There are many buying guides for the Porsche 911. They all speak knowingly of the differences between the T, the E and the S, but those observations always seem to relate to new-car issues. They fail to tell you what you need to know about owning a 911E today.
The Bosch MFI mechanical fuel injection system is wonderful. It starts easily in any weather and runs like a freight train all the time. I switched my mechanically-injected Alfa to Weber carburetors because the Spica MFI system was not well developed, but the Porsche stays injected. You do have to maintain the system: The shafts on the throttle bodies wear (90,000 miles for mine); The injection pump may need to be rebuilt (mine didn't); the injection nozzles are also back-pressure valves (mine need to be rebuilt/replaced -- they leak down when the engine's not running, causing the engine to sputter upon start-up).
In short, the injection is perfect.
The 911T lacks many of the premium parts in the 911E/911S engines. The 911S has cams and compression that are somewhat impractical for use on the street. The 911E is the just-right engine for most folks. The 911E cams are in great demand for backdating later-model cars to eliminate the CIS fuel injection.
In short, this is the ideal motor.
911Es were built with no external oil cooler. In most North American climates, if you intend to use the car hard (track time or 80 mph cruising) in hot weather, you will reach oil temperatures that will damage the oil (245°F+). You need to install a front oil cooler. I put in the trombone and bronze piping from a 1977 911S. It's all I needed to keep oil at a steady 180°F. Many will tell you that you need more.
Why didn't anybody mention this little detail?
Boge Nivomat Self-Leveling Front Suspension
The 100% failure rate of these struts was a source of real concern when the cars were new. Because it was cheaper to replace the whole system with the Koni suspension for a 911S, there are no more Nivomat suspensions out there. Don't worry about it.
The down side is that the Nivomat system also provided the anti-roll (anti-sway) function. Most owners were in such shock over having to spend thousands replacing the front suspension neglected to install bars. I acquired the complete front and rear bar systems from a 1970 911S and installed them. Front is no trick. In the rear, you have a decision to make. The rear semi-trailing arms (bananas) on 911Es do not have the nubs that the drop links have to attach to. You can either:
o Buy the nubs and have them drilled in and welded on your existing bananas.
o Buy bananas that have the nubs -- either steel bananas from an early 911S (what I did) or the trick aluminum bananas from a later car. Swap out the bananas (careful with those wheel bearings -- they are a little tricky).
The rear is also missing the bosses that the bar hinges on ("consoles"). These are available from Porsche and are fairly easy to weld onto the floor pan.
Why didn't anybody mention any of this??
Fuchs 14" Wheels
The 911S came with 15" x 6" Fuchs wheels mounting 185/70 VR 15 Michelin XWX tires. Porsche judged these new, low-profile tires as too harsh for the 911E's intended executive demographic. The 911E came with 14" x 5.5" Fuchs wheels mounting 185(80) VR 14 XWX. Tires are no longer available in this size. Most 911Es are now running around on 185/70 SR 14 touring tires. These are unsuitable in several ways:
o The speed rating is not up to the car's potential -- one lap on a track will melt them (ask me how I know)
o They have disappointing grip
o They have a much smaller circumference, so the gearing is 10% more aggressive (great at the stoplight grand prix, but not so hot on the highway, and the fuel economy stinks). Also, the speedometer reads 10% faster than you are actually going.
o They have a lower overall height -- the car sits 3/4" too low and drags on high spots in the street.
I decided to switch to 15" x 6" wheels and 185/70 tires. I tried to acquire a set of the correct 1970 "deep-dish" wheels, but these are extremely rare and expensive. They also lack modern safety humps. So I punted and bought a set of 1977 911S Fuchs (flat area between the rim and the wheel center). These are dimensionally identical, have safety humps and are plentiful and reasonably priced. Only early 911S geeks can tell the difference.
I found a used set of XWX, and they were a fabulous tire by 1970 standards. They wore out in a few thousand miles. Michelin XWX are still available from Coker Tire in 185/70 VR 15, but they are over $400 each. Now I am running Sumitomo HTR 200 in 195/65 VR 15. They don't look as original, but they work really well and they are remarkably inexpensive.
Why didn't anybody mention any of this??
The Bottom Line
I got a lot of surprises after I bought my 911E. I dealt with each issue as I discovered it. I spent more money than I expected. But now I have the 911 that I still feel is best suited to my mix of hard driving on the street and occasional track time. I just wish I had known this stuff going in.