15% lower Cd x A.

Russ

PsYcHe · 27-07-2010, 08:01 PM

could well be different bits inside, also the r8 revs to 8000 so you would get a chunk more bhp that way

cruiser647 · 30-07-2010, 07:56 AM

It's the way they want the engine to behave in each car. That's the only real difference.

An S8 owner is 'less' likely to rev the thing to 8K, and due to the weight, will need to extra torque produced lower in the range.

Just my 2p!

27-07-2010, 07:42 PM	#1 (permalink)
RS2_Russ Shank's Pony Join Date: Apr 2010 Posts: 8	S8 and R8 V10 engines Does anyone know what the differences are between the S8 V10 and R8 V10? Looking at the obvious specs they look mighty similar. From 2009 Audi R8 Spyder specs, specifications, tech specs - 2 door 5.2 litre (5204 cc) V10 525.2 PS, 6 speed manual and 2005 Audi S8 5.2 FSI quattro specs, specifications, tech specs - 4 door 5.2 litre (5204 cc) V10 450.2 PS, 6 speed automatic BOTH have the same: Bore × stroke 84.50 mm × 92.80 mm 3.33 in × 3.65 in Cylinders V-10 in 90.0° vee Displacement 5.2 litre 5204 cc (317.568 cu in) 4 valves per cylinder 40 valves in total Compression ratio 12.50:1 Fuel system direct petrol injection Bore/stroke ratio 0.91 Unitary capacity 520.4 cc/cylinder The R8 is dry-sumped and has 525.2 PS (518 bhp) (386.3 kW) @ 8000 rpm with 530.0 Nm (391 ft·lb) (54 kgm) @ 6500 rpm The S8 is wet-sumped and has 450.2 PS (444 bhp) (331.1 kW) @ 7000 rpm with 540.0 Nm (398 ft·lb) (55.1 kgm) @ 3500 rpm Apart from tuning, anyone know why they're so different? Tell you what else is amazing if true: The R8 has a Drag coefficient of 0.37 (which is middling), but the S8 has a Drag coefficient of 0.286, which is amazingly low! So low that even with 15% larger frontal area it has a 15% lower Cd x A. Russ

27-07-2010, 08:01 PM	#2 (permalink)
PsYcHe BMW 130d Join Date: Jun 2006 Location: Blantyre, UK Posts: 1,016	could well be different bits inside, also the r8 revs to 8000 so you would get a chunk more bhp that way __________________ The Driveway of joy... Hers - D2 '98 A8 4.2 Quattro Sport - Silver, retrofitted Xenons, replica 18's & a PhatNoise (now off to a caring new home) Mine - D3 '03 A8 4.2 Quattro SE - Silver with 19" 12-spokes. Sport seats & suspension, ACC

30-07-2010, 07:56 AM	#3 (permalink)
cruiser647 BBC Correspondant Join Date: May 2004 Location: Anywhere but work.... Posts: 17,038	It's the way they want the engine to behave in each car. That's the only real difference. An S8 owner is 'less' likely to rev the thing to 8K, and due to the weight, will need to extra torque produced lower in the range. Just my 2p! __________________ "There will be no whitewash in the White House." Richard M Nixon. Speaking of liars, look at this website!:- http://www.labour.org.uk/home