Which plugs are people using for the above, i hear alot about the NGK racing 8's but wondered if there were cheaper alternatives, which are as good/better?

Heard the NGK 8's don't last very long either.

If it's the NGK's that are suggested then looks like it will have to be them.

Cheers

 

I'm running 7's over 500

 

Realy? Didn't think the 7's would stand for that sort of power.

What power is it Chris?

 

521.8 to be exact! lol. I am going to change my injectors soon and hopefully get more from it too.

 

I ran with racing 8's for a while & car was never right with them. 7's on now & it runs like a dream

TX.

 

Nice Chris! Sounds like 7's then, have you guys a part number you could give me?

 

http://www.ebay.co.uk/itm/NGK-spark-...#ht_1438wt_905

 

Cheers Chris, cheap as chips too.

May get a couple of sets then

 

Just looked back at my invoice where I was charged £45 for 4

TX.

 

What boost are you running Chris?

Well, you didn't pay too much more so i wouldn't worry too much

 

1.8, but will take it to 2 if needs be.

 

Only poofs run less than 1.8bar

TX.

 

lol, too true We only stopped as the injectors maxed out.

 

Your choice of plug will be dictated by the intended use of your 500+ bhp engine...

If it is going to be a daily driver or a weekend car, then the NGK PFR7 will be adequate, although I would opt for the PFR7-G series as opposed to the PFR7-B as the "G" plug has a superior center electrode and is more capable of withstanding the increased temps and boost pressures that you will be asking it to cope with.

If on the other hand, your engine is going to be used purley for competition, then you would benifit from using a cooler spark plug such as the "8" or "9" series as they are designed to run at high boost and temps for prolonged periods of time without overheating and causing a missfire... The downside of running the cooler plugs is that they are quickley fouled by soot when they are run from cold, so it's important to run them up to operting temperature and ensure that they have been subjected to boost everytime the engine is started so that the plugs are both hot & clean before the engine is switched off... You will suffer from cold start missfires/non start problems if you don't run them through a comlete heat cycle to clean them.