Those of us who want a colder heat range spark plug for our MCS's can order them from NGK. My MCS came with NGK BXR-6-E spark plugs installed. The next heat range colder plug in the NGK line with the same 4 ground electrode configuration is the NGK BXR-7-E. The NGK numbering system is the opposite of most plug manufacturers. That is a higher number in the NGK line represents a COLDER plug, but a higher number in the other spark plug lines usually means a HOTTER plug. This particular heat range spark plug is apparently not usually listed for some reason but can be found using the NGK "order number" 6074. My local discount auto store could find no listing for any other heat range excpet the BXR-6-E. My local NAPA store didn't list any BXR-7-E's either but could get the 6074's. Go figure.

I'm installing a set for the next track day. The warmer weather with my pulleyed car will surely increase the potential for detonation. I have a lot of confidence in the BMW engine management system with it's "knock detector" to protect my engine at the expense of power output. What I want is improved consistency and dependability in power output from my engine on hot and cold days, on lap 1 and lap 4. Maybe a colder plug will reduce the detonation risk and take some of the pressure off the engine management system. I can only hope.

John Petrich in Seattle

 

I am sure lots of people would be interested to see how they work out for you.

Would love to get updates on the performance of the plugs.

 

Interesting idea - I will be interested to here your results. Unless you belive that your current plugs are ruuning to hot - I doubt this will help much. Find someone with a spark plug microscope, and a racying background. Have them read a plug. For best results - after a few hot laps - kill the engine and engage the clutch from full throttle on a long straight (worked great at Road Atlanta -old config) and coast all the way to your pit. Pull and read the plug then. This will tell you - by color and texture (pitting) how conditions are under load. Try both heat plugs. As the mini runs rich - I doubt you will find a problem with the factory heat range. If it was my money - I would be more inclined to try some higher octane track (un-leaded) fuel. Put 1/3 tank of 104 octane in with 2/3 Amoco premium. That should gice you a nice buffer from any knock issues.

Good running.
Wes

 

Just to let you know, if you check my msd thread, you will noticed i gained approximatly ten HP by going to a colder plug!!!

 

10 hp? From just plugs? Colder ones @ that? Wow. Every one of the stock plugs that I have pulled off a MINI has been very black, tons of carbon. I am very suprised that a colder plug yielded such results, what did the colder ones look like when you pull them out, what about the stock plugs?

 

>>Every one of the stock plugs that I have pulled off a MINI has been very black, tons of carbon.

Mine looked great in my 02/02 MINI Cooper 5-speed

 

Look on my MSD thread it will talk about and show the dyno, there were other factors, and you have to take into considerations of my mods!!

MSD

 

I have had a bad day. Went to install the NGK BXR-7-E spark plugs and realized that they are not the 4 electrode platinum center electrode spark plugs that I was expecting . These colder plugs are the traditional non-platinum center electrode and single ground electrode variety. I am sorry to have mislead people that they were of the same construction as the installed NGK BXR-6-E spark plugs.

These colder plugs should function just fine in their intended application: track day. For the street, their service life will be like any ordinary spark plug. Yes, the MCS runs rich and the shells are sooted. The center insulator does get a light tan color after a power run and cut-off. The stock ignition and the MSD DIS-2 ignition seem to fire them just fine.

We'll see. Don't expect measurable improvement on a typical dyno run. Am expecting to reduce the combustion chamber detonation tendency under hot running conditions, take the pressure off the engine management system, and get more consistent power.

John Petrich in Seattle

 

The search for a colder premium park plug for the MCS has been an interesting odessey. Most of the factory websites provide little substantive information and are badly in need of updates. A sad state of affairs. Did run across a wonderful website that gives usefull old fashioned cross reference data and not just application restricted data. The website is: http://www.sparkplugs.com/ This website allows you to begin with the stock MCS spark plug number and then cross reference with a variety of different manufactures and then look at colder and hotter heat ranges. A must in your "favorites" folder. If your local NAPA store cannot or won't obtain what you want, you can try Monarch who will sell mail order:http://www.monarchproductsinc.com/

I am experimenting with a colder heat range plug for my MCS in anticipation of warmer weather and track days. Jeff from Alta gave me some good advice from the WRX racing crowd which sounds very similar to what might help the MCS performance group. He recommends the Iridium electrode spark plugs. Iridium spark plugs offer long service life and lower voltage demands compared to ordinary spark plugs. How the Iridium spark plug compares to the stock platinum semi-surface gap plug is uncertain. Racers endorse them.

The Iridium Denso replacement for stock MCS spark plug is the IK-20, order number 5302. The next heat range colder premium plug for the MCS is the Iridium NGK BKR7EIX-11, order number 6988, or the Denso IK-22, order number 5313. The next colder yet spark plug is only available from Denso, the IK-24, order number 5314. The order numbers are the "magic" numbers that the NAPA store needs to place an order. Am running the NGK Iridium BKR7 plug on the street and find no problems in starting and low speed running. Very satisfied, so far................

Don't expect any reproducible dyno gains. Expect more consistent high temperature, high output performance, unencumbered by the ECU's detonation management system.

John Petrich in Seattle

 

Petrich,

What did you set the gap to for the Iridiums?

retroom

 

Set the gap to 0.080". Seems to start okay and no misfires that I can tell. The Iridium plugs have a fine wire type of center electrode and therefore they require somewhat lower voltage to fire the gap to the ground electrode: the lightening rod effect, concentration of charges in a small area.

Might get away with it. With distributor ignition systems, gaps this wide place a large high voltage dielectric stress on the distributor cap and the rotor. Over time you always burn a hole some where. With this distributorless system, I would guess that the coils will withstand the high voltage dialectric stress.

Not sure what I am gaining. Most older generation of engines would demonstrate improved low speed driveability, smoother idle and those things that come from improved mixture ignition in a slow speed, low turbulance, combustion environment. The MINI engine management system seems so tightly calibrated and evolved that I can detect none of those improvements with wide plug gaps and multiple spark ignition systems. Might just change things back to 0.044" gap and call it good.

John Petrich in Seattle

 

I didn't think you could use precious metal plugs with the MSD ignition systems?

Thats what I have heard at least. Does precious metal include iridium or just platnium?

 

Azwed,

Search under "MSD ignition" in the Performance Modifications forum. There is a recent discussion of the question of precious metal plug electrodes and MSD ignitions. I am not sure that Iriidium would fall under that same category pf precious metal, but who knows. The primary issue in that discussion is spark plug service life. If you are content to change spark plugs every 10K miles or so, then you can probably use anything, I guess. Any serious motor enthusiast does change plugs at about that frequency. The average motorist will be interested in the 100K potential miles claimed by the stock ignition and the platinum spark plugs.

Not sure that the MSD ignition actually adds any value, given the sophistication of the stock MINI ignition and engine management system. Not sure what the ECU reads. The MSD multiple sparks may give the ECU a headache when the ECU tries to adjust ignition timing to ever changing operating conditions.

What are your thoughts?

John Petrich in Seattle

 

Petrich,

.08 is a large gap, how did you come up with this size? I gapped mine to .034, my Iridium plugs came gapped at .044 from the factory.

I tried .040, and notice a different exhaust tone and better low rev response. Do you know what gap is recommended for Cooper and Cooper S? The factory four electrode plugs are gapped at .044.

retroom


>> Set the gap to 0.080". Seems to start okay and no misfires that I can tell. The Iridium plugs have a fine wire type of center electrode and therefore they require somewhat lower voltage to fire the gap to the ground electrode: the lightening rod effect, concentration of charges in a small area.
>>
>> Might get away with it. With distributor ignition systems, gaps this wide place a large high voltage dielectric stress on the distributor cap and the rotor. Over time you always burn a hole some where. With this distributorless system, I would guess that the coils will withstand the high voltage dialectric stress.
>>
>> Not sure what I am gaining. Most older generation of engines would demonstrate improved low speed driveability, smoother idle and those things that come from improved mixture ignition in a slow speed, low turbulance, combustion environment. The MINI engine management system seems so tightly calibrated and evolved that I can detect none of those improvements with wide plug gaps and multiple spark ignition systems. Might just change things back to 0.044" gap and call it good.
>>
>>John Petrich in Seattle
>>

 

Retroom,

Excuse me if this comes back as a double message. Some cockpit troubles with my computer.

Not sure what the "recommended" gap really is. The spark plug gap is determined by the high voltage capability of the coils balanced by the high voltage dielectric stress that the entire ignition system can reliabily handle. I got to 0.080" using a standard round feeler guage and a ground electrode bending tool. Standard spark plug adjusting tools. Entirely arbitrary.

Glad that you noticed a combustion difference with a wider gap. Consistent with theory. You may be much more in synch with your engine than I am with mine. Keep up the good work.

Again, not sure what we are gaining, but we are learning. The stock plug gap is a bit ambigious. The air gap is just what it is. However, the plug seems to have a combination of surface gap characteristics and air gap characteristics, so that the total gap from the edge of the center electrode to the edge of the ground electrode is closer to 0.080". Don't have the time tonight to measure it exactly. An interesting spark plug technology. May be more to the stock plug than I realize.

Anyway, this entire thread started with an attempt to find a premium spark plug that is in a colder heat range than the stock spark plug. All that has been determined is that there is are premium spark plugs for those that need them.

Any further thoughts?

John Petrich in Seattle

 

>>Just to let you know, if you check my msd thread, you will noticed i gained approximatly ten HP by going to a colder plug!!!

Can you provide a part# or other details on what plugs you bought?