I'm a bit confused can some one tell me the full ngk plug number for a tt I want platinum garde 7 can't seem to find any on ebay thanks

Prf6-11B

 

If my memory serves me correctly ?

 

Alan......

You don't want platinum grade 7, choose either copper BKR7E or Iridium BKR7EIX. If you must stay stock, then it's PFR6B-11B, platinum grade 6.

Can I not use a 7 grade platium plug then I'm running a bar of boost and wanted a cooler platium plug I thought that was a 7

Platinum plugs are for 60k mile service intervals. I would never recommend any platinum plug for a turbocharged vehicle, let alone for a modified VG30DETT. Maybe PFR7B are made, I have no idea :laugh:

A stock UK plug was a grade 5 and uses the C and in the US was a grade 6 and uses the B, this link below at post number 4 should be of some use.

 

http://www.300zx.co.uk/forums/showthread.php?90470-Spark-plugs&p=859825&viewfull=1#post859825

Smithy

A grade 5 plug is the wrong heat range for a VG30DETT, UK or not. That will have been someone somewhere getting something very wrong in their calculations :laugh:

 

From one of the links provided:

 

Hello,

 

The spark plug designed for the 300ZX uses a special design. The spark plug

has a extra long projection with an extended shell.

The purpose of the long projection is to ignite the A/F mixture deeper in

the combustion chamber, allowing fast flame kernel growth as well as good

anti fouling characteristics.

 

Since the PFR6B-11B uses an extended projection, the insulator needs to be

protected from thermal shock. Thermal shock is the heating and cooling of

the insulators firing end. If you look at the PFR6B-11B firing end you'll

notice the insulator is narrow and gets wider the further down in the shell,

like all spark plugs. The insulator tip is hotter than the insulator down

inside the shell. The difference in temperature can cause insulator

breakage. If you notice the PFR6B-11B is a 3/4 thread reach and has a

section past the threads, which has no threads. This section is designed to

prevent thermal shock on the insulator and enables us to reduce ground

electrode length from the weld to the bend. If we didn't use the shell

extension the ground electrode would be very long from the weld to the bend.

This would make the ground electrode prone to failure.

 

We don't list an iridium spark plug due to the fact we don't make this exact

design in iridium. For liability issues we won't list an iridium spark plug

for this application due to it's special design. However by calling or

emailing we can make the recommendation of an iridium spark plug with less

projection, especially in modified applications. Of course the end user

will use at there own risk. In modified applications you don't want as much

projection as a daily driver so performance isn't an issue.

 

You can use the iridium spark plugs BKR series in this application. Again

it will have less projection then the spark plug originally designed for the

vehicle.

 

Jon MacQuarrie

Technical Support Specialist

NGK Spark Plugs

 

I'm going to change my plugs soon. What are the recomended plugs for the zed running 15.5psi?

Cheers.

 

NGK PFR6B-11B gapped to .95mm

 

15.5 psi is a little over what the turbos can take 15 or below is the guideline!

 

Things move on. I've ran my car well outside the perceived guidelines for nearly 2 years now, culminating in peak boost levels of 1.68bar (24.7psi - matching the Garrett compressor map) on stock auto turbos & 370cc injectors, 482lb·ft and 12.6s@113mph on the stock auto gearbox. Not bad for a daily. Improvements can be made on OEM design & specifications, one of them being not using grade 5 or 6 platinum plugs in a modified late 80's turbocharged engine :wack:

 

I use a relatively short BCR8ES plug without issue, have done for 2 years. Never once had any fouling issues, unlike when I ran the same plug in my 200SX. The BKR range of plugs are only very slightly shorter than the OEM platinums, and are a much better choice for an old VG.

Wrong grade in your opinion or not, am simply pointing out a reference from NGK themselves, Topless supplied one of 3 statements from NGK given to the forum over the years in relation to the spark plugs Nissan commissioned them to use in the Zed engine.

It also points out the slight error made in post number 2 above, simples :-)

ta

smithy

No worries. OP requires Grade 7 plugs, so it's important he doesn't fit the stock OEM items which are too hot a grade, so anything else is kind of moot and opinion doesn't come into it. BKR7EIX is what he wants if it's a long-life plug he's after. BKR7E if fitting coppers. Simples.

 

Good links though, was interesting to read the NGK statement regarding liability and also how things have moved on.