My 928 S4
1990 Porsche 928 S4

On May 3rd 2000, Mark Anderson of 928 International posted an email on the 928 Rennlist about a 1990 S4, white/saddle, GT wheels, 79,000 miles. I did some initial correspondence with the owner, Eddie Skelton, but had to go to Washington DC.

A few weeks later I was contacted again with an offer I found hard to refuse, and worked out a deal. Well today (6/8/2000) I'm the owner of this fine automobile.

Since I bought the car I have replaced the timing belt, water pump, cam seals, brake lines, pads and fluid, cooling fan, radiator hoses, thermostat, oil pan gasket, rod bearings, steering rack, and motor mounts. I have also replaced the 2 rear tires, installed a Rear Muffler Bypass (RMB), Tire Pressure Warning (RDK) bypass and GTS Oil Pan Baffle. For track and open road racing use, I have installed a rollbar, fire extinguisher and 5 point racing harness.

During the first year I owned the car, it had performed well. I was able to get the car up to 142 mph perparing for the Pony Express II open road race that summer. At first it had trouble accelerating over 120, but after a few high speed practice runs and a bottle of octane booster, I was able to easily reach and exceed the 130 mph tech limit. The engine is rated at 316 hp and has been dynoed at 263 rwhp (~328 hp at the crank).

In 2002 I entered the Bonneville 100 and Pony Express open road races. I ran in the Grand Sport Division with at 165 mph tech limit and 140/145 target speeds. I was able to get the car up to 168.6 mph on the GPS while getting the car prepared for these events. Before this summer I had replaced both my fuel pumps, rear brake pads and rotors, installed a DEVEK aluminum belly pan, and installed new Koni externally adjustable shocks. Marc and Brad from DEVEK then set up the suspension (lowering, corner balance, alignment, and shock adjustments). The engine felt very strong and the car was stable at all speeds. It was a thrill to be able to go through corners at over 160 and still feel secure and confident in the car's ablity.

For the 2003 season, I entered 3 open road rallies, the Bonneville 100, Pony Express, and Gambler's Run Twin 50. I again ran in the Grand Sport Division 145 class and finished 2nd in all three. I averaged 144.965, 145.055, and 144.916 mph and was radared at over 163 several times and maxed at 165.6 mph on the gps in 2 of the rallies. Before the season I installed 4 new BF Goodrich g-Force KDW tires, replaced my front brake pads, and changed to Amsoil 20-50 racing oil.

In 2004 I installed a Tim Murphy Supercharger Kit, including a Vortech V-2 SQ S-Trim supercharger, intercooler, adjustable raising rate fuel regulator, larger fuel injectors, plus misc. pulleys, gauges, belts, and hoses. Bill Ball (Norcal928), Tom Cloutier (The Power Broker), and Dennis Kao helped me with the install. I used Tom's dynapack to tune the air fuel mixture and measure the rwhp (thanks Tom it was a great help). So far I've only gotten 3.7 psi boost with 330-340 rwhp (~425 at the engine). I entered the Grand Sport division 155 mph class at the Pony Express 130, Bonneville 100 and Gambler's Run. The Pony Express got red flagged while I was only 19 miles into the rally, so I was not able to finish. I finished 2nd at the Bonneville 100 with a 155.047 mph average and 1st at the Gamblers Run with a 154.764 mph average. Because my tech limit was 168 mph, I had to run more then 44 miles at over 165 in both rallys. The car ran great at those speeds.

In 2005 I worked on removing restrictions in the intake, installed a fan on the intercooler radiator and added an X-pipe with free flowing Random Tech Cats. I was able to get 8.9 psi boost and 439 rwph (~545 hp at the crank). In February I had DEVEK install a roll cage. I also installed racing seats (should be 50-70 lbs lighter) and a fire suppression system. I ran the Bonneville 100 in the 155 mph class again and finished 3rd with a 154.316 mph avg. After the race, I had DEVEK install a fuel cell so I could compete in the Super Sport Division. I was able to run the Gamblers Run and Pony Express 130 in the 160 mph class. I finished 1st in both events, 160.241 avg at the Gamblers and 159.055 mph avg at the Pony. We were clocked at 179 mph in the time traps (180 mph tech limit).

For 2006 I added a second fire suppression system (for the engine compartment), a removable steering wheel, and 18" wheels with Michelin PS2 (Y) rated tires. This allows me to tech unlimited (over 200 mph). I again ran the Bonneville 100 and Pony Express 130 in the 160 class. I finished 1st again in both events, and was timed at 187 mph. I had hit 190 on the GPS, but apparently not in the right spot.

2007-10 were disappointing years. I had DEVEK install a new air dam to improve aerodynamics. I was hoping to hit 195 mph at the June 2007 Bonneville 100. But on the return leg while entering the speed trap zone, the engine suffered a rod bearing failure at 188 mph. The engine was destroyed. The replacement engine from an 87 S4 was unable to finish a race. Rich Sanders and I spent many hours at multiple events trying to get the car working properly. We were able to hit 199 mph in the speed trap at the 2008 Pony Express 130, before braking down while running through The Gap.

In 2009 Jim Morton, Bill Ball, Dennis Kao, and I decided to build another engine. We started with a motor I pulled from a wrecked 88 S4 Richard Sanders and I bought the year before. We disassembled it, replaced the crank with a "Taylor" drilled one, had the original 90 heads reworked by Tri-Valley Machine, and used Jim's expertise to put it back together. After several tuning sessions I ran the car at the 2009 Silver State Classic Challenge (SSCC), in the 160 class. Unfortunately it had an overheating issues with the fuel was unable to complete the race.

In 2011 I was able to finish a race, the Nevada Open Road Challenge (NORC). I had replaced the supercharger, transmission, many fuel system components, and both drive axles. I ran the 160 class again and finished 3rd with a 157 mph average. In 2012 the car was fully sorted out and I finished both the NORC and SSCC. I was able to hit 200+ mph in both races and got 3rd in the 160 class at the NORC and a 2nd in the 170 mph class at the SSCC. In 2013 I again completed in the 170 class at the NORC and finished 1st with an average of 170.6027 mph and a top speed of 210 mph.

Pictures taken 4/6/01 near my house in Oakland, California.

First Day photos
Photos 12/04/01
First Day photos
More Photos
Photos 03/02/02
Track and Rally

My Old 928

Back to My 928 Home Page

Contact me at:

Copyright 2001, George A Suennen
written: 06/08/00
rev: 04/26/16