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PLATIN vs. Platinum The real story - long
What can I say, just don't sleep, this guy....
Anyway, before any of this debate of, "I thinks" goes any further, your
humble MacGuyver servant meandered out to the garage and grabbed three "old"
plugs to take my swiss army knife to, in the name of science.... Here ya go
2 - WR7DP - Platinum - Ex's from my car
2 - WR7DTC - Triple Copper - Ex's from my wifes car
5 - F5DPOR - Current flavor both cars, extra set here
1 -New Dremel from Santa
1 -Mitutoyo dial Caliper - accurate to .001" - zero calibated 6-95
1 -Swiss army knife
1 - attitude - hey I got over 150USD in my three sets of OR's!
Well, if anyone tells you the Platins and the Platinums are the same, have I
gots a surprise for you...... As Eric would say, Bzzzzzzzzt. That is
incorrect sirs..... Here's the beef:
WR7DTC - Bosch Super - Tri - electrode copper
Lots of miles on them, they were stuck in the head when I removed them at
150k on Carole's car 5 months ago..... Well worn.... Here's exactly why you
don't want to use them.... Plug 1 Gaps: .035, .039, .045 Plug 2 Gaps: .038,
.042, .043 Now, everything that I know, your knowlege may vary, is that the
reason you don't use these on a single trigger coil ignition, is that the
trigger resistance varies as the spark jumps from one electrode to the other
two, hence not optimal spark...... On a individual coil (S4) it doesn't
matter, cuz the 5 plugs are independent coil triggering. Optimally, you want
the gap to be as close as possible in a single trigger coil within and
between plugs, doesn't look to be the case here. The advantages of using
this plug: that it hardly will foul, is a "side gap" vs "top gap" plug, so
more of the electrode is exposed (that's .150 and .155 length respectively,
plugs 1 & 2) reducing "blowout" phenomenon, and longer life expectancy, since
the wear is on 3 sides vs 1...... A truely great motorcycle plug too......
WR7DP - Platinum
Plug tip coated in ceramic except for .035" dia. platin spot at the very tip.
The tip is conical, but has no protruding tip (see platin) to measure.
Stripped ceramic away, no surprises the very tip is all that shows to the
"ground tip". No visible wear, but not sure of mileage on these pups either,
my guess is that they are new, no pits even under ground tip. Advantage here
is price.... At 1.50 at trak auto and Kmart availability, it's no wonder it
sells as well as it does. Disadvantages: Many. 1) a .035 spot (and that's
used BTW) on a ceramic tip is hardly an optimum sparker, prone to fouling
(esp with 4 mikunis, BTDT), is a "top fire" plug, and is known to most
tweekers, Ned and others included, as a no-no, go with the cheaper coppers,
cuz of the tiny electrode fire spot. On a tweeked car, has a common
propensity to "blow out" the spark at high rpm and "spirited" driving.
Impossible to find a 6 or < heat range on this plug. Ceramic barrier is
only a coating from tip to top of threads inside plug.
F5DPOR - Bosch PLATIN
A totally different animal than the Platinums. The electrode stands .140 OUT
of the closest ceramic, and the ceramic is thick (.050" thick) where is
starts, not a coating (that I could scrape off the Platinums all the way to
top of the thread on inside), need the dremel here...... Advantages: side
fire plug, platinum tip protrudes .060 out of electrode, and grounding tip
has a .040 "wear tip" on it. Looks like a tough one to foul, and an easy one
to pull, adjust and replace (and is, BTDT) for the 30k miles Bosch claims
they are good for on an S4. Good heat ranges available from 5,6,7(BTDT) I
heard there is a 4, but can't say for sure. Disadvantages: Price, price
price.... at 15 bucks (discount) they are a chunk of change. Need to take
off or modify the "resistor shields" from the stock pug wires..... Have seen,
or more specifically, heard no ills from this procedure, including CB
reception. Just don't get enough drooling and "look cool" expressions from
the crowd. Did I say they were expensive?
WR7DC - Bosch Coppers - from BTDT, no patient available
Same basic config (cept is top fire) as the tris only with one electrode.
Advantages: price, availability, performance for a fraction of the
PLATINS. Disadvantages: Heat range of less than 7 hard to find, top fire
plug. Bang for the buck a great buy.
Well folks, there you have it. To say a Platin and Platinum are Bosch-speak
is just not right. Is the performance difference noticeable with any of
them? For the average car I would say, go with the single electrode coppers,
they make the most sense, and for the price, you could replace them a few
times over, before you justify the PLATINS. But, if you run Ned's or
homebrew or others' stage xx mods, I think they are worth serious
consideration, if nothing else, for the ease of availability of a 5 heat
range. Running Platinums? I think that is a harder argument over the
coppers than the PLATINS are over any of them. For the extra $.60 a piece,
just get the coppers, then get a Beck's Bullet, you earned it for smart
So as I see it, my post stands as written:
F 5/6/7 DPOR - best
WR7DC - next
WR7DTC - third - but the why question
WR7DP - Dead last
MacGuyver would be proud, nomex off, knife folded..... Back to the Pheonix
Foundation for a beer.