[itsrichierich]

Sorry to bring up an old thread.

But I am going to be getting FBO with BM3 license, plan is to get custom tune by Jordan.

With that being said, I have read that I need to get 1 step colder plugs. If I read correctly, I need:

NGK 97506 (SILZKBR8D8S)

Is this correct?

[thejeremyman9]

Originally Posted by itsrichierich

Sorry to bring up an old thread.

But I am going to be getting FBO with BM3 license, plan is to get custom tune by Jordan.

With that being said, I have read that I need to get 1 step colder plugs. If I read correctly, I need:

NGK 97506 (SILZKBR8D8S)

Is this correct?

If you are set on getting a custom tune, email the tuner and confirm exactly what plug and gap he wants you to run. I would potentially make a different case for a OTS tune, but with a custom tune you want to run the plugs they expect your car to be running.

I am pretty sure the NGKs are two steps colder.

[itsrichierich]

Originally Posted by thejeremyman9

If you are set on getting a custom tune, email the tuner and confirm exactly what plug and gap he wants you to run. I would potentially make a different case for a OTS tune, but with a custom tune you want to run the plugs they expect your car to be running.

I am pretty sure the NGKs are two steps colder.

Copy that, thank you!

[johnung]

Originally Posted by itsrichierich

Sorry to bring up an old thread.

But I am going to be getting FBO with BM3 license, plan is to get custom tune by Jordan.

With that being said, I have read that I need to get 1 step colder plugs. If I read correctly, I need:

NGK 97506 (SILZKBR8D8S)

Is this correct?

For BootMod3 on an N55

Stage1 just use stock Bosch plugs with stock gap

Stage2 use NGK 97506 gapped down to 0.022"

Lots of counterfeit 97506 on eBay etc. Buy from reputable dealer like FCP Euro which provides lifetime replacement

[thejeremyman9]

Originally Posted by johnung

For BootMod3 on an N55

Stage1 just use stock Bosch plugs with stock gap

Stage2 use NGK 97506 gapped down to 0.022"

Lots of counterfeit 97506 on eBay etc. Buy from reputable dealer like FCP Euro which provides lifetime replacement

He's going to run a custom tune, not a OTS tune, so he should use what the tuner recommends, which may or may not be the NGK 97506 gapped down to 0.022".

Also, the blanket recommendation to run those plugs/gap with a stage 2 tune is unnecessary. MHD recommends OEM Bosch even for stage 2+ and it is what i personally run for stage 2+ E20 tune. Also, ozymandias435 switched from those plugs/gap back to the OEM Bosch and had immaculate timing on BM3 stage 2 93 OTS map, and logs looked better in other respects as well.

There really is no reason to go to a colder and a significantly smaller gap unless you have a tuner than wants you to run that or you have issues with the OEM plugs. At the same time, people can experience cold start/idle issues with the colder plugs and smaller gap. Additionally, you could consider if you will have other issues running a colder plug, such as fouling if you frequently take the car on short trips.

Everyone's car responds differently so it's a little hit and miss, but generally speaking, theres no reason someone needs to immediately switch to the NGK 97506 gapped down to 0.022" just because they are going to run a OTS stage 2 tune.

I do agree with being careful about counterfeits.

[Marlinman]

For the record they aren't 2 steps colder for the n55 motor. the plugs referenced in this thread are only one step colder in relation to n55 and 2 steps for n54. He'll be fine either way. Check with tuner.

[johnung]

Originally Posted by thejeremyman9

He's going to run a custom tune, not a OTS tune, so he should use what the tuner recommends, which may or may not be the NGK 97506 gapped down to 0.022".

Also, the blanket recommendation to run those plugs/gap with a stage 2 tune is unnecessary. MHD recommends OEM Bosch even for stage 2+ and it is what i personally run for stage 2+ E20 tune. Also, ozymandias435 switched from those plugs/gap back to the OEM Bosch and had immaculate timing on BM3 stage 2 93 OTS map, and logs looked better in other respects as well.

There really is no reason to go to a colder and a significantly smaller gap unless you have a tuner than wants you to run that or you have issues with the OEM plugs. At the same time, people can experience cold start/idle issues with the colder plugs and smaller gap. Additionally, you could consider if you will have other issues running a colder plug, such as fouling if you frequently take the car on short trips.

Everyone's car responds differently so it's a little hit and miss, but generally speaking, theres no reason someone needs to immediately switch to the NGK 97506 gapped down to 0.022" just because they are going to run a OTS stage 2 tune.

I do agree with being careful about counterfeits.

I literally quoted the Pro Tuning Freaks BootMod3 spark plug recommendations for the N55 engine which he said that he is installing. The custom tune that he said that he might get is based on BootMod3 as its foundation. It isn't like he's going to some custom tuner who is doing something completely different than BootMod3.

[johnung]

Originally Posted by Marlinman

For the record they aren't 2 steps colder for the n55 motor. the plugs referenced in this thread are only one step colder in relation to n55 and 2 steps for n54. He'll be fine either way. Check with tuner.

Great point! Guys always leave off the the part of "Colder...in relation to what?

The N54 was the previous engine so spark plug conversations were typically how much colder plugs were in relation to stock N54 plugs.

Then the N55 engine came along and used stock plugs that were one step colder than N54 stock plugs.

So NGK 97506 are one step colder for N55 engines.

AND the same NGK 97506 are two steps colder for N54 engines.

[ozymandias435]

Originally Posted by johnung

I literally quoted the Pro Tuning Freaks BootMod3 spark plug recommendations for the N55 engine which he said that he is installing. The custom tune that he said that he might get is based on BootMod3 as its foundation. It isn't like he's going to some custom tuner who is doing something completely different than BootMod3.

What thejeremyman9 is saying is that we have a virtual dyno of my car with nothing else different other than me switching plugs back to factory plugs and making more power with improved timing.

Every log I have taken since putting factory plugs back in has had better timing than any log that I took while I had NGK .022 plugs in.

As soon as I flashed Stage 2 BM3 I installed the NGKs per their recommendation but my timing was never clean. In search for better timing I bought the Bosch factory plugs, checked them all (.030 out of the box), reinstalled them and produced perfect timing in logs and more power on Virtual Dyno.

He was one of the reasons I went back and tried the factory plugs again. I am certain that he knows the recommendation but is just stating that the recommendation may be a little premature for the power levels of a stock turbo. For my car specifically I was able to prove this. Could be totally different on other peoples cars without a doubt as some people do have success with .022 gaps on stage 2 maps.

This is just my experience with plugs and timing so far.

[johnung]

Originally Posted by ozymandias435

What thejeremyman9 is saying is that we have a virtual dyno of my car with nothing else different other than me switching plugs back to factory plugs and making more power with improved timing.

Every log I have taken since putting factory plugs back in has had better timing than any log that I took while I had NGK .022 plugs in.

As soon as I flashed Stage 2 BM3 I installed the NGKs per their recommendation but my timing was never clean. In search for better timing I bought the Bosch factory plugs, checked them all (.030 out of the box), reinstalled them and produced perfect timing in logs and more power on Virtual Dyno.

He was one of the reasons I went back and tried the factory plugs again. I am certain that he knows the recommendation but is just stating that the recommendation may be a little premature for the power levels of a stock turbo. For my car specifically I was able to prove this. Could be totally different on other peoples cars without a doubt as some people do have success with .022 gaps on stage 2 maps.

This is just my experience with plugs and timing so far.

Thanks for the detailed explanation. There seems to be some varying experiences out there with the two typical spark plug options for the N55 engine with BootMod3 Stage2.

I haven't had any issues. Engine runs smoothly and logs look good.

I have an N55 EWG. Is yours PWG? I haven't taken note if there is any PWG/EWG correlation to spark plug observations.

Anyway, I was running stock Bosch plugs at stock gap on BM3 Stage1. When I installed BM3 Stage2 I also followed the PTF recommendation to upgrade the spark plugs to NGK 97506 and gap them down to 0.022".

NGK 97506 are considered to be 1-step colder for N55 and 2-steps colder for N54. Its important to note that there is no "coldness" standard. Different brands of plugs usually have numbers in their model numbers that provide a coldness value so that their products can be compared to each other up and down their own product line.

But since there is no standard, there is nothing reliable that says that (made up numbers) a Bosch "3" is the same coldness value as an NGK "8". So just in terms of coldness, the NGK 97506 are presumed to be colder than the stock Bosch plugs in an N55. Is it one full coldness number? Is it actually 1/2 of a value colder? Who really knows. It does not matter. It's just presumed to be a colder plug.

I suspect that the gap is more noteworthy. A very experienced senior BMW dealer tech who mods his cars told me not to try to gap down the stock Bosch plugs. He said that they're not constructed for that. They are brittle and often break if you attempt to reduce the gap.

NGK 97506 are constructed differently, so their gap can easily be reduced.

Most guys don't understand why a spark plug gap would be reduced. Stock engines have spark plugs and gaps chosen for their characteristics including the amount of air and fuel in the engine cylinder when the spark plug fires.

A turbocharged engine that has been tuned is now shoving a lot more air and fuel into the engine cylinder than was calculated by the original engine designers when they decided on the best spark plug and gap for the engine. Going back to high school physics, there are many more air and fuel molecules so it's much more dense. That spark now has a lot more molecules in its way when it's trying to jump the gap. It just gets too thick inside the cylinder at high boost levels.

If the spark can't reliably jump the gap because of this increased fuel/air density it's called "blowout". This makes it sound like a candle that is blown out. This term is a misnomer because the spark doesn't make it across and get blown out. The spark never gets started in the first place.

There are two typical solutions: 1) install some upgraded coils to increase the power of the spark, which can have its own issues, or 2) reduce the distance of the gap so that the spark can fire effectively and efficiently even in that new high boost, thick with fuel/air molecules environment.

Pure Tuning Freaks must have done some calculations and trials based on these factors before deciding on making their NGK 97506 gapped at 0.022" recommendation for N55 BootMod3 Stage2.

[thejeremyman9]

Originally Posted by johnung

I literally quoted the Pro Tuning Freaks BootMod3 spark plug recommendations for the N55 engine which he said that he is installing. The custom tune that he said that he might get is based on BootMod3 as its foundation. It isn't like he's going to some custom tuner who is doing something completely different than BootMod3.

I know you quoted PTF. For the record it doesnt matter what platform the tuner uses, the tuner could infact do something completely different than BM3 OTS tunes even if he uses the BM3 platform... the BM3 platform is just a means for him to flash the custom map; with a custom tune it has no bearing on the tune itself. That's why i recommend he follow tuner guidance on plugs - they will tune with the expectation you are running what they told you to, and doing something different might have undesirable results.

Originally Posted by johnung

Thanks for the detailed explanation. There seems to be some varying experiences out there with the two typical spark plug options for the N55 engine with BootMod3 Stage2.

I haven't had any issues. Engine runs smoothly and logs look good.

I have an N55 EWG. Is yours PWG? I haven't taken note if there is any PWG/EWG correlation to spark plug observations.

Anyway, I was running stock Bosch plugs at stock gap on BM3 Stage1. When I installed BM3 Stage2 I also followed the PTF recommendation to upgrade the spark plugs to NGK 97506 and gap them down to 0.022".

NGK 97506 are considered to be 1-step colder for N55 and 2-steps colder for N54. Its important to note that there is no "coldness" standard. Different brands of plugs usually have numbers in their model numbers that provide a coldness value so that their products can be compared to each other up and down their own product line.

But since there is no standard, there is nothing reliable that says that (made up numbers) a Bosch "3" is the same coldness value as an NGK "8". So just in terms of coldness, the NGK 97506 are presumed to be colder than the stock Bosch plugs in an N55. Is it one full coldness number? Is it actually 1/2 of a value colder? Who really knows. It does not matter. It's just presumed to be a colder plug.

I suspect that the gap is more noteworthy. A very experienced senior BMW dealer tech who mods his cars told me not to try to gap down the stock Bosch plugs. He said that they're not constructed for that. They are brittle and often break if you attempt to reduce the gap.

NGK 97506 are constructed differently, so their gap can easily be reduced.

Most guys don't understand why a spark plug gap would be reduced. Stock engines have spark plugs and gaps chosen for their characteristics including the amount of air and fuel in the engine cylinder when the spark plug fires.

A turbocharged engine that has been tuned is now shoving a lot more air and fuel into the engine cylinder than was calculated by the original engine designers when they decided on the best spark plug and gap for the engine. Going back to high school physics, there are many more air and fuel molecules so it's much more dense. That spark now has a lot more molecules in its way when it's trying to jump the gap. It just gets too thick inside the cylinder at high boost levels.

If the spark can't reliably jump the gap because of this increased fuel/air density it's called "blowout". This makes it sound like a candle that is blown out. This term is a misnomer because the spark doesn't make it across and get blown out. The spark never gets started in the first place.

There are two typical solutions: 1) install some upgraded coils to increase the power of the spark, which can have its own issues, or 2) reduce the distance of the gap so that the spark can fire effectively and efficiently even in that new high boost, thick with fuel/air molecules environment.

Pure Tuning Freaks must have done some calculations and trials based on these factors before deciding on making their NGK 97506 gapped at 0.022" recommendation for N55 BootMod3 Stage2.

I am EWG.

The varying experiences is exactly what i was getting at, and why i always say everyone's car responds differently. This is precisely why the spark plug debate will never die:

- Some people try bosch and have misfires/timing issues, go to NGK, and it solves the problem.
- Some people switch from bosch to NGK and have cold start/idle/other issues, switch back to a new set of bosch, and it solves the problem.

All i was saying is that theres no reason to switch to the NGKs just because you are going to a stage 2 tune. Its not a prerequisite, but i feel like it is spoken like gospel. I am in no way saying the NGK are worse, or wont work, or anything of the sort. Its a perfect example of "YMMV".

I agree the heat range ratings are different between plugs. The only warning i gave for heat range is potential fouling if you make only short trips with the car.

I also agree that you should not change the gap on the bosch plugs unless you have an issue with one out of the box and need to correct it. But the gap out of the box is fine, so there is no need to gap down.

Just do you know, I am fully aware of why a spark plug gap should be reduced, as i dealt with spark "blowout" and misfire issues on my 3000gt for years. I kept trying different plugs, heat ranges, gaps, etc, until finally a year ago i switched to a non resistor copper plug with a 0.026 gap and it finally solved my issues. If you want some non BMW reading, i even posted a thread about it here: https://www.3si.org/threads/spark-pl...ost-1056307591

So i agree that generally speaking you do need to reduce the gap as you increase boost - its a direct relationship with cylinder pressure. However anecdotal evidence has shown that this may not be necessary for our platform unless you are pushing extremely high power/boost levels. Infact i think it was Harkes that was running 20+psi with meth on OEM plugs and gap... again YMMV.

I believe that the NGK plugs, colder (potentially) and with smaller gap are recommended because that is the "safer" plug for two main reasons:

- Smaller gap is less likely to have misfire or "blowout" issues at higher boost levels
- Colder plug is less likely to have detonation if the plug is overheated at higher boost/power levles

So these recommendations are the conservative approach - they are more likely to run well at WOT even if there are some potential tradeoffs.

Hopefully people can learn from reading our conversation here, but i can guarantee the spark plug thread will live to die another day, because there is no "best" plug nor one size fits all.

[ozymandias435]

Originally Posted by johnung

Thanks for the detailed explanation. There seems to be some varying experiences out there with the two typical spark plug options for the N55 engine with BootMod3 Stage2.

I haven't had any issues. Engine runs smoothly and logs look good.

I have an N55 EWG. Is yours PWG? I haven't taken note if there is any PWG/EWG correlation to spark plug observations.

Anyway, I was running stock Bosch plugs at stock gap on BM3 Stage1. When I installed BM3 Stage2 I also followed the PTF recommendation to upgrade the spark plugs to NGK 97506 and gap them down to 0.022".

NGK 97506 are considered to be 1-step colder for N55 and 2-steps colder for N54. Its important to note that there is no "coldness" standard. Different brands of plugs usually have numbers in their model numbers that provide a coldness value so that their products can be compared to each other up and down their own product line.

But since there is no standard, there is nothing reliable that says that (made up numbers) a Bosch "3" is the same coldness value as an NGK "8". So just in terms of coldness, the NGK 97506 are presumed to be colder than the stock Bosch plugs in an N55. Is it one full coldness number? Is it actually 1/2 of a value colder? Who really knows. It does not matter. It's just presumed to be a colder plug.

I suspect that the gap is more noteworthy. A very experienced senior BMW dealer tech who mods his cars told me not to try to gap down the stock Bosch plugs. He said that they're not constructed for that. They are brittle and often break if you attempt to reduce the gap.

NGK 97506 are constructed differently, so their gap can easily be reduced.

Most guys don't understand why a spark plug gap would be reduced. Stock engines have spark plugs and gaps chosen for their characteristics including the amount of air and fuel in the engine cylinder when the spark plug fires.

A turbocharged engine that has been tuned is now shoving a lot more air and fuel into the engine cylinder than was calculated by the original engine designers when they decided on the best spark plug and gap for the engine. Going back to high school physics, there are many more air and fuel molecules so it's much more dense. That spark now has a lot more molecules in its way when it's trying to jump the gap. It just gets too thick inside the cylinder at high boost levels.

If the spark can't reliably jump the gap because of this increased fuel/air density it's called "blowout". This makes it sound like a candle that is blown out. This term is a misnomer because the spark doesn't make it across and get blown out. The spark never gets started in the first place.

There are two typical solutions: 1) install some upgraded coils to increase the power of the spark, which can have its own issues, or 2) reduce the distance of the gap so that the spark can fire effectively and efficiently even in that new high boost, thick with fuel/air molecules environment.

Pure Tuning Freaks must have done some calculations and trials based on these factors before deciding on making their NGK 97506 gapped at 0.022" recommendation for N55 BootMod3 Stage2.

I am N55 EWG as well. I will be going custom tune in the near future and this will be a conversation I will have as well with whomever I choose to work with. I also have a PR ignition kit sitting here waiting to install so that is something that could factor in down the road as well. But for now the stock plugs/stock coils are producing some nice timing in my logs lol.

[johnung]

Originally Posted by thejeremyman9

I know you quoted PTF. For the record it doesnt matter what platform the tuner uses, the tuner could infact do something completely different than BM3 OTS tunes even if he uses the BM3 platform... the BM3 platform is just a means for him to flash the custom map; with a custom tune it has no bearing on the tune itself. That's why i recommend he follow tuner guidance on plugs - they will tune with the expectation you are running what they told you to, and doing something different might have undesirable results.

I am EWG.

The varying experiences is exactly what i was getting at, and why i always say everyone's car responds differently. This is precisely why the spark plug debate will never die:

- Some people try bosch and have misfires/timing issues, go to NGK, and it solves the problem.
- Some people switch from bosch to NGK and have cold start/idle/other issues, switch back to a new set of bosch, and it solves the problem.

All i was saying is that theres no reason to switch to the NGKs just because you are going to a stage 2 tune. Its not a prerequisite, but i feel like it is spoken like gospel. I am in no way saying the NGK are worse, or wont work, or anything of the sort. Its a perfect example of "YMMV".

I agree the heat range ratings are different between plugs. The only warning i gave for heat range is potential fouling if you make only short trips with the car.

I also agree that you should not change the gap on the bosch plugs unless you have an issue with one out of the box and need to correct it. But the gap out of the box is fine, so there is no need to gap down.

Just do you know, I am fully aware of why a spark plug gap should be reduced, as i dealt with spark "blowout" and misfire issues on my 3000gt for years. I kept trying different plugs, heat ranges, gaps, etc, until finally a year ago i switched to a non resistor copper plug with a 0.026 gap and it finally solved my issues. If you want some non BMW reading, i even posted a thread about it here: https://www.3si.org/threads/spark-pl...ost-1056307591

So i agree that generally speaking you do need to reduce the gap as you increase boost - its a direct relationship with cylinder pressure. However anecdotal evidence has shown that this may not be necessary for our platform unless you are pushing extremely high power/boost levels. Infact i think it was Harkes that was running 20+psi with meth on OEM plugs and gap... again YMMV.

I believe that the NGK plugs, colder (potentially) and with smaller gap are recommended because that is the "safer" plug for two main reasons:

- Smaller gap is less likely to have misfire or "blowout" issues at higher boost levels
- Colder plug is less likely to have detonation if the plug is overheated at higher boost/power levles

So these recommendations are the conservative approach - they are more likely to run well at WOT even if there are some potential tradeoffs.

Hopefully people can learn from reading our conversation here, but i can guarantee the spark plug thread will live to die another day, because there is no "best" plug nor one size fits all.

All good stuff! 👍

[harkes]

Originally Posted by thejeremyman9

Infact i think it was Harkes that was running 20+psi with meth on OEM plugs and gap... again YMMV.

Correct.

Stock Bosch at 0.03" gap:

[harkes]

https://f30.bimmerpost.com/forums/sh....php?t=1434415

[DreamerJoe]

I wonder how well the S55 plugs will work in the N55. they are still a step colder but gapped @ .25 instead of the .18-.22 NGK's some people are running.. I think it's more popular for the 4 cylinder guys because they're running higher boost, but if some people are having trouble going as low a gap as what's recommended by some with the NGK's, maybe less of a gap while also going colder might help? I would also think they're cheaper than the NGK's.. any thoughts? dumb question?

[thejeremyman9]

Originally Posted by DreamerJoe

I wonder how well the S55 plugs will work in the N55. they are still a step colder but gapped @ .25 instead of the .18-.22 NGK's some people are running.. I think it's more popular for the 4 cylinder guys because they're running higher boost, but if some people are having trouble going as low a gap as what's recommended by some with the NGK's, maybe less of a gap while also going colder might help? I would also think they're cheaper than the NGK's.. any thoughts? dumb question?

I thought i read in some posts people said specifically not to run the S55 plugs in the N55. Forgot the exact reason, or if there was even a good one.

[DreamerJoe]

Originally Posted by thejeremyman9

I thought i read in some posts people said specifically not to run the S55 plugs in the N55. Forgot the exact reason, or if there was even a good one.

I've seen a few threads on people asking, but not a solid yes or no as to it being a good idea, more speculation and guessing, or someone that's actually done it and shared results. I am finding threads of them being used on the N20 or N26, something about them using the same type of coil and the N55 being different. does that mean they won't fit? idk.. I would imagine someone has tried them, and if it worked well their would be a lot more people using them.

[Nircom]

I wonder how octane levels will change the recommendations here
Some people use 91 octane, others 93. I'm using 95 octane as standard, and have the option to use 98 as well. The higher the octane level, it is less likely to have early detonation if im not mistaken, and this by itself may resolve the need to replace or upgrade the plugs.
So , my question is should I go with 1 step colder plugs if I tune my car and use 98 octane?

[thejeremyman9]

Originally Posted by Nircom

I wonder how octane levels will change the recommendations here
Some people use 91 octane, others 93. I'm using 95 octane as standard, and have the option to use 98 as well. The higher the octane level, it is less likely to have early detonation if im not mistaken, and this by itself may resolve the need to replace or upgrade the plugs.
So , my question is should I go with 1 step colder plugs if I tune my car and use 98 octane?

You are correct that higher octane will reduce the change of knock/preignition. However, it does not change the recommended approach. Go with a set of new OEM plugs and only switch to colder NGKs if you have timing issues with OEM. I have ran OEM plugs on 91 and E30, and E30 should be about 94-95 octane. This assumes you are on stock turbo. If you are on a upgraded turbo and running 20+ psi, you might want to coniser the NGKs and smaller gap, but some people have ran OEM even at those levels.

Just curious, what is the price of your 95 and 98 per gallon?

[Nircom]

Originally Posted by thejeremyman9

You are correct that higher octane will reduce the change of knock/preignition. However, it does not change the recommended approach. Go with a set of new OEM plugs and only switch to colder NGKs if you have timing issues with OEM. I have ran OEM plugs on 91 and E30, and E30 should be about 94-95 octane. This assumes you are on stock turbo. If you are on a upgraded turbo and running 20+ psi, you might want to coniser the NGKs and smaller gap, but some people have ran OEM even at those levels.

Just curious, what is the price of your 95 and 98 per gallon?

Oh, you don't want to know . We pay about 6.5 usd per gallon for the 95 and around 25% more for 98..

[thejeremyman9]

Originally Posted by Nircom

Oh, you don't want to know . We pay about 6.5 usd per gallon for the 95 and around 25% more for 98..

Dang, well i guess you will have to balance the power tradeoff with cost, depending on how often you drive the car and for how many miles.