Iridium spark plugs




racingp

Registered
Hello,

I have to change the spark plugs in my gsxr turbo and I had thought about putting iridium ref.Cr9eia, is it advisable or better to put the standard?
 

KZScott

Registered
we run cr9e in stage 1 turbos and 650+hp builds. like Frank said, gapped at 18 thou. a regular plug has less resistance and delivers more of the spark output than the higher priced, "longer lasting" plugs. they are cheap enough that it doesnt really matter if you throw a set in once a yr with your regular maintenance.
 

Kiwi Rider

Registered
Just some info about how critical it is to have the correct plug for the correct application re spark plugs. . . .

I thought I'd experiment with fitting Iridium CR9EIX plugs to my 99 Busa, they are not listed as recommended for this model, CR9E is the only one listed by NGK as being correct fitment for this model.
I went for a 140 mile ride today and noticed a brief misfire occasionally at low rpms in the lower gears (2nd,3rd) as I was opening the throttle smoothly.
With the CR9E plugs this has NEVER happened before, so I can only put it down to the Iridium plugs and they were gapped at 0.9mm, the CR9E is gapped at 0.8mm.
Anyway, I,m changing back to CR9E's tomorrow!

Regular CR9Es are always gapped tight in any blown configuration. Boost pressures
can snuff out spark, and you eliminate that possibility when the gap is close . . . .

I worked at the Subaru Dealership for many years in the service workshop and the WRX turbo always needed the plug gaps to be less gap than a non-turbo (N/A) for the very reason Frank from Powerhouse stated, the boost pressure air/fuel charge can snuff out the spark on a wider gapped plug.
And the turbo Subarus always ran standard NGK plugs, NOT Iridium, and all the N/A Subarus ran Iridium long life plugs (100,000kms)
 

Sandow

Registered
Thanks frank by the way! I got it...!

And for non turbo busas... I assume the iridium plugs are better? I mean the cost is significantly higher then the standard plugs. Is it really worth it- Or ist there such a difference?
 

Sandow

Registered
IMHO it is NOT worth it. Some of the newer ignition systems are designed around iridiums. the Busa is not
going to make more horse or give you more throttle response because you put more expensive plugs
in it. You might go faster because your wallet is lighter . . . :race:
When i got my first busa in 2009 i got it new from the dealer and they told me at the first service (500km) they replace the plugs with iridium because its supposed to be "better" and charged me 4x 35 euros which equals about 120 Us dollars at the time for 4 spark plugs......:lol:
 

Kiwi Rider

Registered
When i got my first busa in 2009 i got it new from the dealer and they told me at the first service (500km) they replace the plugs with iridium because its supposed to be "better" and charged me 4x 35 euros which equals about 120 Us dollars at the time for 4 spark plugs......:lol:
Wow! 35 Euros back 10 years ago, at my shop we charge full retail for iridiums NZ$29 each, NZ$116 a set of 4 so a bit cheaper than what you paid!
 

Sandow

Registered
Wow! 35 Euros back 10 years ago, at my shop we charge full retail for iridiums NZ$29 each, NZ$116 a set of 4 so a bit cheaper than what you paid!
i just looked the other day on amazon (not because i need some- i wanted to see how much they are) over 40 can dollars. Its crazy. especially since its not a difference in power!
 



Latest Bikes

Forum statistics

Threads
172,862
Messages
3,092,559
Members
47,694
Latest member
Liquidspace
Top