Cooler Plugs
- Thread starter 944Turbo
- Start date
I can't explain what the difference is, but plugs all have a number - I remember BP9ES for some reason. The 9 refers to the heat. I think a BP8ES was 1 grade cooler, but I don't remember what engine it was for. 1700 x-flow perhaps? Anyhow, the principal is the same, but I'm ashamed to say I have never bought 944 plugs - I've always paid someone else to fit them for me - so I don't know the specific numbers.
Kevin Welch
New member
Hi Tony
I believe the difference with the plugs is the diameter of the central core. This dissipates the heat to keep the plug within its ideal working range. For you boostie boys this means higher boost equals higher internal temperatures thus the need for a colder grade of plug ( which runs cooler ) to remain at its optimum.
Us normally aspirated chaps keep our cool anyway.
I believe the difference with the plugs is the diameter of the central core. This dissipates the heat to keep the plug within its ideal working range. For you boostie boys this means higher boost equals higher internal temperatures thus the need for a colder grade of plug ( which runs cooler ) to remain at its optimum.
Us normally aspirated chaps keep our cool anyway.
Guest
New member
Tony yes i wondered about that, not sure why you would want to fit them. The cooler plugs run cooler at the electrod tip, if you fit cooler plugs its like very slightly retarding the ignition so as to prevent early detonation, i assume its becase when you are using standard injectors at hight boost then you are getting into the lean territory. So to try and counter that as best possible then use slightly cooler plugs. Thats the theory anyway.. I might get a set fitted next week, its on the list!!!
Can you remember what ones Danno reccomended?
Can you remember what ones Danno reccomended?
So its simply the heat transfer capacity nothing to do with the 'heat 'of the spark (would a yellow spark be cooler than say a blue one? and dont ask me how you would change that [] ), ,
Thanks
Slim,
Danno recommended -
"Use one-range colder spark-plugs: NGK-BPR7ES, ND-W22EPR-U, Bosch-WR6DC"
I assume ND (2nd option) is Nippon Denso
Tony
] ), , Thanks
Slim,
Danno recommended -
"Use one-range colder spark-plugs: NGK-BPR7ES, ND-W22EPR-U, Bosch-WR6DC"
I assume ND (2nd option) is Nippon Denso
Tony
That'd be right - makes no sense, but the way it works.
BTW I think the point is that higher boost increases the temperature in the combustion chamber which obviously makes it hotter for the plug tip. Cooler plugs cope with that better, so you probably should run a grade cooler if Danno says it's recommended - if your plug gets too hot it may not spark efficiently or it may even cause detonation by being a hot spot in the chamber. The general rule I always thought was that you cool the plug if you do anything significant to up performance like increase CR or fit a hot cam - I'm sure that goes for increasing the boost as well.
BTW I think the point is that higher boost increases the temperature in the combustion chamber which obviously makes it hotter for the plug tip. Cooler plugs cope with that better, so you probably should run a grade cooler if Danno says it's recommended - if your plug gets too hot it may not spark efficiently or it may even cause detonation by being a hot spot in the chamber. The general rule I always thought was that you cool the plug if you do anything significant to up performance like increase CR or fit a hot cam - I'm sure that goes for increasing the boost as well.
Diver944
Active member
Hmmmm, I'd better re-read my Guru instructions as I can't remember any mention of plugs. Maybe I also better be prepared to eat a large portion of humble pie with regard to my other post about the BERU Silverstone plugs[&:]
Maybe these are a cooler plug?. I'd better call Andrew (Promax) when he returns from the States
Maybe these are a cooler plug?. I'd better call Andrew (Promax) when he returns from the States
Guest
New member
I believe that when you boostie boys fiddle about for even more power you do end up with a hotter combustion chamber due to the mixture becoming week under boost. So a cooler plug will only mean that you're correcting the possibility of an overheating spark plug. Can you not adjust you're fueling to compensate for the boost preasure? I'm not an expert or owt.
There's lots more thought goes into the fuelling than the boost these days.
There is also additional heat created by the hotter charge (due to being compressed more - upgrading the intercooler is the only way to help here) and that sueezing more air in and then adding the fuel to suit results in burning more mixture which releases more energy, hence more power but also more heat, to be considered.
There is also additional heat created by the hotter charge (due to being compressed more - upgrading the intercooler is the only way to help here) and that sueezing more air in and then adding the fuel to suit results in burning more mixture which releases more energy, hence more power but also more heat, to be considered.
Guest
New member
As has been stated before it not a question of a hot plug, its how efficient the plug is at transfereing heat to the coolent. Spark plugs have 2 rolls, obviously providing a spark, but also to remove heat from the combustion chamber and pass it on to the coolent. A cooler plug is more eficent at this, the problem comes if you get too cool a plug then the combustion chanber gets too cool and you will get fouled plugs oil will not be burned off completely. Too hot and you get pre-ignition.
I have just bought some cooler plugs will fit them on Sunday. NGK BPR7E v-grooves. I would rather err on the cool side, long term its much better for your engine.
I have just bought some cooler plugs will fit them on Sunday. NGK BPR7E v-grooves. I would rather err on the cool side, long term its much better for your engine.
Guest
New member
Well plugs are in and wooowwweeeee must be an extra 40-50bhp...No just kidding..[]
The plugs i took out were only in about 2500miles so they are hardly used, just starting to go that light brown colour, so looks like the fueling is ok.
The ones i fitted arnt the very best ones, but i am pretty sure that the car is ideling better, much more consistant less hunting.
Time will tell about the difference they make, i am going to order some Iridium NGKs from the US.. $30 and they are £35 over here!! Will leave the ones i have in for about 3000miles till next service then change them and have a look see if there is much difference.
Ordered 6mm cotton braided fuel hose to connect the wastegate to the Accuboost so will get tha done next week with the exhaust. Then its time to try and calibrate the Accuboost. I am sure i migh be getting some boost spikes with it connected though the CV.
]The plugs i took out were only in about 2500miles so they are hardly used, just starting to go that light brown colour, so looks like the fueling is ok.
The ones i fitted arnt the very best ones, but i am pretty sure that the car is ideling better, much more consistant less hunting.
Time will tell about the difference they make, i am going to order some Iridium NGKs from the US.. $30 and they are £35 over here!! Will leave the ones i have in for about 3000miles till next service then change them and have a look see if there is much difference.
Ordered 6mm cotton braided fuel hose to connect the wastegate to the Accuboost so will get tha done next week with the exhaust. Then its time to try and calibrate the Accuboost. I am sure i migh be getting some boost spikes with it connected though the CV.
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