Does anyone know if the Denso Iridium Plugs (ik22) that are for the Xterra, or the Honda S2000, and the Acura RSX type S are the same thread pattern as the ones for the "S" ? Is there anything else that might make them not work? They are listed on Ebay with the various models noted above as cheap as $39.....

 

I checked their website and they only list one set of spec's for the IK22 plug. They must be the same. That's a very good price, I paid $59 for my set from Sparkplugs.com

Dan

 

I would think that the IK-22 plugs are the same.

Although many of us use IK-22 plugs for MCS that are upgraded with a reduction pulley there is still no reliable dyno evidence that shows that there is much of a measurable gain in HP or torque.

So no rush to do that install. The stock plugs will work just fine,

 

The plugs are not for increasing hp but to reduce detonation. At the higher boost with higher temperature, detonation becomes an increasing concern. When detonation occur, timing is retarded and hp is decreased. Under normal load with normal to cool temperatures, most people may not notice any detonation, although it may be possible. Most times the anti-knock sensors catch it quickly and it is not noticeable. Under higher loads and higher temperatures, detonation becomes more prevelant and therefore hp is decreased.

The JCW cars come with a one range colder NGK plugs. The Denso's are just as good if not better. The JCW comes with the NGK because it comes with four prong plugs, which provide a better contact area as they wear. If the plugs are in good condition the four prongs do not provide any enhancement whatsoever. You will have to remember that going to an aftermarket plug will require you to change them out more often compared to the 100,000 mile recommendation on the stock plugs. Most require a change every 15,000 or more. This is because the OEM plugs from the same manufacturers are rated much higher. Unfortunately these are never usually offered to the public.

The Denso IK22's are the same for all cars and come pre-gapped. There is no need to re gap them with the stock ignition system. If you ignition system is upgraded you would need to gap them based on the manufacturer of the ignition system's guidelines.

For the small cost, it is a good protection against detonation and preserving the most power from your pulley upgrade under varying conditions. BMW has replaced them in their JCW car, so that should give you some consolation in purchasing these. With so many people willing to spend $100 or more for silly plug wires, the plugs are a much more important bang for the buck.

I hope this wasn't too much info.

 

All,
Would like to supplement the postings of Minihune and dgszweda1 about the IK-22 spark plugs.
The advantage of colder range spark plugs is the reduction in detonation potential. Yet, many, repeat "many", drivers get perfectly satisfactory performance from the stock plugs. There is no immediate rush to change plugs for some advantage beyond detonation considerations. Let your conscience be your guide.
The multiple prong plugs by NGK, and others, feature a platinum center electrode and so offer longer service life and excellent ignition performance due to the combination of the platinum center electrode and the large surface area offered by the multiple ground electrodes. The Denso Iridium spark plug line uses a very fine diameter wire center electode made of an Iridium alloy. These plugs offer comparable service life to the platinum plugs, a modestly lower voltage requirement due to the small wire diameter, and theoretically improved combustion performance due to the reduced spark "quench" from a more "open" electrode configuration compared to the multiple electrode platinum plugs. These characteristics are described and measured in a technical paper that is available for reading in a PDF format on www.sparkplugs.com
The electrode gap for the MINI ignition system is about 0.065". Go measure the gap from the side of the center electrode to the ground electrode on your stock MINI spark plugs. Simply regap the Denso plugs to the same 0.065 value to use them to the maximum effectiveness. The proper spark plug gap is a car specific ignition system parameter NOT a spark plug specific parameter. All spark plugs come "pre-gapped" to the most commonly specified application for that particular spark plug type and heat range. So, your Denso, IK-22 spark plug will come gapped at about 0.039" because this gap is the system specified gap for some Japanese car that is the intended common application.

Regards,
John Petrich in Seattle

 

I am not a Denso fan for boost applications, as I have had too many prove to be very fragile with tendencies to break the ceramic with any incidents of detonation. That aside, I run one range colder with my 19% pulley, gapped to .039" on a set of NGK copper single ground strap plugs. The smaller gap is in response to the higher boost levels, and is a fairly standard practice for force inducted performance applications where at stock gap sometimes the spark can be "blown out".

As I intend to monitor and change them fairly often, the single ground strap is fine and allows for the greatest exposure of the ignition spark. The 4 strap versions are designed primarily to maintain a gap over tens of thousands of miles, at the sacrifice of a minor amount of ignition performance. If you are using your car in performance applications, and can turn a wrench to replace your own plugs, you're better off cost and performance wise to go with a more standard design. Be it iridium or copper (no likey platinum at all), it will work better for you.