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..

 

[Catbox_95]

I am about to install my NGK BPR7ES plugs. Those are the cooler ones, right? I figure with my mods those would be better.

Check out my mods, and I am running 21 psi. What would be the best gap for those plugs?

Thanks-

 

[weith1111]

I'd stick with .028

Tried and true.

Those are the cooler plugs and you will hear stories either way, pointless or yes they are a good idea. I use them and am just on 18-19 psi s16g. Work fine for me.

 

[ECLIPSE4x4]

I would agree with .028. But you could experiment with .026.

 

[weith1111]

I would agree with .028. But you could experiment with .026.

Why would you want to gap smaller? Wouldn't the ideal situation be the biggest gap possible without things going awry?

 

[95blackGsTurbo]

The short the distance the spark has to jump the better.

 

[ECLIPSE4x4]

this is correct, however under higher boost levels the gap may have to be closed. It also depends on the ignition system output.

Here is a blurb I got off of NGK's site.

Since the gap size has a direct affect on the spark plug's tip temperature and on the voltage necessary to ionise (light) the air/fuel mixture, careful attention is required. While it is a popular misconception that plugs are pre-gapped from the factory, the fact remains that the gap must be adjusted for the vehicle that the spark plug is intended for. Those with modified engines must remember that a modified engine with higher compression or forced induction will typically require a smaller gap settings (to ensure ignitability in these denser air/fuel mixtures). As a rule, the more power you are making, the smaller the gap you will need.

A spark plug's voltage requirement is directly proportionate to the gap size. The larger the gap, the more voltage is needed to bridge the gap. Most experienced tuners know that opening gaps up to present a larger spark to the air/fuel mixture maximises burn efficiency. It is for this reason that most racers add high power ignition systems. The added power allows them to open the gap yet still provide a strong spark.

With this mind, many think the larger the gap the better. In fact, some aftermarket ignition systems boast that their systems can tolerate gaps that are extreme. Be wary of such claims. In most cases, the largest gap you can run may still be smaller than you think.

 

[SlowboyCSE]

Why would you want to gap smaller? Wouldn't the ideal situation be the biggest gap possible without things going awry?

This is true, but the bigger gap combined with harder to combust mixtures (more boost, slower burning fuels, nitrous, leaner a/f etc.) will then equal more juice to get the spark to jump a certain distance (MSD's, CDI's, better coils). It's physically known how many thousands of volts it takes to get a spark to jump 1 inch at a certain air temperature/humidty etc... but sadly i don't know it.

*** EDIT ***

Called my elec. engineer buddy, he said "12,000 volts will jump something like 1/2 to 3/4 inch in good dry air, don't quote me on this as i control electricty for a living, not make sparks and also remember this is not on the inside of a combustion engine where it would take more because your trying to use a spark for igntion of an air fuel mixture not just measure it dance across a lab table"

 

[weith1111]

Makes sense, but kind of contradictory in a way. You want the biggest gap possible, but the more boost you run the smaller the gap has to be to ensure proper ignition.

I had learned smaller gap=more reliable ignition, larger gap=better burn/more power. You just need more voltage to get that large gap to be reliable, as stated from NGK.

It's not a correct statement to say the smaller the gap the better, why not gap to .001 then? I still believe the opposite is the truth. You want the largest gap that you can provide efficient voltage for. This will give you the best possible burn.

Although, if you are running 21 psi on a stock ignition system, the largest you may be able to run may actually be smaller than stock, as Eclipse4x4 has said.

 

[MNGSX]

Also try the NGK BR7ES or BR8ES plugs. The non projected tip helps.. Its harder to blow out the spark....

 

[rightaway]

i run .025. thats what turbo trix told me to try bc i'm running 21 psi on the E16g. i felted no difference.

 

[snox135]

And this is one of the reasons alot of racers use egt's on each cylinder. They do make egt's guages that will pick up a single misfire at 10,000 rpm. Which can help determine if this happening in your engine.

 

[project_tsi]

rofl felted. .28 seems to be the common. I'm going to try .36 on buschurs COP that i just got, and see what happens.

But I know of the other "special" mods you have to support that. Your also going to try 8's right?

 

[Defiant]

If you're not having trouble with sixes, stay with them.

Air's resistance goes up under compression, which is why supercharged cars need a smaller gap.
Buschur's COP doesn't make a better spark, it's just tidier in the bay. .038 is far too large.
Projected tips run cooler and cleaner than non-projected. Stay with them.

 

[sweet97]

I've ran projected tips on 25psi and it knocked, going to non projected just took the knock away.

I didn't say COP makes a better spark, but it does elimate any resistance within cables themselves, giving hopefully a bit more juice to jump. Like I said thou, I'm gunna try, and see what happens with .36, which I don't think is thaaaat much. .46 like some of the other homies with their 'upgraded coiles' is a lot.

project_tsi: no I plan on sticking with my 7's, even thou I had my 6's running on 25psi as well. Mind you yes, this is all on piss 91 @22degrees of timing without any knock. (i didnt go past 25 because my e16g just couldn't flow 25 past 6k on cams.. thou I do run a lot of cylinder clearance)

I wanted to get a better burn @idle and the COP was cheaper than a dis-2, hopefully itll let me run more gap, and hopefully prevent any spark blowout if I ever wanted to go into 35+

Some random info I found.

Hac you say a NON -projected tip runs cooler, Defiant says the oppostie. This is good onfo but which is credible? Where did you find your info Hac? The info you "randomly came across"? Losing "X" counts of knock with a plug change is great but how much knock was it?. Perhaps BR7ES are the way to go? Guys, where did you get your projected tip info? Mark

 

[andymoraitis]

I'd be interested in knowing this as well. I have a DIS-2 and would like to open the gap slightly from .028 on BPR7ES, however not at the expense of misfire since I've upped the boost to 24-25 psi.

Andy

 

[mavisky]

Andy I'd start with something like .32 and go from there. I'm running .028 gapped BPR7ES's in the talon and they are doing great on the 18g at 20psi and pump gas, I have no doubt that with the msd you should easily be able to jump up some. It's hard to say w/o trying as to what exactly you can get away with on the MSD since I've never had any experience with one.

 

[gsx951]

I didn't say COP makes a better spark, but it does elimate any resistance within cables themselves, giving hopefully a bit more juice to jump.

The DC resistance of a plug wire doesn't make a difference. The signal from the coils act like high frequency AC and travel on the surface of the conductor.

 

[sweet97]

http://66.102.7.104/search?q=cache:...e+a+cooler+tip"&hl=en&ie=UTF-8&client=firefox

It had to be cached, I think the page is toast. But I can concure with their findings. Elimating my knock with non-projected tips. There is a few threads you can search for where people were recieving some knock, and switching to non-projected did remove their knock as well.

The problem with non-projected is that they foul out faster.

I went to COP and 7's for insurance.

Thanks for the link! mark

 

[gsx951]

Yes but distance traveled over wires will reduce the voltage from distance traveled. Bigger gauged wires will help hold, but you have to account for some loss in voltage.

This is more like an electromagnetic pulse. Your thinking about DC currrent flow.
The signal is on the surface, not in the conductor but on it.

http://whatis.techtarget.com/definition/0,,sid9_gci541369,00.html

 

[andymoraitis]

Andy I'd start with something like .32 and go from there. I'm running .028 gapped BPR7ES's in the talon and they are doing great on the 18g at 20psi and pump gas, I have no doubt that with the msd you should easily be able to jump up some. It's hard to say w/o trying as to what exactly you can get away with on the MSD since I've never had any experience with one.

Kyle,

I tried going from .028 to .030 and she started burping up top under heavy boost. I took them back down and the misfire's gone so I suppose the DIS-2 doesn't make that much of a difference.

Thanks for the tip though!

Andy

 

[mavisky]

Well stick with what works I guess, I changed out my 6's from the track that were burping at 21+psi for some 7's today at 028 and it's running 22 on pump w/o burping. I turned it back down to 20, I just missed my spot on the mbc after turning it down for the autox. I saw you pull in, but I was working the course and it didn't get much better even after you left. Sorry I didn't get a chance to talk.

Btw, I'll be moving back to Auburn for an unknown amount of time starting in November over in the next edition.

 

[andymoraitis]

Well stick with what works I guess, I changed out my 6's from the track that were burping at 21+psi for some 7's today at 028 and it's running 22 on pump w/o burping. I turned it back down to 20, I just missed my spot on the mbc after turning it down for the autox. I saw you pull in, but I was working the course and it didn't get much better even after you left. Sorry I didn't get a chance to talk.

Btw, I'll be moving back to Auburn for an unknown amount of time starting in November over in the next edition.

Kyle,

Would you believe she's now burping at .028 with 25 psi? This DIS is a wasted hunk of space. I'll likely drop the gap down to .026 just to see if it stops. I know the plugs are a bit loaded from all the leaded I run and I'm even thinking of trying the non-projected tip plugs hakcenter was talking about (BR7ES) to see if I can squelch some knock until we do WI.

Sorry I didn't get a chance to talk at the autox, but I had Melissa with me and while I would have hung out in the rain, she wasn't game and I couldn't blame her. Looking forward to spending MUCH more time with you once you get to Auburn. If you bring the boost leak tester, I'll bring the beer!

Talk soon!

Andy

 

[sweet97]

Guys-Kyle,Andy please describe this "burping" you are talking about. I get what I call mini fuel cut at high boost levels(25+PSI) and am wondering if gapping the plugs at .026 would eliminate it. thanks, mark

 

[andymoraitis]

Guys-Kyle,Andy please describe this "burping" you are talking about. I get what I call mini fuel cut at high boost levels(25+PSI) and am wondering if gapping the plugs at .026 would eliminate it. thanks, mark

Mark,

It's a high-rpm misfire plain and simple. It feels like mini ignition cuts and starts, or almost as if the spark was interrupted for a millisecond. I KNOW my plugs are being trashed so I'm going to try non-projected units (if they're available) and see what happens.

I'll bet that taking your gaps down will help.

Andy

 

[gsx951]

Andy, if you can't find the plugs at your local auto parts monger, check with Motorcycle PWC shops. The non projected plugs are O.E. on my SeaDoo GSXL.