Another spark plug question

[850tgul]

Hi All,

I just went dual pulley and picked up a fresh set of NGK BKR8EIX plugs per APR's recommendation but have yet to swap them in. Doing some reading on plugs, there seems to be some debate on what plugs to use depending on usage, fuel blend, climate, pulley ratio, etc. and I doubt my tuner's blanket recommendation cared for all of those variables. I was curious what uprated plugs (if any) and gap folks would recommend for my particular setup:

B8.5 S5
6MT
20k miles
APR stage 2 93 octane tune and I only use 93, no mixing for me
APR upper pulley + 034 179mm crank so, 3.1 pulley ratio
APR CPS

I'm in Massachusetts. The car is driven year round but only on above freezing and dry winter days, so figure typical usage is between 35-90 degrees. I don't beat on it. I'm not going to the dragstrip. I mainly use the power for highway passing and squirting around town.

I'm on stock plugs now and the car drives great, no issues. I have been a little underwhelmed with the power of both APR stage 2 SP and now DP, so was curious if switching from the stock plugs to the NGK BKR8EIX may improve performance a bit or if I shouldn't bother for my use case. Thx

[Izzyz28]

Hi All,

I just went dual pulley and picked up a fresh set of NGK BKR8EIX plugs per APR's recommendation but have yet to swap them in. Doing some reading on plugs, there seems to be some debate on what plugs to use depending on usage, fuel blend, climate, pulley ratio, etc. and I doubt my tuner's blanket recommendation cared for all of those variables. I was curious what uprated plugs (if any) and gap folks would recommend for my particular setup:

B8.5 S5
6MT
20k miles
APR stage 2 93 octane tune and I only use 93, no mixing for me
APR upper pulley + 034 179mm crank so 3.1 pulley ratio
APR CPS

I'm in Massachusetts. The car is driven year round but only on above freezing and dry winter days, so figure typical usage is between 35-90 degrees. I don't beat on it. I'm not going to the dragstrip. I mainly use the power for highway passing and squirting around town.

I'm on stock plugs now and the car drives great, no issues. I have bee a little underwhelmed with the power of both APR stage 2 SP and now DP, so was curious if switching from the stock plugs to the NGK BKR8EIX may improve performance a bit or if I shouldn't bother for my use case. Thx

Per 034, there is no benefit to switching out the stock plugs. My setup is the same as yours, I drive in all climates year-round. I had run the 9's, they worked just fine, but I am now on the original 50K factory plugs gapped to .026" and they too are just fine. You will get exactly 0 power gain from plugs, coils, or any of that stuff unless the car is misfiring with the old stuff. If it is, you will feel it, get a CEL, and likely the EPC light and limp mode every time you stand on it.

[850tgul]

Per 034, there is no benefit to switching out the stock plugs. My setup is the same as yours, I drive in all climates year-round. I had run the 9's, they worked just fine, but I am now on the original 50K factory plugs gapped to .026" and they too are just fine. You will get exactly 0 power gain from plugs, coils, or any of that stuff unless the car is misfiring with the old stuff. If it is, you will feel it, get a CEL, and likely the EPC light and limp mode every time you stand on it.

Thanks. IIRC, the stock gap is .028", so you would recommend pulling and re-gapping the stock plugs to .026", or just leave them alone since it's running fine??

[Izzyz28]

Thanks. IIRC, the stock gap is .028", so you would recommend pulling and re-gapping the stock plugs to .026", or just leave them alone since it's running fine??

I personally wouldn't waste my time. I only gapped mine because they were out when my CATS and intercooler bricks shit the bed.

[RoofRails]

Hi All,

I just went dual pulley and picked up a fresh set of NGK BKR8EIX plugs per APR's recommendation but have yet to swap them in. Doing some reading on plugs, there seems to be some debate on what plugs to use depending on usage, fuel blend, climate, pulley ratio, etc. and I doubt my tuner's blanket recommendation cared for all of those variables. I was curious what uprated plugs (if any) and gap folks would recommend for my particular setup:

B8.5 S5
6MT
20k miles
APR stage 2 93 octane tune and I only use 93, no mixing for me
APR upper pulley + 034 179mm crank so, 3.1 pulley ratio
APR CPS

I'm in Massachusetts. The car is driven year round but only on above freezing and dry winter days, so figure typical usage is between 35-90 degrees. I don't beat on it. I'm not going to the dragstrip. I mainly use the power for highway passing and squirting around town.

I'm on stock plugs now and the car drives great, no issues. I have been a little underwhelmed with the power of both APR stage 2 SP and now DP, so was curious if switching from the stock plugs to the NGK BKR8EIX may improve performance a bit or if I shouldn't bother for my use case. Thx

Yhe only difference between a stock plug and a NGK BKR8EIX is the IX is iridium and the stock plug is platinum. The 8 range Iridium plugs are perfectly fine for your set up I believe the selling point for Iridium is that they last a little longer. These vehicles love fresh plugs so you may as well gap those new plugs down to .026 and install them. If your going through the trouble to pull old plugs and regap you may as well drop the new plugs in. As far as the underwhelming power you are feeling that could be a lot of things from bad gas , High IAT , a poorly calibrated butt dyno or some more serious issue. If you have a VCDS you could log it to see what's going on. If you don't have one it should be the next mod to on your list.

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[audigsr]

I was also in the same dilemma and went with BKR8EIX (not installed yet). As I'm due for a spark plug change as well and noticed more people are having issues with one step colder than not. Climate here in the pnw is about the same as yours.

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