Visceral Thirst

Well, after six weeks and 2800 miles with the RS4, I think it’s time for an update.

I’m not really even sure where to start. I’ve really been enjoying the car, to say the least. Since I’ve had it, I’ve driven the S4 to work ONCE, and I haven’t even started up the Jeep.
Previously, we took my girlfriend’s ‘06 A4 everywhere we went together to take advantage of its fuel efficiency. In the past 6 weeks, we took it to dinner once — and only because my S4 and RS4 had empty gas tanks.

It’s such a pleasure to drive, both casually and aggressively, that I haven’t really been lured by the hooligan nature of the S4. Sure, it’s faster in a straight line and has gobs more stuff-you-into-the-back-of-your-seat-and-beg-for-mercy torque than the RS4; but its age, inferior refinement, lack of bluetooth/nav, and out-of-warranty status contribute greatly to the decision to drive the RS4 every time I leave the house.

On that note, I’ll take this time to compare the two vehicles, which many have inquired about.

You know about the RS4 (2008, Daytona Gray w/ Titanium, Exclusive, and Premium packages — bone stock), but you may not know much about its stablemate, my 2001 S4, so here’s a bit of info on it…

I bought this 2001.5 S4 back in late ‘06 after I finished at UCSD and started my first full-time, salaried job. It was the car I had lusted after since being introduced to Audis, and I found a clean, low-mileage specimen a couple hours away from San Diego. It didn’t take long before I started modding. First the Vogtland Coilovers went on with the H-Sports from my old B5 A4, then Labree turbo-back exhaust and GIAC tune. That lasted about 6 months, then I realized I needed bigger brakes and opted for the StopTech 355mm ST-40 kit with slotted rotors for the front and the STaSIS 298mm rear upgrade. RS4 intercoolers lasted about 3 months before I upgraded to the larger, more efficient Evolution Racewerks offerings. Finally, once I was tired of 350hp, I upgraded the surprisingly-still-alive K03 turbos to K04/RS6 hybrids… which lasted a few months before they blew up. Having had enough of homebrew tuning and modified turbos, I swapped out for plain-jane K04s and the AWE fueling kit. I took the opportunity to also remove the Labree exhaust for AWE downpipes and Twin2 setup. That’s where the car stands today.
To recap:
2001.5 Audi S4, 6spd manual, sport package (silver alcantara seat inserts + aluminum interior trim)
AWE Stage 3 (K04s, Green Giant injectors, AWE 5x program with boost controller)
ER Intercoolers
AWE Downpipes + Twin2 cat-back
APR Bipipe and 710N DVs
ClutchMasters Stage 4 clutch
ClutchMasters Lightweight aluminum flywheel
Vogtland Coilovers
H-Sport sway bars (front and rear)
StopTech 355mm front brakes (ST-40 four-piston calipers)
STaSIS 298mm rear brake upgrade (stock calipers)
Ferodo DS2500 brake pads (front and rear)
AWE drivetrain stabilizer
ToyGuy short shifter
18″ OZ Superleggeras
225/40 Michelin Pilot Sports
…and probably some other stuff that I’ve forgotten that does not impact the handling/braking/accelerating characteristics of the car

DISCLAIMER: I offer the below as a personal opinion only! I don’t have a horse in this race as I am fortunate enough to now be happily enjoying both cars. The B5 S4 vs. B7 RS4 comparison exists beyond the scope of this article and this blog. The online enthusiast community can beat this subject to death, with egos and keyboards being damaged along the way, so I intend to keep this as honest and unbiased as possible.

Power
For those of you unfamiliar with Audis, this may come as a surprise to you. Although, to enthusiasts everywhere, this is no more shocking than a contrived “twist” on your favorite reality show. The fact is, math rarely lies. With the RS4 coming in at just a tick under two tons (3957 lbs), the 4.2L FSI’s 420hp and 317 ft-lbs of torque is enough to make it “fast” by most standards. However, with the S4 nearly 400 pounds lighter (3593 lbs), the 450hp — and torque to match — produced by the 2.7T and RS4-K04 turbos is enough to propel the S4 across pavement at a noticeably quicker pace.

The power delivery between these two great machines is drastically different as well. With twin turbos producing 22 PSI as early as 3500 RPM, the S4 hits its peak torque around 4000 RPM, where it’s already making 325hp. That torque curve begins to dip 1000 RPM later while its horsepower continues to climb, reaching peak power at about 5500 RPM on the way to its 7100 RPM redline.
In contrast, the RS4’s power is much more linear, with the torque remaining relatively flat from 3000 to 6000 RPM. Peak horsepower isn’t achieved until after 7000 RPM, about 1000 RPM shy of the rev limiter. The 4.2L FSI really seems to come alive after 5500 RPM, pulling effortlessly for its last 2500 revs. Below that mark, however, it can feel anemic in comparison — not because it is, but because the power delivery is so smooth and seamless. It’s an incredibly fun engine to drive around, especially while winding it out, but it needs another 50hp and 150 ft-lbs to keep up.

Despite the RS4’s amazing V8 engine and displacement advantage, it just can’t overcome its obesity and loses to the S4 in this comparison.

Handling
This is a rather broad category, and without any special testing equipment, primarily subjective. But, this should be for entertainment purposes only anyhow!
Upon first introduction to the RS4, its typical nose-heavy, understeering Audi-ness was apparent. The steering feel is fantastic, but even with its 255/35/19 Pirelli P-Zero Rossos, initial turn-in leaves a little to be desired. Great, another Audi super-sedan that still can’t figure out how to turn.
Wait a moment, not so fast.
Just like its power can be deceptive, so are its handling abilities. Those Pirellis provide an incredible amount of grip, thanks largely to the quattro system driving them. The lengths gone to reduce front-end weight — the hood and front fenders are lighter than their A4/S4 counterparts, and the battery has been moved to the trunk at the expense of a real spare tire — coupled with the 40/60 split center TORSEN differential make corners boatloads of fun. I still haven’t garnered enough courage to explore the limits of the RS4’s cornering abilities, even though it is remarkably confidence-inspiring. On the same backroads that I have driven home from work for the past year and a half, I can easily carry more speed with the RS4 than I can with the S4, and with less drama doing it. The S4 can be a little twitchy towards the limit, which I attribute to my rear sway bar being on the “stiff” setting to minimize understeer.
Ride quality between the two cars is roughly the same. I have more sidewall on the S4 and only 18″ wheels, versus the RS4’s 19″ beauties, and the Vogtland springs are progressive. The RS4’s DRC system is impressive, but there is still some harshness to it — as with most Audis, it seems. It’s very livable, and I’ll take a slightly-harsh, well-performing suspension over a floaty comfort cruiser any day of the week.
The S4 is more “tossable” than the RS4, given it’s 10% weight savings and upgraded suspension, but I’m not convinced it’s more capable. Given wider, stickier rubber on the S4, this may be even closer, but in this segment, I’ve got to give the RS4 the nod.

Braking
We weren’t lucky enough to get the ceramic brake option in the US, but I’m not so sure they’re necessary. So far, the RS4’s brakes have been tremendous. The pedal feel is superb, and the stopping power is enough to catapult your eyeballs from your skull. Given that these 8-piston monsters are derived from the Lamborghini Gallardo, this should be no surprise.
The S4, with its upgraded brakes, doesn’t quite have the same effect, but I’m going to attribute this in part to the smaller contact patch on the road. The 10% narrower tires can’t seem to provide enough traction to keep ABS from kicking in under extreme braking conditions. That said, of the time the S4 has spent on the track, I haven’t spent a millisecond worrying about braking. It’s able to consistently slow down from high speeds at impressive rates with nearly no nose-dive, thanks to the suspension and upgraded rear braking power.
Again, we’ve got a close match, but the confident feel of the RS4 brakes give it the advantage here.

Interior
This is where the RS4 really separates itself, and largely why the S4 has spent most of its past 6 weeks parked on the street. Although the S4’s interior still outshines and outclasses many offerings on the market today, the RS4 is on another level entirely.

The Exclusive package provides the red leather inserts in the seats and doors, as well as matching stitching around the headrests and steering wheel. The piano black trim is very classy, and the quality of the plastics on the dash and doors is a huge improvement over the B5’s… at least after eight years of use. Although I miss the alcantara of the S4’s seats, the improved lateral support provided by the RS4’s seat design is noticeable the first time you throw the car into a corner. Keeping upright and in control of your body is the first step in keeping control of the car, so the importance of this should not be overlooked.
Nearly eighty thousand miles have taken their toll on the S4’s alcantara, as it shows signs of the all-too-common pilling, which is accented by the aging leather.

While being an audiphile, I’m also a bit of an audiophile. To be honest, neither of these factory systems are all that impressive in terms of sound quality. I expected the premium Bose system in the RS4 to be a little better than the regular system in the A4, but it’s not. It lacks bass and suffers from the typical distortion found when cranking up a factory audio system beyond a mild listening level. While the sound quality is not much improved over the S4, the addition of navigation, Sirius radio, and the ability to listen to MP3s loaded on SD cards are all huge usability improvements. Throw in the color information screen in the gauge cluster, and the eight years of technological development becomes even more apparent.
Advantage RS4 here, by at least the margin that the S4 exceeds the RS4 in the power department.

I’m not sure if this counts as an interior bit, but it most certainly deserves mention. The gearbox in the RS4 is such a dramatic improvement over older Audis that I didn’t realize what I was missing. The S4’s gearbox is known to have its troubles, with first- and second- gear sliders and synchros giving out after a modest amount of use (okay, and some abuse). But not only is it prone to failure, it’s not the most communicative gearbox either. It’s a little sloppy and the throws are too long. The ToyGuy short shifter in my S4 helps a bit, but it’s still nowhere near the joy the RS4 is to bang through the gears. It’s got a binary, mechanical feel that somehow still feels organic. There’s no fighting to get into gear, yet there’s still plenty of tactile separation between gates. I never worry of mis-shifting, even during the quickest of gear changes. This is another one of those little things that goes a long way in creating a pleasurable driving experience.

So, which do I like better? Well, they’re really very different animals. Both are fast, capable, beautiful, luxurious four door sedans with all-wheel drive, so neither can possibly be a disappointment. For daily driving duties, it’s a no-brainer for me, as evidenced by the 2800 miles I’ve logged in the RS4 since I’ve had it, compared to the 40 that the S4 has been driven.
For simple hooliganism, going out and roasting tires, and demolishing all speed laws, the S4 takes the cake.

In a competitive environment, of course the S4 gets the privilege of being taken to the drag strip, and I plan on taking it to Willow Springs Raceway later this month in lieu of the RS4. Why? Well, I’ve already got track pads and tires for the S4, and on the fast Willow Springs track, the extra power should be a lot of fun… especially with the extra 100 hp and 100 ft-lbs I’ll have with 110 octane on AWE’s race file.

I will, however, be taking the RS4 to the more technical Infineon Raceway in October with the Audi Club, and I hope to take it to Buttonwillow later this year as well. Audi’s given me the stamp of approval to take it to HPDEs (driving schools), so I will definitely be doing so. I’m not looking forward to the expense of burning through 265/35/19 track tires, but with a free car, how can I complain?