I use NGK grade 7's in mine. Make sure they are gapped to 0.8mm and see how you go 
In the process of chaning sparkplugs - Advice needed
2
So I'm currently changing sparkplugs on my RB25DET.
It's first time changing them, (atleast for me) and since I don't know when they were last changed, I figured it was a good idea.
I've taken the old ones out and put the new ones in, but now I'm not totally confident wether it'll run better or not with the new ones.
I read around the net and came to the conclusion that NGK BCPR6E was the way to go..
It turned out that the old ones were NGK Iridium BKR8EIX - I've thought that it's quite a difference in heat range, and now I want to be sure I've chosen the right sparkplugs before firing her up.
The BCPR6E are currently installed, but haven't started the engine yet.
Regarding mods it has the following:
3" custom built pipe from the turbo back (no cat)
Large open air-intake
HKS FconS ECU (mapped by local in the UK before I got the car)
HKS Blowoff
HKS EVC set at 0,8 bar
Fuel Pressure Regulator
I think that's all which have been altered and could have an impact regarding the combustion.
I've taken a few pictures of the old plugs. Keep in mind that the 2 last times she has been running has been in idle for about 2 mins each.
![]()
![]()
So, are the sparkplugs I've chosen the right ones, or should I go up in heatrange? (Perhaps Iridium ones again) Thanks in advance.
It's first time changing them, (atleast for me) and since I don't know when they were last changed, I figured it was a good idea.
I've taken the old ones out and put the new ones in, but now I'm not totally confident wether it'll run better or not with the new ones.
I read around the net and came to the conclusion that NGK BCPR6E was the way to go..
It turned out that the old ones were NGK Iridium BKR8EIX - I've thought that it's quite a difference in heat range, and now I want to be sure I've chosen the right sparkplugs before firing her up.
The BCPR6E are currently installed, but haven't started the engine yet.
Regarding mods it has the following:
3" custom built pipe from the turbo back (no cat)
Large open air-intake
HKS FconS ECU (mapped by local in the UK before I got the car)
HKS Blowoff
HKS EVC set at 0,8 bar
Fuel Pressure Regulator
I think that's all which have been altered and could have an impact regarding the combustion.
I've taken a few pictures of the old plugs. Keep in mind that the 2 last times she has been running has been in idle for about 2 mins each.
So, are the sparkplugs I've chosen the right ones, or should I go up in heatrange? (Perhaps Iridium ones again) Thanks in advance.
1 - 6 of 6 Posts
I had grade 6 in mine when it was standard with no problems, it's when you star to up the boost etc you need colder grades. Like i said chuck them in and see what happens
Heatrange 5 is factory for the R33 25DET (6 is factory on the NEO).... 6 should be fine for those mods.
....and yes, BCPR6ES is pregapped to 0.8mm
....and yes, BCPR6ES is pregapped to 0.8mm
1 - 6 of 6 Posts
