Denso Spark plugs

Runnah

New member
Worth while to upgrade or should I just go with stock ones?

I heard some increased performance but also some bad problems with these.

 
I have high praise for NGKs. No experience with Denzo, didn't they go out of business this year?

 
i've heard from the big turbo tuners that regular old coppers are better. cheap to replace so you dont mind pulling them and replacing them all the time, and something about them being a soft metal and dealing with detonation better ??? (maybe they close up and dont fire when you det on them hard enough, causing them to not fire at all and hence not cause any more detonation? i dunno).

i'm not sure if they would have any benefits on n/a cars like ours.

 
I'm not sure about turbo cars but for High horsepower na cars engine builders perfer copper plugs because the spark is wider and the "pucks" tend to hold together better, as the platinum pucks fall off and a tiny bit of platinum/iridium rattling around tends to ruin cylinder walls. And because they can side gap coppers and platinums/iridium don't side gap so well.

runnah doesn't need to worry about detonation but pre-ignion and misfires is a bastard for anyone. My guess would be that his pistons are pretty clean and compression is still nearly stock, no carbon build up for fuel to soak into and pre-ignite, so stock plugs copper or platinum would work if gapped correctly.

that reminds me, I still have OE Wrx spark plugs new in the box and some plug wires laying around if you still want them runnah. Not sure if either will work for your car, but we can look up part number and see.

 
I'm not sure about turbo cars but for High horsepower na cars engine builders perfer copper plugs because the spark is wider and the "pucks" tend to hold together better, as the platinum pucks fall off and a tiny bit of platinum/iridium rattling around tends to ruin cylinder walls.
 
Let me know when you can pick them up. I can bring them to work so you wont have to travel very far.

 
Having tuned hundreds and hundreds of cars over the last few years, I'll offer up my opinion on spark plugs.

First, from a pure tuning perspective, the NGK BKR7EIXs are the best plug I have used on the 2.0L motor. That is a one range colder plug, and iridium tipped. I have ran these in Stage 2 WRXs as well as my personal WRX with Spec C heads at over 540whp. When gapped to .026 - .028, I have never had a spark issue of any kind, even at 32-34psi of boost.

On the 2.5L STI heads, the LFR7AIX is the prefered plug. It is also iridium tipped, and one range colder. We tuned Tim's STI (the black PDXTuning one) to 596whp at 34psi without missing a beat with these plugs. The subaru coil system is very good, and when matched with the right plug, will not be the power limiting factor. I have yet to see a drivablity issue with the colder plugs, however I would suspect it will decrease your change interval. Then again, if you are modifying your $25,000 car, spending $30 on spark plugs every 10k miles should be par for the course.

Cheers,

Jeff Sponaugle

PDXTuning.com

 
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