Stage 2 Spark Plug (what does/doesn't work)

[aaronz]

Looking to change out mine, went OEM last time and then went stage 2 shortly after. Time to change them again and not sure if OEM is still the goto, or if there is anything else recommended out there.

Saw one post on another forum where a guy was running a 9 plug, (OEM is 8).

Jones had posted here:
http://www.audizine.com/forum/showthread.php?t=62510
But other than that not much else to go on.

GIAC tune

@Austin, any recommendations or differences you guys have noticed in a change of plugs (brand or make/ model, etc)

-AZ


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[derek.kritz]

I just picked up NGK iridium's. BKR8IEX. I've used iridium plugs on all my cars and have had great success. Plus they are cheaper. . I'd stick with the 8's for sure.


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[aaronz]

Says not comparable with my car (via Amazon) not sure if that due to b8 to b8.5?

NGK website only goes up until 2010....


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[derek.kritz]

Buddy has been running them for 10k miles no prob. Somebody on here turned me on to them. I'll try to find the thread.


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[derek.kritz]

http://www.audizine.com/forum/showthread.php?t=625109


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[aaronz]

Thanks! Yep that's the same thread I posted up top.




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[derek.kritz]

Haha. Yes it is. Sorry, didn't even look at it...


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[raudiace4]

So will these fit? They are cheaper then OEM recommended from ECS. I need to change out my plugs soon.

[derek.kritz]

So will these fit? They are cheaper then OEM recommended from ECS. I need to change out my plugs soon.

Yup. Fit great and I do like iridium plugs.


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[raudiace4]

Yup. Fit great and I do like iridium plugs.


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Sweet thanks!

[ChobeG]

I have modified a few vehicles in the past and used one step colder plugs to overcome the additional heat being generated by the extra power... that way the car runs smoother... However, it really depends on the modifications that you have in mind and power increase from standard. A cold air intake, an exhaust system, downpipes or headers.. anything bolt on that doesn't add any more than 20hp - 30hp or alter the compression ratio, you should be fine with the factory recommended heat range spark plugs.

However if you alter the compression ratio or if you're adding extra horse power within the range of say; 80hp+ from standard, then you should move to one-step-colder within the heat range of the plug to overcome the extra heat in the combustion chamber. I think the rule of thumb is for every 80-100 HP more, you go one step colder.

One thing to keep in mind is to always check and adjust the gaping on the plug.. as i have noticed that even plugs sold specific to a car the gap varies from plug to plug.... All plugs i have received had different gaps so always adjust it to suit your car recommendation which are normally listed on the service manual.. You can also play around with the gap for improved smoothness, but unless you're well equipped with testing tools to see how much of a difference a gap makes on the engine, i would stick with the recommended.

There's a little more info you might be able to find and sites that conduct performance testing on plugs... I have always used Denso plugs as these have performed better on some tests on Mazdas, but this is the first time i have owned an audi and i'm still finding my way around the car.. you can get NGK Platinums or Denso Iridiums or Bosh... all may perform a little better than others but over all both Platinums or Iridium tips all perform very well...

So... unless your Giac tune will give you 80hp+ improvement on standard... there's no point in changing heat range...

[saxon]

stick with stock, after 10k miles of stage 2 mine looked great

[mrmomo313]

I replaced with stock from ecs, been working great

[Chandler]

I have modified a few vehicles in the past and used one step colder plugs to overcome the additional heat being generated by the extra power... that way the car runs smoother... However, it really depends on the modifications that you have in mind and power increase from standard. A cold air intake, an exhaust system, downpipes or headers.. anything bolt on that doesn't add any more than 20hp - 30hp or alter the compression ratio, you should be fine with the factory recommended heat range spark plugs.

However if you alter the compression ratio or if you're adding extra horse power within the range of say; 80hp+ from standard, then you should move to one-step-colder within the heat range of the plug to overcome the extra heat in the combustion chamber. I think the rule of thumb is for every 80-100 HP more, you go one step colder.

One thing to keep in mind is to always check and adjust the gaping on the plug.. as i have noticed that even plugs sold specific to a car the gap varies from plug to plug.... All plugs i have received had different gaps so always adjust it to suit your car recommendation which are normally listed on the service manual.. You can also play around with the gap for improved smoothness, but unless you're well equipped with testing tools to see how much of a difference a gap makes on the engine, i would stick with the recommended.

There's a little more info you might be able to find and sites that conduct performance testing on plugs... I have always used Denso plugs as these have performed better on some tests on Mazdas, but this is the first time i have owned an audi and i'm still finding my way around the car.. you can get NGK Platinums or Denso Iridiums or Bosh... all may perform a little better than others but over all both Platinums or Iridium tips all perform very well...

So... unless your Giac tune will give you 80hp+ improvement on standard... there's no point in changing heat range...

That is interesting. I never considered needing to move from stock plugs. I intend to run an E85 map which will put out well over 100+ hp from the stock numbers. Would changing the plug ratting by one have negative impacts in the lower RPMs were there are only small gains?

[ChobeG]

That is interesting. I never considered needing to move from stock plugs. I intend to run an E85 map which will put out well over 100+ hp from the stock numbers. Would changing the plug ratting by one have negative impacts in the lower RPMs were there are only small gains?

One step colder plugs will not directly affect or improve your car performance, these are designed purely to prevent heat in the combustion chamber or for such heat to travel right down to the tip of the plug and potentially cause an early detonation of the mixture when extra power is added to an engine. More power means more heat!....So a plug that is one step colder is rated to handle more heat and prevent detonation or knocking. .. engine detonation is never good for a car as we know...

The aim of changing the plug rating is so you can maintain proper ignition, the intended performance and idle smoothness without detonation.. it doesn't have any negative impacts throughout the rev range..

This is my understanding and the things I've learnt from playing with cars :)

[Chandler]

So is a 9 or a 7 rated 'colder'? Would the above me it's advisable for anyone with an aggressive tune to move up a plug? It doesn't sound like there is a negative, only a positive or preventive.... the plugs are not that much more expensive.

[schirm]

I have modified a few vehicles in the past and used one step colder plugs to overcome the additional heat being generated by the extra power... that way the car runs smoother... However, it really depends on the modifications that you have in mind and power increase from standard. A cold air intake, an exhaust system, downpipes or headers.. anything bolt on that doesn't add any more than 20hp - 30hp or alter the compression ratio, you should be fine with the factory recommended heat range spark plugs.

However if you alter the compression ratio or if you're adding extra horse power within the range of say; 80hp+ from standard, then you should move to one-step-colder within the heat range of the plug to overcome the extra heat in the combustion chamber. I think the rule of thumb is for every 80-100 HP more, you go one step colder.

One thing to keep in mind is to always check and adjust the gaping on the plug.. as i have noticed that even plugs sold specific to a car the gap varies from plug to plug.... All plugs i have received had different gaps so always adjust it to suit your car recommendation which are normally listed on the service manual.. You can also play around with the gap for improved smoothness, but unless you're well equipped with testing tools to see how much of a difference a gap makes on the engine, i would stick with the recommended.

There's a little more info you might be able to find and sites that conduct performance testing on plugs... I have always used Denso plugs as these have performed better on some tests on Mazdas, but this is the first time i have owned an audi and i'm still finding my way around the car.. you can get NGK Platinums or Denso Iridiums or Bosh... all may perform a little better than others but over all both Platinums or Iridium tips all perform very well...

So... unless your Giac tune will give you 80hp+ improvement on standard... there's no point in changing heat range...

When I changed my Spark plugs I PM'd the guys at APR they told me not to go with colder plugs, Stay OEM

[ChobeG]

So is a 9 or a 7 rated 'colder'? Would the above me it's advisable for anyone with an aggressive tune to move up a plug? It doesn't sound like there is a negative, only a positive or preventive.... the plugs are not that much more expensive.

the higher the number the better the plug can handle heat.. so a 4 would be a hot plug... a 10 would be a colder plug.. if you move up two rating then you're going two steps colder... HOWEVER... you must keep in mind and i will add that this is why it is important to know your HP increase from base line.. if you go for a colder plug where it isn't necessary, the car may still respond well, but over time since the plug isn't getting too hot (or working at the right temp), carbon deposits will form around the plug which will eventually affect the quality of the spark, as a result the responsiveness of engine may or may not be noticeably affected since the tip will be covered in carbon. SO.. whilst some tuners or books may tell you to move up a rating as a prevention against detonation when power has been increased from base line, you must monitor the plugs if you do change ratings to ensure that these are not getting totally black (covered in carbon)...

In one of my cars i changed from the recommended rating 8 to 9 (colder) since i increased boost from 8PSI (OEM) to 18 PSI along with a few mods that combined on paper were to increase power by 75-80hp... after several kilometers i did a minor service and checked my plugs, that's when noticed that my plugs were completely black or totally covered in carbon.. that was an indication that the plugs were not getting hot enough so i stepped back down to a temp rating of 8.

Hope that explains it well...


Chandler,

With the tunes the mainstream tuners do on these cars... i don't think I would change the temp rating of the plug as APR may have advised you either, unless a dyno proved to me that my engine had gained an extra 100hp on paper..and if i did ... i would still monitor the plugs to make sure there were no carbon deposits being build up.. which will be very obvious as the plug will be covered in total darkness.. haha...

[Austin@GIAC]

Looking to change out mine, went OEM last time and then went stage 2 shortly after. Time to change them again and not sure if OEM is still the goto, or if there is anything else recommended out there.

Saw one post on another forum where a guy was running a 9 plug, (OEM is 8).

Jones had posted here:
http://www.audizine.com/forum/showthread.php?t=62510
But other than that not much else to go on.

GIAC tune

@Austin, any recommendations or differences you guys have noticed in a change of plugs (brand or make/ model, etc)

-AZ


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I still run stock plugs in my car and haven't had any issues with them.

[derek.kritz]

Just asked my tuner, EPLabs, what plugs they run on their stage 2. They said 8's.


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[Chandler]

the higher the number the better the plug can handle heat.. so a 4 would be a hot plug... a 10 would be a colder plug.. if you move up two rating then you're going two steps colder... HOWEVER... you must keep in mind and i will add that this is why it is important to know your HP increase from base line.. if you go for a colder plug where it isn't necessary, the car may still respond well, but over time since the plug isn't getting too hot (or working at the right temp), carbon deposits will form around the plug which will eventually affect the quality of the spark, as a result the responsiveness of engine may or may not be noticeably affected since the tip will be covered in carbon. SO.. whilst some tuners or books may tell you to move up a rating as a prevention against detonation when power has been increased from base line, you must monitor the plugs if you do change ratings to ensure that these are not getting totally black (covered in carbon)...

In one of my cars i changed from the recommended rating 8 to 9 (colder) since i increased boost from 8PSI (OEM) to 18 PSI along with a few mods that combined on paper were to increase power by 75-80hp... after several kilometers i did a minor service and checked my plugs, that's when noticed that my plugs were completely black or totally covered in carbon.. that was an indication that the plugs were not getting hot enough so i stepped back down to a temp rating of 8.

Hope that explains it well...


Chandler,

With the tunes the mainstream tuners do on these cars... i don't think I would change the temp rating of the plug as APR may have advised you either, unless a dyno proved to me that my engine had gained an extra 100hp on paper..and if i did ... i would still monitor the plugs to make sure there were no carbon deposits being build up.. which will be very obvious as the plug will be covered in total darkness.. haha...

This is the best answer with the most amount of useful information I believe. Basically if you feel you need to move up, check the plugs after a few thousand miles to verify they are getting hot enough and not retaining carbon deposits. I will be sticking with the 8s I suppose!

Thanks!

[aaronz]

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[rs4dreams]

What about service interval? The recommendation in the manual is to change at 55k. Does it make sense to do early, especially if running a stage 2 setup?

[CloseEncounters]

Good thread...just had my 35,000k Mile service done and I asked my service adviser to just throw the plugs (Audi calls for a plug replacement at 35K) in the trunk as I've been 25,000 miles on an APR STG 2 Tune with ZERO issues (knock on wood). The OEM plugs are 'VW AG' PN 06H 905 621 ( Made in France :)

Wondering now if i should switch to the NGK's or Iridium's or just install the new OEM plugs I have.

[bpang1]

I still run stock plugs in my car and haven't had any issues with them.

^^^Right thar.

Best advice is what your tuner will recommend to you.

[D-Press]

Good thread...just had my 35,000k Mile service done and I asked my service adviser to just throw the plugs (Audi calls for a plug replacement at 35K) in the trunk as I've been 25,000 miles on an APR STG 2 Tune with ZERO issues (knock on wood). The OEM plugs are 'VW AG' PN 06H 905 621 ( Made in France :)

Wondering now if i should switch to the NGK's or Iridium's or just install the new OEM plugs I have.

http://www.ngksparkplugs.com/part_fi...?engineid=1328

I only see NGK Laser Platinum....do they make Iridium for our car?

[rs4dreams]

Good thread...just had my 35,000k Mile service done and I asked my service adviser to just throw the plugs (Audi calls for a plug replacement at 35K) in the trunk as I've been 25,000 miles on an APR STG 2 Tune with ZERO issues (knock on wood). The OEM plugs are 'VW AG' PN 06H 905 621 ( Made in France :)

Wondering now if i should switch to the NGK's or Iridium's or just install the new OEM plugs I have.

The info I could find said that plugs are to be replaced at 55k. Where did you get that info?