NGK 91006 SILFER8C7ES Spark Plugs for 2015 s3/APR Stage 1

[dhomes]

So I bought a set of these off ecstuning.com, apparently these are the new sparks audi uses for RS3/RS7:

https://www.ngk.com/ngk-91006-silfer...um-spark-plug#

Anyone has had experience with these on a 2015 S3 with APR stage 1?

These come gapped at 0.028", APR recommends 0.024", but for a different set of sparks.

Does 0.004" (1mm) make that much of a difference? right now I have the 91 map but next week I'm taking it for the 93

From NGK:
Torque Specs:
Cast Iron: 18-25.3 lb. ft. Aluminum: 18-21.6 lb. ft.

Is 22 lb-ft adequate for a 2015 S3?

Any help is appreciated

[MikTip]

I have run every spark plug imaginable in my Stage 1 S3. Beru Side fire...NGK Iridium...RS7 plugs...etc...

The SILFER8C7ES have been around for a while...allot of Golf R guys ran them...very few S3 drivers have...



https://www.vwvortex.com/threads/rs7...eview.8230881/

I don't gap them...cause you risk damaging the fine wire electrode and it requires a spark plug gapping tool.

There was an issue with a batch of them a few years ago...

https://www.golfmk7.com/forums/index....339274/page-6

The OE S3 spark plug gap is .032...the RS3/RS7 motors are very different and they run the .028...for reasons their engineers felt was the gap needed.

Do you have upgraded ignition coils? APR coils? Stock?

The spark plug I found which runs the best on my S3 is the NGK 95125 Ruthenium HX.

Its pre gapped to .032.

Combined with RS3 coils and or APR coils I feel a noticeable difference.

[dhomes]

hey Nik, thanks for the input,

Yes I also have the apr coils at hand, was planning on installing all at once

the 0.028" I mentioned is according to what NGK states here: https://www.ngk.com/ngk-91006-silfer...ium-spark-plug

I did buy a gapping tool:
https://www.amazon.com/dp/B08MPM7VJG...roduct_details

You mentioned that you have HAD RS7 plugs, did they give you a problem? what gap did you use? Why do you consider NGK 95125 Ruthenium HX better than the NGK 91006 SILFER8C7ES (RS7)?

I just replaced the stock one during the 75k service with OEM for the car, but after the tune if I do read hard pulls I get rough shifts and misfires here and there (APR coils aren't there yet).

What would the best course of action be?
Just drop the APR coils with OEM?
replace with RS7 + APR Coils?
the ruthenium + APR Coils?

[dhomes]

also, got this for checking the gap: https://www.amazon.com/dp/B06XHXJG31...roduct_details

Those are the supposedly recommended for iridium batteries

[MikTip]

hey Nik, thanks for the input,

Yes I also have the apr coils at hand, was planning on installing all at once

the 0.028" I mentioned is according to what NGK states here: https://www.ngk.com/ngk-91006-silfer...ium-spark-plug

I did buy a gapping tool:
https://www.amazon.com/dp/B08MPM7VJG...roduct_details

You mentioned that you have HAD RS7 plugs, did they give you a problem? what gap did you use? Why do you consider NGK 95125 Ruthenium HX better than the NGK 91006 SILFER8C7ES (RS7)?

I just replaced the stock one during the 75k service with OEM for the car, but after the tune if I do read hard pulls I get rough shifts and misfires here and there (APR coils aren't there yet).

What would the best course of action be?
Just drop the APR coils with OEM?
replace with RS7 + APR Coils?
the ruthenium + APR Coils?

How old are the current coils?

.028 is what comes pre gapped on the RS7 plugs...I personally dont gap them...can if I have too...IMO the S3 runs better with .032 gapped plugs and many come with .032 so no risks.

95% of S3 ignition issues are the coil packs.

If your on 2015 coil packs...they have been superseded by Audi several times since 2015 so replacing the coils should make a noticeable difference.

In the URL I posted above the Golf drivers had issues with RS7 plugs so everyone shy'd away from them...turns out it was a certain batch and ones people regapped incorrectly...

I would just install the APR coils and see how it runs. Then maybe later try a different plug...

[MikTip]

I had rough shifts and miss-fires...turned out to be two bad fuel injectors...

If the new APR coils don't fix the rough shifts and miss-fires...you may have a similar issue.

Audi has replaced the fuel injectors allot since 2015 too!

My original 2015 injectors were "L" version...the new ones were "AK'...

Plus my valves were highly carbon fouled...so had to clean them too.

After all that my S3 runs great!

[dhomes]

How old are the current installed spark plugs? How old are the current coils?

.028 is what comes pre gapped on the RS7 plugs...I personally dont gap them...can have too...but the S3 runs better with .032 gapped plugs and many come with .032.

95% of S3 ignition issues are the coil packs. If your on 2015 coil packs...they have been superseded by Audi several times since 2015 so replacing the coils will make a noticeable difference.

In the URL I posted above the Golf drivers had issues with RS7 plugs so everyone shy'd away from them...turns out it was a certain batch and ones people regapped incorrectly...

Get what ever plug you want. Try the RS7's. They don't have to stay in there forever! Or just install the APR coils and see how it runs.

OEM S3 spark plugs were replaced <3 months ago (78K now, 75K at replacement)
Coils are still the OG that came with car, 75K miles later, have the APR Coils at hand still in box (these I'm installing regardless of plugs)

Yeah I did double check and I do have the M revision they mentioned there, they just got here from ecstuning, link did scare me a bit. These being my first time gapping and changing on my own I'm thinking on being on the safe side and use the ruthenium you recommended (from what I read iridium ones are more delicate on this)

Thanks for the help btw, new to all this tuning world :), was looking forward to get the new RS3 but It just disappointed me big time in the looks department (just my opinion). Might at well use my trusty S3 until I can afford a 911

[MikTip]

OEM S3 spark plugs were replaced <3 months ago (78K now, 75K at replacement)
Coils are still the OG that came with car, 75K miles later, have the APR Coils at hand still in box (these I'm installing regardless of plugs)

Yeah I did double check and I do have the M revision they mentioned there, they just got here from ecstuning, link did scare me a bit. These being my first time gapping and changing on my own I'm thinking on keeping on the safe side and use the ruthenium you recommended (from what I read iridium ones are more delicate on this)

Thanks for the help btw, new to all this tuning world :), was looking forward to get the new RS3 but It just disappointed me big time in the looks department (just my opinion). Might at well use my trusty S3 until I car afford a 911

Let me know how it runs after the APR coils installed!

[dhomes]

Let me know how it runs after the APR coils installed!

How much did the injectors cost? same for valve cleaning?

[dhomes]

just check and the ngk came at .025", think I might go with them after all

[dhomes]

just check and the ngk came at .025", think I might go with them after all

[MikTip]

How much did the injectors cost? same for valve cleaning?

Injectors were $100 each and I DIY'd the carbon cleaning and injectors...

[MikTip]

The factory spec is 0.7mm to 0.8mm on the gaps

[ItsLarryG]

I ran these in my Stage 3 S7 and changed out all of the coils (NGK) at the same time because I was around 100k and wasn't sure if my misfires were because they were old and crossed my fingers it wasn't a bad injector because I would have to pull the whole engine. Everything ran great after swapping plugs and coils out. Without changing any of the gaps, they were all within a couple thousandths of whatever the required RS7 spec was.

This probably doesn't help much for an S3, but I wanted to tell anyone else considering trying these the minor gap variance worked fine and that Rock Auto carries all of these parts way cheaper than any of the tuning companies. I just checked my receipt and 8x plugs and coils was $400 a little less than two years ago, which I think was not a whole lot more than only plugs from a tuner.

[dhomes]

thanks for the info Larry, will check Rock Auto

I put in the APR coils today and left the OEM Plugs for now (they have less than 3k), will return the NGK and get these: Denso Spark Plugs 5749 https://bit.ly/3bXsWI8
Read these are way safer than the ngk and dont need gaping

on the coils... WHAT A DIFFERENCE!!!, the shifts instantly became super smooth and not noticeable misfires, ran my OBD-II tool and no codes showed up.

only tested for about an hour but will report if something changes

[MikTip]

thanks for the info Larry, will check Rock Auto

I put in the APR coils today and left the OEM Plugs for now (they have less than 3k), will return the NGK and get these: Denso Spark Plugs 5749 https://bit.ly/3bXsWI8
Read these are way safer than the ngk and dont need gaping

on the coils... WHAT A DIFFERENCE!!!, the shifts instantly became super smooth and not noticeable misfires, ran my OBD-II tool and no codes showed up.

only tested for about an hour but will report if something changes

Intergrated Engineering stated 95% of ignition issues are coils.

Good to hear it runs good and you replaced those 2015 coils!