I am getting ready to change out my plugs, but I remember Dinan saying to stay with stock heat range. Can anyone tell me why they don't go to a colder plug with their s/c setups?

Does it run lower boost levels than other kits?

7 PSI and conservative tunning...and they want to keep the cars as close to factory as possible.

Not enough power?

yeah they're not making power to require it - no big deal. Going to 7's can't hurt it.

My car was one of first E39's out of Steve's shop. It was mine, Jimmy540i and DanB. They all were running about 9.5 psi, but due to problems with Jimmy540i's car, they started de-tuning this setup. I found this out when I had my car dyno'd and wondered why I was at 400rwhp. Jimmy said the hp was about right based on the original tune the early E39's had. That being said, what should I do?

I was also reading that you can tell whether you should run colder or hotter plugs just by reading them. Is this true for a street car? Also, I have a cold hesitation problem and I was wondering if this could be related. Thanks!

It is true but if your plugs have been in there for a while you won't have much luck.

Trust us - go buy 7 temp plugs, plop them in, it'll cost you about $18 or so. You won't do any damage at all - go see how it feels.

Hopefully on a related note, I went with the colder NGK plugs [4091's] before my C38 installation [i.e., basically stock] and they seemed to work better than the ones I bought from the dealer. Acceleration was smooth throughout the range whereas before I would get some hesitation.

It is true but if your plugs have been in there for a while you won't have much luck.

Trust us - go buy 7 temp plugs, plop them in, it'll cost you about $18 or so. You won't do any damage at all - go see how it feels.

Okay, but what is a 7 temp plug?

Okay, but what is a 7 temp plug?


+1 I would like to know too.

Researched: Stock NGK plugs are BKR6EK. 7 temp plugs would be the next colder plug. I was going to buy iridiums and I want to make the right choice before I spend ~$10 a piece on plugs. BTW NGK does not make iridium plugs for an E39 - I have to go with Denso IK20's or IK22's for the colder version.

Also, I called Dinan to find out if they used colder plugs on my tune.

Also, I called Dinan to find out if they used colder plugs on my tune.
Which plugs are you going with and what did Dinan say?

Iridiums don't fire as well on boosted applications. Stay with copper plugs, and either BKR6EK if you rarely drive it hard or if you live in a cold climate. Go with BRK7EK for running hard.

Biggest difference in plug temp for most engines is how it behaves on cold start. Your aluminum V8 with Dinan parts should never have detonation issues on stock heat-range plugs.

Iridiums don't fire as well on boosted applications.

Really? I thought part of the marketing spiel for Iridiums was that they complemented an FI setup better than 'traditional' plugs.

I know I am not FI'd, but... I use BKR6EK's right now. I drive pretty hard, would the 7's help at all? Or should I just STFU since im not FId

I know I am not FI'd, but... I use BKR6EK's right now. I drive pretty hard, would the 7's help at all? Or should I just STFU since im not FId

HAHAHA my quote made your profile.

If you aren't seeing any misfire issues then you are fine. Heat range doesn't have anything to do with actual performance (voltage). It is an adjustment to the plug insulation to keep temperatures in a ~350 degree range.

http://www.ngksparkplugs.com/techinfo/spark_plugs/overviewp2.asp

I have a set of BKR7E (NGK V-Power) in my car. They seem to work really well.

Iridiums don't fire as well on boosted applications. Stay with copper plugs, and either BKR6EK if you rarely drive it hard or if you live in a cold climate. Go with BRK7EK for running hard.

Biggest difference in plug temp for most engines is how it behaves on cold start. Your aluminum V8 with Dinan parts should never have detonation issues on stock heat-range plugs.
I am not doubting what you say as you must have a reason for recommending the copper over iridium, but I found this on sparkplugs.com and it is very convincing that iridiums do much better on a boosted engine.

http://www.sparkplugs.com/sparkplug411.asp?kw=SRT%2D4+Dyno+Results&mfid=0

http://www.sparkplugs.com/glossaryImages/499.jpg

Iridiums don't fire as well on boosted applications. Stay with copper plugs, and either BKR6EK if you rarely drive it hard or if you live in a cold climate. Go with BRK7EK for running hard.

....

Do we know this to be factually true across the board? Ive detected no difference on dyno and road results with the Denso Iridiums heat range 22 gapped to .028" when compared with a very basic copper R5671A-7 plug.

What is it about the iridiums that dont perform as well. You mention the firing. .Ive read that multi ground strap plugs are not as desirable on FI applications, but I havent seen any problems with the iridiums. I guess Im just lucky on this one.

Ive detected no difference on dyno and road results with the Denso Iridiums heat range 22 gapped to .028" when compared with a very basic copper R5671A-7 plug.

So why do you spend $11 - 12 a plug instead of $2?

So why do you spend $11 - 12 a plug instead of $2?

For similar performance, the r5671a7 plugs required regapping every few thousand miles, and replacement every 10k miles.. The iridiums last a whole lot longer. Im not saying they wind up being more economical, although they might be.. what im saying is for similar performance levels, i appreciate not having to gap and change them nearly so often.. thats why. Anyway, when these need replacing, I wont be spending $11-$12 a plug, but will use the less expensive iridiums by ngk BKR7EIX which cost about $7/plug.

For similar performance, the r5671a7 plugs required regapping every few thousand miles, and replacement every 10k miles.. The iridiums last a whole lot longer. Im not saying they wind up being more economical, although they might be.. what im saying is for similar performance levels, i appreciate not having to gap and change them nearly so often.. thats why. Anyway, when these need replacing, I wont be spending $11-$12 a plug, but will use the less expensive iridiums by ngk BKR7EIX which cost about $7/plug.

I like taking my plugs out to check them and read them anyway. If your plugs sit in your engine for more than 5k miles you may want to pull them out just to see what they say. Even 2 $7 plugs will buy you an entire set of copper $2 plugs.

I like taking my plugs out to check them and read them anyway. If your plugs sit in your engine for more than 5k miles you may want to pull them out just to see what they say. Even 2 $7 plugs will buy you an entire set of copper $2 plugs.

to each his own. Some people like taking their engines apart, just because. Some people do all kinds of things. Once youve seen how your engine relates to your tune, and have had it thoroughly tested on teh dyno and are monitoring all obdii functionality frequently, for me, I prefer NOT checking my plugs all the time.. Besides, it all depends on how much you drive etc, etc. Usually while testing out a new tune or new hardware, sure, I like to examine plugs as much as the next guy. But if youve settled in on a config, and have rung it out well, I personally prefer to not have to srvc them nearly as much as I did with the r5671a-7 plugs..

But, in the end, there IS no right or wrong answer; its a preference. Just like some people prefer dino oil and change it every 3k miles, and others prefer synthetic with less frequent changes. Its one of those things that has been beaten to death, not unlike this sparkplug issue.

I prefer to let people do what they want, without being dogmatic about either solution. Theyre both fine.. lets leave it at that.

I like taking my plugs out to check them and read them anyway. If your plugs sit in your engine for more than 5k miles you may want to pull them out just to see what they say. Even 2 $7 plugs will buy you an entire set of copper $2 plugs.

I posted my original question here because I know you all are looking for any advantage you can get in hp and torque. Based on the chart above I don't know why anyone would use copper.

If you look at the NGK Iridiums, they were consistent with all 3 runs in the hp and torque numbers. The Densos Iridiums have a 10 hp advantage over the OEM plug if you look at their averages. I'll pay $80 for 10 hp all day long.

I posted my original question here because I know you all are looking for any advantage you can get in hp and torque. Based on the chart above I don't know why anyone would use copper.

If you look at the NGK Iridiums, they were consistent with all 3 runs in the hp and torque numbers. The Densos Iridiums have a 10 hp advantage over the OEM plug if you look at their averages. I'll pay $80 for 10 hp all day long.

Combine the equal or better performance of the iridiums with the longevity they provide, while some may choose to stay with copper, I really cant see why anybody likes to criticize the iridiums.

Taking spark plugs out every 5k is hardly comparable to removing an engine. Its a good practice - for all you know your air/water intercooler is low or not doing its job well enough and your spark plugs will tell you. Its maintenance - plugs, like oil, should not sit in an engine for 15k miles.

Its not dogmatic - its practical. If you want to stick a plug in an engine and leave it for 20k miles go for it. But I won't read you say that and not at least suggest you do otherwise. An iridium will last longer, but you should take them out to check them regardless. Now you're holding them in your hand, you can just replace them while you're there. Theres really no point in spending 4x more for a plug that you should be looking at in the same schedule, and at that point can insert a $1.77 plug in its place that is just as good or better.

Being dogmatic is one thing but saying "Eh-before you go and stick plugs in for 20,000 miles on your high compression BMW engine with a supercharger... you should get into practice of checking the plugs every 3 - 5k just to make sure nothing looks out of the ordinary". And, if you accept that practice, then just stick new copper plugs in every other 5k miles. Done and done.

I posted my original question here because I know you all are looking for any advantage you can get in hp and torque. Based on the chart above I don't know why anyone would use copper.

If you look at the NGK Iridiums, they were consistent with all 3 runs in the hp and torque numbers. The Densos Iridiums have a 10 hp advantage over the OEM plug if you look at their averages. I'll pay $80 for 10 hp all day long.

Please do not pay any attention to that chart. There is no way you can consider a spark plug "more consistent" on a back to back dyno. .3 - 1 hp fluctuation on a 200 hp motor is a .5% change which is environmental and a standard deviation (in fact much more than that is expected).

Taking spark plugs out every 5k is hardly comparable to removing an engine. Its a good practice - for all you know your air/water intercooler is low or not doing its job well enough and your spark plugs will tell you. Its maintenance - plugs, like oil, should not sit in an engine for 15k miles.

Its not dogmatic - its practical. If you want to stick a plug in an engine and leave it for 20k miles go for it. But I won't read you say that and not at least suggest you do otherwise. An iridium will last longer, but you should take them out to check them regardless. Now you're holding them in your hand, you can just replace them while you're there. Theres really no point in spending 4x more for a plug that you should be looking at in the same schedule, and at that point can insert a $1.77 plug in its place that is just as good or better.

Being dogmatic is one thing but saying "Eh-before you go and stick plugs in for 20,000 miles on your high compression BMW engine with a supercharger... you should get into practice of checking the plugs every 3 - 5k just to make sure nothing looks out of the ordinary". And, if you accept that practice, then just stick new copper plugs in every other 5k miles. Done and done.

Ok.. so i see u want to continue this... First, did I say anything about leaving them in for 20k miles without checking? Thats a construct of your own making. Ive had my sc in for over 60k miles. .I think I know how long a set of plugs lasts in my car.. But hey, if you want to pull them 3 or 4 times a year, be my guest. I never said there was anything wrong with it. .I just said its not always necessary. .And like I said, its up to you.

Remember, this wasnt about pulling plugs. it was about coppers vs iridiums. You were the one who attacked the rationale of using iridiums.. Maybe youd like to also throw in that synthetic isnt as good as dino.. or that turbos are Better than scs... All of these are preference items my friend. therefore... im asking, again, can we leave it at that? There is no argument here to be won or lost..

Ok.. so i see u want to continue this... First, did I say anything about leaving them in for 20k miles>? Thats a construct of your own making. Ive had my sc in for over 60k miles. .I think I know how long a set of plugs lasts in my car.. But hey, if you want to pull them 3 or 4 times a year, be my guest. I never said there was anything wrong with it. .I just said its not always necessary. .And like I said, its up to you. And again, im asking, can we leave it at that?

Bro I have used coppers exclusively in many vehicles and they can get just as much life as an iridium. Point is, regardless of what plug you're using, you should pull them out every so often and read them. If you're pulling them out, you can stick them back in, or just replace them. I like my car running as best it can as all times. $12 worth of 6 plugs is worth it to me every 5k miles or so. You can say that iridiums last longer, but they foul easier. Its silly that so many people cling to iridium plugs.

Bro I have used coppers exclusively in many vehicles and they can get just as much life as an iridium. Point is, regardless of what plug you're using, you should pull them out every so often and read them. If you're pulling them out, you can stick them back in, or just replace them. I like my car running as best it can as all times. $12 worth of 6 plugs is worth it to me every 5k miles or so. You can say that iridiums last longer, but they foul easier. Its silly that so many people cling to iridium plugs.

Bro, I just think you like to sniff your electrodes. gotta get that electrode fix more than once a year.. Some folks are like that :redspot

Remember, this wasnt about pulling plugs. it was about coppers vs iridiums. You were the one who attacked the rationale of using iridiums.. Maybe youd like to also throw in that synthetic isnt as good as dino.. or that turbos are Better than scs... All of these are preference items my friend. therefore... im asking, again, can we leave it at that? There is no argument here to be won or lost..

You're right it is preference - i prefer not to see a guy spend $70 on spark plugs for no reason. I am giving him that information.

Actually.. just remembered... its over $100 for him to equip his car with iridiums! Lunacy!

You're right it is preference - i prefer not to see a guy spend $70 on spark plugs for no reason. I am giving him that information.

How bout this.. instead of saying 'you prefer to see a guy do whatever', how bout saying 'You prefer to do thus and such'.. That way you dont sound like your speaking for everybody else. Youve got to let others fend for themselves.

IM a devotee of synthetic oil.. I used to say I preferred if others did the same thing.. but I learned they were dogmatic in their beliefs that 3k mile oil changes and dino oil was the best way to go.. I learned to stop trying to change them.

I suggest you might try the same approach. I dont want you deciding whats best for me. if I came to you for a plug recommendation, fine, suggest away.. But when putting forth an opinion on a bbs, its better if you speak for yourself about yourself instead of taking the approach that youre using.

***EDIT*** Btw, I recall that Ive seen similar arguments as yours for both Platinum plugs and multi ground strap plugs. Search hard enough and youll find guys swearing that each is better for NA engines, or for FI engines, etc, etc. Ultimately, we try them all for ourselves.. And believe it or not, not everybody gets the same results as every else.. Hence, a myriad of differences of opininion, proved by experience. I used the NGK race copper plugs I mentioned for many years in my car. And, if I didnt routinely srvc them theyd go out of gap by alot. Ultimately after switching to the iridiums, I initially checked them as frequently as the coppers, and guess what.. The always Read great, so I know how the engine is running.. But they did NOT require nearly the amount of srvc.. So, for me, I found them to be preferable.. You did not.. thats great. Im not telling you youre a fool to be running coppers. Im only saying I didnt enjoy them.. Once and for all, Im asking for the same approach from you!

Paul I like what works. Iridiums make sparks. So do copper. There is no difference except price. Iridiums actually foul easier. Winner? Copper.

I like synthetic oil because it works better and can go a little longer mileage-wise in the car. Winner? Synthetic.

I never spoke for anyone else Paul - and if I did, somehow, who cares? My telling him to get BKR7Es is not going to drive him to the store and push $16 over the counter and stuff them in his car. The marketing hype of iridiums is overwelming for someone who just does not know. Surely you've seen the guy at the counter asking for "Bosch Platinum 4+ for my 1997 328, please!" with a big shit eating grin like he just bought the best you can buy.

Lets just quit - but in summary, iridiums work like any other plug and have slightly longer life in them, at 4x the cost. If it were 4x the life, I'd say go for it if they are the correct plug. But, since I have an issue using a spark plug (and as do 99% of this forum) for over 40 - 50 thousand miles (aka 4x the life of copper... if they had it...), what's the point? Its not like he can even play the "spark blow out" card with a dinan supercharger. There's just plainly no reason for them.

My heat range question has been answered. I just got a call back from Shawn at Dinan. He spoke with Steve Dinan and said that Steve remembered my car and that they put stock plugs in my car. With that being said, I am off to purchase Denso's iridiums (NGK iridiums not available for my car).

BTW, I am going with the iridiums because the data I have found says they last longer, are more consistent and offer more hp/torque over copper. Had the dyno showed copper plugs were better, I would be buying them. Besides, I don't mind paying more for quality.

because the data I have found says they last longer, are more consistent and offer more hp/torque over copper. Had the dyno showed copper plugs were better, I would be buying them.

:clap

what was your source? (more than sparkplugs.com?) I am curious to look at the data myself --valid empirical observation > anecdotal evidence.

:clap

what was your source? (more than sparkplugs.com?) I am curious to look at the data myself --valid empirical observation > anecdotal evidence.

I am referring to the sparkplugs.com dyno results.

I am referring to the sparkplugs.com dyno results.


Goin with IK 20's or IK22's?

I am referring to the sparkplugs.com dyno results.

I have a couple extra gallons of snake oil if you want it

Goin with IK 20's or IK22's?
Yes, I went with the Denso IK20's. Dinan said stay with the factory heat range.

I have a couple extra gallons of snake oil if you want it
I read, I did some research, I called Dinan tech support and bought some dyno data to the the thread to show how different plugs performed in boosted engine. Unless you have something to share with us, your one liners don't bring anything to the discussion.

Maybe start a poll Copper vs. Iridiums, Hot vs. cold. J/K I am glad you got your direct answer from Dinan.

Yes, I went with the Denso IK20's. Dinan said stay with the factory heat range.


I read, I did some research, I called Dinan tech support and bought some dyno data to the the thread to show how different plugs performed in boosted engine. Unless you have something to share with us, your one liners don't bring anything to the discussion.

And I've been putting non-OE spark plugs in aftermarket turbo vehicles for 3 years and tuning them with different plugs. You are not going to see quantifiable data from a dyno showing consistent HP gain with any one spark plug over the next unless you're experiencing spark blow out. If you put a spark plug in, and you don't blow out, and you're using only one spark (not a CDI multispark setup), then you will NOT see a difference so long as the spark ignites the mixture. Plain and simple.

What you're seeing is a marketing ploy to justify a $14 spark plug. Its been beaten to death for years now, and you're just finding out. My one liners are in jest because you won't listen to people with experience. There is NO POWER GAIN to be had by using an iridium plug over a copper plug. PERIOD. If you understood the fundamental function of a spark plug and why iridiums were developed, you'd see their application - but it has nothing to do with more power.

Dinan said stay with a stock heat temperature plug - thats fine and dandy, doesn't matter if its a copper or iridium you won't make more power.

I've used NGK, Autolite, Brisk, and yes Denso - the best results I've gotten are with the proven, NGK plug. Brisk work well too but they're expensive and they didn't do anything that the NGK's did not.

Copper plugs are better for turbo applications. Platinum and Iridium have a smaller electrode and do not dissipate the heat nearly as well as copper.

On the dyno, the difference between plugs, as Snail said, is not seen in power, but rather, they will often manifest their suitability to task at hand when you study the the curves them selves.. ARe they smooth? Jaggy? Do you have inexplicable dips in power? Those dips/spikes etc, are often, although not always, signs of misfire caused by spark issues. I dont want to start the copper vs iridium issue again, but Ive seen smoothest results with current iridiums.. but IVe also seen not so hot results with them in this regard . but that was before current tune was finished.. Ive also seen what looks like misfire results with copper plugs.. Its really very hard to control for all the variables sufficiently so that you can change plugs and attribute any visible differences in the power plots to plugs alone.. Perhaps, a plug swap on the dyno between runs would tell you what you want to know.. I would think if all else is equal, and one set of plugs is accompanied by dips and spikes, and the other isnt, Id say that might tell a story. But testing with different tunes, different weather, different states of wear, etc, etc, is no way to tell anything...

I've had very good results with my current iridiums, and they DO NOT foul out easily with the proper heat range in my experience.

At least for a 4 banger, the extra cost is negligible, and I was having to replace coppers much more often before they'd misfire and foul out.