[s-cars] Which spark plugs

[John Cunningham]

Gaah. This FAQ topic is to UrS cars what 'oil threads' are to the M-car 
crowd... painfully over-covered and yet people always come back to the 
table despite the wealth of answers to the same question... there's 
gotta be 100 spark plug threads on QW with all the answers even if there 
are slightly different opinions.

Cliff notes:
1. Modern production FD5POR's have been known to drop electrodes as 
Scott says. Some still run them fine obv but thats the risk.  And $$$ 
compared to the options.
2. NGK Iridiums and FR5DTC are the 2 that most of the big power guys run 
(Hap's on Irids IIRC, most guys I know are on the Bosch). The FR5DTC has 
a shorter lifespan like an old school plug, and seems to have become 
hard to get as of late.  (I have been on/off both of these myself for 
years w no issues)
3. A smaller minority of guys have had luck w/ some of the other quality 
NGK's and Nippondensos - copper electrodes etc.
4. Other cheapass plugs generally prove problematic.

End of story.  Of course we'll get the same question again in 5 weeks.

On 3/22/2014 2:07, Mike Miller wrote:
> I ran F5DP0R's in my 91 200q's without issue - swapped one set out 
> after 100k+ miles just because. They still looked good and ran fine.
>
> In the current UrS6, running over 25psi boost, I'm using FR5DTC which 
> seem to be doing OK. Not a lot of miles on them yet - maybe 5k.
>
> --mike
>
> On 3/21/2014 10:21 PM, Scott Justusson wrote:
>> Er, ok add me to the list of those *not* using FD5POR *ever* again, 
>> because when I had my shop, I have seen too many fail from the box, 
>> blow a pin hole in the ceramic and or just lose the electrode all 
>> together on high boost.  I had really good luck with NGK Iridiums for 
>> a while, but have recently just been content with a plain old Porsche 
>> Turbo app triple copper plug.
>>
>> FYI, that FD5 is supposed to have a 25k service interval in a stock 
>> 20vt engine, so beyond 30k (IME) you are asking for coil pack issues 
>> from a resistance problem.  I know I am not the exception to the opin 
>> that the FD5POR is hardly first prize at the spark plug county fair.  
>> Bet you won't find m-any I5 tuners using that plug.  Lose and 
>> electrode once, you won't swear *by* them ever again.
>>
>> Just sayin
>>
>> Scott J
>> 7 x 20vt engines = 0 x FD5POR equipped
>>
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: Tom Green <trgreen at comcast.net>
>> To: s-car-list <s-car-list at audifans.com>
>> Sent: Fri, Mar 21, 2014 4:47 pm
>> Subject: Re: [s-cars] Which spark plugs
>>
>>
>> If you are operating the car with the stock turbo and stock or
>> modified chip sets producing ~ 21psi boost, there have been no
>> reported problems with the Bosch F5DPOR plugs.  These plugs cost more,
>> but there are aftermarket sellers online that have them for ~$10 ea.
>> These plugs also last for at least 30K miles.  These are what I use in
>> my cars RS2 and MTM 1+ and my neighbors 2 UrS6 vehicles, 95.5 and 97
>> tuned with MTM 1+ chip sets.
>>
>> This must be more than just a "rumor".  You must have specific
>> information if you feel compelled to ask.  Anyone who is making
>> recommendations to you should stand by them with specifics and their
>> name.  That's  the way we operate.
>>
>> This spark plug thing is much like the oil or tire question. You will
>> get about as many solid recommendations as there are choices.
>>
>> Tom '95 S6
>>            '95.5 S6 avant
>> Knoxville, TN
>>
>> On Friday Mar 21, 2014, at 9:45 AM,  "Radek" <radek at uniserve.com>wrote:
>>
>>> Hello everyone;
>>>
>>> What is the list's wisdom as to the best spark plugs?  I heard
>>> rumours that Bosch may not be the preferred plug for these cars, any
>>> truth to this?  Car is a 1996.
>>> Thanks.
>>>
>>> Radek.
>>
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>
>
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*John J. Cunningham*
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