[F87source]

Ok guys I would like to review the BMS 12 mm spark plug gap tool for bmw's, and I would also like to extend a big thank you to BMS for the absolutely stellar customer service and deal on this tool.


Now lets begin, why would you want a tool like this? Well if you guys are tuned and are buying non-factory plugs (like the ever so popular NGK 97506 2 step colder plugs) that are not pre-gapped it is important to set the gap to either factory specs, or whatever your car requires as determined by Reading the plug, and looking at your cars conditions - not just following the norms set by the internet as you want the largest gap possible to enhance combustion of the air fuel mixture in the cylinder. To set this gap you do not want to be tapping the plug against a hard surface because that could cause damage to the plug itself, instead you'd want a precision instrument to slowly and gently set the gap to ensure you do not damage the plug itself or close the gap too far which could damage the delicate iridium tip.


Now with that aside what kind of tools are there, well there are 2 options:

1) Spending a little bit of money (only $35 so that's pretty much nothing) for a BMS spark plug gap tool: https://burgertuning.com/collections...g_gapping_tool and doing this properly the first time.

2) Cheaping out like I did and buying an absolute POS from China, aka typical aliexpress garbage. Now this is not to trash on made in China, because alot of good quality things like iPhones are made in China. But the difference is that things like iPhones have insanely good quality control, whereas aliexpress items do not which is a huge reason why you should avoid wasting your money initially on aliexpress. Also aliexpress reviews may not be a good indicator of quality, because often times sellers may tell a buyer to give them a 5 star review despite poor quality before giving a refund so this really skews off the review system. Trust me I have been using aliexpress for a long time (I've been a diamond member since 2016, I buy alot of little things like microfiber towels, tools, and wax sponges), and I am finally fed up with them after 65% of my purchases this year had either absolute garbage quality despite good reviews and high number of order, or the item not showing up. Also there is no customer service purchasing from aliexpress, the seller will often ignore you (the seller of this cheap tool ignored me) forcing you to open disputes through aliexpress which will overtime get your account closed if you keep doing it.



Ok with that mini rant aside lets get onto images and different aspects of the items themselves:


1) Build quality:
Here are some images of the top and side of the BMS spark plug gap tool compared to the cheap aliexpress tool.




Immediately right off the bat you can see a noticeable difference in quality. The BMS tool is made of billet aluminium and anodized black and everything feels SOLID. The aliexpress tool is made of aluminium as well but is coated heavily with black powder coating - including the threads which makes turning the knob more difficult - more on this later. Also the BMS tool is slightly larger which makes turning the knob easier.



2) The knob and screw that will close the spark plug gap

a) BMS:




As you can see with the BMS tool has a large easy to hold knob with large grooves around the circumference making it easy to hold and turn. Combined with the anodized threads it makes it really smooth and easy to screw down with small turns - which is vital to not over tightening your gap.

The next extremely important aspect is the screw itself, it is a dog point screw with a flat point. This means the thread itself ends a couple of mm before the point of the screw which is also flat and smooth. This is incredibly important as it contacts the electrode ground on the spark plug itself you do not want it to damage that part. As you can see in the last image the spark plug looks unscathed after use with the bms tool. This is a used spark plug too with some combustion residue left on the electrode ground itself. This residue is extremely soft and easy to scrape off, and you can see the BMS tool didn't even make a mark which is incredible.



b) Aliexpress:





Immediately you can see that the screw portion of the aliexpress tool is just a standard screw where the threads go all the way to the end. Even worse the screw is jagged at the tip and not even flat, this means when you turn the screw it will actually dig into the spark plug electrode ground itself causing damage. You can see the damage in the last image showing yet again another used spark plug with combustion deposits on the electrode ground. But this time you can see the aliexpress tool with its rough screw not only scraped off all of the soft deposits, but actually cut into the ground itself make a deep gouge, this is not ideal and reduces the amount of metal on the ground itself which imo is not a good thing for conduction. Also with the tiny knob it was quite difficult turning the knob slowly and precisely especially since the thick powder coating provided ALOT of resistance.


3) Gap tool with plug inserted



This just shows the two gap tools with the plug inserted, yes the gap on both of them is set all the way so the ground touches the electrode. I only did this to see experiment how easy and how many turns it took, but it is irrelevant to the comparison with the exception that it is easier to over tighten the gap with the aliexpress tool because you have to use so much more force that you can accidentally slip.


4) Spark plug threaded end:

a) BMS:


Here we see the bms tool's threaded end for the spark plug after gapping a used plug. You can see some slight residue leftover from the plug, but that was easily washed away. The important thing is that the thread and the anodization remains in tact.


b) aliexpress:


With the aliexpress tool you can see how thick the powder coating is on the threads. This causes the threads to have a huge amount of resistance on the spark plug threads it actually causes a scrapping effect pulling alot of the residue off of the plug. But the worse part is that the powder coating came off as well and got stuck to the plug (I did not take a photo because it was really hard to see because the plug is so dirty). This is a bad thing as you do not want powder coating on your threads as it will get stuck in the threads of the cylinder head making it hard to remove the next time around, especially since you are not supposed to use antisieze on the plug and are supposed to rely on the plating of the plug for antisiezing properties which will of course be affected if powder coating is stuck on it.



5) Shipping/customer service:
a) BMS:
Shipping: It took 5 days via fedex with the intercooler (spoiler to what I am reviewing next) I purchased.
Customer service: Absolutely top notch and imo is the best I have ever experienced. An example is back in 2014 when I first got started in the turbo bmw platform with my m235i, Terry from BMS would reply to my emails within minutes (he still replies to my emails within minutes, albeit since I do not have a jb4 anymore on my m2 I do not contact him much anymore) even on weekends to answer my questions. Over the period of time with my jb4 m235i he answered like a couple hundred emails without complaint or hesitation and with insanely fast response times, this shows absolutely excellent customer support.


b) Aliexpress:
Shipping: 100+ days with a few extensions of receiving time.
Customer service: nonexistent and don't expect aliexpress to take your side either, I have lost dispute cases on a $500 front lip that came cracked because they wanted me to ship it back which would have costed a couple hundred $ CAD since it was so big. So the best I got was a 50% refund.


Overall what you can see is the BMS tool is superior to the cheap aliexpress tool in every single way, from having a large and easy to manipulate knob, a screw design that does not cause damage to the plug, and an anodized coating providing a smooth near frictionless surface that allows for easy turning of the knob and does not leave residue on the plug. So it is clear you should not waste your money on cheap aliexpress garbage as you will likely have to buy a new one when you discover the inevitable short comings, or end up damaging your plugs.



Also I have to note the anodized versions of the aliexpress ones are pretty crappy as well. The reason why is because the anodization is so thin on those tools it flakes off onto the plug and you have the same issue again. I have also experienced that issue leading me to get a powder coated version which was worse. Also the screw is still defective on the anodized aliexpress version. So again imo just don't waste your time and money trying to cheap out, spend a few extra dollars and get the proper tool.Ok guys I would like to review the BMS 12 mm spark plug gap tool for bmw's, and I would also like to extend a big thank you to BMS for the absolutely stellar customer service and deal on this tool.

[ZM2]

Nice write-up!

What gap would you recommend with the 97506's if running an E47 tune that hits 19-21psi thru a Stage 1 turbo and making ~425whp?

Currently, I'm at 0.020" and get little hiccups at lower RPMs when doing WOT single gear log pulls or dyno runs. No knock events, just little hiccups.

Thanks.

[F87source]

Originally Posted by ZM2

Nice write-up!

What gap would you recommend with the 97506's if running an E47 tune that hits 19-21psi thru a Stage 1 turbo and making ~425whp?

Currently, I'm at 0.020" and get little hiccups at lower RPMs when doing WOT single gear log pulls or dyno runs. No knock events, just little hiccups.

Thanks.

Thanks for the kind words!

Stock gap, I would have also stayed on the stock heat range plugs too but the more accurate advice would be to read your plugs. Here's my logic, m3's and m4s run even more boost and make more power when tuned and have no problems on the stock gap or stock plugs. There should be no reason to gap down so much unless you are experiencing misfires at the stock gap, and there should be no reason to go with colder plugs unless your plugs are reading hot. It's common for tuners to instantly recommend colder plugs and super small gaps immediately when there is no need, and the only result you will get is poor combustion and harsh idles. So I believe in your case the hiccups you see is due to the gap being too small.


Here is a great quote from Justin at twisted tuning explaining all of this, and keep in mind he has an 800 who supra on stock plugs with stock gap and no issues. Another reason why most of the advice on spark plug gap is really bad, and the only way to truly know what gap and plug to run is to read your plugs and data log.

Just recommending someone go to a one or two step colder plug because of a changed tune is not best practice. Poor combustion and misfires can occur.
The stock heat range in the N55 is fine to 700whp or so. One step colder than N54 stock. And the same heat range as nissan GTR stock plugs. GTRs run the stock heat range to 800whp or so.
The old recommendation of one step colder per 100whp is also not accurate. I mention this because ive seen it spewed on a lot of these groups. By that recommendation people would be looking for 6 step colder plugs in some cars.
Also, which is a slightly different topic (has nothing to do with your post) but people need to stop immediately recommending .018 plug gaps just because a car is tuned.
Ideally you want the largest gap possible for a setup that promotes complete combustion without blowout (failure of the spark to jump the gap).
Long story short.... proper spark plug recommendation should come from reading the plugs for a specific setup. Not a blanket recommendation from something you’ve seen people do.
IE- my A90 supra for instance. I’ve seen some tuners already recommended colder plugs or gapped down plugs for immediate process after tuning. Well, my car... stock plugs, stock gap. At over 700whp and 720wtq and reading the plugs show no issues. And the car has not skipped a beat or misfired at all."

[ZM2]

So, we have one tuner vs all the other tuners out there that recommend colder plugs and tighter gap.

I’m happy to try stock, but I have no idea what to believe! Until I find what works, that is.

[F87source]

Originally Posted by ZM2

So, we have one tuner vs all the other tuners out there that recommend colder plugs and tighter gap.

I’m happy to try stock, but I have no idea what to believe! Until I find what works, that is.

Not really, from what I see we have a bunch of bmw tuners who follow the trend of gapping down plugs based on a generic one size fits all recommendation vs. a tuner who recommends seeing what each individual car needs aka reading the plugs and data logs to look for misfires. We also see data from plug types and heat ranges being used on other platforms pushing more power than any bmw can without issue. So if you were asking me I would go with examining each and every individual application vs. following the sheep and gapping down for no reason. Plus you don't see the m4 gts with water injection pushing more power than most tuned n55's require colder plugs or smaller gaps. Plus imo Justin is the best tuner out there, I've seen alot of big name flash tuners who can't deliver and yet everyone raves about that individual (you know who I'm talking about) and then the crowd just follows without asking questions, and other tuners have shady histories of blowing motors. Justin has none of those issues.


But anyways like you said, just experiment around on your car and see what makes your engine happy that's the best way to do it. Make sure you google reading plugs and see the signs of spark plugs being too hot, too cold that will give you a hint on what to do next. One more thing is fcp euro sells the stock bosch plugs for ~$5 each so they're pretty cheap to play around with.




Edit - I wanted to clarify it is not the fault of "every" bmw tuner out there for spreading gap size information. It could also be because a tuner gives a customer a gap size for their particular setup and that gap size and plug is then recommended by said customer because it works so well on their particular setup and the result is the wrong info is spreaded where is should have just remained for that one particular initial setup. Otherwise tuner recommendations could just be a set of guide lines of what to follow. But at the end of it all my opinion is to read the spark plug gap and data logs for your particular car and make the appropriate changes based on that. Remember the goal is to have the largest gap possible to get the best possible combustion, so if you can run stock gaps (most people should) then I would do so.

[ZM2]

Originally Posted by F87source

Not really, from what I see we have a bunch of bmw tuners who follow the trend of gapping down plugs based on a generic one size fits all recommendation vs. a tuner who recommends seeing what each individual car needs aka reading the plugs and data logs to look for misfires. We also see data from plug types and heat ranges being used on other platforms pushing more power than any bmw can without issue. So if you were asking me I would go with examining each and every individual application vs. following the sheep and gapping down for no reason. Plus you don't see the m4 gts with water injection pushing more power than most tuned n55's require colder plugs or smaller gaps. Plus imo Justin is the best tuner out there, I've seen alot of big name flash tuners who can't deliver and yet everyone raves about that individual (you know who I'm talking about) and then the crowd just follows without asking questions, and other tuners have shady histories of blowing motors. Justin has none of those issues.



But anyways like you said, just experiment around on your car and see what makes your engine happy that's the best way to do it. Make sure you google reading plugs and see the signs of spark plugs being too hot, too cold that will give you a hint on what to do next. One more thing is fcp euro sells the stock bosch plugs for ~$5 each so they're pretty cheap to play around with.

Cool, will do.

I have an extra 97506 set from FCP Euro that I’ll try at stock gap to see if it resolves the hiccups. And, my current set will get sent back to them for credit.

[F87source]

I should also mention that stock gaps may not always be suitable for every car under similar circumstances and situations, again this is why reading your plugs and datalogging for misfires is a better way to determine plug gap size and heat range rather than following the pack per say. I am not trying to say this to step on any toes, but I am trying to help you guys out so you don't get misfires or weird stumbles that are plug related, and you will also be saving money running stock plugs compared to the more expensive ngk's.

[ZM2]

And what might be the stock gap for the M2? Anyone?

I tried some searching but it was l muddied by everyone saying gap tighter, like you said.

[F87source]

Originally Posted by ZM2

And what might be the stock gap for the M2? Anyone?

I tried some searching but it was l muddied by everyone saying gap tighter, like you said.

0.028" or 0.7 mm, the bosch plugs are also pregapped to this as well.


Yeah I hate all the spark plug threads because people are just throwing numbers around without any real basis behind it, and imo people shouldn't follow each other with plug advice just do what your own car needs.


Also if you are going to use a gap tool get a bms tool, don't get the amazon or aliexpress ones because you'll just be messing up your brand new plugs, and do not use antiseize.

[ZM2]

Just a heads up that FCP says the NGK’s are pre-gapped to 0.030”

https://www.fcpeuro.com/products/bmw...plug-ngk-96987

[F87source]

Originally Posted by ZM2

Just a heads up that FCP says the NGK’s are pre-gapped to 0.030”

https://www.fcpeuro.com/products/bmw...plug-ngk-96987

That's the stock gap size for n20's and iirc the new supra but the new supra uses a different plug.

[ZM2]

Originally Posted by F87source

That's the stock gap size for n20's and iirc the new supra but the new supra uses a different plug.

Well, new plugs gapped to 0.026” fixed the issue. So, thanks for your input!

[F87source]

Originally Posted by ZM2

Well, new plugs gapped to 0.026” fixed the issue. So, thanks for your input!

No problem at all! I'm glad that the larger gap fixed the issue.