Iridium vs Copper plugs - recent info after plug change

**Bagheera223** · 03-16-2015 12:21 PM

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I got my B5 S4 with 180k miles back in 2010. I am the third owner and car has many HP parts including APR 3 chipset and K04 turbos. Now at 244k miles and though it has some oil leaks and a coolant leak it still can do aorund 0-60 in about 4 secs and will hit almost 29 mpg if I keep it under 70 mph. When I first changed the plugs after getting it I put in the NGK iridiums and after getting some misfires regapped them to around .028. That seemed to help, but if I really got on it there would still be some stuttering so I didn't push it and see the blinking light in dash. Well yesterday I changed the plugs for some copper NGK BRK7Es and immediately noticed a smoother idle and better power off throttle. I decided to check the gaps on the old plugs for reference. These iridiums had somewhere between 25k miles and that should have been well within their usuable lifespan. Well here are the gaps that I found after pulling them: Cyl 1: .035 Cyl 2: .035 Cyl 3: .040 Cyl 4: .040 Cyl 5: .040 Cyl 6: .034

This tells me that the iridium plugs aren't lasting as long as predicted, and since I'm getting better performance now I will never use them again! I was thinking of going with the Bosch side-fires, but have heard about major failures that caused damage and I can't afford to take the chance. But I thought I would share this with all of you since there always seems to be a debate around iridium vs copper. BTW, I gapped them to .025.

**Audimilo** · 03-16-2015 08:22 PM

there is no debate. copper always works better, doesnt last as long. known that since the Quattro Coupe days.

**993GT** · 03-16-2015 08:50 PM

never have I seen a car so picky on plugs(for given power and being C.O.P.!)...
that said, after I installed new BKR6EGP's(with new BERU coils) gapped at .030" my stg2 runs well...out of box gap @~.037" was horrible once coils were heat soaked...

**julex** · 03-17-2015 05:44 AM

yeah, well, it is a known fact that some plugs, especially if you put too hot plugs into your engine (like NGK "6" iridiums designed for grandma with k03 she will never use) which is heavily upgraded, will run too hot and will "grow" the gap with time. It is really about choosing the right heat range for the application. I run BKR8IEX (yes, 8!) which is a cold plug and nothing but awesomely running car being it idling to no end, cruising at -10inhg or stomping at 36psi. No misfires EVER.

**993GT** · 03-17-2015 06:10 AM

^huh? they're platinum's BTW, agree coppers are 'better' but don't feel like swapping them out every other oil change on my K03'd winter beater...
If you aren't pulling timing/see knock, why would you install a colder plug...I'll do another log, but am not expecting to see any change..
....second of all, just going colder on plugs is a Band-Aid solution for detonation control on basic builds...
having to gap a 'hot' plug down to .030" in a F.I. engine making ~110hp/L to avoid misfires is sad...
It's working great now and am enjoying the car.

**MileMan402** · 03-17-2015 06:23 AM

Originally Posted by julex

yeah, well, it is a known fact that some plugs, especially if you put too hot plugs into your engine (like NGK "6" iridiums designed for grandma with k03 she will never use) which is heavily upgraded, will run too hot and will "grow" the gap with time. It is really about choosing the right heat range for the application.[...]

QFT

**NOTORIOUS VR** · 03-17-2015 07:04 AM

Originally Posted by 993GT

If you aren't pulling timing/see knock, why would you install a colder plug.......

second of all, just going colder on plugs is a Band-Aid solution for detonation control on basic builds...

You have completely the wrong idea about plug heat ranges.

**993GT** · 03-17-2015 07:09 AM

I do eh?
want to explain...

Originally Posted by NOTORIOUS VR

You have completely the wrong idea about plug heat ranges.

**NOTORIOUS VR** · 03-17-2015 07:12 AM

Originally Posted by 993GT

I do eh?
want to explain...

Not really. There's lot of info out there that will explain to you the purpose of selecting a correct heat range.

**993GT** · 03-17-2015 07:20 AM

lol exactly...

heat ranges have nothing to do with how hot/strong the spark is, its about insulation value/ability to keep the electrode(s) at a correct operating temp to avoid fouling and detonation.
there is no reason to go to a colder plug if there is no timing being pulled/adjusted from the base map...using a colder plug here has 0 merit in my application.

**NOTORIOUS VR** · 03-17-2015 07:24 AM

Originally Posted by 993GT

lol exactly...

heat ranges have nothing to do with how hot/strong the spark is, its about insulation value/ability to keep the electrode(s) at a correct operating temp to avoid fouling and detonation.
there is no reason to go to a colder plug if there is no timing being pulled/adjusted from the base map...using a colder plug here has 0 merit in my application.

Exactly what? That you don't know why or when you should choose a different heat range?

You don't choose a plug based on knock activity.

**993GT** · 03-17-2015 07:27 AM

Ok, what do you base it on? why should I go to a colder plug when its not required?...
anyone have a technical basis why they went to a colder plug, or just forum hype...

Originally Posted by NOTORIOUS VR

Exactly what? That you don't know why or when you should choose a different heat range?

You don't choose a plug based on knock activity.

**NOTORIOUS VR** · 03-17-2015 07:35 AM

Originally Posted by 993GT

Ok, what do you base it on? why should I go to a colder plug when its not required?...
anyone have a technical basis why they went to a colder plug, or just forum hype...

You're more then welcome to put in some effort and look it up yourself like I said, there's lots of information out there about it.. If you're still confused after some light reading then I can explain further.

Forum hype as nothing to do with it at all. All the more reason for you to actually read up about what you're talking about instead of making assumptions about it.

**993GT** · 03-17-2015 07:42 AM

all right buddy thanks...

no detonation, no fouling, plugs 'read' right when inspected...yup, I have it wrong!

**Meow** · 03-17-2015 07:54 AM

Tune on copper, once the fueling is dialed in moved to iridium so you don't foul expensive plugs, they will work good for any 2.7t car.

**NOTORIOUS VR** · 03-17-2015 07:54 AM

Originally Posted by 993GT

all right buddy thanks...

no detonation, no fouling, plugs 'read' right when inspected...yup, I have it wrong!

CSB

**S4NIK8** · 03-17-2015 07:58 AM

http://www.ngksparkplugs.com/tech_su...k_plugs/p2.asp

**Zba** · 03-17-2015 07:58 AM

CSB?

**JVD** · 03-17-2015 08:07 AM

Originally Posted by Zba

CSB?

**Zba** · 03-17-2015 08:23 AM

oh haha

**christianb5s4** · 03-17-2015 08:37 AM

So for a stage 2 car that gets romped on, 7 heat range is still ideal correct? And sidefires are still the best plugs?

**julex** · 03-17-2015 08:44 AM

since when sidefires are best plugs? On contrary, my experience with sidefires is that they're junk, I had tons of misfires with them and then I also saw that somebody's plug dropped ceramic into the cylinder with rather nasty results.

They're not that great mostly because of non-adjustable gap and the fact that the flame is not centered and not deep in the piston area but shallow and on the side.

Anecdote says that people with sidefires can re-gain lost HP by clocking them properly... haha.

**Maruzen75** · 03-17-2015 08:55 AM

Originally Posted by julex

since when sidefires are best plugs? On contrary, my experience with sidefires is that they're junk, I had tons of misfires with them and then I also saw that somebody's plug dropped ceramic into the cylinder with rather nasty results.

They're not that great mostly because of non-adjustable gap and the fact that the flame is not centered and not deep in the piston area but shallow and on the side.

Anecdote says that people with sidefires can re-gain lost HP by clocking them properly... haha.

I ran bkre7iex for a while on my stage 3 and it never felt that great, switched to bkr7e's and felt a whole lot better. This could be due to the gap (believe it was .26 for both) but I really don't know. I have also been told that the platinum plugs are better for the 2.7 so I have no idea what is best lol. I do know that sidefires are junk though.

**JVD** · 03-17-2015 09:14 AM

I just run the copper 7's at .028ish.

Seems fine. I change them often because they're literally cheaper than peanuts.

Never ran the iridiums so I can't comment.

**christianb5s4** · 03-17-2015 09:27 AM

Originally Posted by julex

since when sidefires are best plugs? On contrary, my experience with sidefires is that they're junk, I had tons of misfires with them and then I also saw that somebody's plug dropped ceramic into the cylinder with rather nasty results.

They're not that great mostly because of non-adjustable gap and the fact that the flame is not centered and not deep in the piston area but shallow and on the side.

Anecdote says that people with sidefires can re-gain lost HP by clocking them properly... haha.

Oh really? I did a fair amount of research into the best spark plugs and I saw them recommended a lot. What would you recommend for a stage 2 car then?

Edit: I went back through and searched, there are so many opinions. Which copper plug and what gap should a stage 2 car run? TIA

**hibiscusS4** · 03-17-2015 09:58 AM

i put lil cavemen discovering fire in my cylinders shit works great everyone in a while i toss down more wood and some peanuts and they go nuts....

**NOTORIOUS VR** · 03-17-2015 10:42 AM

Originally Posted by Maruzen75

I ran bkre7iex for a while on my stage 3 and it never felt that great, switched to bkr7e's and felt a whole lot better. This could be due to the gap (believe it was .26 for both) but I really don't know. I have also been told that the platinum plugs are better for the 2.7 so I have no idea what is best lol. I do know that sidefires are junk though.

I have a feeling that most people don't realize that by gapping an Iridium plugs you can very easily break off or damage the tip without even noticing.

There should be no reason for them not to work unless you have a fault elsewhere in your ignition system. It's wise to keep in mind that a weak ignition system will show it's faults much sooner with Iridium tipped plugs vs copper as well (ie. weak/dying coils & boots).

**christianb5s4** · 03-17-2015 10:53 AM

Going to order a dozen copper BKR7Es, before I do are these gapped at .026 the right setup for a stage 2 car?

**NOTORIOUS VR** · 03-17-2015 11:14 AM

Originally Posted by christianb5s4

Going to order a dozen copper BKR7Es, before I do are these gapped at .026 the right setup for a stage 2 car?

7E's fair well in anything from stock to pretty wild setups for the most part. I use them in most cars up to around 600whp (2wd).

The resulting gap always comes down to ignition system health and cylinder pressure. So for most B5 S4er's with unknown ignition system health anywhere between 0.024-0.026 is going to be fine.

**christianb5s4** · 03-17-2015 11:23 AM

Originally Posted by NOTORIOUS VR

7E's fair well in anything from stock to pretty wild setups for the most part. I use them in most cars up to around 600whp (2wd).

The resulting gap always comes down to ignition system health and cylinder pressure. So for most B5 S4er's with unknown ignition system health anywhere between 0.024-0.026 is going to be fine.

Thank you sir, sorry for the noobish question. Just so many opinions floating around.

**Maruzen75** · 03-17-2015 11:49 AM

Sorry I should've clarified, mine were pregapped I just don't know the gap they were. I believe it was .028. Ignition system is perfect, no codes whatsoever and coil packs are newer but it still runs better with coppers. I'd like to try platinums at some point.

**demonmk2** · 03-17-2015 12:08 PM

I've used NGK 4554's cheap and seem to work good.

**HighPsi(NorCal)** · 03-17-2015 12:50 PM

Originally Posted by demonmk2

I've used NGK 4554's cheap and seem to work good.

Cheap compared to what? From Summit - NGK 4664 = $2.49 / NGK 4554 = $3.49..........................Not to mention the 4554 is a non resisted plug vs. v-power plugs that have a 5k resistor built in. Without the proper resistance the computer can see a variation that is unacceptable and throw a code. Not to mention, a heat range 8+ is not called for most cars on this board and can have negative effects on performance.

http://www.ngksparkplugs.com/techinf...200&country=US

http://www.ngk.com.au/spark-plugs/te...ge-explanation

**killerkali** · 03-17-2015 12:57 PM

Originally Posted by demonmk2

I've used NGK 4554's cheap and seem to work good.

ive been chasing high load misfires and I have always ran BKR7Es, I reluctantly tried the 4554 NON resistors plugs because my friend with a 500+hp AAN has good results with them. It may have been a coincidence or not, but with the 4554s i ran fine for 5 minutes than was misfiring on literally every cylinder, and somehow 2 of my 2.0t coils died in that process........ Put in the old BKR7Es and all is well again. Again could have been a fluke but I say stay away from non resistor plugs !

**dannyn424** · 03-17-2015 01:17 PM

umm no..... ive used ngk 7173 and they were fine.. tried the bk7re's.... didnt like them......my car likes the bk8reix.... now at .024.......

**killerkali** · 03-17-2015 01:19 PM

Originally Posted by dannyn424

umm no..... ive used ngk 7173 and they were fine.. tried the bk7re's.... didnt like them......my car likes the bk8reix.... now at .024.......

you have other issues if your car didn't "like" BKR7Es.

**MetalMan** · 03-17-2015 01:26 PM

Originally Posted by Maruzen75

Sorry I should've clarified, mine were pregapped I just don't know the gap they were. I believe it was .028. Ignition system is perfect, no codes whatsoever and coil packs are newer but it still runs better with coppers. I'd like to try platinums at some point.

BKR7E should come pre-gapped at about 0.032", at least when purchased individually.

**demonmk2** · 03-17-2015 01:36 PM

the ones I've used were v-power..

the bk7re's did not sit well with the car which is why I switched.
I guess these cars have there own individual temperaments.