930 gearbox, turbo questions

Hi, folks:

I have a deposit to hold a 1987 930 ... 25k miles, beautiful car; got a couple of questions for the experts:

1) The car is unmodified except for a 1 bar boost spring that was put in 500 miles ago; what are the ramifications and should it be removed?

2) The 4-speed gearbox is balky on the 2-3 upshift; if you don't rush the shift (wait for a full second) it goes right in. The 4-3 downshift is fine. Something that can be lived with, or is it time to rebuild? I noted that the car had the 1 and 2 synchro rings and sleeves replaced in the past. Cost to rebuild?

3) Accelerating moderately in 3rd gear to about 3500 rpm and then nailing the throttle made the car hitch and shudder with no boost; lifting and then flooring it again brought the boost on with strong acceleration. Mixture issue? Just a confused turbo?

Other than those things, this car is in perfect shape. I've had four 911's, so I know when a car is right, but I'm unfamiliar with the 930, so any help is appreciated.

Vic

I had the spring and diaphragm fitted to my '88 930 wastegate by RUF. It does increase full boost from 0.8 bar to 1 bar with a corresponding increase in performance (0 - 60 in about 4.6). This is a safe limit for the car in it's stock form but you shouldn't run it any higher as this puts the car to it's thermal limits. The only other thing to remember is that more boost means more internal pressure so if you have any oil leaks (specially at the cylinder head joint) these are likely to get worse. Fixing these leaks means removing the engine from the car followed by a complete top end rebuild !

The gearboxes in these cars are notoriously noisy - whines, rumbles and synchro baulking. You can improve them by rebuilding but unless it's really bad it's just not worth the hassle. Some 'normal' gearbox noises include:

Noisy reverse gear, especially at low speed;
Springing out of gear when changing up (if you have a lazy clutch foot);
peculiar rumble in 2nd and 3rd (but only at 1200 rpm).

Lot's of jobs can be done on this car at home but you will need a fairly extensive tool kit or more than a modicum of ingenuity !

Hope this helps.