Spark Plug discussion.

I have run stock wires, MSD and I am currently running the duralast. The duralast actually have a lower resistance than the OEM and obviously bigger than the MSD's. I really haven't noticed much of a difference. The reason I grabbed the duralast is because of the lifetime warranty. I had 2 sets of MSD's and 1 set of OEM's crap out on me and I have a heat sheild as well as the turbo heat sheild is coated.

I would pull your plugs and look at them as well as check the gap that should point you in the right direction.

 

Actually he heard right. On a Stage 3 car running NGK 4306 the plugs should be changed every 3k miles as the side of the porcelin starts to show burn marks and the car runs like crap.

I change my plugs more often probably every 3 months or so. My wife's S3 SRT-4 every 3k miles. Both cars run NGK 4306.

Remember each SRT-4 is different

Your S3 so I would gap them at .032 as that seems to be the common setpoint S3 cars are gapped at. If your not having spark blow out at .035 then you should be fine.

I run the Mopar Performance wires. The MSD to me are garbage even though I owned like 5 sets lol.

 

than someone likes to waste money and time cause i have no problems with my 50 trim and the miles i have on them at 25 psi boost

 

Then someone is being a bit more closed minded as mine nor any other SRT-4 doesn't act the same as yours. 26psi on my wife's S3, your 50 trim doesn't compare to other cars now does it?

$12 for a set of spark plugs is chump change and not wasting money. That just tells me I take more car of both my wife and I SRT-4's then you do yours :thongue2:.

 

i still think there has to be a problem if your changing plugs every oil change sorry dude cause i can pull my plugs at 1k miles and again at 7k miles and what do u know they look the same and again at 10k and im spraying meth and i do have a safe tune i did also

 

I've been using Autolite Iridium plugs gapped at .038 in my car for a while now and it seems to be the only plug my car likes. I get them at Autozone for about $25 a set and they come with a 5 year warranty. I've tried Champions and NGK plugs and my car feels like it has more power and idles smoother with the Autolites.

 

You can get them at autozone or advance autoparts i think the 5 year warranty is through advanced auto

 

This makes me wonder if my car doesn't like the 4306's. Best dyno runs were with iridiums IIRC and similar set ups.

 

S3 likes 4306

Iridiums are a waste IMO. I've tried them as well as many other spark plugs on the market for these cars. Each SRT-4 is different though. I found that both my and my wife's SRT-4's like the NGK 4306. Results vary, so try different ones and see what is best for YOUR car. You do have to be careful gapping Iridiums.

I always like pulling information so I mean here are some dyno results from a Sparkplug Shootout. The NGK Iridiums did put 2hp/6tq then the NGK 4306.

 

I pulled my plugs last night since monday morning when I started it the car missed & sputtered while idling for about a minute. Weird part was all the plugs went in with a 35 gap but came out with 45,34,30,36 gaps respectively. Just something weird I thought I would share.

I also was looking at past dyno runs and it seems that my best numbers were with 1 step colder iridiums and a s2 wga. I have a FM wga and the same iridiums in now so I will have to get some numbers for comparison.

Interesting side note I noticed while comparing dyno sheets, each WGA was under PCM control but each hit peak power at different RPM's.

s2-4600 rpms
AGP-4000 rpms
FM-4800 rpms

 

The problem is if the plug is too hot you are going to run into something called pre ignition. Meaning the plug itself is so hot it is going to ignite the fuel before the spark actually occurs. Like when the piston is on the compresson stroke. Is the stock heat range too hot for your setup probably not.


I am running 1 step colder plugs. First thing I noticed is that the car was pulling 2* less of KR and the AFR's are still dead on. Butt dyno says the car is a bit more responsive and datalogger says less timing is being pulled due to knock.

 

The sparkplug dude is right about the heat range

 

Tune for no knock or your motor won't last long

 

He is running a canned tune of the mopar s3 ECU IIRC. Which means it is going to use the predictive algorithm for knock. So at 4800 rpms the ECU is going to pull out a couple degrees till it gets past the "danger zone" around 5200 rpms and then put it back in if conditions are right. So 1 to 2* on a canned mopar tune is not unheard of.