Spark plugs for 400bhp T51 turbo FD?

[lockwood77]

Am I right in thinking that 10s all round is the way to go with a T51 KAI turbo running 400bhp (fly)? Or should I have 11s in the trailing positions?

I use the car on road and track, so would prefer not to have issues when sitting in traffic, but obviously on track it will be pretty warm and on WoT a lot!

Any suggestions for which plugs to get and from where? I see the NGK R7420-10 or 11s are £21.98 here: http://www.sparkplugs.co.uk/pages/pricing/ccp/NGK-spark-plugs-ccp.asp?offset=700

Anything better or cheaper places to go?

[RotorHeid]

used have a 11.5 plugs for PP engine ( 8500-10500rpm at most time)
 need to warm up the engine with normal plugs, prior to change over to R7420 plugs.
R7420 are racing plug at race track only.
for the road, use normal plugs and  for the trackday  use R7420.
11.5 cost over £100 and it\'s worth it if in the championship race and for funday>>> forget it<<<<
that\'s my 1/2p

[batman]

i have 400 bhp and im using 9s

[shaunwil]

I use the NGK racing plugs all the time. No flooding issues. Not sure if they are 10.5 though.

Shaun

[lockwood77]

Hmm, I haven\'t seen anyone else say they\'re an issue on the road either. I\'m really not into changing plugs for every trackday (chaging pads is enough of a hassle!) and I don\'t like the idea of det on track when everything\'s toasty, so if running 10s on the road is fine, that sounds like the solution.

[BlitzBoy]

I ran on 10s and 11 on bridgeport on the road no probs.
At your power level 10s all round will be fine

[lockwood77]

Sweet. I\'ll get some ordered - are those NGK R7420s the best, or is there something else (cheaper!?) I should be using?

[davehg]

You can use those or bike plugs but they don\'t have such a deep head so you need to modify the standard plug tool to fit but they are much cheaper. Can\'t remember the part number off the top of my head though.

[BlitzBoy]

I wouldnt use some of those bike plugs, due to some of them being no resistance causing problems with the ecu signals and operations.

Dont skimp I say, you already investing a heap of money in the car

[BlitzBoy]

And I quote from the NGK site

"As well as reducing electrical noise for radio, television and mobile telephones etc, many modern ignition systems require resistor plugs to stop electrical noise from interfering with the vehicle\'s on-board electronic control units (ECUs). If non-resistor plugs are used in place of resistor ones, the result can be malfunction and in some cases immobilisation of the vehicle. Resistor spark plugs should always be fitted, therefore, where specified. NGK resistor spark plugs contain a single ceramic monolythic resistor of approximately 5000 ohms. Because of the type and construction of the resistor (ie no springs), the problems of vibration and sudden changes in temperature that can occur with some other brands do not apply. The function of the resistor is to reduce electrical noise generated by the ignition system. The most effective place to situate a resistor in the high tension circuit is as close to the spark plug as possible. This makes the spark plug an ideal place to house the resistor. Because the resistance value is only approximately 5000 ohms, there is no detrimental effect on engine performance, power output, vehicle emissions etc. It is also a fact that many motor sport world champions only use NGK resistor spark plugs. In nearly all cases - apart from some very old low output ignition systems - resistor spark plugs can be used in place of the non resistor versions "