more power

[Paedster]

I have a 82SC 911 with 51000 miles on it, and is very strong but I would like more power. What are my options in increasing HP
Thanks

[emcon5]

Are there smog requirements where you live and how much you want to spend?

Early style exhaust/sport muffler would be the most bang for the buck, (15-20hp for about $1000) but technicly won't pass some smog checks because it removes the cat (even if it passes the tailpipe test).

If you live somewhere where smog isn't a concern, you can dump the CIS for carbs, twin plug, bump the displacement and compression and run a wild cam and get up towards 300hp, but it will cost a fortune and won't be drivable on the street*.

There is a good discussion of upgrade options here or you can search the archives. This topic has come up a bunch of times.

*edit, added for clarity

Tom

[Kemo]

you will get many points of views...

start with a Cool Collar

[Lothar]

That's simple:

Higher compression, more displacement, radical cams, headers and a Motec engine management system should do just fine. Be sure to twin plug the motor while you're at it.

Of course I jest. There is nothing simple or inexpensive about any of the above suggestions. Perhaps the experts here could suggest a way to implement these things over time and cash.

[dean]

Another option is to put a turbo motor in.

[RarlyL8]

or......

[juan ruiz]

Turbocharging is a much longer term investment, where supercharging doesn't tend to keep it's reliability nor longevity. Turbochargers tend to be more efficient and produce more power per unit boost pressure due to no parasitic losses.

Turbo systems tend to be more expensive due to the extra plumbing involved with the exhaust system vs. a supercharger just being hooked up to the intake.

Whipple superchargers have instant always on boost, but can create some light throttle driveability problems due to excessive surging from always trying to produce boost on a engine that's under vacuum.

Paxton and Vortech superchargers, though always on, tend to produce boost linear to rpm's, so if you want 7psi at 7k rpm's, you'll only have 3 psi at 3k rpm's and have to rev the engine up very high to get any torque and power advantages from the increase in boost pressure.

Turbo's are somewhere in the middle, producing boost only on demand, having a slight lag time in doing so, but being able to obtain full boost somewhere in the mid-rpm range and carry that on through to redline.

Porsche doesn't supercharge their vehicles... They only turbocharge them.

[Wayne 962]

"Turbocharging is a much longer term investment, where supercharging doesn't tend to keep it's reliability nor longevity."

What is the rationale behind this statement?

-Wayne

[Jim Sims]

Originally posted by juan ruiz
Turbochargers tend to be more efficient and produce more power per unit boost pressure due to no parasitic losses.

A turbocharger does utilize otherwise wasted heat from the engine but it has it own set of parasitic losses. The power turbine puts a back pressure on the gas generator (the reciprocating engine in this case) which affects engine performance. It just puts back more power to the system than it consumes but there are still losses.. Jim

[tbitz]

Originally posted by juan ruiz
....
Paxton and Vortech superchargers, though always on, tend to produce boost linear to rpm's, so if you want 7psi at 7k rpm's, you'll only have 3 psi at 3k rpm's and have to rev the engine up very high to get any torque and power advantages from the increase in boost pressure.....

Any centrifugal compressor based supercharger (ie: Paxton) produce boost with square of rpm (not linear). This is worse since if you get 7psi at 7000rpm you only get 2.6psi at 3500rpm

The modern EATON type superchargers (screw type) have a bypass valve so when the engine is at high vacuum (idle or low rpm) the supercharger is bypassed and the engine is allowed to run unboosted.