slivel

For a long time I've been annoyed with the tight space available when checking or changing spark plugs in our 951's. After some research on-line and some e-mail to the customer service desk at Bosch, I've found the conversion to a more modern small base plug for our cars.

Normal stock plugs in Bosch are WR7DC+ and are 14mm thread pitch, projected tip, .750 " reach and 13/16 (or 21mm) socket size.

Small base equivalent plugs in Bosch are FR7DCX and are the same functionally except that the socket size is 5/8 (or 16mm). This change to the smaller socket makes it much easier when working to extract and install plugs.

I actually use the Bosch FR6DCX which is 1 heat range cooler since my engine is about 300 rwhp.

If you don't like Bosch, you can cross-reference the small base Bosch to whatever plug brand you like.

numbskull

My last spark plug set was smaller base, they were e3's. They were 12 bux a piece, and performed really well. The box end was a weird design.

V2Rocket

every bit of weight saved counts

good find.