Necessary to upgrade OEM IX Spark Plugs with Alky Injection and higher boost?
Dec 4, 2006 | 10:44 PM
#1
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From: Addison, IL
Necessary to upgrade OEM IX Spark Plugs with Alky Injection and higher boost?
Hey guys...
I know that a lot of the Evolution VIII cars that have alcohol injection or those that run high boost upgrade their spark plugs. Ive been searching and there is no real info on upgrading the OEM Evo 9 spark plugs one step colder.
Is it necessary to upgrade the IX spark plugs when running 26-30 psi (high boost) or 365-400 whp (high horsepower)? Do a lot of you IX guys with high boost / horsepower upgrade your plugs or are the OEM plugs fine? Lastly, are the 8 and 9 cars the same coldness or are the IX's colder and thats why no one seems to upgrade them?
Thanks!
I know that a lot of the Evolution VIII cars that have alcohol injection or those that run high boost upgrade their spark plugs. Ive been searching and there is no real info on upgrading the OEM Evo 9 spark plugs one step colder.
Is it necessary to upgrade the IX spark plugs when running 26-30 psi (high boost) or 365-400 whp (high horsepower)? Do a lot of you IX guys with high boost / horsepower upgrade your plugs or are the OEM plugs fine? Lastly, are the 8 and 9 cars the same coldness or are the IX's colder and thats why no one seems to upgrade them?
Thanks!
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Dec 5, 2006 | 11:20 PM
#11
To start off, the B(P)REIX are NOT recommended for high boost applications as the iridium tips foul up much easier than an equivalent copper tip. Sure, iridium tips is newer technology which allows the plugs to last 30k miles whereas copper tips last only 9k miles, but the gist of it is if you run boost, run copper aka NGK B(P)R#ES!! Although having to change the spark plugs might seem like a bad trade off, the price is also a 1/3 less for the ES so one must factor that in as well.
From my research this what I can gather. The stock plugs, which are Denso IW24 who supply oem batches to HKS I might add, have a heat rating of 7. For applications on the stock turbo, one step colder is recommended NGK are the most used, model B(P)R8ES, p means protruding spark which is what we have stock. Non-p is recommended for nitrous applications although many evo owners run them anyways since they run slightly colder than the protruding one.
Think of it as trying to keep the combustion process within the heat range but also closer to the lowest part of the range (lower combustion temps is always good) so that the process can occur at which is between 450C-800C. Basically when you run alky, like somebody mentioned, you are already lowering the temp in the cylinder. Colder plugs are necessary for this reason alone. When upping the boost temps go back up, but not as high as a single step down in heat range so you're still running colder overall.
If you not running an ignition amplfier, a side effect of running colder plugs is blow-out or the ability for the combustion gases to literally blow out the spark on the spark plug which leads to a mis-fire. This can be remedied by gapping the plugs smaller.
Of course, running an ignition amp allows for a more stable spark which in term allows for plugs to be gapped wider. Although this sounds coutner-intuitive since no matter which application you run, a smaller gap will get the job done, a wider gap will allow a more powerful spark since the electrodes are placed farther apart which in turn needs more energy to jup that gap. One won't see a benefit of a higher gap unless running higher boost and above 5k rpms. Misfires are quite common on the stock turbo with alky without some sort of ignition amp at high rpm ranges.
Note1: Heat range varies between manufacturers so only comparing models within this context. Stock plugs and NGK are close enough though to compare.
Note2: Whether you choose P or non-P is up to you, but I've read that people who have run non-ps have miraculously fixed
Application summary:
stock turbo + stock boost = NGK BPR7ES(IX) @ gap???
stock turbo + higher boost + alky = NGK B(P)R8ES @ smaller gap (ie. 22)
stock turbo + higher boost + alky + ignition amp = NGK B(P)R8ES @ standard gap (ie. 28)
upgraded turbo + higher boost = NGK NGK B(P)R9ES @ lower gap (ie 26)
upgraded turbo + higher boost + alky = @ standard gap (ie 30)
upgraded turbo + higher boost + alky + ignition amp = NGK B(P)R8ES @ higher gap (ie. 32)
By the way, I am no way a guru on the subject (evident of my first post above). If anything, this shows how anybody who properly searches the forum can gain the same wealth of knowledge I did in about 30min. I just choose to summarize it all here for future reference.
From my research this what I can gather. The stock plugs, which are Denso IW24 who supply oem batches to HKS I might add, have a heat rating of 7. For applications on the stock turbo, one step colder is recommended NGK are the most used, model B(P)R8ES, p means protruding spark which is what we have stock. Non-p is recommended for nitrous applications although many evo owners run them anyways since they run slightly colder than the protruding one.
Think of it as trying to keep the combustion process within the heat range but also closer to the lowest part of the range (lower combustion temps is always good) so that the process can occur at which is between 450C-800C. Basically when you run alky, like somebody mentioned, you are already lowering the temp in the cylinder. Colder plugs are necessary for this reason alone. When upping the boost temps go back up, but not as high as a single step down in heat range so you're still running colder overall.
If you not running an ignition amplfier, a side effect of running colder plugs is blow-out or the ability for the combustion gases to literally blow out the spark on the spark plug which leads to a mis-fire. This can be remedied by gapping the plugs smaller.
Of course, running an ignition amp allows for a more stable spark which in term allows for plugs to be gapped wider. Although this sounds coutner-intuitive since no matter which application you run, a smaller gap will get the job done, a wider gap will allow a more powerful spark since the electrodes are placed farther apart which in turn needs more energy to jup that gap. One won't see a benefit of a higher gap unless running higher boost and above 5k rpms. Misfires are quite common on the stock turbo with alky without some sort of ignition amp at high rpm ranges.
Note1: Heat range varies between manufacturers so only comparing models within this context. Stock plugs and NGK are close enough though to compare.
Note2: Whether you choose P or non-P is up to you, but I've read that people who have run non-ps have miraculously fixed
Application summary:
stock turbo + stock boost = NGK BPR7ES(IX) @ gap???
stock turbo + higher boost + alky = NGK B(P)R8ES @ smaller gap (ie. 22)
stock turbo + higher boost + alky + ignition amp = NGK B(P)R8ES @ standard gap (ie. 28)
upgraded turbo + higher boost = NGK NGK B(P)R9ES @ lower gap (ie 26)
upgraded turbo + higher boost + alky = @ standard gap (ie 30)
upgraded turbo + higher boost + alky + ignition amp = NGK B(P)R8ES @ higher gap (ie. 32)
By the way, I am no way a guru on the subject (evident of my first post above). If anything, this shows how anybody who properly searches the forum can gain the same wealth of knowledge I did in about 30min. I just choose to summarize it all here for future reference.
Last edited by silex; Dec 5, 2006 at 11:32 PM.
Dec 7, 2006 | 12:56 PM
#13
Totally forgot to address the original question! I have no proof that the IX spark plugs are any different from the VIII. It would be simple to verify as one of us with a IX can just remove our plug and check it as well as somebody with an VIII. Spark plugs are so cheap anyways, $13 for 4, that I don't why you wouldn't buy a couple sets and keep some as backup or to mess around with different setups.
In any case I'm positive the IX runs iridium tip plugs just like the VIII so my above report applies to the IX as well. Higher boost will lead to fouling of the oem plugs (read my first sentence).
In any case I'm positive the IX runs iridium tip plugs just like the VIII so my above report applies to the IX as well. Higher boost will lead to fouling of the oem plugs (read my first sentence).
