let's start the plug war....

scoober78 · 01-31-2001, 02:46 PM

Hello all,
I was jsut doing a tune up on my baby, and when I was checking the gap on the plugs, it occurred to me to ask what people are using ou there not only for gapping, but plug-wise in general. I have an '87 951 with about 40k on it and since I had a bad experience with Bosch platinums in the Turbo, have only used the stock Bosch copper plugs with stock gapping. Your comments please...

Erik

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Go the distance....

Tabor · 01-31-2001, 03:13 PM

I use Bosche Platinum in my 1987 944 NA.

As for not using the Platinums, I don't think you have to worry. I believe it is the Platinum+4's that you shouldn't use.

-Tabor

Lawrence Coppari · 01-31-2001, 03:15 PM

I use Champions and set it at the recommended gap. Previous plugs were Autolite. Champions seem a bit cleaner but they could be slightly hotter plugs. I can't tell any difference in track use.

p0r2chby · 01-31-2001, 03:47 PM

I am now running Bosch Platinum+4's in my 86 na.

scoober78 · 01-31-2001, 03:57 PM

I'd love to run the +4's but like I said I had a bad experience. Let us just say that I found out that sometimes the hottest plugs aren't the best. Anyway I'm pretty sure you aren't supposed to use the +4's in the turbo.

Erik

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Go the distance....

todd951 · 01-31-2001, 04:05 PM

Correct, you're not supposed to use the +4's in a 944 Turbo, although I used them for a while before I found out that they're not recommended, and I didn't have any trouble with them. In fact, I was getting very good gas mileage with them in there. But everyone says I shouldn't use them in my car, so now I'm using the Beru silver plugs.

[This message has been edited by todd951 (edited 01-31-2001).]

drew1 · 01-31-2001, 05:12 PM

Have used Bosch thin wire with one ground electrode in 924T. Ran good with motor & injection in top shape. Champion , Bosch copper, & AC grooved electrode OK. Bosch +4 agree with others about turbos, spark knock.

drew1

scottewid · 02-01-2001, 01:15 PM

1984 944na

When not running nitrous: Bosch+4

With nitrous: NGK copper, one range colder

You're not supposed to use platinum plugs with nitrous, due to the increased heat and pressure. Platinum supposedly doesn't hold up well in those conditions, so I'd imagine it should also hold true for turbo.

Obin Robinson · 02-02-2001, 05:34 AM

NGK

all my cars get them.

obin

Guitarsmith · 02-02-2001, 09:13 AM

I use the factory recommended silver tipped Bosch plugs in my 931.
I use to use platinum's in the carbed 914, but they are a no-no in Turbo's.

I'll never use NGK's since my buddy's bus got stripped holes from them--and they had anti-seize on them! Made me wary....

too each his own on this one, like oil and filter and gas choices.....

Guitarsmith · 02-02-2001, 09:13 AM

I use the factory recommended silver tipped Bosch plugs in my 931.
I use to use platinum's in the carbed 914, but they are a no-no in Turbo's.

I'll never use NGK's since my buddy's bus got stripped holes from them--and they had anti-seize on them! Made me wary....

too each his own on this one, like oil and filter and gas choices.....

Kaos · 02-03-2001, 06:16 AM

The Anti-seize was probably the cause of the stripped threads, not the plug itself.

I have seen time and time again, when too much anti-seize is used when inserting an O2 sensor into an exhaust, the threads will get welded in the exhaust. I suspect that using anti-seize on spark plugs would do the same thing.

Just don't use it!

drew1 · 02-05-2001, 03:47 PM

kaos,

I'm a believer in anti-seize on high temp applications & some others(stainless to stainless, etc).

drew1

1.2gees · 1.2gees's Garage

You're supposed to barely coat one of the surfaces with anti-seize. Make sure you use a high quality product btw.

Keep in mind, almost all good spark plugs come already coated with anti-seize, as well as all Bosch oxygen sensors, they don't need any applied on them the first time around.

As for the platinum plugs:

The reason the +4s are not recommended seems to be that first platinum can get very hot, and contain the heat, cause pre-ignition. Another good argument was that the 4 tips of the +4 could cause pre-ignition, simply because there's a larger mass, that stays hot, after ignition.

Since factory actually recommended normal platinum Bosch plugs at the time, I'd think that the second seems to be the more believable.

A good friend of mine (engineer/shop owner/mechanic) says that aluminum heads and platinum don't work too well together.

So there are MANY opinions on why NOT to use the +4s on 951s, however I haven't heard a solid reason. However the fact that Bosch doesn't list the +4s for the 44 turbo is (I presume) enough reason to not suggest them for this application!
Ahmet

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It's all the driver...

scoober78 · 02-05-2001, 06:54 PM

Yup...you know Ahmet, i never thought of that....duh!!!

Erik

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Go the distance....

wolfrpi · 02-05-2001, 09:08 PM

I use the standard Bosch Platinums in my 86 951 and I am very happy with them. Out of the box though the gap was off from the factory setting, so I bought a gapper and gapped them. Even running 17psi, I have not heard a hint of detonation. I've always used Platinums in all of my cars, including about 5 Saab turbos I've had over the course of the past 10 years. I think I tried an Autolite or something like that in a tricked out turbo convertible I had and the bottom of the plug actually blew right off into the cylinder! Since then, I have never bought a different type of plug on my own free will. Good luck,

Erick