Spannerhead Dot

On the Significance of Six Inches

June 30, 2011 by Matt

B7 and B8 A4

No, this isn’t another Anthony Weiner post. If I never read another story referencing that poor sap’s internet escapades, it’ll be too soon. What I’m talking about is the forward shift of the Audi B-platform’s (A4’s) front wheels, illustrated above. It may be subtle, but look at the width of the fender in between the back of the wheel arch and the beginning of the front door. On the newest A4, the B8, shown at right, that little span of metal is noticeably wider than on the B7 (at left), and the front overhang, between the front of the wheel arch and the nose of the car, is obviously shorter.

Most car styling evolves in much more drastic ways from generation to generation, you say; is it really such a big deal? In a word: Yes. You know how financiers and consultants are always looking for that little bit of overlooked information in the industry they cover (or even outside their area of specialty) that will be the harbinger of a larger movement of capital; the beginning of a trend; the inside tip; the pebbles that start the landslide? You get the idea. I believe the slight forward shift of the A4’s front wheels is the sign that Audi will actually achieve something they’ve been pursuing for 30 years: Parity with BMW in the minds and hearts of enthusiast drivers.

Audi has been the odd man out among the big three premium German automakers, nipping at the heels of BMW and Mercedes-Benz for years, carving out their own engineering niche in the form of their signature quattro AWD system. But despite the brilliance of that system, or the excellence of their engines (especially their 20-valve 5-cylinder of the early-mid ’90s), or the fine-tuning of their cars’ chassis, Audis suffered from an inherent limitation of the quattro system: As designed, it required the entire engine to overhang the front axle. This presented a formidable obstacle to overcome when it came to balancing the cars’ masses (the engine being the most significant), a critical part of achieving nimble and enjoyable handling. Imagine trying to thread a shopping cart with a 12-pack of soda duct taped to the front of the basket through an obstacle course, and you have an idea of what Audi has always been up against when it came to refining their cars’ handling. Their chassis engineers were every bit as good as their German competitors’, but they started with a handicap, so to speak.

And this was reflected in tests by publication after publication. All spoke of understeer at the limit, an inescapable nose-heavy feeling, and a reluctance to rotate intuitively. Audi tried what they could to reduce the weight over the noseā€”aluminum blocks for their post-20V engines, the shorter block of a V6 versus an inline configuration, and even aluminum fenders, introduced on their B7 S4. All of it helped, but none of it could really bring Audi to a place where they could tell enthusiasts, without crossing their fingers behind their backs, that their cars were as well-balanced and tossable as those from their rivals in Munich.

However, with the latest A4, the B8, introduced in 2008, Audi has finally taken steps to rectify the imbalance. As illustrated below, the red axle shaft and steering rack represent their traditional position, from the B2 through the B7 platforms. The front axles couldn’t advance forward past the clutch or torque converter, by virtue of the fact that they were connected by a bulky differential that had nowhere to go except aft of the bellhousing area:

B8 A4 versus B7 A4 technical profile

The blue axle shaft and steering arrangement is the B8’s. Audi has finally applied themselves and figured out a way to rearrange the mechanical organs so the front axle can be pushed forward, greatly improving weight distribution, and having the side effect of allowing the steering rack to be relocated to its present position, improving geometry and steering feel. The front/rear weight distribution, which used to be stuck in the 65/35 range, can now move closer to 55/45, with the ideal 50/50 on the horizon. The 12-pack can be effectively moved rearward in the cart. They’ve done it. The car’s masses can be much better-balanced, and BMW’s reign as the king of impeccable-handling cars will soon crumble; I’ve no doubt. Oh sure, they’ll still make handling superstars, but they won’t be the only kid on the block any more.

I realize this may be old news to some of you, but I think about it every time I see a B8 A4, and as an Audi buff, it just makes me feel good to finally see them reeling in their Bavarian competition once and for all.

Filed under: Audi, Technical

1 Comment

  1. Joseph says:

    Biased much? Lol what a crap article.

    Your own article explains that at the limit is where people complained the most. Guess who is not driving at the limit. 99.9% of all drivers whether that’s BMW, Audi, or Mercedes.

    And maybe I’m way off, but I thought it was more like a 60/40 split. If that’s the case there are tons of other brands that have similar splits and sell plenty of cars, and drive just fine for when we’re not on the track.

    Now if you’re talking just playfulness then yes, there is a difference. But factor in the fact that Audi has a true mechanical AWD system (at least on their longitudinal engines, and not the most recent iteration) and how much that helps in poor weather (BMW’s AWD system sucks honestly, I have it), and that most of the time people are just driving to work, doing road trips, going to the store, etc., none of this really matters.

    As a BMW and Audi owner, the Audis are so much nicer places to spend my time, and I’ll take the BMW’s out for the playful driving sometimes though.

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