Hello everyone i just changed my plugs last week and a half,and i have to say its the best spark plugs so far.The car feels like it has 30% more power.We tested on four cars 3 different makers-2Mercedes,Nissan,Porsche.Everyone agreed on the result.Please let me know what you guys think.Thanks

 

They are not going in one of my cars.

30% more power, did you have a hole out?

 

I hope not,its for an unblown motor.

 

I have Bosch +4 platinums in my car, but think i will just go with the copper WR7-DTC as speced for the GTS. I found them online for $3.75 each

 

Hi Ryan,
Do share on the GTS plugs.
Roger

 

30% more power? Um....you do realize that is 90hp on most 928's.

Bosch Fusion = Platinum + iridium all in one plug. Since I will never run a plug of either material, mixing them together doesn't seam any better.

I use WR7DC, I'm not sure what the "T" is for.....edit - ah, triple electrode otherwise the same. I'm not a fan of multi electrode plugs since it's tricky to gap them.

Unless you spend a lot of time sitting stopped in traffic - go with the 6's.
The colder the plug, less chance of detonation. Hotter plugs are only necessary for emissions.

Spark plug rule of thumb - run the coldest plug you can without fouling. I've been running 6's in my 81 for three years now (stock is 8). No issues. I'll be installing 5's very soon (or a different racing plug)

Platinum plugs have one advantage over copper, longevity (same for multi point). So if changing your plugs every 10,000 or so miles is real hassle, go with the platinum.

I've "fixed" quite a few cars by throwing away the "fancy" plugs in exchange for good old copper.

The plugs I might install next are non-projected electrode NGK plugs (still copper). The 4-banger turbo crowd swears by these plugs (700+whp out of 2.2 liters in a street car) Here is a comparison pic, Todd has been running these in his motor for a few years:

 

Hi

I am about to change my Plugs from BP7ES TO B9ECS for my Nitrous system, I will let you know if they are usable on the street as its my daily driver

All the best Brett

 

Red Shark what was the condition of the plug that was removed from the engine?

 

IMHO, any 32V can run 5's (WR5DC) and stay clean, unless there is a sensor/fuel injector problem.

Even with a colder thermostat, my 5's are always clean in my '86. I have 6's in my '81.

Fouling is a non-issue with electronic fuel injection systems which have an oxygen sensor. On engines with a knock sensor, you'll lose less power from knock retard with a colder plug.

 

The only thing that seems important is to make sure its a spark plug with an un-obstructed spark arc - meaning the spark goes across, laterally instead of the usual manner

 

Cool, good to know. I'll find out soon if a plug in the 5 range with a non-prjected electrode will stay clean with the early ignition / fuel system.

I guess if you are caught in grid lock on a regular basis with your 928 on cold days, it could become an issue.

6's were installed in Shane's new car, I'm sure you will swap in some 5's

 

Non-projected tip might be a different story. WR5DC is the coldest Bosch projected. The next step is WR5C = non-projected. They say the projected tip is better for spark kernal placement, but they say a lot of things that don't really turn out to be true.

Once the engine is up to temp, the combustion chamber doesn't know if it's cold outside. Sitting in traffic, air is normally being pulled in after passing over (through) the radiator, and the intake is nice and warm.

Shane's car will obviously need some PK'ing to reach it's full potential.

 

The non-projected plugs I'll be running are NGK in a temp range cimilar to a Bosch 5.
Good point.
Hey now.....I'm telling Z

Wait until you see the custom one-off (so far) intercooler Todd made

 

has anyone ever tried silver plugs?
In theory, these seem to have superior potential. Properties of metals for both electrical conductivity and heat are, from best to next are: Silver, Copper, Gold, Aluminum, Platinum. Platinum is actually not a very good conductor of electricity but it resists corrosion and heat well.

_Allen in Allentown, PA

 

I had bosch plat4-before the changed-they looked clean,several looked brownish.Then i read the thread using ngk v-plugs-the ngk made the car works harder-pressing the gas pedal more.Had them in 2 weeks yanked them out to try the bosch plat4 fusion- the power band is instant at every level going to turn at 60mph to 80mph effortless without floring the darn pedal as before.At straight away the car runs without feeling sluggish.Race a Nissan 300z the other night doing 130+ as he was 3 or 4 car lenght back trying to catch up.I hope one member try them out and see.