I have a softronic flash in my Turbo, I have been very happy with it !!! When I flashed the car about 11k miles ago I also installed a set of Denso IK22 iridium plugs and they worked perfect until today.

During high boost I get a slight miss and its the same issue I had when I first flashed the car with stock plugs. Denso IK22 iridium is a colder plug but paying $700 for a plug change I am wondering if there is a plug that has good performance but last longer than 11K miles. I have heard that Denso PK20PR is another good plug.

Thanks for any information..

 

Search is your friend, tons of threads on this already

 

MJA,
I think you went too cold for just a flash and perhaps the plugs are not getting hot enough to burn off residue especially at WOT. This is just my opinion as it appears to be somewhat an art and not an exact science. Below is a re-post from another thread that I put up.

Denso IK-20 for performance in lieu of PK20 for duration (I definitely recommend the PK20 for those that don't want to deal with changing plugs or paying $600 for the dealer to change plugs). The PKs are double platinum (platinum tip and ground) which I would recommend at a minimum. They are recommended for changing at 60K-100K miles. The IKs are iridium tip and ground providing for a larger flame basket and better ignition (blah blah blah, btw NOT affiliated), these are recommended to change every 30K miles. The gap at .025 is the same, but recommended you reduce the heat resistance for every 100 hp you add to the engine. This is a ball park and not an exact science for most mere mortals on this forum. The heat of the plug refers to how much heat it removes from the combustion chamber through the insulation material. A spark plug’s heat range is its ability to dissipate heat. The “colder” the plug, the more heat it can channel out of the combustion chamber. In a performance application, colder heat ranges may be necessary to handle the extreme temperatures brought on by higher compression ratios, forced induction, and high RPM’s. While “Colder” plugs may seem to be the way to go, remember that the spark plug must achieve its “self-cleaning” temperature where it can burn off fuel and carbon deposits. Otherwise, the plug could “foul out” where it is prone to misfiring and poor acceleration. A plug that is too “hot” can overheat, also causing power loss, detonation, pre-ignition, and possible engine damage. A good, general rule of thumb is to start with the factory recommended heat range. For every 75 to 100 hp you add to your engine, you may go to the next colder step. DENSO heat ranges move up as they get colder; 16 would be our hottest Iridium Power plug, 34 would be our coldest (ranges; 16,20,22,24,27,31,34)

IK20 is the recommended heat range, but you could go to 22 for an additional 75-100 hp and then 24 for an additional 150-200 over stock and so on.

BTW, I got the IK20 plugs at ADVANCE AUTO PARTS for about $6-8 per plug. They can't pull up the exact part number as IK-20, but it comes up online and they definitely carry these plugs. The IK-22 or IK-24s may have to be special ordered depending on how much extra juice you are squeezing.

Here is the link if you are interested or have any other questions. http://www.densoiridium.com/ir_power.php

Last thing, they also claim an additional 10-20hp on turbo charged engines based off a Mustang 5.0L shootout hosted in some magazine, but I don't know if I would buy into that just yet.

 

I agree with the above info. these are the ones I went with:

http://www.titanmotorsports.com/dedoplspplpo.html

 

Thanks Zippsub I remember reading that post, and repped you as well. Good info.

 

Thanks for the information,,, I am either going to go with the IK 20,s or the Denso PK20PR .Paying $600 for 11k miles is not a pattern I want to continue.

 

bro , we are running NGK BRK7EIX (#2667) with a big Success !!
with stage 1 cars , till stage 4 !! and we are running softronic tuning

 

What gap are you running?