Spark plugs

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Spark plug number deciphering.
Stock spark plug # DPR8EA-9
D= Thread diameter =12 mm, other D are A=18, B=14, C=10mm, D=12mm.
P= Projected insulator type
R= Resistor type.
8= heat rating scale from 2 Hot-------------11 Cold.
E= Thread reach = 19mm
A= Special design
-9 = gap width = 0.9mm

Stock NGK=DPR8EA-9
Iridium= DPR8EIX-9
ACCEL= 882
AC-Delco = R121XLS
Autolite=2593
Champion= C61C
Bosch= XR4CS (SILVER) Race, best price found $6.25 each, gap = 0.7 mm factory set.
silver - a soft white precious univalent metallic element having the highest electrical and thermal conductivity of any metal.from the dictionary!I finally used the bosch and they are sh** compared to the NGK regular or iridium, total wast of money:( I put them,took a 15 mile ride came back took them off and put the old NGK Iridium that have 5K on them, they work flawlessly,
NOTE: the bosch gap is 0.7, I will try to gap it 0.9 as the stock and will try again one more time then post my findings again.
Some useful sites:
http://www.sparkplugs.co.uk/pages/technical/ngk_symbol_code.htm
http://www.gadgetjq.com/spark_plug_cross_reference_motorcycle.htm
http://www.euromotoelectrics.com/SparkPlugBMWAPPLICATION.html
________
AMC Javelin
 
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Non resistor spark plugs

I have heard that it helps combustion and ignition strength to replace the stock DPR8EA-9 spark plugs with DP8EA-9 non resistor plugs. It was also mentioned to not use the resistor caps. Is there such thing as a non-resistor spark plug boot? If those aren't used, how do you fasten the plug wire to the spark plug? I would think that the spark would short to the engine if the plug wire boots aren't used.

Thoughts?
 
Re: Non resistor spark plugs

I have expiermented with non resistor plugs along with the Spitfires and tried solid copper core accel wires
Your wasting time there are no gains in ET MPH meaning no extra HP its a gimmick
Why take a chance and mess up a CDI box with cross feed
Invest your money in a MSD box Multi Spark Discharge if you want to have anything for the money IMO:th_image003::th_fridaay:
 
Re: Non resistor spark plugs

Lankee, thanks. I wasn't really expecting HP/torque gains but just better fuel efficiency and/or combustion.
 
Re: Non resistor spark plugs

Mark, if you really want to do this you can use a regular automtive boot, wire end connectors and whatever wire you want.

I bought an Accell 8mm universal kit and am using that, but I am currently using resistor plugs.

To use regular automotive wire end connectors you'll have to find a cheap spark plug with the screw on/ screw-off tops to put on your spark plugs to convert your plugs to the full size wire end that will accept the connector, instead of the threaded end only you get with the normal NGK's for the Max.

I tried this once with solid core wire, automotive boots and the normal Vmax plugs and my TCI acted like it was on a three day drunk.

I removed the solid core, non-suppression wire and went to accell 8 mm suppression wire and it's been running that way for a couple of years with no issues.

My guess is that you COULD run the non-resistor boots as I do, and the non-resistor plugs (which I don't) as long as you run suppression wire.

I have to agree with Lankey in that RF interference can be an issue for the TCI and that suppresionis needed.

When I saw the problem I already had the Dyna 3000 so I don't know if the factory TCI would have the same problem.

One way to tell if your getting RF output is to use an AM radio and sweep it across the freq. and see if it's hearing the firing of the engine, it'll be most obvious when you're between stations. We use this method sometimes at work to look for High Voltage Corona discharge on H.V. switchgear

Rusty
 
Re: Non resistor spark plugs

I think that's probably a suppression type wire, even tho' it's pretty low resistance. You could probabaly go on Accell's site and find out more detail.

Most of the universal sets I've bought usually come with all the boots and caps for both ends, with only one end being made up already.

Make sure you pick a set that has straight plug boots and terminals.

Another thing that worked out nice on mine is that the little rubber grommet that goes on the factory boot and that fills that area around the plug in the head fit nicely on my new boots so I put it back in there.
 
Silver Nology Plug number

I am looking to purchase a set of 4 silver Nology plugs on the Internet but cannot find an application chart for the 2007 Vmax.
Does anyone know the plug number to order?
Thanks in advance!
 
Re: Silver Nology Plug number

Are you using their "hot" wires? You can try going to www.nology.com and asking them. Otherwise, probably could use NGK DP8EA-9. These are the non-resistor plugs.
 
Re: Silver Nology Plug number

All max's use the same plugs so if they have any other year you'll be fine.

I would just use a normal non resistor plug.

Chris
 
Spark plug number deciphering.
Stock spark plug # DPR8EA-9
D= Thread diameter =12 mm, other D are A=18, B=14, C=10mm, D=12mm.
P= Projected insulator type
R= Resistor type.
8= heat rating scale from 2 Hot-------------11 Cold.
E= Thread reach = 19mm
A= Special design
-9 = gap width = 0.9mm

Remember that the above only applies to NGK plugs. Each company has their own designations for things, and they're NOT interchangable. For example I believe Champion's numbering for heat range are reversed, the lower the number the cooler the plug.

-MikeS
 
I'll have to check when I get home as far as the Vmax is concerned, but an
old XS 500 I used to have you could take the NGK plug boots apart and the resistor could be removed. I replaced it with a piece of copper wire the same diameter and had no problems. I have no idea if it helped in any way, but it was something to mess with.:biglaugh:
 
I run Autolite #4163.

$6 for a set of 4 at Advance Auto!

Honeywell makes them in the USA.
 

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