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NGK difference between BR7ES and BPR7ES

Hertz

Staff member
Would running a non-projected tip help reduce knock? I guess the idea is that the insulator will hold less heat because it is out of the chamber further. Any drawbacks?

At what point do people go to the 8 heat range? Is the only disadvantage quicker fouling? What kind of life expectancy do they have vs. a 7 or 6?

These days spark plugs are relatively cheap so I have no problem having to change them more often if it will help me improve performance (more psi, less knock).
 

CP

Well-known member
As clarification for those who don't know, most of us running higher boost/bigger turbos are using the BPR7ES NGK plugs...and changing them at each oil change.
 

powerplay

Well-known member
Really! You are running a bigger turbo? And you change you plugs every 3K miles? I certainly don't follow any of this information. I guess I am just not in the "most of us" crowd. /ubbthreads/images/graemlins/rolleyes.gif
 

steve

Well-known member
Whats with the sarcasm?
 

im using the 7's on a big 16g.

anything bigger than the 16g, the 8's would be a better choice
 

IncorpoRatedX

Well-known member
^^ nice info mike, but thats not what hertz is asking about

he's asking about resistor type plugs vs. non resistor

in my experience. If i use resistor plugs on a decently modded car running substantial boost (19 psi or higher) i pretty much have to change them every oil change due to electrode deterioration. The non-resistor types seemed to hold up better under long term high boost applications.

just obervations i've made. I have no scientific reason to base an opinion but i prefer running non-resistor style plugs. /ubbthreads/images/graemlins/dunno.gif
 

atc250r

Staff member
Quote:
he's asking about resistor type plugs vs. non resistor



Acutally he's asking projected vs. non-projected. Unfortunately I have nothing useful to offer other than I've been running 7's in my car for a couple of years and only fouled them twice. Both times is was due to me "jockeying" the car around the driveway for several days in a row during the dead of winter. Eventually the plugs just go gas soaked. I've been meaning to order a set of 8's but haven't gotten around to it. It seems that most parts stores around here stock the 7's but not the 8's. I'm running around 25psi on pump with an SCM61 so I'm pushing it pretty hard.

John
 

Hertz

Staff member
I guess I should have added:

I've been running the NGK BPR7ES ever since I got an MBC. At the local parts place all they had the other day was the BR7ES (same plug, same heat range, but it doesn't (P)rotrude very far past the threads).

I posted this in Newbies since spark plug education should be had by all, therefor clarifications are okay, sarcasm is not.

Anyhow, I'm trying them out. I put a set in last night. Now, the weather was definitely cooler (and I don't know if any of my knock is plug related) but I definitely did not get any knock on my first pull (sometimes I'd see 1-5 counts). This is by no means scientific because of the temperature change (a) and the new plugs factor (b). I did not measure any O2 difference (i.e. do the non-protruded plugs have more difficulty in getting a complete burn), but I don't have wideband anyhow.

Otherwise, so far in my application (and with only 20 miles of testing) the driveability seems normal.
 

Gordian79

Well-known member
non projected tip ones are used when running high boost (over 35 psi)in order to prevent blow out.They do foul out quicker im guessing because of heat.Im not sure what im running in my car now i use whatever plugs i have left over from the race car i might have 8's.On the race car if im running it on just boost ill run BP8's and if im running n20 ill run 9s
 

OldHairyBastard

Well-known member
Run what ever plug makes you car run better. If your changing your plus on every or every other oil change then it shouldn't matter about fouling as long as you open her up every once in a while to clear out the carbon build up. I think most of us here don't have too much of an issue with Hitting The Gas.--"Sometimes you need to feed a little speed to your ride"-clue Martin Lawrence.
 

CP

Well-known member
Quote:
You are running a bigger turbo?


Nope, just elevated boost.

Quote:
And you change you plugs every 3K miles?


More like every 2500. I drive my car every day and flog it at the racetrack for 25 minute sessions a few times a month when it's warm out. I change my plugs, oil and filter before EVERY event that I attend, sometimes within the same month.

Scott, we have different goals for our cars. My car gets me to work every day (most of the time), takes me around racetracks lap after lap, and plays in the snow (especially during and just after storms). Do you do any of these with your garage queen? I didn't think so, because we have different goals. Mine gets babied as much as possible, but not to the point where I spit shine it daily or care about a dent or paint chip here and there. It's going to get crashed some day, either by some Masshole while commuting or at the track during an "incident."

Back on topic: My local NAPA told me that the only time they sell the "8" plugs is for snowmobile applications. The reason for my first post was because it was in the the "Newbies" forum, and I was trying to minimize the type of questions I'd expect about the heat ranges of the plugs, and who uses what. Sorry if I struck a bad chord with you...tough guy /ubbthreads/images/graemlins/wink.gif
 
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joec

Well-known member
Yamaha uses the 8's on two-stroke street bikes. I think the 84-85 RZ350's came stock with BR8ES's with the 9's recommended for extended high rpm use?
 

OldHairyBastard

Well-known member
I use the BPR9ES on my sleds. 1995 ZRT 800 with a 1994 T-Cat 900 motor that has a 1002 D&D Big Bore in it & a 1997 ZRT 600. Not to thread jack but I've used these plugs in cars too and they work great for spray and high boost aplications but foul fast on DD driving unless your boosting all of the time driving the car like you stole it.
 

Polish

Well-known member
I run 9's in my Sled too (800cc 2 stroke Yammy) but I never considered putting them in the car.

I run BR7ES in my VR4 with a S16G, 20PSI, Pump gas. I would have gotten the BPR7ES but the store only had the BR7ES, the car doesn't seem to care at all. Although I only drive it once a week or so. The oil has been changed 3 times this year, plugs 3 times and it has like 1500 miles so far for the year so they'd never foul anyway. /ubbthreads/images/graemlins/rofl.gif
 

atc250r

Staff member
Quote:
non projected tip ones are used when running high boost (over 35 psi)in order to prevent blow out.



I might have to give that a try once I get back on track with tuning the GVR4. I don't run that much boost but I've had problems once or twice with the car "breaking up" at higher RPM's at higher boost levels. I put fresh BPR7's in it and a set of new NGK wires which seems to have done the trick but I'll know for sure when I get back to the track and make a full pass.

John
 

There's a couple cars around here in the 10's and 9's and they both run BR9ES plugs, because those are the plugs that have the least tendency to sputter under that application. They foul out faster, but they work.

That's likely not the same application as many people here, which would do just fine with BPR7ES plugs. The true measure of a problem with the plugs is sputtering. If you aren't, there is no reason in the world to change plugs.

I have run 7's, 8's, and 9's, and never seen ANY change in knock on the logger. I don't think heat range matters for most people.
 
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