So I was reading on the VT forums and someone posted about NGK plugs with our cars and also using their race plugs since the are recessed. He talked to a rep there and this is what he found out
Copied from Velosterturbo.org
"I spoke with a technical rep at NGK last Friday about using these plugs on our car. The reason for the call was to confirm I had the proper gap and to find out what could be causing the carbon fouling I had after only a month of use. He literally LOL'd when I told him I was using them for my daily driver. He went into great detail explaining why their website does not offer a plug for our car and also why their racing plugs should NEVER be used on a daily driver. The absence of the projected ceramic tip completely prevents the plug from being able to self clean and combined with low speed driving, the expected life you should see out of this plug is around 100-300 miles, depending on how much stop and go driving you do. I can't tell you how much he was stressing THIS PLUG IS NOT INTENDED FOR DAILY DRIVING USE! Its for racing ONLY! Quarter mile and circuit races where the engine will be used very aggressively is where it shines. Any slow/low speed engine use on these plugs causes them to foul out, fast, after which they recommend throwing them away. The fouling has caused lots of spark related problems for people trying to use them as daily driver plugs. I can't remember exactly what they all were, but they were NOT GOOD. These plugs cannot be sandblasted and reused safely, and he stressed the point that I was not being told that because he was not trying to sell me some other plug to replace it with because NGK does not recommend the use of their plugs on our car. He repeated that one a couple times as well because I told him our cars come with NGK plugs, but he would not recommend even reinstalling the stock plugs. He just kept saying they DO NOT offer a plug that is appropriate for our car, they do for the N/A, but not the Turbo. He also mentioned that the race plugs do not have the reach into the chamber the the OEM plugs have, so even in the case that I wanted to use a set of racing plugs on our car, these are not the right length and they do not offer a race plug with that reach. I will be either going with the Autolite XP570(1, 2 or 3...still trying to find an Autolite spec with the actual heat range for these, I want 8) or the HKS M40XL plugs after that conversation."
So after reading this I got a bit worried since the guy said we shouldn't be using any NGK plugs in our car. Well I have been running the NGK 1422's for a while now. So this got me thinking about them because on cold start I always have misfires and can hear it popping out the exhaust. It has done this since new with the stock NGK plugs also. Well I searched around and found out the Autolite XP5701 is their cold plug that is comparable to the NGK 1422. For those on stock setup with no tune you can use either the XP5702 or XP5703.
Since I put these in my car I have no misfires on cold start and my car runs so much better. Mine are gapped to .028 and is running great. Today was my first day on the fwy with them and the car gets up to speed a lot better and is super smooth when crusing and if I have to get into the throttle it just pulls harder now. I would recommend these for the price. They were $27 at the local auto parts store
Edit:
Here is a description of what plugs work with what...
XP5703 Stock replacement
XP5702 Mildly modified to full bolt ons (i.e intake, dp, exhaust, fmic, 60mm tb, ect)
XP5701 Tuned to highly modified
Heat Range Explanation
Typically the heat range for NGK Spark Plugs varies from 2-11. This number indicates the thermal characteristics of a spark plug, or how ‘hot’ or ‘cold’ a spark plug is. The term hot/cold is commonly used to describe whether a spark plug heats up easily (hot) or whether it provides resistance to heating up (cold).
Generally, low power engines such as lawn mowers don’t produce a large amount of heat, hence use a low heat range (or hot) spark plug such as a 4 heat range. This means the spark plug will heat up easily and reach its optimal operating temperature. High performance engines on the other hand produce a large amount of heat, hence a high heat range (or cold) spark plug such as a 10 heat range needs to be used to resist the heat developed by the engine.
Several factors influence the heat range of a spark plug, although typically the insulator nose design provides an indication of the heat range of a spark plug.
When a spark plug absorbs heat produced from combustion, the heat is transferred through the center electrode and insulator nose to the metal shell, which then transfers the heat into the engine casing and circulating coolant.
View attachment 1317
A low heat range (or hot) spark plug typically has a long thin insulator nose which will heat up easily however will not dissipate readily to the metal shell (above left). Conversely, a high heat range (or cold) spark plug has a short thick insulator nose which will dissipate heat much easier (above right).
When the heat rating is too high:
The spark plug temperature remains too low and causes deposits to build up on the firing end; the deposits offer an electrical leakage path that gives rise to loss of sparks.
When the heat rating is too low:
The spark plug temperature rises too high and induces abnormal combustion (pre-ignition): this leads to melting of the spark plug electrodes as well as piston seizure and erosion.
NGK Spark Plugs pioneered the use of a copper cored electrode in 1958, which enables a spark plug to heat up quickly and also dissipate heat quickly giving an ultra wide heat range. It is essential to use a spark plug that fits a specific engine and its conditions of use.
As spark plugs are positioned in the head of an engine, their analysis can give a good indication of how your engine is operating.
Directly from the Technical Information page at NGK
Copied from Velosterturbo.org
"I spoke with a technical rep at NGK last Friday about using these plugs on our car. The reason for the call was to confirm I had the proper gap and to find out what could be causing the carbon fouling I had after only a month of use. He literally LOL'd when I told him I was using them for my daily driver. He went into great detail explaining why their website does not offer a plug for our car and also why their racing plugs should NEVER be used on a daily driver. The absence of the projected ceramic tip completely prevents the plug from being able to self clean and combined with low speed driving, the expected life you should see out of this plug is around 100-300 miles, depending on how much stop and go driving you do. I can't tell you how much he was stressing THIS PLUG IS NOT INTENDED FOR DAILY DRIVING USE! Its for racing ONLY! Quarter mile and circuit races where the engine will be used very aggressively is where it shines. Any slow/low speed engine use on these plugs causes them to foul out, fast, after which they recommend throwing them away. The fouling has caused lots of spark related problems for people trying to use them as daily driver plugs. I can't remember exactly what they all were, but they were NOT GOOD. These plugs cannot be sandblasted and reused safely, and he stressed the point that I was not being told that because he was not trying to sell me some other plug to replace it with because NGK does not recommend the use of their plugs on our car. He repeated that one a couple times as well because I told him our cars come with NGK plugs, but he would not recommend even reinstalling the stock plugs. He just kept saying they DO NOT offer a plug that is appropriate for our car, they do for the N/A, but not the Turbo. He also mentioned that the race plugs do not have the reach into the chamber the the OEM plugs have, so even in the case that I wanted to use a set of racing plugs on our car, these are not the right length and they do not offer a race plug with that reach. I will be either going with the Autolite XP570(1, 2 or 3...still trying to find an Autolite spec with the actual heat range for these, I want 8) or the HKS M40XL plugs after that conversation."
So after reading this I got a bit worried since the guy said we shouldn't be using any NGK plugs in our car. Well I have been running the NGK 1422's for a while now. So this got me thinking about them because on cold start I always have misfires and can hear it popping out the exhaust. It has done this since new with the stock NGK plugs also. Well I searched around and found out the Autolite XP5701 is their cold plug that is comparable to the NGK 1422. For those on stock setup with no tune you can use either the XP5702 or XP5703.
Since I put these in my car I have no misfires on cold start and my car runs so much better. Mine are gapped to .028 and is running great. Today was my first day on the fwy with them and the car gets up to speed a lot better and is super smooth when crusing and if I have to get into the throttle it just pulls harder now. I would recommend these for the price. They were $27 at the local auto parts store
Edit:
Here is a description of what plugs work with what...
XP5703 Stock replacement
XP5702 Mildly modified to full bolt ons (i.e intake, dp, exhaust, fmic, 60mm tb, ect)
XP5701 Tuned to highly modified
Heat Range Explanation
Typically the heat range for NGK Spark Plugs varies from 2-11. This number indicates the thermal characteristics of a spark plug, or how ‘hot’ or ‘cold’ a spark plug is. The term hot/cold is commonly used to describe whether a spark plug heats up easily (hot) or whether it provides resistance to heating up (cold).
Generally, low power engines such as lawn mowers don’t produce a large amount of heat, hence use a low heat range (or hot) spark plug such as a 4 heat range. This means the spark plug will heat up easily and reach its optimal operating temperature. High performance engines on the other hand produce a large amount of heat, hence a high heat range (or cold) spark plug such as a 10 heat range needs to be used to resist the heat developed by the engine.
Several factors influence the heat range of a spark plug, although typically the insulator nose design provides an indication of the heat range of a spark plug.
When a spark plug absorbs heat produced from combustion, the heat is transferred through the center electrode and insulator nose to the metal shell, which then transfers the heat into the engine casing and circulating coolant.
View attachment 1317
A low heat range (or hot) spark plug typically has a long thin insulator nose which will heat up easily however will not dissipate readily to the metal shell (above left). Conversely, a high heat range (or cold) spark plug has a short thick insulator nose which will dissipate heat much easier (above right).
When the heat rating is too high:
The spark plug temperature remains too low and causes deposits to build up on the firing end; the deposits offer an electrical leakage path that gives rise to loss of sparks.
When the heat rating is too low:
The spark plug temperature rises too high and induces abnormal combustion (pre-ignition): this leads to melting of the spark plug electrodes as well as piston seizure and erosion.
NGK Spark Plugs pioneered the use of a copper cored electrode in 1958, which enables a spark plug to heat up quickly and also dissipate heat quickly giving an ultra wide heat range. It is essential to use a spark plug that fits a specific engine and its conditions of use.
As spark plugs are positioned in the head of an engine, their analysis can give a good indication of how your engine is operating.
Directly from the Technical Information page at NGK