Just wanted to mention Denso iridium plugs if no one has yet. These plugs seem to yield dyno-proven hp gains especially in forced induction applications (heads up S owners!). Read the "Tuner's Tales" on the Denso website:

http://www.densoiridium.com/tunerstales.php

Expensive plugs, though. Although they don't list MINI as an application, there should be some cross reference that matches up to the OEM plugs in the Cooper and Cooper S.

 

FYI, the stock MINI plugs are platinum with quad contact tips, Bosch I think. So you probably won't see as much of a gain switching to the Denso plugs (as you would switching from cheaper plugs).

If anyone has switched theirs out and seen an improvement, please post and let us know!
:smile:

 

>>FYI, the stock MINI plugs are platinum with quad contact tips, Bosch I think. So you probably won't see as much of a gain switching to the Denso plugs (as you would switching from cheaper plugs).
>>
>>If anyone has switched theirs out and seen an improvement, please post and let us know!
>>

OEM's are probably Bosch +4's I bet.

 

How do sparkplugs help power???

 

I ran +4's for a while, great plugs. Purchased some Denso Iridium's, and I was blown away. Very noticeable difference. Idle was smoother, and acceleration through the gears was smoother. If they make them for the the MINI I'll buy them again.

Grinder, bigger, hotter spark burns better in the engine.

One more thing, in the +4's the spark goes to the cleanest electrode right? So does anyone know if this should make the plug last longer? I never had a problem with Bosch products and think very highly of them, and I'm sure I'll use them again. However I would think the normal Platinum plug would work just as well as the +4. Anyone with any ideas on this?

 

I've always thought that the double/quad electrode plugs are silly. Seems like one good strong spark would be better than multiple weaker ones. Pure speculation on my part, though. I have the irridiums in my bike. I've muffed the carburetion, though, so I don't have a report yet.

Irridium lasts much longer, and due to heat resistance they can use a much smaller electrode--which is good for spark. If the plugs are hard to get to to change, it seems like they're worth the extra dosh just because you don't have to change as often. I wouldn't swap out just for the sake of it unless I were dealing with a weak electrical system.

Jeff

 

that's the thing, there aren't multiple sparks, just one "choosing" which electrode is cleaner and going to that one. then bouncing around to other ones during the spark. i would think if there were multiple sparks, like you said, they'd be weaker. misfire?

 

Cooper44 is spot-on about the iridiums and the Bosch 4's. The Bosch 4's, to me, are sort of a gimmick plug. Like the Splitfire joke of a plug.

The Denso iridiums are for real, just expensive at $11.99/each.

 

hmmm... the Bosch plugs are OEM in all BMW's though, right?

also, on the Iridiums : we should not have to wait for a MINI version, I don't think... it's just a matter of getting the gap space right, isn't it??

 

I don't really get this post...sometimes I think I'm denso....

 

>>hmmm... the Bosch plugs are OEM in all BMW's though, right?
>>
>>also, on the Iridiums : we should not have to wait for a MINI version, I don't think... it's just a matter of getting the gap space right, isn't it??


i believe there is a heat range we need to stick with.

i do think the +4's are kinda gimmicky too, and if there aren't any iridium's i'll go with the platinum plus (single electrode)

 

Suprisingly enough, the Parts List calls out the same plug for both the Cooper & the S - and it's an NGK ! #BKR6EQUP

 

>>I ran +4's for a while, great plugs. Purchased some Denso Iridium's, and I was blown away. Very noticeable difference. Idle was smoother, and acceleration through the gears was smoother. If they make them for the the MINI I'll buy them again.
>>
>>Grinder, bigger, hotter spark burns better in the engine.
>>
>>One more thing, in the +4's the spark goes to the cleanest electrode right? So does anyone know if this should make the plug last longer? I never had a problem with Bosch products and think very highly of them, and I'm sure I'll use them again. However I would think the normal Platinum plug would work just as well as the +4. Anyone with any ideas on this?

Bigger and fatter is right hotter is where you need to be careful. Hotter is not always a good thing. Hotter taken too far can cause detonation or spark retarding if the sensor catches it soon enough. Either way, not what you want.
The multi electrode plugs are an advantage in one way; when all the electrodes are clean the spark can jump to any electrode. It may even hit more than one per pulse. But the real advantage to the newer designs is that the spark is open to the intake charge. In the old single electrode L shaped design the electrode actually covered some of the spark, bad thing.
Presenting a wider spark to the intake charge will propogate a larger wave through the charge resulting in a more efficient burn. More efficient means more power for a given amoutn of fuel.
Some one called the SplitFire plugs a joke. I'd say this was unnecessarily harsh. I used them for years on some pretty decent performing V8s. But yes it was years ago. They did perform better but more importantly they initiated a change in plug design.
If you want a REAL whacking spark check out an MSD system. Very nice but I have no idea how/if it would work on a MINI. I loved mine on my old small block Chevys.
Sorry for yammering


_________________
EB/W MCS Can't get enough seat time in the car

 

According to my owners manual, the MC has NGK plugs fitted as standard. The code is "BKR 6 EQUP". Ichecked the cross reference guide on the denso site and found that the Denso "IK20" can replace the NGK plug.

 

How about IK22 and DENSO racing plugsIK01-■?
I am using NGK now but I am thinking to replace them to DENSO.

 

Are you talking about a MC or MCS? Pulley'd MCS' use IK22's.

Oh, and way to resurrect a 2 1/2 year old thread

 

As I re-call, Randy Webb, some time ago, posted on his site that he saw a 1.5 whp gain on dyno just by switching to Denso IK-22 plugs.
I have them with good results, but since I added them at the same time as my 15% SC pulley, can't judge the difference.
I did install them some years ago in my 99 Accord V-6 and did notice a difference in smoother idle and better responce a lower RPM. Of course at WOT really couldn't tell difference but, even if they do add 1-2 whp, you couldn't tell at WOT.

 

The Denso Iridium Spark Plugs for a Mini S are IK20 or IK22 (colder) for cars with supercharger reduction pulleys. They can be found at www.urdusa.com for less than $50 for 4 including shipping.

 

Thanks for reply.
mine is MCS 15% pulley +0% crank.
shall I choose IK22 or racing IK01-24?
racing one starts from 24 and the price is triple of IK22.

 

http://www.denso.co.jp/cgi-bin/plug/...=+%B8%A1%BA%F7+

 

I have a 2005 MCS that has/had a surge at idle after starting cold.
The dealer could not fix and talking to several dealer techs. they aggree this problem is built into the 2005.

Put a promini cai on, still has surge.
Put 15% pulley on, surge.
Put Miltex exhaust on, surge.
Installed Denso Iridium IK-22 spark Plugs, surge gone, totally amazing!!!

 

What is a surge @ idle?

 

I have yet to see a plug cause a gain in HP. Especially on a modern car where there is more than enough spark. The gain comes from replacing an old plug that was having trouble... HP gains are a function of markerting when it comes to plugs.
Buy what you want... but don't believe all the hype.. and stay away from splitfires...

 

surge ([font=verdana, sans-serif] P [/font]) Pronunciation Key (sûrj)
v. surged, surg·ing, surg·es
v. intr.

1. To rise and move in a billowing or swelling manner.
2. To roll or be tossed about on waves, as a boat.
3. To move like advancing waves: The fans surged forward to see the movie star.
4. To increase suddenly: As favorable reviews came out, interest in the software surged.
5. To improve one's performance suddenly, especially in bettering one's standing in a competition.
6. Nautical. To slip around a windlass. Used of a rope.

In automotive terms, or how I interpret the word.

The idle speed increases and then decreases rapidly in a period of a few seconds with a deviation of 200-300 rpm. This continue for about 15 seconds and then doses not occur until the next cold start

 

Interesting way to answer. I have not heard of surge used to describe a issue with the engine.