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spuggy spuggy is offline
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Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 2,826
Originally Posted by jly535 View Post
I called Squire here in Seattle who installed them. He recommends 5s for street and 3 or 4s for track.
Yeh. The lore is that Porsche only really built the car to homologate the turbo for racing, and originally built 500 for "friends of the factory". Which they figured would almost certainly live most of their lives on the track, or at least get driven really hard.

So they selected a suitable plug for that usage, and that's what the car was EPA-approved with.

Taken by surprise when the car became an icon and kept selling, they said "o well", and didn't really develop the car much over the years. Changing the plug specification would have required re-certification of the entire car, a not insignificant cost.

I forget exactly when they revised the plug, but it's not until the 965 Turbo 2 or the 993 TT. And they made it much hotter...

Upside of the hideously expensive platinum plugs are two-fold; better throttle response (general characteristic of a cold plug) and the fact that they don't foul in conditions where a regular plug would.

It's well-known that the stock plugs are far too cold for street. But I run them and have yet to foul one - despite the weather/traffic or road conditions not always being conducive to winding up the turbo and cleaning off the plugs...
'77 S with '78 930 power and a few other things.
Old 03-25-2008, 06:42 PM
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