photos: Jim Murphy's 928 S4
THIS WAS THE CAR THE WORLD WAS WAITING FOR -- the 5.0 liter 32-valve 928 Series 4. Boasting 316HP, redesigned front and rear fascias (it takes a very sharp eye to see the rear section was elongated slightly to improve airflow), as well as updated interior trim, the 928 S4 was the fastest 928 yet. Numerous other aerodynamic subtlies were employed to lower the body's coefficient of drag - the front spoiler was redesigned to allow air to pass smoothly under the car with the aid of a new aero belly pan; a set of grill flaps opened and closed depending upon speed and driveline temp. Radiator cooling was serviced by a dual, infinitely adjustable electric fan set. Porsche created controversy again with the S4's foldable matte-black rear wing spoiler. On later cars the spoiler was fixed in place. Astute observers will note the S4 features wider rear rims than before measuring 16 x 8. 

Computerized driver readouts were placed in the gauge binnacle in 1989 and reported on various operating stats such as fuel consumption and estimated time before empty. I do believe the driver and passenger underdash parcel trays were deleted beginning with airbag-equipped S4's. Rear passenger AC was another available option as before. The S4 driveline was upgraded with a larger-diameter single disc clutch replacing the sometimes problematic twin-disc unit of the 928 and 928 S.

The 928 S4 also featured upgraded brakes using four-piston Brembo calipers, even larger rotors and pads, as well as ABS. One ride in an S4 and you'll see the need for such massive stoppers! 

As testament to the S4's supercar status, Al Holbert set two FIA world land speed records of 171+mph in a stock, catalytic converter equipped 928 at Bonneville - the same car which could be bought at any Porsche authorized dealer! Provided, of course, you had the wherewithal to have placed an order a long time previously - the sales furor over this latest GT from Porsche was not unlike the what we saw with the release of the Boxster. 

The S4 is an excellent starting point for the serious 928 enthusiast - 32v big HP engine, matching S4 'big-brakes', ABS, etc. Prices on the secondary market seemed to have flattened out as of this writing and may be poised to begin rising (especially for manual transaxle cars), though they won't reach the original list price of over $60k+ for a while. Production: 1987 5,403 ; 1988 3,663 ; 1989 2,919 ; 1990 3,088 (note 1 & 2). 

note 1: production figures for 1989 and 1990 include both S4 and GT cars 
note 2: Porsche Power, Performance, and Perfection

Year Type HP@rpm Engine Serial Number Chassis Serial Number
1987 928 S4 316@6000 81H00051-01401 or 81H05051-08546 (AT) WPOJBO92xHS860001-2481
1988 928 S4 316@6000 81J00001-01287 or 81J05001-05379 (AT) WPOJBO92xJS860001-1852 or 865001-5062
1989 928 S4 316@6000 81K00051-00629 or 81K05051-07642 (AT) WPOJBO92xKS860001-1250
1990 928 S4 316@6000 81L50501-01449 (AT only) WPOJBO920LS860001-0518
1991 928 S4 316@6000 81M00001-01148 (AT only) WPOAA292xMS810001-0448
table source: The Porsche Family Tree, published by the Porsche Club of America, Inc.
note: The 928 Club Sport was a non-US version of the 1988 928 S4. The Club Sport featured a lightened interior and accessory deletions to pare approx. 220 lbs. off the car. Though the engine was reworked, the factory claims identical power and top speed as the S4. However, the rpm limit was raised from 6000 to 6775 revs and independent testing confirmed the CS outperformed the S4. The 'CS' did receive suspension upgrades and came with a manual transaxle only.Therefore the Club Sport was almost a test-market car in preparation for the 1989 928 GT. It also appears there are two distinct CS versions - Euro vs. UK model. The UK model was a CS but with all luxury items intact ie. radio, AC, etc. and renamed the 928 SE (note 3). This was done as market data indicated buyer preference for fully equipped cars for UK sales. A dedicated Club Sport page will be included here in the future. If you find one in the US and can verify it's authencity with Porsche (don't be fooled by just the Club Sport stickers on the front fenders) - buy it! It will undoubtedly be the only one in this country...