Beast From The East

I know you do quite a bit of racing and motor rebuilding JD, so you're no noob .... but my experience with 10.5's differs from yours. My idle on a 13BRE TO4S is smoooooth on 91 CA pump gas, especially since I've spent the last two weeks doing serious detailed refinement on my voltage compensation settings (Wolf 3D v 4 plus system). With the colder weather and all the extra accessories I run (gauges, wideband, etc.) I find when I turn on wipers, defroster, fan, wipers, headlights, and push on my brake pedal (activate brake lights) I'd get voltage drop from 12 down to 10.9 v, with a new alternator (type 51 battery). Adding in compensation of a very thousandths of a millisecond to as much as two hundredths of a milisecond depending on the drop has really helped.

I do run 2nd gen coil packs relocated to the side of the motor to keep them from getting heat soaked by the engine block, and also run a Twin Power, and also don't have the same below freezing air temps you guys see back on the East Coast. Today ambient temp before starting the car was 16 C, and it's going to get in the high 60's F today ... bright and sunny as the fog burns off:-) Myabe the extra spark and slightly warmer temps helps? I just pulled the plugs after 6K miles and they are just about perfect from a wear and color perspective (nice rusty brown color with almost zero buildup and no degredation in the cathode/anode area).

What conditions were you in when you experienced poor idle on 10.5's with pump gas?

Beast

RX794

Beast, I'm not going to post any boost levels at this time, I probably will once the car is leaned out, fined tuned, and I go back to the dyno again to get the final HP results on pump 93 octane gas, and stock plugs.

Boostn7

motor rebuilding ?? mine or others ?? I do build motors for people and as far as mine....well, I would have a 2nd car if I was rebuilding it often.
I'm probably one the most abusive with my car, explains why I just replaced the diff !!!

Beast: Let me correct my previous statement since there's no NGK 10's.

NGK 10.5 race plugs work well on top end and idle ok.
NGK 11 or 11.5 work better for high boost and race gas and idle suffers a bit mainly if you drive the car daily, mainly the 11.5's.
On a ~430rwh dyno pull I actually picked up 5-8 rwh from a change of plugs from reg 9 EQs to NGK 10.5 race plugs.

Keep in mind I'm comparing them to stock 9EQs.

JD

FB II

any porting done?

RETed

8<

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Um, not to rain on your parade, but what does "NOT RACING #9..." have any difference with NGK BUR9EQ(P)'s?

Heat range 9 = Heat range 9, and it's just a rebadged NGK spark plug anyways.
Now don't people feel stupid for paying ~$30 for something that says "HKS" or "Trust / GReddy" on it?

The dyno graph you posted had all kinds of weird break-up in it.
I'm almost certain it's ignition break-up.
Are you using a CDI box? Or did I miss that part.

Another option is to run Iridium plugs...
Have you tried that?
A CDI box + Iridiums might be the combination you're been looking for...


-Ted

RX794

#1 What I mean by "NOT racing 9s" is exactly that, the Greddy and HKS #9 plugs are NOT rebadged stock plugs, and they are NOT identical to the stock NGK BUR9EQ(P)'s, even though they are all made by NGK. The electrodes and insulation is different, even though it's still a #9 heat range plug.

#2 The breaking up on the top of the graph is caused by excessive fuel because I increased the lag time on the 1680 secondaries WAY too much on the dyno causing the A/F ratios to be in the 10.7s. I did this for safety reasons but went WAY too far causing this to happen with stock spark plugs if this pull was done with racing plugs it wouldn't have broken up. When the car is dialed in with the proper injector lag time it doesn't break up at all. I explained all of this on the post attached to the dyno sheet, sorry if I wasn't clear.

#3 I have an MSD box(It's stated in my sig)

#4 This experiment is to see how far I can get with the stock BUR9EQ(P) plugs, so I haven't tried iridiums as of yet.

Beast From The East

Ted, don't suppose you have a line on less expensive ways to acquire NGK 10.5's or better? I'm paying $28 each via Mazdacomp, which is the best price I've seen through any retail outlet......Jason isn't making much on this at $32....

Just wondering...I know you've got some connections since your work with K2RD.....

Beast

RX794

Here's some info I got on sparkplugs from NGK's website to add to this thread:


Tech Info - Spark Plugs Overview

Spark plugs are one of the most misunderstood components of an engine. Numerous questions have surfaced over the years, leaving many people confused.

This guide was designed to assist the technician, hobbyist, or race mechanic in understanding, using, and troubleshooting spark plugs. The information contained in this guide applies to all types of internal combustion engines: two stroke engines, rotary engines, high performance/racing engines and street vehicles.

Spark plugs are the "window" into your engine (your only eyewitness to the combustion chamber), and can be used as a valuable diagnostic tool. Like a patient's thermometer, the spark plug displays symptoms and conditions of the engine's performance. The experienced tuner can analyze these symptoms to track down the root cause of many problems, or to determine air/fuel ratios.

SPARK PLUG BASICS:
The spark plug has two primary functions:

To ignite the air/fuel mixture
To remove heat from the combustion chamber

Spark plugs transmit electrical energy that turns fuel into working energy. A sufficient amount of voltage must be supplied by the ignition system to cause it to spark across the spark plug's gap. This is called "Electrical Performance."

The temperature of the spark plug's firing end must be kept low enough to prevent pre-ignition, but high enough to prevent fouling. This is called "Thermal Performance", and is determined by the heat range selected.

It is important to remember that spark plugs do not create heat, they can only remove heat. The spark plug works as a heat exchanger by pulling unwanted thermal energy away from the combustion chamber, and transferring the heat to the engine's cooling system. The heat range is defined as a plug's ability to dissipate heat.

The rate of heat transfer is determined by:

The insulator nose length
Gas volume around the insulator nose
The materials/construction of the center electrode and porcelain insulator


A spark plug's heat range has no relationship to the actual voltage transferred though the spark plug. Rather, the heat range is a measure of the spark plug's ability to remove heat from the combustion chamber. The heat range measurement is determined by several factors; the length of the ceramic center insulator nose and its' ability to absorb and transfer combustion heat, the material composition of the insulator and center electrode material.

Heat rating and heat flow path of NGK Spark Plugs



The insulator nose length is the distance from the firing tip of the insulator to the point where insulator meets the metal shell. Since the insulator tip is the hottest part of the spark plug, the tip temperature is a primary factor in pre-ignition and fouling. Whether the spark plugs are fitted in a lawnmower, boat, or a race car, the spark plug tip temperature must remain between 500C-850°C. If the tip temperature is lower than 500°C, the insulator area surrounding the center electrode will not be hot enough to burn off carbon and combustion chamber deposits. These accumulated deposits can result in spark plug fouling leading to misfire. If the tip temperature is higher than 850°C the spark plug will overheat which may cause the ceramic around the center electrode to blister and the electrodes to melt. This may lead to pre-ignition/detonation and expensive engine damage. In identical spark plug types, the difference from one heat range to the next is the ability to remove approximately 70°C to 100°C from the combustion chamber. A projected style spark plug firing tip temperature is increased by 10°C to 20°C.


Tip Temperature and Firing End Appearance



The firing end appearance also depends on the spark plug tip temperature. There are three basic diagnostic criteria for spark plugs: good, fouled and overheated. The borderline between the fouling and optimum operating regions (500&def;C) is called the spark plug self-cleaning temperature. The temperature at this point is where the accumulated carbon and combustion deposits are burned off.

Bearing in mind that the insulator nose length is a determining factor in the heat range of a spark plug, the longer the insulator nose, the less heat is absorbed, and the further the heat must travel into the cylinder head water journals. This means the plug has a higher internal temperature, and is said to be a hot plug. A hot spark plug maintains a higher internal operating temperature to burn off oil and carbon deposits, and has no relationship to spark quality or intensity.

Conversely, a cold spark plug has a shorter insulator nose and absorbs more combustion chamber heat. This heat travels a shorter distance, and allows the plug to operate at a lower internal temperature. A colder heat range is necessary when the engine is modified for performance, subjected to heavy loads, or is run at high rpms for a significant period of time. The colder type removes heat more quickly, and will reduce the chance of pre-ignition/detonation and melting or damage to the firing end. (Engine temperature can affect the spark plug's operating temperature, but not the spark plugs heat range).


Below is a list of some of the possible external influences on a spark plug's operating temperatures. The following symptoms or conditions may have an effect on the actual temperature of the spark plug. The spark plug cannot create these conditions, but it must be able to cope with the levels of heat...if not, the performance will suffer and engine damage can occur.


Air/Fuel Mixtures seriously affect engine performance and spark plug operating temperatures.
Rich air/fuel mixtures cause tip temperature to drop, causing fouling and poor driveability
Lean air/fuel mixtures cause plug tip and cylinder temperature to increase, resulting in pre-ignition, detonation, and possibly serious spark plug and engine damage
It is important to read spark plugs many times during the tuning process to achieve the optimum air/ fuel mixture


Higher Compression Ratios/Forced Induction will elevate spark plug tip and in-cylinder temperatures
Compression can be increased by performing any one of the following modifications:

a) reducing combustion chamber volume (i.e.: domed pistons, smaller chamber heads, mill ing heads, etc.)

b) adding forced induction (Nitrous, Turbocharging or Supercharging)

c) camshaft change
As compression increases, a colder heat range plug, higher fuel octane, and careful attention to igni-tion timing and air/fuel ratios are necessary. Failure to select a colder spark plug can lead to spark plug/engine damage


Advancing Ignition Timing
Advancing ignition timing by 10° causes tip temperature to increase by approx. 70°-100° C


Engine Speed and Load
Increases in firing-end temperature are proportional to engine speed and load. When traveling at a consistent high rate of speed, or carrying/pushing very heavy loads, a colder heat range spark plug should be installed


Ambient Air Temperature
As air temperature falls, air density/air volume becomes greater, resulting in leaner air/fuel mixtures.
This creates higher cylinder pressures/temperatures and causes an increase in the spark plug's tip temperature. So, fuel delivery should be increased.
As temperature increases, air density decreases, as does intake volume, and fuel delivery should be decreased


Humidity
As humidity increases, air intake volume decreases
Result is lower combustion pressures and temperatures, causing a decrease in the spark plug's tem-perature and a reduction in available power.
Air/fuel mixture should be leaner, depending upon ambient temperature.


Barometric Pressure/Altitude
Also affects the spark plug's tip temperature
The higher the altitude, the lower cylinder pressure becomes. As the cylinder temperature de-creases, so does the plug tip temperature
Many mechanics attempt to "chase" tuning by changing spark plug heat ranges
The real answer is to adjust jetting or air/fuel mixtures in an effort to put more air back into the engine


Types of Abnormal Combustion

Pre-ignition
Defined as: ignition of the air/fuel mixture before the pre-set ignition timing mark
Caused by hot spots in the combustion chamber...can be caused
(or amplified) by over advanced timing, too hot a spark plug, low octane fuel, lean air/fuel mixture, too high compression, or insufficient engine cooling
A change to a higher octane fuel, a colder plug, richer fuel mixture,
or lower compression may be in order
You may also need to retard ignition timing, and check vehicle's cooling system
Pre-ignition usually leads to detonation; pre-ignition an detonation are two separate events


Detonation
The spark plug's worst enemy! (Besides fouling)
Can break insulators or break off ground electrodes
Pre-ignition most often leads to detonation
Plug tip temperatures can spike to over 3000°F during the combustion process (in a racing engine)
Most frequently caused by hot spots in the combustion chamber.
Hot spots will allow the air/fuel mixture to pre-ignite. As the piston is being forced upward by mechanical action of the connecting rod, the pre-ignited explosion will try to force the piston downward. If the piston can't go up (because of the force of the premature explosion) and it can't go down (because of the upward motion of the connecting rod), the piston will rattle from side to side. The resulting shock wave causes an audible pinging sound. This is detonation.
Most of the damage than an engine sustains when "detonating" is from excessive heat
The spark plug is damaged by both the elevated temperatures and the accompanying shock wave, or concussion


Misfires
A spark plug is said to have misfired when enough voltage has not been delivered to light off all fuel present in the combustion chamber at the proper moment of the power stroke (a few degrees before top dead center)
A spark plug can deliver a weak spark (or no spark at all) for a variety of reasons...defective coil, too much compression with incorrect
plug gap, dry fouled or wet fouled spark plugs, insufficient ignition timing, etc.
Slight misfires can cause a loss of performance for obvious reasons (if fuel is not lit, no energy is being created)
Severe misfires will cause poor fuel economy, poor driveability, and can lead to engine damage


Fouling
Will occur when spark plug tip temperature is insufficient to burn off carbon, fuel, oil or other deposits
Will cause spark to leach to metal shell...no spark across plug gap will cause a misfire
Wet-fouled spark plugs must be changed...spark plugs will not fire
Dry-fouled spark plugs can sometimes be cleaned by bringing engine up to operating temperature
Before changing fouled spark plugs, be sure to eliminate root
cause of fouling

RETed

Nope, wish I did though!
The other option is to use those "bike plugs"...
B10EV's or something like that?


-Ted

FB II

lol thats what i always use... B9ES all around gapped to .020. i have an msd 6a on the leading and i never get any cut-out or detonation (this is using a blow-thr carb setup)

these plugs cost less than 1.50 as well

Beast From The East

I'll pass on bike plugs - if using the right stuff cost extra, so what? Not worth f'ing up a 3K motor and 3K turbo.....besides, this system I have now seems to really be dialed in nicely. Based on the color chart from NGK above, with 10.5's, 91 octane, Twin Power, and TII coil packs my plugs are in the self-cleaning range. The color is a little lighter brown like the 'pre-ignition' color, but it doesn't have the pitting, so I'm going to go to 11's next (this spring) and see how those work during the warmer weather. If they work, then I'll run 11s during the summer and 10.5s during the winter, and I might even get a set of 11.5's just to see how low I can go.....Mazdacomp sells NGKs all the way down to 13, which is damn frosty.....

FB II

didn't know the bike plug was detrimental to my engine.... i must be super uber lucky

Beast From The East

I don't know if bike plugs are good or bad.....I just know that Mazdacomp sells the NGKs for this engine specifically, therefore I use them. Bike plugs might be a perfectly viable substitute, I've just not seen much on them or heard much either. Don't take my ignorance as meaning these plugs are bad.....they might be fine.


Beast