Spark plug heat rating -> amount of advance?
#1
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Spark plug heat rating -> amount of advance?
Is this directly linked?
I believe this is true but i just wanted this confirming....
a grade 6 plug, will not allow as much timing advance as a grade 7 and similarly a 7 to an 8?
im trying to understand why my engine doesnt seem to like much timing being thrown at it, and i think that this may be one issue that needs addressing. I believed that i had 7s put in after my build but until now it didnt occur to me to check. So when i do, i am half expecting to find a set of 6s in there....
I believe this is true but i just wanted this confirming....
a grade 6 plug, will not allow as much timing advance as a grade 7 and similarly a 7 to an 8?
im trying to understand why my engine doesnt seem to like much timing being thrown at it, and i think that this may be one issue that needs addressing. I believed that i had 7s put in after my build but until now it didnt occur to me to check. So when i do, i am half expecting to find a set of 6s in there....
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i realise that, but colder rated plugs are recommended in higher power applications, so if mine are 6s then they are technically holding the car back at the moment.
#4
A PFR7B will run a little cooler than a PFR6B so should be less likely to contribute to detonation.
There may be other reasons why your car isn't happy with the timing you expect though.
There may be other reasons why your car isn't happy with the timing you expect though.
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Neil with regards to the mods you have done I'd strongly recommend a heat grade 7 plug as the standard 6's will be holding the car back in the sense that it'll run alot smoother and throttle response will increase with the 7's.
As the number increases the thermoconductivity ratio of the spark plug decreases, meaning that a hotter engine will require a higher number rating of plug to cope with that added and increased heat.
I knew sum1 that had a Supra which had 9 rated plugs... think he was pushing out 800bhp!
Cars such as Mondeos... Vectras... Passats will have 5 or 6 rated plugs as standard.
7 rated will be good on a Scooby upto about 380-400bhp But get rid of those 6's mate!
As the number increases the thermoconductivity ratio of the spark plug decreases, meaning that a hotter engine will require a higher number rating of plug to cope with that added and increased heat.
I knew sum1 that had a Supra which had 9 rated plugs... think he was pushing out 800bhp!
Cars such as Mondeos... Vectras... Passats will have 5 or 6 rated plugs as standard.
7 rated will be good on a Scooby upto about 380-400bhp But get rid of those 6's mate!
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if they are 6s...
i did have 7s before, but i havent checked these since the build. they are due for a change, but ideally id like 8s but no idea where to get them
i did have 7s before, but i havent checked these since the build. they are due for a change, but ideally id like 8s but no idea where to get them
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Thanks all, they are due for a change so ill try a set of 8s as its no longer a day to day car anyway and it should give me a little more flexibility with my overall plans
#11
Ecu Specialist
Neil depending on which '8's you will probably suffer from fouling, they don't clear well either, I'm using some Denso racing Iridiums for general and performance use and they are the only plug that I have managed to take past 5k miles, first set I changed at 15k, this set has been in since Feb. Trouble is they are expensive. Stick with '7's. IK01-24 is the part number of the Denso's. Fouled up plugs will cost you 50-60 bhp.
bob
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Thanks Bob, i think that i will change mine at my earliest opportunity. I suppose the worst case is having 6s that are fouled!!
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Originally Posted by alex_00s
Can you really argue or question this man??
I'm just adding my tuppence worth
#15
Neilo
Must check my plugs but RCMS fitted 8's recently again to my Bugeye AFAIK which Bob has mapped and I have been running them for the past 18mts, I thought I had probs with idle but it was the idle solenoid !!
When I looked at them at RCMS it seemed a shame to throw them away as they looked pretty good to me
Shaun
Must check my plugs but RCMS fitted 8's recently again to my Bugeye AFAIK which Bob has mapped and I have been running them for the past 18mts, I thought I had probs with idle but it was the idle solenoid !!
When I looked at them at RCMS it seemed a shame to throw them away as they looked pretty good to me
Shaun
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So what mileage (ideally) should you change 7's..? (suppose it depends on car and driving style as Andy has said).
Probably worth checking them periodically, even if it is a bit of a PITA..? (although I don't mind doing them TBH..)
Probably worth checking them periodically, even if it is a bit of a PITA..? (although I don't mind doing them TBH..)
#19
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Typically about 15k depending on what you are using the car for. 7's are fine for Neil I expect, its just that they never lasted long in my car "going off" very noticably. But for the use he is intending then I know the Denso's will work nicely.
bob
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