7s or 9s ?

[michaelb]

Hi
I am pushing up to 350 BHP still on a twin turbo with supporting mods
Shall I go for NGK Iridium plugs ( 9s ) ?
Are 7s the standard once?  If so am I going to have problems starting the car from cold occasionally with the 9s?
I really don’t want to flood the thing..and, as you know, we generally get about 2 chances to start the RX7, if it doesn’t by then we flood it LOL
Regards,
Michaelb

[fil_auto]

BUR9EQP\'s should be fine for that power n setup

[Grant Monkhouse]

9s all round should be fine.

Normally have 2 x 7s and 2 x 9s as standard.

[michaelb]

Thanks for your input, so NGK Iridium plugs are BUR9EQP\'s ?

Regards,
Michaelb

[Ricco_04]

Thanks for your input, so NGK Iridium plugs are BUR9EQP\'s ?

Regards,
Michaelb

No. NGKBUR9EQP\'s are platinum coated, not iriduim.

[clive]

As above /

BUR9EQP\'s or BUR9EQ will be fine and one will last as long as the other /

UK FD owners manual recomends using four 9\'s, I don\'t think 7\'s are even avaliable any more.

I would only suggest using 7\'s in an FD if it have low compression and starting problems.

[Cashpoint]

I\'m running 10s (on a ported and single)and car started on first attempt Friday and that was when it took me 5 mins to clear the frost of the wind screen as it was so hard. So dought you\'ll have any issues with 9s

[michaelb]

Many thanks for your replays
Ok 9s it will be...
So which ones are better platinum coated, or iriduim and what is the difference really?
My mechanic suggested iriduim and so far he has been absolutely on the button with all he has done on the car so far..
Regards,
Michaelb

[Ricco_04]

Many moons ago when I got a Mazda service they put 9\'s all round anyway - never noticed any difference at all