Spark Plugs for 4G63T? [Merged 12-28-2021]

[TsiRacer93]

yea so my cars got like 100,000 miles on it, what are some good plugs to be using? i was thinkin bosh 4s but someone told me they would be bad for my car..

 

[mitsuowner1991]

many, many threads on this topic
lots of conflicting opinions
at the risk of repeating again, generally speaking most fine success with bpr6es for stock, bpr7es for ~20psi, then some try br7es to try and control knock. whether it actually works, i dont know if there is solid evidence. gap according to lb/min and compression ratio.

i myself am am br7es and 0.028, 20-23psi, 36lb/min on 7.8:1

Its a fully built motor with a stock turbo.. i know i know i ran outta of cash wheb building the car so i figured id just run my stock turbo until i get some cash for a manifold and turbo setup

 

[rabenne]

Marty, at what boost levels do you consider it to be "hi boost"?

Did you change to them (8s) preemptively or was it to "combat knock"? Did you try wider gaps and 0.018" is where you ended up with it running smoothly?

Just curious how you landed there because I have been going through the various heat ranges trying to smooth out my top end. I think I am getting some blowout at 28psi on bpr7es @ 0.028". Perhaps its time to close them down to .024" or smaller.

Thanks!

 

[1990TSIAWDTALON]

With 10:1 compression and 40+ lbs of boost, I was blowing out spark with a wider gap. I went with the colder plugs and the motor likes it. It doesn't foul them. The small gap is what cured my hi rpm sputter at around 8000-8500.

 

[curt-s]

Its a fully built motor with a stock turbo.. i know i know i ran outta of cash wheb building the car so i figured id just run my stock turbo until i get some cash for a manifold and turbo setup

if its a 14b and youre pushing past 18psi and higher than 8.5:1 compression, i personally would run bpr7es. you can try br7es and take them out every one in a while to check fouling but i usually cruise 90% of the time and my plug ceramics are super clean

 

[Vegas Smith]

It was trial and error for me. I'm currently settled on 35psi, br8es and 0.026 gap with an arc-2 CDI.

 

[mitsuowner1991]

if its a 14b and youre pushing past 18psi and higher than 8.5:1 compression, i personally would run bpr7es. you can try br7es and take them out every one in a while to check fouling but i usually cruise 90% of the time and my plug ceramics are super clean

Only boostin 15psi. And im just cruising.

 

[curt-s]

6 or 7 ought to do but at that level bpr6es would do just fine.
some claim non projected lessened their knock but i dont entirely buy that and if youre knocking at 15psi on a 14b id be looking at checking timing, commanded afr, and actual afr accuracy first.

why did i switch to br7es you didnt ask? i dont really recall.. but these just work fine so i stayed with them.

 

[iHavok]

+1 for BPR7ES, based on your profile.

Give this a read:
https://www.dsmtuners.com/threads/spark-plug-faq.233421/

 

[Steve92talon]

I put the NGK stock plugs in my car and the .35 gap was causing issues at 15 psi so it tightened it up to .20 and the cars happy as can be. I run 91 or 89 octane all the time just to be safe.

 

[Steven A Schiltz]

Are copper plugs the best to run in these cars? I have iridum 9s in the car right now but the research IV done saying the copper plugs are the best I was wondering why ?

 

[luv2rallye]

I've never had a problem with copper. But read here and some of the posts after: https://www.dsmtuners.com/threads/spark-plugs.198308/page-15#post-1642842

 

[Steven A Schiltz]

Man you have some really good and info on these cars how long you been in the dsm life? Have you heard anything good of these new e3 plugs?

 

[Steven A Schiltz]

I put iridium plugs mine from autolights and I'm getting it n anything higher than 5 lbs of boost a boost cut I know my fuel pump is cutting but I wonder if it's from theplugs there at a .26

 

[luv2rallye]

I still drive my 1999 Eclipse gst which I bought new and its been my only car the entire time. Don't know anything about the e3 plugs, sorry.

 

[Mello]

I did not have a very good experience with E3's. They crapped out & started misfiring in about 100 miles. Was a bummer, spent 3X the money & threw them in the trash a week later. Autolite copper core lasted longer than E3's & they're crappy too. Never had a problem with the OEM NGK BPRxES's at which ever heat range is best pending on boost.

 

[Steven A Schiltz]

I'm just asking because I saw a commercial on them. So what the techical part of the copper plugs?

 

[Mello]

Buy some & try them out. Lucky for us plugs are easy to change.

 

[Sniffbooger]

I still drive my 1999 Eclipse gst which I bought new and its been my only car the entire time. Don't know anything about the e3 plugs, sorry.

Damn... You've had that car for 21 years as your only vehicle??? Wow...

I just changed to the NGK bpr6es from some Autolites and I can say it's a noticeable improvement....

 

[Steven A Schiltz]

Oh I'm looking for techical terms haha I mainly do engine work so I'm wondering do they cool down the cylinder or do they do more constant spark at higher temps or do they lessen the spark knock or pre ignition or do they do better at high boost levels right now I'm running at 15 psi and running extremely leN I know my pump has to do with it but I'm wondering if the iridum plug have to ad well

And my next question it pretruding plug to non pretruding plugs sorry not that good at spelling hahaha

 

[bastarddsm]

Stock car, run a stock plug. Modded cars need different plugs. I run a BR9ES or a BR9EIX in my 700+hp car. Seems like the iridium plugs work better at high boost. The P in an NGK number stands for projected. Non projected plugs pull the electrode further out of the chamber, reducing it's heat load, and slowing down combustion a touch. Good things for high power applications. Bad for mileage/efficiency on street cars.

Deciding what plugs to run, and weighing the pros/cons are part of becoming a tuner.

 

[Steven A Schiltz]

Yea that's true I ran this plugs in all my other cars and worked great haha but in this one not so much right now. It's not stock but it's not that much off of it probly a little boost from the stock hp

 

[Eclipse 1998]

Additional concise info
https://www.dsmtuners.com/threads/spark-plug-question.523007/

 

[Steven A Schiltz]

Thanks I must have missed that one while I was searching

 

[bastarddsm]

Yea that's true I ran this plugs in all my other cars and worked great haha but in this one not so much right now. It's not stock but it's not that much off of it probly a little boost from the stock hp

Yep, probably would have better results with a stocker plug. Shouldn't hurt to step down a heat range to like a BPR7ES. Might help quiet any activity the knock sensor is picking up.

 

[Steven A Schiltz]

Yea that's one of the issues I'm having and I don't know if it's spark knock or phantom knock