Questions about colder plugs and detonation
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From: Sharon, PA
Questions about colder plugs and detonation
OK, I understand how detonation is the enemy and can do serious harm to your engine, which is why the knock sensor will retard timing to guard against detonation.
So, lots of modders will put colder plugs in their cars to guard against knocking and the retarded timing.
My question is how do you know how many steps colder to go?
I see several folks with SRT-6s have gone two steps colder. Why two? Why not one? Why not three?
The reason I ask is because over in Mini Cooper land, they all seem to recommend one step colder, whereas here in Crossfire land they recommend two. That makes me wonder why.
So, lots of modders will put colder plugs in their cars to guard against knocking and the retarded timing.
My question is how do you know how many steps colder to go?
I see several folks with SRT-6s have gone two steps colder. Why two? Why not one? Why not three?
The reason I ask is because over in Mini Cooper land, they all seem to recommend one step colder, whereas here in Crossfire land they recommend two. That makes me wonder why.
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From: Murfreesboro, TN
Re: Questions about colder plugs and detonation
Originally Posted by tom2112
and the retarded timing.
Do you think it might have something to do with compression ratio? What's the CR of the Mini?
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From: Houston in my blood, and under my tires...
Re: Questions about colder plugs and detonation
Originally Posted by JHM2K
The timing has feelings too man, you shouldn't call it names.
On a more pertinent topic, I went one step colder in my plugs and have thought about going another step colder when I change them again (read: soon). I know there is definitely a limit, just because one keeps going colder does not make it better and better.
There are several MBs I have seen that actually suffer from using colder plugs, though they are, from what I've seen, the 63 AMGs.
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She can ride with me ;)
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From: Sharon, PA
Re: Questions about colder plugs and detonation
Originally Posted by JHM2K
The timing has feelings too man, you shouldn't call it names.
Do you think it might have something to do with compression ratio? What's the CR of the Mini?
Do you think it might have something to do with compression ratio? What's the CR of the Mini?
The compression ratio is 10.6 to 1 for the Mini Cooper S.
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From: Akron, Ohio
Re: Questions about colder plugs and detonation
Originally Posted by tom2112
LOL, too funny.
The compression ratio is 10.6 to 1 for the Mini Cooper S.
The compression ratio is 10.6 to 1 for the Mini Cooper S.
By the way, when I get my new tires on my Crossfire, you're welcome to test it out. That is, if you're not "manually challenged" when driving a Crossfire.
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From: Houston in my blood, and under my tires...
Re: Questions about colder plugs and detonation
Tom,
Who's picture is that in your avatar now? I need to make friends with this person. Haha.
I like the Mini Coopers, they are cute girly cars.
Haha, kidding. They are great cars, like street legal go-karts. Very responsive handling and a little bit of go.
Who's picture is that in your avatar now? I need to make friends with this person. Haha.
I like the Mini Coopers, they are cute girly cars.
Haha, kidding. They are great cars, like street legal go-karts. Very responsive handling and a little bit of go.
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She can ride with me ;)
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From: Sharon, PA
Re: Questions about colder plugs and detonation
I dunno who she is, but her pic was in the gallery, so I swiped it.
For whoever put her pic in the gallery: tell her she is invited to do that near my car anytime she wants.
For whoever put her pic in the gallery: tell her she is invited to do that near my car anytime she wants.
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From: IA
Re: Questions about colder plugs and detonation
Originally Posted by tom2112
OK, I understand how detonation is the enemy and can do serious harm to your engine, which is why the knock sensor will retard timing to guard against detonation.
So, lots of modders will put colder plugs in their cars to guard against knocking and the retarded timing.
My question is how do you know how many steps colder to go?
I see several folks with SRT-6s have gone two steps colder. Why two? Why not one? Why not three?
The reason I ask is because over in Mini Cooper land, they all seem to recommend one step colder, whereas here in Crossfire land they recommend two. That makes me wonder why.
So, lots of modders will put colder plugs in their cars to guard against knocking and the retarded timing.
My question is how do you know how many steps colder to go?
I see several folks with SRT-6s have gone two steps colder. Why two? Why not one? Why not three?
The reason I ask is because over in Mini Cooper land, they all seem to recommend one step colder, whereas here in Crossfire land they recommend two. That makes me wonder why.
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She can ride with me ;)
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From: Sharon, PA
Re: Questions about colder plugs and detonation
Sheesh! 3 to 6 thousand miles?!? That's insane. I don't even change my oil that often.
I've had a mechanic of 30 years tell me that in many cars, you should not change the plugs just to change them. If nothing's wrong, don't mess with them, as you're just as likely to install them improperly (incorrect gap, I guess) as you are to help it in anyway. Now, he was referring to non-performance environment, but still that's a big difference between Tony and that mechanic.
I've had a mechanic of 30 years tell me that in many cars, you should not change the plugs just to change them. If nothing's wrong, don't mess with them, as you're just as likely to install them improperly (incorrect gap, I guess) as you are to help it in anyway. Now, he was referring to non-performance environment, but still that's a big difference between Tony and that mechanic.
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From: Houston in my blood, and under my tires...
Re: Questions about colder plugs and detonation
Originally Posted by billvp
Another question is how often to replace the plugs? I saw on the MBWorld blown engine thread that Tony@Eurocharged said every 3k-6k miles, which everyone else thought ridiculous.
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From: Plainfield,Illinois
Re: Questions about colder plugs and detonation
In my Drag boat every week changed plugs and gave them to the fishing boat guys.
Put 22,000 on my car and been through 5 sets and right now eurocharged is installing a fresh set as I type.
Put 22,000 on my car and been through 5 sets and right now eurocharged is installing a fresh set as I type.
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From: Sharon, PA
Re: Questions about colder plugs and detonation
So....
Back on topic:
Does anyone know what the limiting factor to colder plugs is?
How cold is too cold? Where do the trade offs begin and what are they?
Back on topic:
Does anyone know what the limiting factor to colder plugs is?
How cold is too cold? Where do the trade offs begin and what are they?
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She can ride with me ;)
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From: Sharon, PA
Re: Questions about colder plugs and detonation
Well, Wikipedia has this to say:
Originally Posted by Wikipedia
If the tip of the spark plug is too hot it can cause pre-ignition leading to detonation/knocking and damage may occur. If it is too cold, electrically conductive deposits may form on the insulator causing a loss of spark energy or the actual shorting-out of the spark current.
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From: Sharon, PA
Re: Questions about colder plugs and detonation
OK, I think I found an answer that will be useful to everyone here. According to NKG's website:
http://www.ngk.com/charglossary.asp?kw=Heat+range
http://www.ngk.com/charglossary.asp?kw=Heat+range
Originally Posted by NKG
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.
Do not make spark plug changes at the same time as another engine modification such as injection, carburation or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single precalibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage
Do not make spark plug changes at the same time as another engine modification such as injection, carburation or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single precalibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage
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From: Plainfield,Illinois
Re: Questions about colder plugs and detonation
Shesh anymore of these threads left...4th website I have had to clean up...
Last edited by RIOT; Mar 29, 2010 at 12:29 PM.
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From: Chicago, IL
Re: Questions about colder plugs and detonation
Originally Posted by RIOT
AAAAAAAAAAAAAAAAHHHHHHHHHHHHHH
beat on ya car....if it don't implode let me know what range plug you were using.............................................
FFFFFFFFFFFFOOOOOOOOOOOORRRRRRRRRRRR
WWWWWWWWWWWWWHHHHHHHHHHHOOOOOOOOOOOMMMMMMMMMMMM
THE BELL TOLLS.................
beat on ya car....if it don't implode let me know what range plug you were using.............................................
FFFFFFFFFFFFOOOOOOOOOOOORRRRRRRRRRRR
WWWWWWWWWWWWWHHHHHHHHHHHOOOOOOOOOOOMMMMMMMMMMMM
THE BELL TOLLS.................
I do second letting us know how it works out. I have a set of Iridium's but I should maybe go 2-steps colder to be sure everything will be alright.
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She can ride with me ;)
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From: Sharon, PA
Re: Questions about colder plugs and detonation
Originally Posted by RIOT
AAAAAAAAAAAAAAAAHHHHHHHHHHHHHH
beat on ya car....if it don't implode let me know what range plug you were using.............................................
FFFFFFFFFFFFOOOOOOOOOOOORRRRRRRRRRRR
WWWWWWWWWWWWWHHHHHHHHHHHOOOOOOOOOOOMMMMMMMMMMMM
THE BELL TOLLS.................
beat on ya car....if it don't implode let me know what range plug you were using.............................................
FFFFFFFFFFFFOOOOOOOOOOOORRRRRRRRRRRR
WWWWWWWWWWWWWHHHHHHHHHHHOOOOOOOOOOOMMMMMMMMMMMM
THE BELL TOLLS.................
Doing a little drinking Riot? LOL
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From: Plainfield,Illinois
Re: Questions about colder plugs and detonation
I already run a set colder....sort of cheap insurance...but should I run two sizes colder?
Did have #6 misfire around 128 while beating on a 750i two weeks ago.
Car went into limp mode....pulled off the highway,stopped at the light counted to 10 and prayed and started the car back up and been fine ever since.
Damn I was scared!!
Thinking about trading it in on a clk63 vert amg.
And staying stock! Getting tired of breaking stuff to go fast with the top down!
Did have #6 misfire around 128 while beating on a 750i two weeks ago.
Car went into limp mode....pulled off the highway,stopped at the light counted to 10 and prayed and started the car back up and been fine ever since.
Damn I was scared!!
Thinking about trading it in on a clk63 vert amg.
And staying stock! Getting tired of breaking stuff to go fast with the top down!
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From: Houston in my blood, and under my tires...
Re: Questions about colder plugs and detonation
Originally Posted by RIOT
Thinking about trading it in on a clk63 vert amg.
And staying stock! Getting tired of breaking stuff to go fast with the top down!
And staying stock! Getting tired of breaking stuff to go fast with the top down!
.