JDM D15B - Best plugs?
Thread Starter
Joined: Mar 2002
Posts: 185
Likes: 2
From: Birmingham, UK, UK
JDM D15B - Best plugs?
Just wondered what spark plugs people are running, I have a mildly modified D15B, with IHE and a little advance, and was running Denso Iridiums IK22's, but after a problem with one of the plugs, discovered the engine is running lean, and it look like i am pre ignition. Checking out the fueling too, as i think thats the route problem.
But the plug problem meant i did some digging, and found the right plug should be a NGK ZFR6J-11 , which is a projected (long nose) plug, and the IK22's are a 0.8mm gapped(i thought they were 1.1mm) standard nose plug, and a 7 heatrange, so should be ok, but they did idle badly
What i was wondering is what plugs others are using, and if you had found a good one. I have a replacement set of IK22's to go back in (correctly gapped this time), and am going to try the standard NGK's too, but if anything else works i am interested.
But the plug problem meant i did some digging, and found the right plug should be a NGK ZFR6J-11 , which is a projected (long nose) plug, and the IK22's are a 0.8mm gapped(i thought they were 1.1mm) standard nose plug, and a 7 heatrange, so should be ok, but they did idle badly
What i was wondering is what plugs others are using, and if you had found a good one. I have a replacement set of IK22's to go back in (correctly gapped this time), and am going to try the standard NGK's too, but if anything else works i am interested.
Honda-Tech Member
Joined: Jun 2002
Posts: 2,180
Likes: 0
From: melbourne, Fl
Re: JDM D15B - Best plugs? (CivicESi)
Goto Discount and ask for NGK plugs for a 92 SI Civic plugs....I forgot the part number......the d15b vtec has VX botton end parts and SI head parts....
Thread Starter
Joined: Mar 2002
Posts: 185
Likes: 2
From: Birmingham, UK, UK
Re: JDM D15B - Best plugs? (1990hondaHF)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1990hondaHF »</TD></TR><TR><TD CLASS="quote">the d15b vtec has VX botton end parts and SI head parts....</TD></TR></TABLE>
I know thats what i thought, but the Si plugs are not correct even though it is meant to be the same head, these are NGK BKR6E-N-11, but as above they arent long nose plugs, and are effectively a 6.5 heat range, so seem to run cold too
I have now fitted the ZFR6J-11's (stated as the OEM plug on the engine) and the car is running sooo much better, esepcially the low throttle drivability and low end torque is much improved, so untill i do some serious engine mods i am sticking with them, though may give my IK22's a second chance as my top end seems to have lost a little urgency
If you can get hold of them, give em a try, especially if yours is a daily driver, its a lot smoother round town anyway, and if you are running a different plug and like em, let me know, as i will need a cooler plug in the future
I know thats what i thought, but the Si plugs are not correct even though it is meant to be the same head, these are NGK BKR6E-N-11, but as above they arent long nose plugs, and are effectively a 6.5 heat range, so seem to run cold too
I have now fitted the ZFR6J-11's (stated as the OEM plug on the engine) and the car is running sooo much better, esepcially the low throttle drivability and low end torque is much improved, so untill i do some serious engine mods i am sticking with them, though may give my IK22's a second chance as my top end seems to have lost a little urgency
If you can get hold of them, give em a try, especially if yours is a daily driver, its a lot smoother round town anyway, and if you are running a different plug and like em, let me know, as i will need a cooler plug in the future
Thread Starter
Joined: Mar 2002
Posts: 185
Likes: 2
From: Birmingham, UK, UK
Re: JDM D15B - Best plugs? (CivicESi)
Oh and i got a load of tech info from a helpful guy at Denso, here goes
CAR / ENGINE CODE
Because it is a Japanese Domestic Market car, I have checked our Japanese catalogue
Honda Civic EG4 (/ EG8)
D15B = K20PR-U11 (NGK BKR6E-11) (standard 3mm projection) (like iridium power plugs)
D15B VTEC-E (Economy VTEC)= KJ16CR-L11 (NGK ZFR5F-11) (extra projected = 5mm projection = long=nose)
D15B VTEC (Power VTEC) = KJ20CR-L11 (NGK ZFR6F-11or ZFR6J-11) (extra projected = 5mm projection = long nose)
The customer said the standard plug was the NGK BKR6E-N-11 (Denso K20PR-L11)
According to our and Honda information, this is the plug for the Civic 1.6 and 1.8 VTEC engines.
The "L" in the Denso code (for this plug) and the "-N-" in the NGK code mean that it is a half heatrange colder type.
The K20PR-L11 is like a "K21PR-11" and the NGK BKR6E-N-11 is more like a "BKR6,5E--11
In the owners manual of these cars, there is also the option mentioned for a colder plug (K22PR-L11 or BKR7E-N-11)
Honda advised this for 'a hot climate and/or continuous high speed driving"
By choosing the IK22, the customer has made the right choice of heatrange. (if original is BKR6E-N-11 or K20PR-L11)
(In my personal car (Mazda 323F-coupe), there are are also 2 heatranges recommended in the owners manual. std = heatrange 16 and cold=heatrange20. I have been running the cold heatrange iridium VK20PR-Z11 plugs for 4 years now without problems even in low speed and traffic jam conditions. (2 year std car, 2 year K&N filter + Laser sport exhaust)
However, to be sure about the type, it is best to check the owners manual or check the chassis code and engine code.
How can you know what are the original plugs ?
If projected nose plugs are fitted as Original Equipment, Honda usually puts a sticker in the engine bay that says this (Extended type)
If you use an non-projected (racing or karting plug) with the SAME heatrange as an extra projected type, then the spark plug tip (insulator nose) is not cooled by the relatively cool incoming air/fuel mixture and therefore can overheat.
On the other hand, if you use a extra projected (long-nose) spark plug in a tuned engine, then you will have the risk of the tip of the ground electrode being much more sensitive to damage as a result of the combination of heat and vibrations.
For extremely projected plugs (7->9mm) there is even the risk of plug to piston contact.
TYPE OF PLUG
I have checked the package, but I cannot find where it says 1.1mm.
The specifications in our iridium power information and catalogue show that the IK22 comes from the factory with a 0.8mm gap.
(IK16 + IK20 are 1.1mm, IK22 and higher heatrange K-types are 0.8mm)
In our catalogue we list 1.1mm, but this is to show what the car should have, (not what the plug itself is)
However, because Denso is original equipment on all the Japanese makes, Denso OE plugs come pre gapped to the correct size.
Iridium power is an aftermarket series and in this aftermarket most cars that run heatrange 22, need a 0.8mm gap.
Indeed in the iridium power leaflet it is not recommended to change the gap of the iridium plugs, but this is done because some people set the gap by placing a feeler gauge between the centre electrode and ground electrode and then hitting the ground electrode down to close the gap. This can damage the iridium tip.
On the other hand, if you use a gap setting tool, and do it carefully there should be no problem.
Like I said, if the gap is 0.8mm, while Honda recommends 1.1mm, this will mean that your spark is a little too short and this will affect performance and emissions at low loads and low RPM.
Another danger of a gap smaller than specified is that you have a bigger chance on pinging and detonation.
(However, if you run an increased compression ratio, compressor/turbo or nitrous, you will need a smaller gap than standard)
TUNING ON THE ENGINE
The IK22 will be suitable for a slightly modified car (exhaust, filters, slightly higher RPM) used in tough conditions and continuous high speed driving. (As long as ignition timing is within Honda specifications)
Increasing compression ratio will give a slight increase in power and efficiency, but will also put the engine over the limit for standard fuel. It will have to run on higher octane fuel.
However advancing the ignition out of the Honda tolerances and on top of that increase the compression ratio, will bring the engine closer if not over the knock limit. The increased load and temperature will require colder heatrange spark plugs or even special racing types with shorter ground electrode to resist heat load and vibrations.
Both increasing compression ratio and advancing ignition create huge increases in combustion chamber temperatures so to compensate, ignition advance must not be advanced even more (or even retarded), and to "cool" the engine, the mixture must be slightly richer.
The only way to get more power from a normally aspirated engine by chiptuning is by:
- advancing the ignition (dangerous) and
- richening the air/fuel mixture (slightly more chance on fouling during low-load+idle and risk of melting the catalyst during high speed driving).
Personally I would say. you are stressing the engine enourmously and making it very sensitive for detonation, for only a couple of horsepower that could also be gained by safer measures. (Exhaust, filter, ram air ducts, camshaft)
(extra B)
Standard projection/spark position for almost all automotive spark plugs is 3mm. (indicated by "P")
(NGK BKR6E-11, BKR6E-N-11, BKR7E-N-11, Denso K20PR-U11, K20PR-L11, K22PR-L11 etc....)
Extra projected or long nose for Denso (or "extended" for Honda) is 4mm and up to 9mm projection/spark position)
Honda "long nose" means a spark position at 5mm
(NGK ZFR5F-11, ZFR5J-11, ZFR6F-11, ZFR6J-11, Denso KJ16CR-L11, KJ20CR-L11, PKJ20CR-L11 etc)
For more upgrade options with different prices/performances and service lifes, feel free to contact us with the original plug reference. (If the original plug is a long-nose plug, then there are other performance options)
If the IK22 has the correct heatrange and spark position in the current engine, there are a couple of other options:
Standard engine
If you would have been running a standard engine, then we would recommend to use the same extra projected (long-nose) plug as original, but the high performance thin electrode version of this plug. (5mm projection)
Original = NGK ZFR6F-11, ZFR6J-11, Denso KJ20CR-L11)
High performance version of this plug =
- Denso iridium KJ20SR11 (0.7mm iridium centre electrode)
- Denso iridium VKJ20RZ-M11 (0.4mm iridium centre electrode, platinum tipped ground electrode) (63.000 miles service interval)
The VKJ20RZ-M11 is the ultimate performance option for the standard plugs ZFR6F11, ZFR6J-11, PZFR6F-11,KJ20CR-L11 , PKJ20CR-L11. It is originally fitted to the new Honda BF200 and BF225 V-6 outboard engines.
Hovever, this is not the most suitable plug for your engine.
However, your Civic is a slightly tuned engine (in a risky way by ignition timing) and therefore it is better to go for a slightly colder heatrange.
Also the tuning type (ignition, compression ratio) will give a greater thermal load on the plug and ground electrode and bring it closer to the knock-limit. Therefore you will need a plug that has a colder heatrange and a shorter ground electrode.
Whichever head in on your engine now, it is more important that the plug survives and performs well, than that you have the spark at the same location as the original plug. Therefore moving from a 5mm projected plug to a 3mm projected plug is a smart decision. (NGK BKR..E-.. or Denso K..PR-.. or IK.. are all 3mm projected types)
Looking at the specs that we know from your engine, heatrange 22 (IK22) seems like the correct heatrange.
If fuelling and engine are all wel tuned/adjusted and the plug still comes out bright white and maybe even with some melted spots of carbon or aluminium, then it is safer to go one heatrange up to 24 (IK24)
Please be aware that a colder heatrange plug can transfer more heat, so in low load/low temperature start-stop use, the spark plug will be more sensitive to carbon fouling
Before paying too much attention to the plugs, is is wise ot check if the timing is correct and the engine gets enough fuel.
POSSIBLE PLUGS
In both 22 and 24 heatranges there are the iridium power and the (more expensive) iridium power-longlife 63.000 mile types. The longlife types already have the gap at 1.1mm.
If you increase compression ratio, you will need to set the gap smaller to ± 1.0mm instead of the original 1.1mm.
-DENSO ZU platinum performance 0.7mm centre electrode= K22PR-ZU11
Slightly cheaper than IK22, and no need to set the gap (0.4mm tip is better than 0.7mm tip)
(11 means standard gap is factory set at 1.1mm)
3-DENSO iridium power longlife 0.4mm centre electrode
= VK22PR-Z11 (Honda partno. 98079-5715U) (63.000 miles)
(Same performance as IK22, but correct gap for Hondfa and service life of 63.000km)
(Optional cold plug for Honda VTX1800 motorcycle or optional warm plug for CRF450R crosser)
4-HONDA iridium longlife plug 0.7mm centre electrode
= SK22PR-M11 (Honda partno = 98079-5715V) (63.000++ miles)
(Plug from 7th generation Civic EU.. TYPE-R with 2.0 K20A2 I-VTEC engine)
Heatrange 22
1- K22PR-ZU11 (0.7mm platinum centre electrode, taper cut U-grooved ground electrode, gap = 1.1mm)
2- IK22 (0.4mm iridium centre electrode, taper cut U-grooved ground electrode, gap = 0.8mm) (regap to 1.1)
3- VK22PR-Z11 (0.4mm iridium centre electrode, taper cut, platinum tipped ground electrode, gap = 1.1mm)
(VK22PR-Z11 = warm optional plug for Honda CRF450R crosser. Honda partno = 98079-5715U)
4- SK22PR-M11 (0.7mm iridium centre electrode, platinum tipped ground electrode, gap = 1.1mm)
(SK22PR-M11 = original plug for Honda Accord CL7 2.0 Euro-R and Civic EU Type-R)
(Honda partno = 98079-5715V, 98079-571CV, 12290-PRB-A020M2 )
Heatrange 24
5- IK24 (0.4mm iridium centre electrode, taper cut U-grooved ground electrode, gap = 0.8mm) (regap to 1.0)
6- VK24PR-Z11 (0.4mm iridium centre electrode, taper cut, platinum tipped ground electrode, gap = 1.1mm)
(VK24PR-Z11 = original plug for Honda CRF450R crosser. Honda partno = 31918-MEB-672)
With any of the plugs above you need to run a 1.0 to 1.1mm gap as Honda recommends for almost all of their normally aspirated engines.This is to keep stable idle and low/rpm performance and is needed for good emissions and catalyst.
If you increase compression ratio, you may need to use a 0.95 to 1.0mm gap.
Why not run a very cold heatrange plug ?
A racing-style plug transfers heat so quickly that there is a chance that during idle or repeated cold start start-stop driving, the insulator nose does not reach it's selfcleaning temperature. This means that slowly (conductive) carbon will deposit and start to cause misfires. Any misfire means unburnt fuel in the catalyst and this can cause the catalyst to be damaged or overheat.
So: plug heatrange too warm = risk on pre-ignition and engine damage,
plug heatrange too cold = risk on carbon fouling and damage to the catalyst
CAR / ENGINE CODE
Because it is a Japanese Domestic Market car, I have checked our Japanese catalogue
Honda Civic EG4 (/ EG8)
D15B = K20PR-U11 (NGK BKR6E-11) (standard 3mm projection) (like iridium power plugs)
D15B VTEC-E (Economy VTEC)= KJ16CR-L11 (NGK ZFR5F-11) (extra projected = 5mm projection = long=nose)
D15B VTEC (Power VTEC) = KJ20CR-L11 (NGK ZFR6F-11or ZFR6J-11) (extra projected = 5mm projection = long nose)
The customer said the standard plug was the NGK BKR6E-N-11 (Denso K20PR-L11)
According to our and Honda information, this is the plug for the Civic 1.6 and 1.8 VTEC engines.
The "L" in the Denso code (for this plug) and the "-N-" in the NGK code mean that it is a half heatrange colder type.
The K20PR-L11 is like a "K21PR-11" and the NGK BKR6E-N-11 is more like a "BKR6,5E--11
In the owners manual of these cars, there is also the option mentioned for a colder plug (K22PR-L11 or BKR7E-N-11)
Honda advised this for 'a hot climate and/or continuous high speed driving"
By choosing the IK22, the customer has made the right choice of heatrange. (if original is BKR6E-N-11 or K20PR-L11)
(In my personal car (Mazda 323F-coupe), there are are also 2 heatranges recommended in the owners manual. std = heatrange 16 and cold=heatrange20. I have been running the cold heatrange iridium VK20PR-Z11 plugs for 4 years now without problems even in low speed and traffic jam conditions. (2 year std car, 2 year K&N filter + Laser sport exhaust)
However, to be sure about the type, it is best to check the owners manual or check the chassis code and engine code.
How can you know what are the original plugs ?
If projected nose plugs are fitted as Original Equipment, Honda usually puts a sticker in the engine bay that says this (Extended type)
If you use an non-projected (racing or karting plug) with the SAME heatrange as an extra projected type, then the spark plug tip (insulator nose) is not cooled by the relatively cool incoming air/fuel mixture and therefore can overheat.
On the other hand, if you use a extra projected (long-nose) spark plug in a tuned engine, then you will have the risk of the tip of the ground electrode being much more sensitive to damage as a result of the combination of heat and vibrations.
For extremely projected plugs (7->9mm) there is even the risk of plug to piston contact.
TYPE OF PLUG
I have checked the package, but I cannot find where it says 1.1mm.
The specifications in our iridium power information and catalogue show that the IK22 comes from the factory with a 0.8mm gap.
(IK16 + IK20 are 1.1mm, IK22 and higher heatrange K-types are 0.8mm)
In our catalogue we list 1.1mm, but this is to show what the car should have, (not what the plug itself is)
However, because Denso is original equipment on all the Japanese makes, Denso OE plugs come pre gapped to the correct size.
Iridium power is an aftermarket series and in this aftermarket most cars that run heatrange 22, need a 0.8mm gap.
Indeed in the iridium power leaflet it is not recommended to change the gap of the iridium plugs, but this is done because some people set the gap by placing a feeler gauge between the centre electrode and ground electrode and then hitting the ground electrode down to close the gap. This can damage the iridium tip.
On the other hand, if you use a gap setting tool, and do it carefully there should be no problem.
Like I said, if the gap is 0.8mm, while Honda recommends 1.1mm, this will mean that your spark is a little too short and this will affect performance and emissions at low loads and low RPM.
Another danger of a gap smaller than specified is that you have a bigger chance on pinging and detonation.
(However, if you run an increased compression ratio, compressor/turbo or nitrous, you will need a smaller gap than standard)
TUNING ON THE ENGINE
The IK22 will be suitable for a slightly modified car (exhaust, filters, slightly higher RPM) used in tough conditions and continuous high speed driving. (As long as ignition timing is within Honda specifications)
Increasing compression ratio will give a slight increase in power and efficiency, but will also put the engine over the limit for standard fuel. It will have to run on higher octane fuel.
However advancing the ignition out of the Honda tolerances and on top of that increase the compression ratio, will bring the engine closer if not over the knock limit. The increased load and temperature will require colder heatrange spark plugs or even special racing types with shorter ground electrode to resist heat load and vibrations.
Both increasing compression ratio and advancing ignition create huge increases in combustion chamber temperatures so to compensate, ignition advance must not be advanced even more (or even retarded), and to "cool" the engine, the mixture must be slightly richer.
The only way to get more power from a normally aspirated engine by chiptuning is by:
- advancing the ignition (dangerous) and
- richening the air/fuel mixture (slightly more chance on fouling during low-load+idle and risk of melting the catalyst during high speed driving).
Personally I would say. you are stressing the engine enourmously and making it very sensitive for detonation, for only a couple of horsepower that could also be gained by safer measures. (Exhaust, filter, ram air ducts, camshaft)
(extra B)
Standard projection/spark position for almost all automotive spark plugs is 3mm. (indicated by "P")
(NGK BKR6E-11, BKR6E-N-11, BKR7E-N-11, Denso K20PR-U11, K20PR-L11, K22PR-L11 etc....)
Extra projected or long nose for Denso (or "extended" for Honda) is 4mm and up to 9mm projection/spark position)
Honda "long nose" means a spark position at 5mm
(NGK ZFR5F-11, ZFR5J-11, ZFR6F-11, ZFR6J-11, Denso KJ16CR-L11, KJ20CR-L11, PKJ20CR-L11 etc)
For more upgrade options with different prices/performances and service lifes, feel free to contact us with the original plug reference. (If the original plug is a long-nose plug, then there are other performance options)
If the IK22 has the correct heatrange and spark position in the current engine, there are a couple of other options:
Standard engine
If you would have been running a standard engine, then we would recommend to use the same extra projected (long-nose) plug as original, but the high performance thin electrode version of this plug. (5mm projection)
Original = NGK ZFR6F-11, ZFR6J-11, Denso KJ20CR-L11)
High performance version of this plug =
- Denso iridium KJ20SR11 (0.7mm iridium centre electrode)
- Denso iridium VKJ20RZ-M11 (0.4mm iridium centre electrode, platinum tipped ground electrode) (63.000 miles service interval)
The VKJ20RZ-M11 is the ultimate performance option for the standard plugs ZFR6F11, ZFR6J-11, PZFR6F-11,KJ20CR-L11 , PKJ20CR-L11. It is originally fitted to the new Honda BF200 and BF225 V-6 outboard engines.
Hovever, this is not the most suitable plug for your engine.
However, your Civic is a slightly tuned engine (in a risky way by ignition timing) and therefore it is better to go for a slightly colder heatrange.
Also the tuning type (ignition, compression ratio) will give a greater thermal load on the plug and ground electrode and bring it closer to the knock-limit. Therefore you will need a plug that has a colder heatrange and a shorter ground electrode.
Whichever head in on your engine now, it is more important that the plug survives and performs well, than that you have the spark at the same location as the original plug. Therefore moving from a 5mm projected plug to a 3mm projected plug is a smart decision. (NGK BKR..E-.. or Denso K..PR-.. or IK.. are all 3mm projected types)
Looking at the specs that we know from your engine, heatrange 22 (IK22) seems like the correct heatrange.
If fuelling and engine are all wel tuned/adjusted and the plug still comes out bright white and maybe even with some melted spots of carbon or aluminium, then it is safer to go one heatrange up to 24 (IK24)
Please be aware that a colder heatrange plug can transfer more heat, so in low load/low temperature start-stop use, the spark plug will be more sensitive to carbon fouling
Before paying too much attention to the plugs, is is wise ot check if the timing is correct and the engine gets enough fuel.
POSSIBLE PLUGS
In both 22 and 24 heatranges there are the iridium power and the (more expensive) iridium power-longlife 63.000 mile types. The longlife types already have the gap at 1.1mm.
If you increase compression ratio, you will need to set the gap smaller to ± 1.0mm instead of the original 1.1mm.
-DENSO ZU platinum performance 0.7mm centre electrode= K22PR-ZU11
Slightly cheaper than IK22, and no need to set the gap (0.4mm tip is better than 0.7mm tip)
(11 means standard gap is factory set at 1.1mm)
3-DENSO iridium power longlife 0.4mm centre electrode
= VK22PR-Z11 (Honda partno. 98079-5715U) (63.000 miles)
(Same performance as IK22, but correct gap for Hondfa and service life of 63.000km)
(Optional cold plug for Honda VTX1800 motorcycle or optional warm plug for CRF450R crosser)
4-HONDA iridium longlife plug 0.7mm centre electrode
= SK22PR-M11 (Honda partno = 98079-5715V) (63.000++ miles)
(Plug from 7th generation Civic EU.. TYPE-R with 2.0 K20A2 I-VTEC engine)
Heatrange 22
1- K22PR-ZU11 (0.7mm platinum centre electrode, taper cut U-grooved ground electrode, gap = 1.1mm)
2- IK22 (0.4mm iridium centre electrode, taper cut U-grooved ground electrode, gap = 0.8mm) (regap to 1.1)
3- VK22PR-Z11 (0.4mm iridium centre electrode, taper cut, platinum tipped ground electrode, gap = 1.1mm)
(VK22PR-Z11 = warm optional plug for Honda CRF450R crosser. Honda partno = 98079-5715U)
4- SK22PR-M11 (0.7mm iridium centre electrode, platinum tipped ground electrode, gap = 1.1mm)
(SK22PR-M11 = original plug for Honda Accord CL7 2.0 Euro-R and Civic EU Type-R)
(Honda partno = 98079-5715V, 98079-571CV, 12290-PRB-A020M2 )
Heatrange 24
5- IK24 (0.4mm iridium centre electrode, taper cut U-grooved ground electrode, gap = 0.8mm) (regap to 1.0)
6- VK24PR-Z11 (0.4mm iridium centre electrode, taper cut, platinum tipped ground electrode, gap = 1.1mm)
(VK24PR-Z11 = original plug for Honda CRF450R crosser. Honda partno = 31918-MEB-672)
With any of the plugs above you need to run a 1.0 to 1.1mm gap as Honda recommends for almost all of their normally aspirated engines.This is to keep stable idle and low/rpm performance and is needed for good emissions and catalyst.
If you increase compression ratio, you may need to use a 0.95 to 1.0mm gap.
Why not run a very cold heatrange plug ?
A racing-style plug transfers heat so quickly that there is a chance that during idle or repeated cold start start-stop driving, the insulator nose does not reach it's selfcleaning temperature. This means that slowly (conductive) carbon will deposit and start to cause misfires. Any misfire means unburnt fuel in the catalyst and this can cause the catalyst to be damaged or overheat.
So: plug heatrange too warm = risk on pre-ignition and engine damage,
plug heatrange too cold = risk on carbon fouling and damage to the catalyst
Thread Starter
Joined: Mar 2002
Posts: 185
Likes: 2
From: Birmingham, UK, UK
Re: JDM D15B - Best plugs? (CivicESi)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CivicESi »</TD></TR><TR><TD CLASS="quote">
I have now fitted the ZFR6J-11's (stated as the OEM plug on the engine) and the car is running sooo much better.....
</TD></TR></TABLE>
I decided to try the original plugs, which were actually written on the cambelt cover if i had bothered to look. I assumed they were the BKR's like my ESi/Si, as everyone says its a D16Z6 head, but Honda decided to be different
They are sweet, though i was having a fueling issue too (running super lean top end and detting
), which caused my problems in the first place, and have sorted that too, but it is definately idling better, and the general torque is much better, but its not revving as freely as with the Denso Iridium IK22's. I was runnning them at the wrong gap, as they come gapped to 0.8mm not 1.1mm, which i did not know 
, but i am still very happy with the NGK's now 
So as the man said when i have done a little more tuning, and am confident the fueling is 100% sorted, particularly the increased compression and cam gear then i will go back to them, but for now, the Honda/NGK plugs are staying
Cheers for helping out and sticking the link in the EG forum, didnt see it when i posted the tech stuff, but hopefully some D15B guys get some info out of it
I have now fitted the ZFR6J-11's (stated as the OEM plug on the engine) and the car is running sooo much better.....
</TD></TR></TABLE>
I decided to try the original plugs, which were actually written on the cambelt cover if i had bothered to look. I assumed they were the BKR's like my ESi/Si, as everyone says its a D16Z6 head, but Honda decided to be different
They are sweet, though i was having a fueling issue too (running super lean top end and detting
), which caused my problems in the first place, and have sorted that too, but it is definately idling better, and the general torque is much better, but its not revving as freely as with the Denso Iridium IK22's. I was runnning them at the wrong gap, as they come gapped to 0.8mm not 1.1mm, which i did not know , but i am still very happy with the NGK's now So as the man said when i have done a little more tuning, and am confident the fueling is 100% sorted, particularly the increased compression and cam gear then i will go back to them, but for now, the Honda/NGK plugs are staying
Cheers for helping out and sticking the link in the EG forum, didnt see it when i posted the tech stuff, but hopefully some D15B guys get some info out of it
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Re: JDM D15B - Best plugs? (CivicESi)
i was also curious as to what plug to get for a turbod d15b. The plugs are shorter than the z6 plugs, and the heat range is already lower. SHould i still go heat ranges lower, i am having trouble finding a plug.
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From: 92127
Re: JDM D15B - Best plugs? (snoochtodanooch)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by snoochtodanooch »</TD></TR><TR><TD CLASS="quote">i was also curious as to what plug to get for a turbod d15b. The plugs are shorter than the z6 plugs, and the heat range is already lower. SHould i still go heat ranges lower, i am having trouble finding a plug. </TD></TR></TABLE>
I have used zfr6j-11 and Denso IK20 Iridium plugs. Both have similar detonation thresholds. I have not found the colder NGK zfr7j-11s at any retailer, performance of otherwise.
I have used zfr6j-11 and Denso IK20 Iridium plugs. Both have similar detonation thresholds. I have not found the colder NGK zfr7j-11s at any retailer, performance of otherwise.
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Re: JDM D15B - Best plugs? (Jim Truett)
yea, i found a plug for a volvo that is a 7 i think but i can't find it anywhere.
And i have found some marine stuff that are 8s, but once again i can't find them anywhere.
So you running fine with the 6s in you turbod engine?
And i have found some marine stuff that are 8s, but once again i can't find them anywhere.
So you running fine with the 6s in you turbod engine?
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From: 92127
Re: JDM D15B - Best plugs? (snoochtodanooch)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by snoochtodanooch »</TD></TR><TR><TD CLASS="quote">
So you running fine with the 6s in you turbod engine?</TD></TR></TABLE>
Yes, but I had to pull more timing at 7+ psi than I would have liked to. Gotta love that California CARB 91 octane.
So you running fine with the 6s in you turbod engine?</TD></TR></TABLE>
Yes, but I had to pull more timing at 7+ psi than I would have liked to. Gotta love that California CARB 91 octane.
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From: 92127
Re: JDM D15B - Best plugs? (snoochtodanooch)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by snoochtodanooch »</TD></TR><TR><TD CLASS="quote">the price isn't outrageous either.</TD></TR></TABLE>
How much is it?
I pay $2.18/gal for the 91
How much is it?
I pay $2.18/gal for the 91
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Casey
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