This thread is to clear up any question people have in regards to spark plugs for a tuned B46, B48, and B38 engine. Also to clarify incorrect information people are being told about colder heat range or spark plug upgrades for our engines.

There are a couple tuners for our platform that are selling spark plugs as an upgrade/required part in order to obtain a tune. I have received part numbers from various customers from these tuners to confirm the part numbers they were sold. The plugs you were sold are NOT a heat range colder. There is not a single spark plug on the market that will fit the B series engine that is anything but an 8 heat range.

Here are all the applicable spark plugs for the b46, b48, and b58
SILZKBR8D8S- Heat range of 8, 26.5mm reach (oem on the m3/m4 S55 and 340i b58 engines as well as the 330i B48)
SILZKGR8C8S- Heat range of 8, 28.5mm reach (oem bmw i8 plug and what is being sold to people as an upgrade)
SILZKBR8B8S- Heat range of 8, 26.5mm reach (oem plug on the mini b46 and b48 and the bmw 320i B48)

The 9th digit in the part number is the NGK designation for plating. There are minor differences in the actual plating of the three spark plugs referenced above. Theoretically MIGHT help with heat dissipation considering the c and d plugs are higher power engines running more boost. BUT they are still the exact same heat range.

The most important part is that the plugs being sold as an upgrade have a 2mm longer reach. This means the threads will actually be exposed in the combustion chamber. Typically you always want to keep the reach the exact same as oem. With a longer reach there will be an increased amount of deposit where the threads protrude into the chamber. Added combustion chamber deposits can lead to hot spots as well as increasing the risk of misfires. IMO the upgraded plug everyone is running is actually a downgrade. Longer reach plugs also put you at risk of piston contact to the spark plug. I don't know the actual clearance there is at TDC on the B46 and B48 but you are moving the spark plug 2mm closer to the piston at TDC.

SILZKBR8D8S (pn: 97506) that are standard on the M3, M4 are the best you can get. These are the go-to upgrade for high power n54, n55, s63, n63tu, and s63tu engines and are 2 heat ranges colder compared to what is stock. These would be the best option for going to an alternative plug to stock but again there is not a single plug on the market that is a higher heat range for our cars.

 

Those aren't the only plugs being sold with tunes, granted I just looked them up and they are also heat range 8

The plugs I have you do not have listed in your post

SILZKGR8C8S

So what the hell gives here. Seems like we were all sold pretty expensive plugs that are the same heat range as stock. We were told these plugs were 1 heat range colder.

 

Based on our dyno testing on these 8C8S plugs, they do provide an edge over the stock 8B8S bc it is designed to run higher boost in the I8 motor.

 

Sorry I had a typo on the C plugs. I had the 6th digit as a B and not a G.

 

these have a 2mm longer reach than what is designed for the b46, b48, b58. These are not a heat range colder as you have stated they are multiple times.

This is what happens to a spark plug with a longer reach.....

 

I looked back through my emails and you are promoting these plugs, as are other companies, as 1 step colder (reason for buying them) and they are not. The 2mm longer reach is also concerning seeing how tight tolerances are.

 

THE best plug to go with is SILZKBR8D8S. This plug is being used by 700+hp bmw's and working flawlessly. I would highly suggest anyone running the longer reach plugs to remove them and get a proper fitting spark plug. An overheated ground electrode is not what you want when running the aggressive timing that some of these tuners run. Risking a large inspection hole in the block due to detonation.

 

 

Going back through the mail I too purchased the plugs recommended being that I was told that they were/are one step colder.

Here's whats listed on the invoice:

NGK-F56-BMW
NGK one-step colder spark plug (OEM)
4 $21.95 $87.80

Really not liking the fact that their sold as one step colder and are not the case.



EDIT: Edited info about possible protruding into the cylinder to which they appear to not; being that additional length is w/in the exposed porcelain not total length.

 

We selected the 8C8S at first b/c it's the engine series as the B48/B38 and the I8 motor boost a lot more than the F56 B38. Comparing the electrode between the 8B8S and the 8C8S, and the 8C8S does have an advantage. So while it not be a true "one-step" colder, it is "colder" than the 8B8S.

Regarding the 2mm extra length, we have examined this and it does not come in contact with the piston. In all honesty, the profit margin for each plug is $2; so we did not recommend these to make a huge profit - we truly thought this was a better plug than than the 8B8S.

We will test the 8D8S and see these compare to the 8C8S and 8B8S.

 

I just saw this thread and have a huge concern. I'm also upset that I was sold a set of expensive spark plugs that are not 1 step colder and protrude 2mm.

I contacted Bytetronik to see if this can be resolved.

 

did you truly think it was a 1 step colder plug or just thought anyone would believe you. It is not colder. It is an 8 heat range plug just like the stock b48 plugs with a 2mm longer reach (which WILL cause overheating of the ground which significantly increases the risk of detonation) and a slightly different plating on the plug.

This also leads me to believe that this is a contributing factor as to why your replacing pistons at a way lower power than the 3rd gen experts in europe I have spoken to.

 

 

So I too have sent an E-mail to BT asking for a refund on the plugs. If I'd have known that they were the same heat range, I'd have passed.

I was told to pull the plugs and take a look to see if there was any interference / indication of issues to which I cant say that there appears to be any. But - I will say that the idle of the car seems to be smoother then when I had the other plugs in. Could be placebo, but I had noticed that there was a rough idle while in and about town prior to this issue coming to light. After being out running errands last evening it does "seem" to idle smoother.

Being that I do know know specifically "what" a plug should look like - other then the standard clean, oil issues and damage; it does look weird that there's inconsistent carbon buildup along the plug. Is this the natural progression of what plugs do while being used?

This is the first time that I have pulled a plug back out of the head w/in ~2000 miles of its installation so I have no basis to relate to in this matter.




bytetronik provided plugs

 

I guess technically if they extend further there is more surface area (the exposed threads) to take up heat, so they may effectively be colder even if not rated as such.

Doesn't appear to be any interference from that photo. I would expect interference to smash the ends of the plugs off, not gently tap them.

I am curious what this does to the flame propagation. I'm not of the school that believes that design engineers are infallible (you should *hear* some of the guys in the Ducati community!) but so much effort goes into optimizing the cylinder geometry for smooth flame propagation that I tend to assume they knew what they were doing, and set the spark depth for a reason.

 

Found a solid source for the SILZKBR8D85 NGK part # 97506
$13.50 each from Rock Auto. Depending on where you live you can get a set of these shipped for just under $60 for the set.

I would also suggest adjusting the gap to 0.020"

These are the go-to and recommended plug for high power bmw's including the M3/4 and M5/6.

I also found a part number for a NGK plug that I believe is a 9 heat range and is also specified for flex fuel use. I am waiting on a spec sheet from my friend to confirm the reach and heat range.

 

Thanks, charrigan!


I'm still that I have to pay an additional $57.99 for the correct set of plugs.


Waiting on Bytetronik's response as to whether they will step up and correct this issue.

 

One thing not mentioned is that if you use the incorrect plugs with extended thread, that thread will fill up with carbon, the 'accumulation of deposits' in the diagram.
This makes it hard to remove the plug, damages/strips the threads in the head & as a result may be the cause of plugs being blown out.

 

We're compiling all the facts and findings and address everything all at once. In the aftermarket industry, we typically have to venture out of the box and find products that may not be the perfect fit to the novice.

On the Mini R53 platform for example, when we first introduced the Bosch 550cc injectors in 2008, everyone and their mom said that was "too big" and unnecessary and called us all sort of names... But now, everyone is using it and some are even needing to go bigger to the 650cc, 700cc and even 800cc for the turbo application.

Stay tuned...

 

I'm curious to see if you have anything to backup this claim. To show the I8 plugs being 2mm longer reach then b48 stock plugs. Seeing part numbers is one thing, any measurement have been done in person? I've look into this a while back, SILZKGR8C8S has been working fine no issue.

 

This is not a claim. This is all facts pulled from NGK data sheets as well as my friend who works for NGK corporate here in Michigan. Please go look at the data sheets yourself on the NGK website and confirm this all for yourself.

Have you pulled your plugs to look for evidence of overheating the ground?
Have you logged your vehicle for multiple high load pulls to confirm you are not experiencing timing pull or experiencing detonation?

 

you and a couple other tuners (not sure who followed who) ventured out of the box without the basic understanding to reference a data sheet that is publicly available.

the facts:
you advertised and mislead customers into thinking they had a 1 colder heat range plug compared to OEM. The lack of basic ICE knowledge by recommending and selling 2mm longer plugs put your customer engines at risk.

2mm longer is going to do a few things.

1. Change the position of the the ignition. Ideally ignition is omidirectional. On older engines wouldn't matter much because tumble and swirl were not really understood. In short a 1962 hemi does not really care. It also gets 14mpg and 20% of the fuel in the chamber did not actually burn. On a newer engine the quench zone is so finely tuned (which includes spark plug position) you will get shitty ignition. Essentially lighting the fire on the floor vs. the middle of the atomized mixture. Causing a slow burn rate. So slow in fact it could be classified as detonation. Position is critical in new engines especially DI engines.

2. Your plug may get dangerously close or even hit the Piston. We know this plug does not hit the piston but it's for sure extremely close. The quench zones are very tight and anything moved 2mm inside an engine from it's OEM spec scares the **** out of me.

3. It will run hotter because the plug is protruding into the combustion chamber more. Not just the electrode. This along with closer proximity to the hot piston surface could cause a hot spot on the plug to form and likely cause detonation.

 

Well, I've been busy conspiring with BT about how we were gonna split up all the money we were making on the new plugs.


ByteTronik has replied that they're looking into it. Give them a little time to respond. Probably the reason some of us haven't responded to your thread is the fact that we're not experiencing any problems to date. Just out of curiosity, do you have their tune?

I am disappointed with them about the misleading heat range, but am willing to wait for their response and go from there. I'm curious to see how much difference 2mm or 78/1000 of an inch in length will make. The picture of the plugs that has been posted and reposted in this thread is a little misleading too. The example looks more like 1/4" than 2mm.

 

I understand you have a friend that works at NGK. I wonder which department, hopefully not shipping. The data sheet is correct according to ngk. I understand the reach data listed there. Does anyone else here knows what that means? I'm sure BT does. I have loggs that shows everything is running fine, spark plugs are fine.

 

he is not in shipping.