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Reading a few posts I notice that some people are running the cooler BCR8ES plugs on high states of tune.
I was about to place an order for the usual BCPR7ES-11 but was thinking of trying the 8's as I'm hopefully moving to Maptun stg 4 soon.
From what I read the 8's will run better/cooler than the 7's under heavy use but are there any disadvantages to them when I'm cruising around on very low boost (which tbh is 80-90% of my driving)
 

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mmmm tasty reduced price too.

Me thinks a birthday present coming up. cheaper than Konis, Aero interior or ARB and ARB bushes.

Not quite the smae benefits though.
 

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These pugs are advertised for highly tuned cars - what does that mean? Is stage 1 highly tuned?
Obviously stage 3-4 is.
When one considers that a BSR stage 1 for example on a 2.0 lpt increases BHP by over 40%, one may consider this to be highly tuned. Considering most of the noticible
factor is in driving 4k-6 rpm (its the reason I got stage 1, before very mundane) would these plugs be beneficial. What are the pro's and con's?
To play devi's advocate, so what if I run on standard plugs and give the old girl a bit of welly!??

Cheers
 

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The colder plugs help to keep combustion temps down by being able to conduct more heat away from the combustion chamber. This really only becomes necessary running stage 4+ IMO.
 

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Bubbles,
I was sure I put 6ES in my car when I 'serviced' the DI. I replaced the ones put in by a Saab dealer. Checked last night and they are 6ES. The Saab book also states that 6ES should be used in 20t 23t and 20t with saab 192hp. Mine is a M00 model.
What do you think? I read somewhere that the older models 97,98 used the 7ES.
 

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I would imagine that putting the 7 plugs in a car that normaly runs on the 6 plugs would not be harmfull or undesirable for the engine..... It would actualy just help keep the engine run a little cooler?? And then the 8 plugs would be even more than the 6 & 7....

Is this fair to assume or totaly wrong?
 

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How cold is cold??? You let the engine warm up, everything under the hood should be warm.... Are you talking about temperature difference between the combustion chamber and the plugs??? (or something like that)
 

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Originally posted by drioux15:
[qb]How cold is cold??? You let the engine warm up, everything under the hood should be warm.... Are you talking about temperature difference between the combustion chamber and the plugs??? (or something like that) [/qb][/b]
Basically the plugs are graded into heat bands so that the electrode temps are kept within a standard temp range for all the plugs in the range

i.e say the plug electrodes work best at 650c (not cold enough to cause fouling, not hot enough to glase or melt.

if you had an old low compression engine which ran with cumbustion cylinder temps of say 500c, you whould want a hot plug lots of ceramic covering the electrodes to insulate and retain the heat.

If you have a fire breathing high compression turbo monster, with 800c temps, you would want a much colder plug with less ceramic and more exposed plug metal work to draw the head out and into the head.

Andrew
 

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Originally posted by drioux15:
[qb]How cold is cold??? You let the engine warm up, everything under the hood should be warm.... Are you talking about temperature difference between the combustion chamber and the plugs??? (or something like that) [/qb][/b]
Basically the plugs are graded into heat bands so that the electrode temps are kept within a standard temp range for all the plugs in the range

i.e say the plug electrodes work best at 650c (not cold enough to cause fouling, not hot enough to glase or melt.

if you had an old low compression engine which ran with cumbustion cylinder temps of say 500c, you whould want a hot plug lots of ceramic covering the electrodes to insulate and retain the heat.

If you have a fire breathing high compression turbo monster, with 800c temps, you would want a much colder plug with less ceramic and more exposed plug metal work to draw the head out and into the head.

Andrew
 

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The colder plugs help to keep combustion temps down by being able to conduct more heat away from the combustion chamber.  [/b]
Hot plugs running in a tuned engine where conbustion temps are higher than standard will be prone to tip melting as the plug cannot dissapate its heat fast enough and can also be the cause of pre ignition as the tip becomes red hot and ignites the fuel before the spark occurs.
Colder plugs can get rid of the higher temperatures the plugs experience in tuned engines and thus don't cause pre ignition, however, if the engine doesn't get the plugs up to operating temperatures they are prone to fouling...although this is rare on modern 4 strokes nowadays, common on older engines and 2 stokes.
Combustion temps stay the same, the hot/cold title is purely the operating temp of the plugs, as posted by Andrew
 

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Fouling is caused by deposits which adhere to the plug tip and aren't burnt off if the plug doesn't get up to its optimum operating temperature, it then forms a layer which means the ability of the spark to jump the gap is diminished due to a higher electrical resistance. This then causes more fouling and gets to the point where the spark arcs around the circular end of the plug rather than the tip and is so weak no fuel ignition can occur.
 

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So, going back to my earlier posts, what do people think about running on 6ES ( as manufacturers handbook) bearing in mind the power increase of a stage 1? 7ES better, or am I just worring about nothing?
 
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