IanM

The OEM specified spark plug for 951's is a Bosch "WR7DS". However, I was recently talking to guy who builds race cars, and he says on big turbo and big boost cars he normally runs a cheapo NGK copper plug. He says they work really well, and has installed them on Supras that make over 600hp at the wheels. So, what's the scoop? What do you guys use? What gap, factory spec? What about you guys with modified cars like mine?

adrial

After much searching...I went with Bosch copper's..standard gap. I asked my mech how much silvers were...he said about $10/each I believe. The only place I found the plugs was at my mech...I checked 2 auto parts stores and 1 speed shop...neither had em or could get em.

I don't remember the number of it, but it's the one listed in all the Bosch books and under the hood.

Whatever you get, make sure its single tip. The multiple tip plugs (especially platinum) can cause detonation.

belz

I use NGK Copper plugs in my 951 race car.
Love 'em. The NGK tech recommended one to two plugs colder than stock. I use stock to slightly larger gap.
Inspect them frequently and replace as necessary. Don't waste your money on platinum plugs etc.

Luke

all of the parts stores have the wrong part number for Bosche 951 plugs. They will try to set you up for 944s plugs. And they are TOO hot!!! I have Bosche plats(the single ones) BUt I will use NKG's next time for sure.

Dan87951

I run the NGK Coppers about $5bux a plug.

IanM

Thanks for the info. I got the exact same recommendation from the chief mechanic at my local Porsche dealership. He uses NGK copper plugs (12 of 'em!) in his 996 twin turbo racecar. That's good enough for me! The NGK copper plug listed for the 951 is a BPR6ES plug. I went one colder due to my engine mods and extra heat/hp, and chose plug number BPR7ES. Cost only $2 each. Nice!!

K27w

NGK's in my 951, runs fine, too many myths about plugs out there to worry about it.
no one has ever dyno proven any difference in power between plugs that I know of.
I suppose longevity is the only concern, but they are cheap to replace at every oil change.
That's my thoughts anyway.

fc-racer

A very good friend of mine is an R&D engineer at NGK. He spent considerable time writing me an email about plug technology. It is truly amazing the technological strides they've made. He predicts that in 4-5 years, there will only be four plugs on the market for cars and trucks. The heat range tolerance of new tech plugs is outstanding.

Since he's such a bright guy and the fact that he truly knows what he's talking about, I've always run NGK in all my cars and karts. For the 944 Turbo, you want to run a BPR7ES which is one range colder than stock. The car will idle a bit bumpier, but performance otherwise is fine. If you are running stock boost, stick with the BPR6ES. You can also go for the EVX line which are platinums.

Farzaan

86944turbo

My 2.5 used Bosch W4CS. The 3.1 Litre uses Bosch W2CS. I've never had a spark plug related problem. They are not cheap and are somewhat difficult to come by. I run Sunoco GT-Plus exclusively and the motor regularly sees 230-240kpa. Prior to adding the spray bar on tyhe intercooler, I saw intake temps. at 60C, on 100F ambient days. The plugs start quickly under all conditions that they have been in and I've never had the motor misfire.

belz

Just in case you haven't noticed:
NGK plug numbers increase for "colder" plugs and Bosch plug numbers decrease for "colder" plugs.