tomyfoo

Pls advise a good premium performance spark plug for Porsche engine 28/42 81H08002

SeanR

Bosch WR7DC+ copper.

Rob Edwards

Be forewarned, even though they're premium plugs and the best choice for your '87 automatic, they can be as much as $2.50. Each.

Mrmerlin

dont be fooled that paying 6.75 per plug means it going to work better in your engine..............
In this case less IS better.

GregBBRD

Agreed.

SwayBar

Witness...

The Forgotten On

Use what the owner's manual recommends. Unless you are tuning and using colder or hotter plugs, stick with what Porsche used.

Bosch or NGK equivalents are the best.

Garth S

Have also had long term success with Bosch plugs .... but use the silver electrode versions: WR7DS for 32V, and WR8DS for 16V: they seem immune to erosion at the gap, and have a great life span.

Petza914

So the older cars need a different heat range plug (7 vs 8)? I haven't changed mine yet but probably will soon. What's the consensus on a recommendation for a supercharged 79 K-Jet car?

SeanR

Boosted cars need a cooler plug, on mine I'm happy with the WR5DC+ plugs.

hacker-pschorr

In 83 the plugs changed to 7's and for the life of me never understood why and always run 7's in the 78-82 cars too.

Best to ask the manufacturer of your kit what they recommend since they've probably tuned it around a specific heat range.

Petza914

Thanks Sean and Hacker

GregBBRD

An important "engine tip" to remember....the silver tip melts at a lower temperature. Great for use where cylinder chamber temperatures might get "beyond" what is normal.....supercharged, turbocharged, and race engines running **** fuel.

The silver tip will "melt" and sometimes a misfire will occur, before any engine damage occurs.

Of course, selling a silver tipped spark plug to anyone that runs **** fuel in their race engine is tough.....cheaper is always better!