it'S2klean

I got a GPW 2004 S2000. Ive it in the shop for the past few weeks, my good mechanical friend is helping me with the install. Right now i got an aftermarket header, angled single exhaust and injen intake. I got a text this morning from my mechanic friend that he feels like the spark plugs seem like they are starting to crap out. Its only got 45,000 miles on it. I trust the guys word, but i don't plan on replacing them immediately because I've had the car for a little over a month and have already almost put in $1,500 in it.

Im going N/A and was wondering if anyone can recommend a set of spark plugs that would give me the greatest benefit.

Stealth Operator

These are all pulled from the JDM S2000 spec sheets.

Platinum Pregapped 1.1 | PFR7G-11S (OEM Honda Recommended)
Iridium Pregapped 1.1 | BKR7EIX-11 (NGK Upgrade Recommended)

wadzii

I use bkr8eix, gapped to about 0.030"

they will last a long time and work very well. When it got hot i was getting some detonation with the 7 heat range plugs.

they are only about 8 bux a pop at advance auto. I'd never leave plugs in my car for 40k miles.. they are cheaper than an oil change.

Gernby

That's a great spark plug choice, especially for Florida, but why gap it to .030"? Unless you are FI, you should gap it to .040".

Gernby

Or if you want a pre-gapped plug that is much cheaper, get the NGK BKR8E-11. They are less than $2 per plug, but you have to replace them about every 5K miles (copper).

it'S2klean

i was thinking of going Irdium NGK-R's but i don't know what kind of size i should get them as i do not know how they would effect the car.

wadzii

i found my car to run a little smoother with the plugs gapped down.

the ngk r's typically are non resistor plugs, which you do NOT want to use, they can cause all sorts of issues.

ngk iridiums are the way to go, they work much better than the cheaper copper plugs.

it'S2klean

NGK-R are Iridium?
I dont see why one wouldnt go with the R's

Gernby

If it runs smoother with a spark plug gap 25-30% below spec, then I would suspect a bad plug, coil pack, or power source. I would also suspect that you will be making a bit less power with the smaller gap, like retarding timing.

wadzii

spec is 0.044 if i remember right. most of the time the iridiums come gapped at 0.030.

I run my car much leaner under cruise and light accel than the stock ecu does, that will stress any ignition system. I was also experimenting with running the car on e85, i was going back and forth between e85 and gas. That very well could have had something to do with it.

when you gap down the plugs it has the effect of advancing the timing, not retarding the timing.

NGK r's are non resistor most of the time (it depends on the exact part number)

Non resistor plugs will mess with electronic fuel injection systems, they can cause all sorts of EM interference.