When I first installed my HKS spark plugs about 1 K miles ago, it was Very strong, stronger than stock plugs feeling ~~~ u know, butt dyno kinda feeling

My car has been running like **** lately, yesterday I had some time so I changed my oil, Hmm, it look like crap, then I pour some Castrol Syntec 0w-30 into it ... pretty good, it looks really thin when I pour it.

Anyway, Since I jacked my car up, I Was like hmm maybe I should pull the HKS plugs out and see what happens after 1 K miles.

...

After I accidently cut myself in the process(It @*#$)@*$ hurts), I took the leading plug out and ... WOW

MAD Carbon ! Its like almost pitch black, just a little bit of brown on the side. I cant even believe my eyes. I was like "Damn, this is what the plugs suppose to look like after at LEAST 10 K miles, not 1 K !!!"

I pull all 4 out, hmm, looks like crap, all of them.

Do I drive hard? Yes sir, I drive really hard (I have to fill my gas up every 2-3 days, go figure) But the plugs still pretty bad so ...

In conclusion : These HKS plugs is GOOD for Race Tracks, NOT for streets. For the first 500 Street miles, It seems to be fine, After that, performance starts going down hill, I had a lot of misfire problems after 500 miles. now about 1K miles its running like **** so I pull it out.

I put some stock Mazda hot start plug (RE6C) in and the car is running like new again No misfires, no chokes.


(I will update this thread with pictures later)

 

Which plugs were you using? You don't have FI, right?

 

Too cold?

Yeah driving hard should give less black carbon on them.

 

Nope

Im thinking, these plugs might be a better choice if you're FI.

Oh These plugs are 2 steps colder than the Stock plugs. I believe if you use NGK chart to define them, HKS plugs are 9 (Leading) and 11(Trailing)

I think its too cold for NA use. Maybe good for a couple of track events, but for street ... not good.

 

I'm still debating if the plugs are too cold even for FI use. I should be getting my set any day now.

 

You got a set of HKS too ?

hmm, I dont know about FI, but for NA, thats a 100% no no no no no no no no no no ....

 

Mine came with the turbo kit. Just have not received them yet. Should be here in the next day or 2.

 

If u're in Boost most of the time it might be fine ...

but who actually stay in boost most of the time ? ...

 

I wish I could stay in boost all the time..

When you get that camera, take some pics and we will discuss. Hopefully some other people will chime in with their opinions also.

The thing to remember is the heat range of the stock plugs, RX7 plugs, and these. I don't have them available right now or I would post the heat ranges for each so that we could discuss. Anybody know them all?

 

Is the same, 7 and 9

BUR7EQP
BUR9EQP

 

LET THE BATTLE BEING !



it looks like it has been in my car for 10K miles ... but in fact it just barely reached 1K miles and its running like crap already (random misfiring ... choke ...)

 

Those plugs don't look bad at all.

You can test plugs by pulling them out like you did.

You were ilding your car. And before that you were driving slow.

Only way to really check a plug is at speed and RPM.

You drive at certain RPM turn off car. Pull over and examine plugs.

That will tell you what they are like at that RPM.

All that gunk on the plugs is from low city spped and idling.

Ja, I know. Its not practical to do what I said but that's the real way you need to do it unless you have an onboard dianogstic unit.

You can do this all the time with motorcycles real easy.

 

it looks worst in person. and I already wipe these plugs a bit b4 I took this picture

The point is, these plugs is in my car for only about 1 K miles

My last set of stock plugs look a lot better than these even with 15 K miles on it

 

i think the point is, for his application and driving condition, the stock NGK plugs work much better than these HKS ones

 

more like, for streets use, these plugs are no no

for racing, yes yes, streets, no no.

 

These are several heat ranges colder than stock. And we should be surprised they are not working out for city driving because...?

 

which is basically your driving application/driving condition, right?

 

Just dont want other ppl to fall into this *trap* and wasting money like me

 

These are my plugs(changed yesterday) they've done 16k.


Heat range is 7L 9T

 

I wouldn't use anything colder than 9's for under 350-400rwhp

 

I posted a while back that changing your plugs, especially if you drive fairly hard on you car, every 10-15k miles is a way of keeping your car tuned and running well. I was mocked by a couple of people as I offered to change plugs for 8 owners if they lived in my area and didnt want to fool with the plugs for 150 dollars. As most people can see, as well as myself from owning and 8 that, 10-15k miles on a set of plugs is about right. I have not had my plugs look near as bad as posted here, then again, I change mine out every 10k miles. My car dynos 194 at the wheels and I have a few mods but not many. Thank you guys for posting and showing people that good maint. on the 8 means that it will run well. Anyone living in the Atlanta area that needs their plugs changed and doesnt want to do it themselves, I can do it for you and will drive to where the vehicle is for the above stated. I love to see and hear a good tuned 8.

 

NA street cars should stick with the OE heat ranges, nothing to be gained here except fouled spark plugs ...