joeycannoli

I just picked up a bunch of parts from my supplier including spark plugs. I was referenced to get 999-170-195-90 like CT (same PN that Suncoast gave me).

Quick question. Who makes the OEM plug? The plugs that came were BERU Ultra- 14FR-5LDU

Are these the wrong plugs? Should I return them?

SH || NC

I have the same p/n (999-170-195-90) listed on my service records from ~ a year ago.

joeycannoli

Im just curious with the 5LDU that i have vs everyone else saying 6LDU

911SLOW

Beru has two spark plugs that fit the mk2 gt3
same size 14mm one is 14 FR-6 LDU the other is 14 FR-5 LDU
http://www.beru.com/english/produkte...&action=step04

Bosch has only the 14mm FR6LDC type
http://www.boschsparkplugs.net/resul...tTypeID=1&pt=1

all the above fit but i don't know the differences FYI the RoW pet says:

999 170 195 90 6LDU 14 FR 6LDU and that means Beru..

JMcD

I spoke to Suncoast and Sunset Porsche Parts recently and they said to use 999 170 195 90. That's BERU 14 FR6 LDU in our 2004-05 GT3's; but only after I bought 12 Bosch Y 5 DDC's from a independent Porsche parts supplier as recommended.

911SLOW

Very nice parts supplier.. : )

enthusiast

I also bought new plugs from a Porsche dealer using 999.170.195.90 and they are Beru ultra 14FR - 6LDU.

Porsche Parts Catalog lists 14FR 6LDU. I haven't changed plugs or checked them so I do not know what is currently installed in my GT3.

The maintenance book that comes with the 2004-2005 996 GT3 under Section I. Required for the Emission Control System, lists replacing spark plugs at 30,000 mile intervals. The GT3 marketing literature (dated 2003) stated every 24,000 miles or four years.


** Tightening Torques for M 96/97 Engine - GT3/GT3 RS **

ignition coil to cylinder head - 10 Nm (7.5 lb-ft)

new spark plug - 30 Nm (22 lb-ft)

used spark plug - 25 Nm (19 lb-ft)

.

Dudley

I also ordered 999-170-195-90 and received Beru Ultra 14FR-5LDU rather than the 14FR-6LDU.
I believe the difference is in the Thermal Rating of the plug.
"Beru, along with nearly all of the world's plug makers, use a number-based code to designate heat range. Foreign firms follow a system in which higher numbers mean colder plugs."

Therefore, the 5LDC is a hotter plug. Does this mean this plug will stay hot enough to burn away deposits (oil, carbon, etc.) that otherwise might build up and short-circuit the spark of a colder plug? On the flip side, a plug that is too hot could cause pre-ignition - not good.

Is 5LDC too hot?

The difference in heat ranges of this manufacturer could be so miniscule as to have little effect but who knows? John?