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Thread: Bosch plugs

  1. #26
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    Quote Originally Posted by gsjohnson View Post
    Just remember... that although copper core plugs fire better, give you a little smoother idle, and may give you tiny bit more umph, they will not last as long...about 15K. I'm lazy and I don't want to change plugs again so used the oem NGK BKR6BEQUP...and I'm willing to sacrafice that little missing umph.
    Au contraire; there are plenty of V12s out there with 100k miles on the plugs, not that it's considered good practice. Low compression motor, low voltage ignition; what's to wear on a plug?
    How come the middle half of any project always takes the most time?

  2. #27
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    RAFFEAL , What Cartoonz said is correct , F8LCR is no longer around . F8LCR ,
    which was original OEM and had a 1k ohm resistance value , has been replaced by FR8LC , which has a much higher resistance value , not sure but could be 4k - 6k ohm . I stand to be corrected here . Pretty easy to mistake one for the other . Lots of good things said about NGK . If they make a 1k ohm plug in the
    right heat range , I'd say go for it . If you have already replaced the coils in 2011 , they should be fine , but remember , they are low voltage coils , 10k V ,
    not so good with exotic spark plugs .

  3. #28
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    Quote Originally Posted by Max Lumens View Post
    Au contraire; there are plenty of V12s out there with 100k miles on the plugs, not that it's considered good practice. Low compression motor, low voltage ignition; what's to wear on a plug?
    A 100K on copper plugs??? Any advantage that you thought you gained is long gone way before the 30K mark. Traditionally and originally, copper plugs were always recommended to be changed at 15K...high voltage, low compression, or not. Most production engines today are low compression. It is the heat that breaks down the copper plug. Even low voltage ignition won't save them. The short life of copper plugs is what sparked (pun intended ) the platinum and other conductor type plugs.

  4. #29
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    Quote Originally Posted by garylafortuna View Post
    RAFFEAL , What Cartoonz said is correct , F8LCR is no longer around . F8LCR ,
    which was original OEM and had a 1k ohm resistance value , has been replaced by FR8LC , which has a much higher resistance value , not sure but could be 4k - 6k ohm . I stand to be corrected here . Pretty easy to mistake one for the other . Lots of good things said about NGK . If they make a 1k ohm plug in the
    right heat range , I'd say go for it . If you have already replaced the coils in 2011 , they should be fine , but remember , they are low voltage coils , 10k V ,
    not so good with exotic spark plugs .
    I've been running the Bosch replacement plugs, the Super Plus FR8LC+, for about a year (10K miles) in my 8's M70 and have been happy with them. The Super Plus plugs have a "Yttrium-enhanced copper core center electrode for 50% longer service life", so they are still considered a copper plug.

    I also ran the Super Plus plugs in my 735i (M30) for 60K miles which shares many ignition components. After 60K miles, I replaced them, but they were still running well and looked great.

    Proper plugs, like tires, are one of those hot button topics sure to 'spark' a debate. Remember there is a variety of different engine/ignition configurations, a variety of experiences (positive and negative), and a bit of contradictory information. Four things that are generally agreed upon are
    1) That Platinum plugs do not belong in stock M70 ignition systems
    2) The 'proper' NGK plugs are highly regarded in the M70 ignition systems (hard to find a disagreement)
    3) What is applicable to one type of engine/ignition system is not always applicable to others (My M30/M70/M50TU all have different preferred brands/voltages/etc)
    4) There will be disagreements about which plugs have the best performance/costs/longevity/etc
    Last edited by EEDegreeToDrive; 05-08-2012 at 01:35 PM.

  5. #30
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    Quote Originally Posted by gsjohnson View Post
    A 100K on copper plugs??? Any advantage that you thought you gained is long gone way before the 30K mark. Traditionally and originally, copper plugs were always recommended to be changed at 15K...high voltage, low compression, or not. Most production engines today are low compression. It is the heat that breaks down the copper plug. Even low voltage ignition won't save them. The short life of copper plugs is what sparked (pun intended ) the platinum and other conductor type plugs.
    No argument here, per my original statement. The fact remains that I see plenty of motors with the original plugs, wires, caps, rotors 20 years and 100k miles on. Plugs with 100K miles on them have tested within specs and worked well. You might opt to replace them anyway, but not necessarily because of verifiable failure.
    How come the middle half of any project always takes the most time?

  6. #31
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    NGK 3199 brilliant plugs.

  7. #32
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    F8LCR is correct Bosch you have to check arrangement of the letters

  8. #33
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    Quote Originally Posted by RAFFEAL View Post
    ok thanks i will sreach for those bosch ones
    Yeah, when given alternatives that are fully compatible and available, I always opt to search for unicorns too....

  9. #34
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  10. #35
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    Ok, just to get this straight, the Ohm values of the original F8LCR are 1 KOhm and the replacement ones the FR8LC+ is 4 KOhms?

    That isn`t good news to me, just got these in out of Ebay now and am going to change plugs in the weekend, not so sure now.

    Espesially if the Coils are 10KV ones and the 4KOhm-plugs are intended to run on the 40KV Coils.

    Anyone got any hard facts to reasure a fella on this?
    It would suck if the replacement plugs that BMW lists as OEM has different electrical values..
    Last edited by Nor850; 05-09-2012 at 05:25 PM.

  11. #36
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    Those are remarkable for their dual electrodes, but what is their resistance? Would you measure one, please? I ask because virtually every modern plug with an "R" in the model number has a resistance in the 4k- 6k ohm range. That's universal industry practice now, and if these NGKs are different it would be a refreshing change.

    BTW, for those who subscribe to superstitions and prejudices regarding makes of plugs, you should be aware that the manufacturers have carved up the markets and production. Autolite makes the insulators for NGK plugs in their Mexico plant, for instance. They're commodity items in a mature and contrived oligopoly market, and the name on the side is essentially meaningless. Marketing is everything.

    Quote Originally Posted by Nor850 View Post
    Ok, just to get this straight, the Ohm values of the original F8LCR are 1 KOhm and the replacement ones the FR8LC+ is 4 KOhms?

    That isn`t good news to me, just got these in out of Ebay now and am going to change plugs in the weekend, not so sure now.

    Espesially if the Coils are 10KV ones and the 4KOhm-plugs are intended to run on the 40KV Coils.

    Anyone got any hard facts to reasure a fella on this?
    It would suck if the replacement plugs that BMW lists as OEM has different electrical values..
    This got flogged a bit last year-

    http://forums.bimmerforums.com/forum....php?t=1704851

    Partial explanations, no resolution. I tried to get some 1K plugs made, no luck so far.
    Last edited by Max Lumens; 05-09-2012 at 05:30 PM. Reason: Automerged Doublepost
    How come the middle half of any project always takes the most time?

  12. #37
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    Ok, so I have read the entire post you gave as info here Max.

    Have to say that I`m even more confused now than before i started reading about this subject.

    Not confused in the way a ignition system works, but confused as to why BMW replaced a 1Kohm item with a 4Kohm one.

    Going to se what type of plugs that are in the car now(runs great as is-the change of the plugs was just because we don`t know the age of the ones that are in the car now.)

    So I bought the one that BMW listed for the car, the FR8LC+ but I`m not to happy to put them in the car if it turns out that the car runs worse with them or if they break the coils.

    I`m thinking I shall have a go with my electrical insulator-tester(megger) at 250V/500V to see if this instrument will give out a more accurate Ohm-reading then my Mulimeter(Fluke) on the plugs.
    Your results seem to vary alot from what I have been reading.

    If infact the car has the original F8LCR ones that would be great to compare it with the FR8LC+ ones in Ohm-values.

    But the closest plug you have found are the NGK ZFR5F? I only found one named ZFR5F-11, does the Ohm values differ between these as well?
    Last edited by Nor850; 05-10-2012 at 11:24 AM.

  13. #38
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    What is the real reason for resistance in the ignition system . I've always thought it was because of radio signal interference . Back in the early 60s
    I was running solid copper core ignition wire in my 59 Catalina . Whenever
    I went to pick up my girl friend , her dad would scream at me that I was screwing up his television signal . Don't know if this is something written into our statutes , or something agreed upon by the auto industry . Maybe I'm all wet here .

  14. #39
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    which is better to use beru distributor CAPS and rotor, or the bosch ones
    Last edited by RAFFEAL; 05-10-2012 at 09:08 PM.

  15. #40
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    i installed Bosch BMW R1 383 super... nice and smooth... of course i upgraded my coils to MSD...
    "...i haven't taken leave of my senses Bob, I've come to them..." -- Ebenezer Scrooge

  16. #41
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    I received an NGK BKR6E, stock number 6962, single electrode. Resistance is 5K ohm. BKR6EK, stock # 2288, and BKR6EQUP, stock # 3199, on order, will test ASAP. It would be a bonus to find that last one in low resistance, a 4-electrode platinum design, should last forever.

    I suspect that the heat range on all of these is more suited to the V8 motors than the V12; at least that's the way they keep turning up in the application guides.
    How come the middle half of any project always takes the most time?

  17. #42
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    Plug, Plugs, Plugs - What to do.
    I use the F8LDCR plugs in my M73 (10:1 compression) from 1998 740, M62 (a dual ground strap plug). The F8LDCR plug is also an R1 designation, measured spark plug resistance @ 1.47k ohms. I installed them @ 43785 mi. now 74900 mi. they work great (stand a quarter on the engine cover to show smooth idle).

    Certainly it is a myth to assume your engine can develop more HP from a special plug, i.e. electrode configuration. However, the wrong plug can easily cause idle, part throttle and WOT performance issues.

    The issue is to obtain a plug with the correct heat range, reduce the opportunity for ping and provide good service life. If the engine has problems like oil consumption you’re kinda on your own to find something that works through the oil fouling in the affected cylinders only.

    I’ve done several high performance upgrades over the years (high compression, long duration cams, high RPM engines) and when all other plugs failed the Bosch "Copper" always worked. So I'm sticking with them.

    After that:
    The info below is from an old post-

    "850 Spark Plug changes
    Here it is straight from Robert Bosch:
    Just got off the phone with a Tech Support Engineer at Robert Bosch and asked him a few questions in regard to our sparkplug dilemma.

    The old F8LCR has been discontinued, it's stock # was 7559. The "new" FR8LC (same stock # as the old one) is not really the plug we want. The plug we want is the FR8LC+ (if you want a copper plug) Stock #7959. If you want the same plug in a platinum version, it is the FR8LPX (stock #4030).

    In regards to the resistance value on the plugs (R1 vs. R6) and even metering the plug between the electrode and the cap, the resistance has little to do with the "spark" delivery (contrary to what we are all thinking) The "higher" the resistance the better the noise suppression on the radio - that is what I was told was the reason behind putting a higher resistance in the plugs.

    Now, I am going to buy a set of the FR8LC+ and put them in my 750iL and see how they run - going to be the "guinea pig" here, and report back.

    On a side note, the engineer did say that the reason for the platinum plugs is that the electrode lasts longer than conventional copper electrodes (40-50,000 miles as opposed to 100,000 miles for the platinum), and that there is no difference in the quality, amount or intensity of the spark itself.
    Only time will tell..."
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    Last edited by m6bigdog; 05-12-2012 at 01:29 PM.

  18. #43
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    Good info, thanks. Be aware that Bosch plug specs are subject to change, and there are differences by country. IIRC the FR8LC+, AKA stock #7959, is a 5Kohm plug, despite what they say. I couldn't find one to test in my plug pile, but think I did so in the past. I also have a supply of F8LCR2 plugs, which weren't sold in the US AFAIK. They test at 1.4k ohms, single ground electrode. Beyond my own curiosity on plug resistance, there were reports of poor performance with 11k ohms of total wire resistance and 10kv coils, back when Bosch made the switch to the new plugs.

    Eventually I'll test all the plugs on a scope with various ignition parts, see how they stack up. We should be able to figure out an optimal setup, until laser plugs come along....

    http://www.autoblog.com/2011/04/24/l...sh-in-the-pan/
    Last edited by Max Lumens; 05-12-2012 at 03:22 PM.
    How come the middle half of any project always takes the most time?

  19. #44
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    I was back at my workshop today to do some otherwork than the car, suddenly I remembered the Bosch-discussion here.

    Tok out the Fluke and measured my brand new FR8LC+ plugs, and the showed exactly 6KOhms from the top of the electrode and down to the spark-gap end of the electrode.

    So the FR8LC+ are not 4KOhm, they are even worse-they are 6KOhms.

    Haven`t taken out the plugs in the car yet to measure them, car runs great and idles good(Coin-trick is no problem)

  20. #45
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    I bought NGK 7558's initially and tested them. All plugs were tested with a Fluke 87 true RMS meter, they tested at 5.453 Kohm. I just returned them and bought the NGK 2288's discussed here and they tested at 1.386 Kohm. The #6 plug I removed is a Bosch F8LCR that is well worn. The resistance is 1.189 Kohm on it. For the money spent I believe that the 2288's are the ticket being they are close. And they're a lot cheaper than buying a couple of MSD coils.

  21. #46
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    I FOUND THIS 7959 Bosch Spark Plug; Ytrium Enhanced Copper; Standard Electrode Updated replacement to original factory spark plug, F8LCR and FR8LC. Pregapped for normal usage.THIS IS THE RIGHT ONE RIGHT

    I ALSO SEEN THIS NGK BKR6EK Pregapped for normal usage ,BUT IT DON'T SAY ANYTHING ABOUT COPPER
    Last edited by RAFFEAL; 06-13-2012 at 10:30 PM. Reason: Automerged Doublepost

  22. #47
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    Hi I just read comments on recent thread and I looked up the comments here regarding Bosch plugs,etc. I have a 96 850CI with 85k miles. The car had the original BMW marked Bosch super R1 187 F9LCR2 plugs. I was ordering various parts frm FCP Euro parts and they sent me Bosch Super FGR7DQP plugs. I am running complete stock set up and I am concerned about the issues mentioned in this thread. I hope I have seen enough in this thread but wanted to know if the plugs FCP sent me are just not going to work long term. They were not cheap! Thx for any comments

  23. #48
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    An important factor missing in many of these discussions is the resistance of the WIRE.
    IF the theory that high resistance and relatively weak coil is the cause of the M70 engine woes that many of us have experienced after changing to newer spark plugs, then we must consider the total resistance of plug + wire.
    The OEM wires are resistors, so adding a higher resistance plug may tip the total resistance value over the top, especially if the OEM coil is weak.

    Low ohm wires may allow the stock coils to work with the new high ohm plugs.

    Mark in mid-MO
    1993 BMW 850Ci 6-speed
    2011 Cadi CTS coupe 6-speed

  24. #49
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    All you need to understand is if you like the idle you had when you got te car stick with those plugs. I changed plugs and it was a bad idea the idle got a lil rougher and here i am complaining to you.


    Quote Originally Posted by JTM850 View Post
    I have heard that these NGK plugs are recommended also by BMW to replace the old F8LCR plugs and they are also the closest matching plugs out there to replace it.

    I installed NKG BKR6EK to my M70 and it runs idle smoothly and goes like a charm
    Ohh i like that desighn
    Last edited by smokum; 07-24-2012 at 10:44 AM. Reason: Automerged Doublepost

  25. #50
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    Quote Originally Posted by m6bigdog View Post
    Plug, Plugs, Plugs - What to do.
    I use the F8LDCR plugs in my M73 (10:1 compression) from 1998 740, M62 (a dual ground strap plug). The F8LDCR plug is also an R1 designation, measured spark plug resistance @ 1.47k ohms. I installed them @ 43785 mi. now 74900 mi. they work great (stand a quarter on the engine cover to show smooth idle).

    Certainly it is a myth to assume your engine can develop more HP from a special plug, i.e. electrode configuration. However, the wrong plug can easily cause idle, part throttle and WOT performance issues.

    The issue is to obtain a plug with the correct heat range, reduce the opportunity for ping and provide good service life. If the engine has problems like oil consumption you’re kinda on your own to find something that works through the oil fouling in the affected cylinders only.

    I’ve done several high performance upgrades over the years (high compression, long duration cams, high RPM engines) and when all other plugs failed the Bosch "Copper" always worked. So I'm sticking with them.

    After that:
    The info below is from an old post-

    "850 Spark Plug changes
    Here it is straight from Robert Bosch:
    Just got off the phone with a Tech Support Engineer at Robert Bosch and asked him a few questions in regard to our sparkplug dilemma.

    The old F8LCR has been discontinued, it's stock # was 7559. The "new" FR8LC (same stock # as the old one) is not really the plug we want. The plug we want is the FR8LC+ (if you want a copper plug) Stock #7959. If you want the same plug in a platinum version, it is the FR8LPX (stock #4030).

    In regards to the resistance value on the plugs (R1 vs. R6) and even metering the plug between the electrode and the cap, the resistance has little to do with the "spark" delivery (contrary to what we are all thinking) The "higher" the resistance the better the noise suppression on the radio - that is what I was told was the reason behind putting a higher resistance in the plugs.

    Now, I am going to buy a set of the FR8LC+ and put them in my 750iL and see how they run - going to be the "guinea pig" here, and report back.

    On a side note, the engineer did say that the reason for the platinum plugs is that the electrode lasts longer than conventional copper electrodes (40-50,000 miles as opposed to 100,000 miles for the platinum), and that there is no difference in the quality, amount or intensity of the spark itself.
    Only time will tell..."
    I am running the FR8LC+ Stock #7959 for ~5000 kms and the car has a much smoother idle and better throttle response than the old plugs that they replaced. Before I gutted the muffler and added some dB's + deep vibrations, the idle was so smooth and quiet I sometimes would check that the engine is running !

    Brand new Bremi caps & rotors, all 12x Bremi ignition wires are in spec (along with the 2x cyl i.d. wires) as are both Bosch coils.

    With a 3x chipset and a 3.91 diff the M70 really delivers - I am curious what kind of driveability problems some owners are experiencing with the
    FR8LC+ plugs?
    Last edited by whiteghost1; 07-24-2012 at 09:51 PM.

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