Bosch Quad plugs?

[Woody]

Can any one tell what is the correct # for the Bosch Quad plugs.
Thanks
Kevin

[pwd72s]

I don't use 'em, sorry. Suggest that you ask your mechanic which single electode plug he'd think is best.

[Rouxzy]

Watch out for the quad plugs. I've heard stories of one of the four tips breaking off and ending up making a mess inside the cylinder.
Tom

[pwd72s]

me too, but didn't want to scare the guy too much. Also, think about it, no matter the plug design, there is still only ONE spark...

[ChrisBennet]

I steer clear of the Bosch Platinums (the cheap ones) on the advice of a mechanic friend (and Bosch Master Tech).
-Chris

[pwd72s]

Woody, the following plugs are on a list of plugs suggested to me for my car, a 1972 911S...I don't know how well they'd work in your car, and you may want to play up & down on the heat range depending on your driving habits.
The old Bosh number for my car was W265P21...today's equal is Bosch W3DPO. Others are NGK B8ES, a Japanese brand...NGKB8EV (NGK calatog # for "S" models)...and I'm currently running Bosch W4CS, based on a suggestion by a mechanic I trust...but I'm not a wild driver these days..street only, land on it once in a while, but for the most part just loaf along, trying to avoid trouble. Hope this gives you a starting point at least...but do stay away from the multi tipped plugs...Some of the above I listed are platinum, others not...the price should let you know which is which...

[RoninLB]

Originally posted by Woody
Can any one tell what is the correct # for the Bosch Quad plugs.
Thanks
Kevin

is it because you are fouling plugs?
what plugs are you using now?
how long do the plugs your using last?

[cstreit]

I believe these plugs are a gimmick. THere is a fixed voltage level traveling through the conductor. IF the spark was to jump to all four (which it won't) you'd have 1/4 the spark power at each one... SInce it doesn't and only jumps to one electrode, you end up with 3 others just blocking the proper flame front.

Remember the old racer trick of indexing the plug opening towards the center of the combustion chamber? THis would ensure that it was not able to face anywhere...

[jabb]

With your car I would consider using NGK plugs

[tshih]

Based on the Bosch propaganda the 4 electrodes are suppose to provide a corona discharge of the spark(s) and that provides a uniform and larger flame front leading to cleaner and more efficient burning and resulting in slightly more power. Since Bosch is the OEM supplier of most fuel and ignition parts that are researched and specified by Porsche I'd take their word for it over any other sources. I have a set in my 1985 carrera 3.2 stock and they haven't hurt or performed any better than the chrome tip single ones that came off the car. I doubt any major changes in spark plug design including a ring held by one or more posts actually will improve on the single post designs. The use of platinum is only for longevity of the electrode and the amount you get is only about 25 cents worth in pure weight. Excellence had an article about 3 issues ago which talked about the spark plug making process at Bosch and how much of each ingredients were used in the production of a million plugs (each day's worth).

[Superman]

I use only single-electrode, copper plugs in all my engines. They simply perform the best. Bosch is good. NGK is impossible to beat.

[Epster77]

Stick with the copper plugs. They will perform as well, if not better than the quads. The quads are over priced.

[Wil Ferch]

Hold -on !!...
Let's think rationally about this for a moment. Whether you have one or four elecrtrodes...only ONE will fire at a time. Like a bolt of lightning, it's almost impossible to *time* the spark to the other three at *exactly* the same time...with *exactly* the same voltage potential to EACH of the four ?? C'mon....one of these 4 will "win" at any given point in time.
The REAL advantage of 4 electrodes ( possibly) is that the random nature of the SINGLE spark to any one of the electrodes will enhance total plug life. The center electrode will reach out and hit any one ( of the four) ground electrodes, and spread the "wear" around a bit to promote longer plug life. I believe some models of the 944 Turbo may have come from the factory with 3 or 4 prong plugs just to be able to live a reasonable plug life and to extend plug service intervals.
--Wil Ferch

[RickM]

I think there is an urban legend that the platinum plugs won't foul. This is simply untrue.

[old_skul]

NGK plugs perform the best. Unfortunately they're getting hard to find - even our host here doesn't seem to carry them anymore.

[carnut169]

Need to find a special plug....
http://www.sparkplugs.com/