hacker-pschorr

Why the desire to run platinum plugs???

For performance, copper has always been the best choice (Bosch isn't the only option, I use NGK).

Silver, platinum, and then iridium became popular (with multiple electrodes) to extended the change interval. Car companies wanting to advertise "100,000 miles tune ups" would never happen with copper plugs.

If you #1 goal is not changing spark plugs for 10 years, by all means to platinum. Otherwise the only plugs that should be in a 928 are copper.

FYI - I was also told by a Bosch rep there is a difference between products sold at an auto parts store and a Bosch certified shop. This may be BS, but the spark plugs I purchased at Autozone listed for the 928 were not the same as those purchased from my local Bosch certified independent mechanic.
Same for oil filters. The Bosch filters on the shelf at Pep-Boys are not the same as those stocked by my local shop.

Back to plugs, I switched to NGK when I discovered the local speed shop was installing NGK copper in every car from mildly tuned 1.8 turbo VW's to 1,000hp LS based Chevy's.

simos

I agree with Hacker. One engine builder said to me that plugs are so cheap, that you can replace them every year. Just like you do with oil and filter...
So, I decided to do so and choose copper ones.

Some more info:
http://www.team-integra.net/forum/bl...tml#comment474

Garth S

For both 16V and 32V 938's, I've had exceptional, long term results with the Bosch WR8DS and W7RDS respectively .... the silver electrodes are full sized, as with the copper counterparts, and seem impervious to wear: I pulled a set from my '80 (WR8DS) that had seen more that 10 yrs service, and replaced them more out of guilt than necessity - the old ones could be screwed back in today without apparent efficiency loss.

PorKen

I just changed out the plugs on my new '88 5-speed to what I've been running on my S3s. Wow.

From - NGK BPR6ES randomly gapped (0.024-0.036, stock 0.028-0.032)

To - NGK BP7ES, colder, non-resistor, gapped to 0.040 (1.0mm)

Before, it struggled to rev - now it revs nicely, thank you.
Before, power was so-so at lower revs - now a big uptick in power overall.
It is so smooth at idle, the engine does not appear to be running.

The S3s like 'em, but the S4 -luvs- a big gap.



Note, you must have stock Bosch steel backed ignition amps to run non-resistor plugs!
Aluminum backed amps (Huuco) run poorly with non-resistor.

tv

I said this in a thread in 2006

"I've used bosch, champion and now NGK v-power. Who knows which is best, but my euro has never run smoother than now."

great info on their site -- http://www.ngksparkplugs.com/product...ugs/vpower.asp click on "How they work"

And I believe I went with the slightly cooler ones as the Euro tends to run hot, watch this

Tom in Austin

Yeah, but what kind of dyno did you test them on, not all dynos are the same you know ...

Rob Edwards

Patient Name: 1990 928GT

DOB: 1/10/90

Rx: WR7DC, take 8, q 15K miles.

Sig: Take with anti-seize, 18-22 ft-lbs

Label: http://www.mailordercentral.com/928i...p?number=WR7DC

X No Substitution!

Lizard928

Rob,

Hate to say this but on WR7DC plugs, they have a coating from the factory and should never be used with anti sieze as it changes the torque settings and can lead to further problems.
Also if it is used with copper antisieze then you will really have problems as copper and the aluminium head don't get along famously......

Rob Edwards

I recently ran into this issue when changing the plugs in my daily driver ('08 Honda Odyssey....), which takes NGK plugs. The NGK website mentions this 'Trivalent Metal Plating' and says that one shouldn't use antiseize at all.

So- I installed the laser iridium plugs in the Honda dry.

Didn't realize that the Copper Bosches used a similar coating.

Instead of trying to provide a technical rebuttal that is above my paygrade in terms of understanding metallurgy and specialized plating processes, can I just hide behind the argumentum ad authoritatum that Dr Bob puts a little silver antiseize on his plugs?

hacker-pschorr

You might want to inform Permatex of this......

http://www.permatex.com/component/do...ket=automotive

From that link:

Lizard928

Aluminum/copper corrosion is quite complex. Aluminum has an oxide on the surface and the oxide stability determines its performance. Galvanic series does not always predict the reaction in absolute terms since we would need to take into effect the area of the 2 metals. Chloride & copper can cause pitting in aluminum. So overall copper and aluminium is not a very wise idea.
Zinc however is a less noble metal so it will erode before the aluminium does. So silver coloured anitseize is a FAR safer choice when it comes to using an antiseize where there is any aluminium.
A good example of this is the rear dowel which goes through the hub, shock, and lower a-arm. If you put copper in there with all the road moisture, salt etc. it will rapidly corrode the hub and the expansion caused by corrosion will lock the dowel into place requiring cutting, heat extreme force etc. to remove.

Now when it comes to spark plugs if you have an aluminium head, when you get the spark plug ensure that the metal part of the plug is a silver colour. If it is black, return it and get one with a silver colour as the silver is a plating which will prevent corrosion of the aluminium from taking place (within reasonable time and conditions!). The problem with using any antiseize on spark plugs, or most bolts is that it changes the resistance on the threads. Thus it can lead to over torquing of the bolt.
When you are using a non coated spark plug (black), then yes you can use some silver anti seize on the threads. But I just recommend getting coated plugs from the get go.

Here is a good paper on it http://www.ngkplugpro.ca/content/con...SparkPlugs.pdf

hacker-pschorr

I usually spray a salt water solution on the spark plug threads before installation to promote a good bond to the head that keeps them from falling out.

Rick Carter

Great tip, I'll try it.

Randy V

Even better to brush the threads with a strong solution of phosphoric acid.