Plug Choice R33Gtr

[Robert Knight]

Hi all,Firstly I have read all the threads I can find on GTR plug choices and I ended up confused,I bought my 95 33gtr about 2 yrs ago and it has never had a plug change ,although it has only done about 6000kms since I've had it mostly highway use,it now has 80,000km on the clock, so today I attempted to pull the plugs out and have a look at them and to my surprise they were a type I haven't seen mentioned on the forum but definitely not stock as I had expected them to be, they are NGK R and the heat range seems to be 8 which is written on the opposite side to the R does anyone know those plugs and what recommendations do you have as to replacement new ones??or should I just get a new set of them if they are still available,as they have given me no trouble and only the fine electrode has burned down to about a 2mm gap.

Does anyone know what metal they are made with as I would preferrably like to replace them with iridium or platinum as it is not a job I want to do too soon as it is not that easy,my car has only 245awkw as I have the dyno sheet from the previous owner so I don't think the motor has been worked in any way only the boost restrictor removed I think,any help greatly appreciated.Cheers GREYPEARL

[89CAL]

BKR8E

Is what the copper equivalent would be. The heat range 7 plugs I just put in mine I'm pretty sure had NGK R on the side but yours might be iridums by the amount of km you have done

[Robert Knight]

BKR8E

Is what the copper equivalent would be. The heat range 7 plugs I just put in mine I'm pretty sure had NGK R on the side but yours might be iridums by the amount of km you have done

Thanks for the reply mate,anyone else got any input??GREYPEARL.

[mad082]

heat range 8 plugs are pretty darn cold. for the power you are making i would suggest maybe going back to a heat range 7 plug.

as for the iridium/platinum/copper debate, my personal opinion is to stick with copper. they give the best spark and don't last that much shorter than iridiums. for mostly highway driving you should get around 20,000kms out of them, which is about the same as some people are getting out of iridiums (some get more, some get less).

also plugs aren't that hard to change. it is made a lot easier if you pull all the coils out at once rather than individually. you can undo 2 or 3 bolts that allows you to lift all the coils out at once rather than undoing 4 bolts per coil.

[Robert Knight]

heat range 8 plugs are pretty darn cold. for the power you are making i would suggest maybe going back to a heat range 7 plug.

as for the iridium/platinum/copper debate, my personal opinion is to stick with copper. they give the best spark and don't last that much shorter than iridiums. for mostly highway driving you should get around 20,000kms out of them, which is about the same as some people are getting out of iridiums (some get more, some get less).

also plugs aren't that hard to change. it is made a lot easier if you pull all the coils out at once rather than individually. you can undo 2 or 3 bolts that allows you to lift all the coils out at once rather than undoing 4 bolts per coil

Thanks Mate,I was expecting more bites than this and now due to needing the car I have had to bite the bullet and buy PFR6A11 plugs which are the original plugs supplied for the GTR I didn't want to be wearing out the plug thread holes with multiple changes and the time involved so will see how these go,technically the engine will need a re-build before these plugs wear out as they are listed for 100,000kms.Cheers GREYPEARL.

[mad082]

what boost are you running at the moment? if it is relatively high boost (14psi+) then you will want to wind it down a bit with heat range 6 plugs.

[blind_elk]

... they are NGK R ...

This appears to be part of the standard marking on the plug, doesn't indicate anything special about the plug, AFAICT.

[Robert Knight]

what boost are you running at the moment? if it is relatively high boost (14psi+) then you will want to wind it down a bit with heat range 6 plugs.

Standard boost 1 bar,but they are the plugs that the manufacturer supplied with the GTR so the ngk book says,thanks for the reply.GREYPEARL Edited December 29, 2010 by Robert Knight

[Robert Knight]

This appears to be part of the standard marking on the plug, doesn't indicate anything special about the plug, AFAICT.

Yes the R is a standard marking for many NGK plugs but these had only one other number on the other side of the plug and that was an 8,no listing for those in Australia so I can only assume that they were bought and installed in Japan and represent the heat range??Cheers GREYPEARL.

[Robert Knight]

Yes the R is a standard marking for many NGK plugs but these had only one other number on the other side of the plug and that was an 8,no listing for those in Australia so I can only assume that they were bought and installed in Japan and represent the heat range??Cheers GREYPEARL.

Anyone know what these plugs are??Greypearl.

[Robert Knight]

Anyone know what these plugs are??Greypearl.

Anyone??

[Robert Knight]

Hi all,Firstly I have read all the threads I can find on GTR plug choices and I ended up confused,I bought my 95 33gtr about 2 yrs ago and it has never had a plug change ,although it has only done about 6000kms since I've had it mostly highway use,it now has 80,000km on the clock, so today I attempted to pull the plugs out and have a look at them and to my surprise they were a type I haven't seen mentioned on the forum but definitely not stock as I had expected them to be, they are NGK R and the heat range seems to be 8 which is written on the opposite side to the R does anyone know those plugs and what recommendations do you have as to replacement new ones??or should I just get a new set of them if they are still available,as they have given me no trouble and only the fine electrode has burned down to about a 2mm gap.

Does anyone know what metal they are made with as I would preferrably like to replace them with iridium or platinum as it is not a job I want to do too soon as it is not that easy,my car has only 245awkw as I have the dyno sheet from the previous owner so I don't think the motor has been worked in any way only the boost restrictor removed I think,any help greatly appreciated.Cheers GREYPEARL

Further to this story I have been through a lot to get this sorted,my problems started when my 33GTR began having the odd miss,which had never happened before so thought I will check the plugs and probably replace them as I hadn't touched the car since I bought it,so pulled them out and saw that they were iridiums or platinums,not sure as it was not apparent on the plugs, so went looking for the same plugs and couldn't find any reference to them in any NGK reference anywhere and no-one on the forum had ever heard of them either,just NGK R on one side of the plug and an 8 on the other side,so I then started searching the confused souls on the spark plug threads and couldn't decide what was correct as no-one had used heat range 8 on a GTR and those that answered me thought it most peculiar.

So I found out what the standard plugs were for a stock GTR PFR6A11 Platinums and fitted them,also changed the air filter,was an Apexi for a Ryco A360,started it up seemed ok then took it for a drive about 50km round trip to give everything a chance to settle in and the ECU to re balance to the changes,but it was horrible even compared to the old plugs,couldn't take boost unless fed on gradually,missing profusely,and just disappointed the hell out of me,so came home,got on the forum and started looking at Iridiums because I wanted a .8 gap, and ended up at Kudos motorsports where they have a very comprehensive chart for selecting plugs even though the ones I bought did not list the gap and whether they were a resistance plug or not,a bit disappointing but a couple of emails later had that confirmed as yes, I bought the Iritop7's pregapped to .8mm, as they were recommended for moderately enhanced cars,and as I had been using 8's already very sucessfully ,and had them in my hands 2 days later for the sum of $156.20 including postage,the Platinums had cost $146.00 so I was pleased with the Iridium price which is even better if you buy them and coils together as you save 10% off the plugs doing that.

In the mean time whilst waiting for the plugs to arrive I pulled out the coils and plugs and jumped on the forum again to find out how to test coils and followed the instructions to test the primary side IE: set multimeter to ohms resistance,the little inverted u shape symbol, and put black to centre probe and red to lefthand side probe in the coil to loom connection part and get a reading between .6 and .8,I got a reading of -676 on all of them and knowing that they were all ok and the car still ran ok without boost,I rightly as it turned out assumed the coils to be ok,but still hoping at this stage.I proceeded to fit the new plugs after checking myself to make sure of the gap and yes they were spot on .8,put everything back together and fired it up but now it was doughy when free revving in neutral and sounded missy as well,I thought oh no,what else could it be,so I thought I've never changed the fuel filter,so again on the forum but no reference anywhere,so got online and found the Ryco filter chart and found the correct filter,which the Local Nissan dealer couldn't even tell me,it is Ryco Z387 or it's equivalent if you can't get that brand,for all Rb26 engines

$23.90 from Bursons,$33.00 from Supercheap,it pays to ring around for prices,so as Supercheap is a lot closer I made them match the Burson price which they did,put that in,and this can be a hell of a job as Nissan put as much goodness into the GTR engine bay as they could, and that doesn't leave much room for hands,especially big white man hands!! and believe me you will need both hands and strength for this job!!

I know this is long winded but I feel there is some good learning in this for a lot of people to save themselves some cash and still diagnose their own problems,I will tell you how to change a GTR fuel filter the easiest way,Firstly approach any job in the engine bay with care,and move slowly whilst doing it as there are switches and connections that will break if you hit them hard especially in frustration,go and boil the jug, and have a hot drink while you are there to calm down,have the new filter on hand,unscrew the top hose clip on the filter and get it as loose as you can without the screw coming right out ,you don't want that to happen as there are loose parts that will come off and get lost both sides of the clip,pour the hot water slowly onto the part of the hose where the clip is for about 10 secs,and from the front of the car put one hand to hold the filter and one to pull the hose off,pull in a twisting motion from side to side,really screwing the hose till it comes off,you may have to heat it twice to do this I did,fuel injected hoses are very tight,don't be tempted to cut the hose and do it outside the car as this will be a tempting thought,a couple of times doing that and you will not have enough hose and that's a bigger job,just keep heating and screwing and it will come,fold the top hose out of the way and hook it between some wires that are there so you don't spill fuel everywhere.

Then get a 12 mm socket and remove the filter holderand take it out of the way,you will need the hand room believe me,undo the clip on the bottom hose again as loose as possible without it coming apart,fold the filter and hose into a position where you can pour the hot water on it and repeat the process you have already done on the top hose,I found it a bit easier on the bottom hose as it is secured a bit,then screw the filter this time and hold the hose tightly it should come ok but may require more hot water,the hot water serves 2 purposes,it heats the rubber and washes spilt fuel away,put the filter onto the bottom hose first making sure the clip is in the same orientation as it was so it's easy to undo next time and slide it up to the end of the hose to be in it's right position to do up as you can't slide it over after the hose is fitted to the filter,orientate the filter top so it faces the right way then do up the clip,do not over tighten the clips or they will strip,just nip them,then put back the filter holder put the filter back in it and fit the top hose,use any left over hot water to wash the spilt fuel and you're done,it's not as easy as you think,that's why I went to this trouble to thank the forum for all it's help.

Now the good part for me anyway, I fired it up sounded better but still a bit missy when revved,I thought no, it's still not right, and started thinking coils again,and it was pissing rain,and I usually never take my car out in the wet as it needs a total clean again after that,but I couldn't wait,I had to know,so off I went slowly at first all seemed good,when I hit the freeway it was up to temp so I thought here goes and floored it only to come out on the freeway in front of a cop car but settled it down and he turned off probably couldn't gauge my speed cause of the spray,when he was gone took it through the gears,it was like a jet I tell you it excited me it was so good no miss no pops between gears,a lot less vibration at full revs,just a joy to drive,got home put it in the garage very pleased with myself even though I had spent $146.00 too much on plugs that were wrong for my application,at this point I would like to say that even though my car seems stock,I don't think it is,it has white 320km gauges a Nismo twin 2" titanium exhaust system,Tien coilover suspension all round and 18"X91/2" Volk VC Pro Racing rims,has had the rear windscreen wiper removed and the hole filled and the boot lock taken out and filled,my point being that the japanese guy who owned it seemed to know his stuff and therefore it's not beyond the realms of possibility that he did other things to it as well as it had the heat range 8 plugs in it and they agreed with it,so I guess I'll never know till I rebuild it but the way it's going that won't be any time soon,just for anyone who can't find it, the filters for GTR'S are OIL: Z145A FUEL FILTER Z387 AIR FILTER A360 all Ryco as I did have trouble finding these out at different times in the cars ownership.Cheers GREYPEARL

[Robert Knight]

Further to this story I have been through a lot to get this sorted,my problems started when my 33GTR began having the odd miss,which had never happened before so thought I will check the plugs and probably replace them as I hadn't touched the car since I bought it,so pulled them out and saw that they were iridiums or platinums,not sure as it was not apparent on the plugs, so went looking for the same plugs and couldn't find any reference to them in any NGK reference anywhere and no-one on the forum had ever heard of them either,just NGK R on one side of the plug and an 8 on the other side,so I then started searching the confused souls on the spark plug threads and couldn't decide what was correct as no-one had used heat range 8 on a GTR and those that answered me thought it most peculiar.

So I found out what the standard plugs were for a stock GTR PFR6A11 Platinums and fitted them,also changed the air filter,was an Apexi for a Ryco A360,started it up seemed ok then took it for a drive about 50km round trip to give everything a chance to settle in and the ECU to re balance to the changes,but it was horrible even compared to the old plugs,couldn't take boost unless fed on gradually,missing profusely,and just disappointed the hell out of me,so came home,got on the forum and started looking at Iridiums because I wanted a .8 gap, and ended up at Kudos motorsports where they have a very comprehensive chart for selecting plugs even though the ones I bought did not list the gap and whether they were a resistance plug or not,a bit disappointing but a couple of emails later had that confirmed as yes, I bought the Iritop7's pregapped to .8mm, as they were recommended for moderately enhanced cars,and as I had been using 8's already very sucessfully ,and had them in my hands 2 days later for the sum of $156.20 including postage,the Platinums had cost $146.00 so I was pleased with the Iridium price which is even better if you buy them and coils together as you save 10% off the plugs doing that.

In the mean time whilst waiting for the plugs to arrive I pulled out the coils and plugs and jumped on the forum again to find out how to test coils and followed the instructions to test the primary side IE: set multimeter to ohms resistance,the little inverted u shape symbol, and put black to centre probe and red to lefthand side probe in the coil to loom connection part and get a reading between .6 and .8,I got a reading of -676 on all of them and knowing that they were all ok and the car still ran ok without boost,I rightly as it turned out assumed the coils to be ok,but still hoping at this stage.I proceeded to fit the new plugs after checking myself to make sure of the gap and yes they were spot on .8,put everything back together and fired it up but now it was doughy when free revving in neutral and sounded missy as well,I thought oh no,what else could it be,so I thought I've never changed the fuel filter,so again on the forum but no reference anywhere,so got online and found the Ryco filter chart and found the correct filter,which the Local Nissan dealer couldn't even tell me,it is Ryco Z387 or it's equivalent if you can't get that brand,for all Rb26 engines

$23.90 from Bursons,$33.00 from Supercheap,it pays to ring around for prices,so as Supercheap is a lot closer I made them match the Burson price which they did,put that in,and this can be a hell of a job as Nissan put as much goodness into the GTR engine bay as they could, and that doesn't leave much room for hands,especially big white man hands!! and believe me you will need both hands and strength for this job!!

I know this is long winded but I feel there is some good learning in this for a lot of people to save themselves some cash and still diagnose their own problems,I will tell you how to change a GTR fuel filter the easiest way,Firstly approach any job in the engine bay with care,and move slowly whilst doing it as there are switches and connections that will break if you hit them hard especially in frustration,go and boil the jug, and have a hot drink while you are there to calm down,have the new filter on hand,unscrew the top hose clip on the filter and get it as loose as you can without the screw coming right out ,you don't want that to happen as there are loose parts that will come off and get lost both sides of the clip,pour the hot water slowly onto the part of the hose where the clip is for about 10 secs,and from the front of the car put one hand to hold the filter and one to pull the hose off,pull in a twisting motion from side to side,really screwing the hose till it comes off,you may have to heat it twice to do this I did,fuel injected hoses are very tight,don't be tempted to cut the hose and do it outside the car as this will be a tempting thought,a couple of times doing that and you will not have enough hose and that's a bigger job,just keep heating and screwing and it will come,fold the top hose out of the way and hook it between some wires that are there so you don't spill fuel everywhere.

Then get a 12 mm socket and remove the filter holderand take it out of the way,you will need the hand room believe me,undo the clip on the bottom hose again as loose as possible without it coming apart,fold the filter and hose into a position where you can pour the hot water on it and repeat the process you have already done on the top hose,I found it a bit easier on the bottom hose as it is secured a bit,then screw the filter this time and hold the hose tightly it should come ok but may require more hot water,the hot water serves 2 purposes,it heats the rubber and washes spilt fuel away,put the filter onto the bottom hose first making sure the clip is in the same orientation as it was so it's easy to undo next time and slide it up to the end of the hose to be in it's right position to do up as you can't slide it over after the hose is fitted to the filter,orientate the filter top so it faces the right way then do up the clip,do not over tighten the clips or they will strip,just nip them,then put back the filter holder put the filter back in it and fit the top hose,use any left over hot water to wash the spilt fuel and you're done,it's not as easy as you think,that's why I went to this trouble to thank the forum for all it's help.

Now the good part for me anyway, I fired it up sounded better but still a bit missy when revved,I thought no, it's still not right, and started thinking coils again,and it was pissing rain,and I usually never take my car out in the wet as it needs a total clean again after that,but I couldn't wait,I had to know,so off I went slowly at first all seemed good,when I hit the freeway it was up to temp so I thought here goes and floored it only to come out on the freeway in front of a cop car but settled it down and he turned off probably couldn't gauge my speed cause of the spray,when he was gone took it through the gears,it was like a jet I tell you it excited me it was so good no miss no pops between gears,a lot less vibration at full revs,just a joy to drive,got home put it in the garage very pleased with myself even though I had spent $146.00 too much on plugs that were wrong for my application,at this point I would like to say that even though my car seems stock,I don't think it is,it has white 320km gauges a Nismo twin 2" titanium exhaust system,Tien coilover suspension all round and 18"X91/2" Volk VC Pro Racing rims,has had the rear windscreen wiper removed and the hole filled and the boot lock taken out and filled,my point being that the japanese guy who owned it seemed to know his stuff and therefore it's not beyond the realms of possibility that he did other things to it as well as it had the heat range 8 plugs in it and they agreed with it,so I guess I'll never know till I rebuild it but the way it's going that won't be any time soon,just for anyone who can't find it, the filters for GTR'S are OIL: Z145A FUEL FILTER Z387 AIR FILTER A360 all Ryco as I did have trouble finding these out at different times in the cars ownership.Cheers GREYPEARL

Sorry Guys,What I mean't to say at the end of this shamefully long editorial was not to underestimate the fuel filter as a cause of missfiring and poor performance the difference in my car now is unbelieveable,I know some of it was the plug choice but certainly not all, I'm so glad I changed that $20.00 part first before going for new coils,so check that fuel filter and plugs first then look at the big ticket items is my advice.Cheers GREYPEARL.