Hi

I am upping the boost on my MY97 WRX - does anyone know which denso spark plugs to use - IK20 or IK22s?

Thanks in advnace

 

The 20 plug is the heat range for a standard car. Where as the 22 plug is a step colder, more suited to a modified motor. The IK22 is probably the one to go for in this case.

 

NGK plugs PFR7B good for around 350hp levels. I would personally avoid the Denso range as they have a history of exploding, a number of people on this board have had this happen, mostly when running the HKS labelled items.

Paul

 

Exploding? What do you mean exactly? You mean people have had poblems with killing the plugs because their cars arent running properly and detting their nuts off?

 

No I mean because the centre electrode overheats and the ceramic insulator cracks and falls in the engine. All on highly modified cars, and all properly mapped, not 'detting their nuts off'

Paul

 

So how many cars has this happened to? Do you know them personally?

Ive sold hundreds of sets of Densos and the only failures we've come accross have been on cars that are set up incorrectly.

I myself run them in three cars of varying specs and have never had an issue with anyone of them. Ive not had one single customer come to me saying the ceramic has broken up and fallen off. I have heard rumours of people who know people who know people that its happened to but as I say we have sold loads of them and have not had a single customer come to me with ceramic issues.

 

it happened to harvey, he lost a head due to these plugs!

i have seen the plug in question and i would now never use denso plugs.

 

So you can state catagorically that the plug failure had nothing to do with det?

 

nothing to do with det at all.

 

So the plug was fine apart from the missing ceramic?

 

harvey may still have the plug, if so i will post some pics.

 

ran various race/rally/track cars over the years (not saying how long or you'll call me names!!).......................after problems with most manufacturers the ONLY plugs i use and recomend are NGK!!

i can honestly say we have never had any issues at all, even on poorly running vehicles brought in by customers to sort out!!

alyn - asperformance.com

 

We only use NGK's down here as well...never had any complaints or warranty issues with them in 20 years

 

I have started swapping to NGK iridiums but mainly because theyre cheaper rather than any other reasons, is that what you guys use? I know NGK make Turst/Blitz iridiu plugs so Im assuming theyre the same thing, just half the price.

Do you guys use NGK iridium or copper?

 

the plugs we use are the PFR6B, PRF7B platinums, for higher power the NGK racing 8's and 9's are used

 

I lost a head when an HKS 35i lost part of its insulator around the electrode.
It appears that the insulator broke off, in part, hit the top of the piston/head and the resulting damage was a burned out exhaust valve and seat. Looked like it had been plasma cut.
As far as I know det was not an issue prior to the incident nor post incident, other than changing to NGK 7119-9 there was no mapping or anything else done to lead me to believe this was anything other than a plug failure. STi Wagon M/Y 00.
At the time I came across two other people with similar direct experience of insulators on HKS 35i plugs breaking.
The incident was at Elvington and the engine was giving 585bhp rolling road figures.
Never had any plug problems since, at similar spec and in an extreme performance environment and staying with NGK 7119-9s on this engine and PFR7Bs on the 400+bhp engine in a second car. (WRX Wagon M/Y 95)

 

Blimey - I'll stick with the NGKs then.