NGK Extended Reach Spark Plugs

[igdrasil]

About my turbo, all oil seals are damaged, specially the exhaust part. Some metallic parts (sorry I dont know how to call them) have some wear and tear. I will open a new topic soon with pictures and stuff about the rebuild.

A good replacement for the ZFR7F is the BKR7's or for racing R56's. The ZFR7F is good for mild boost or very rich running cars.

 

[TurfBurn]

Hmm... interesting... I put the ZFR7F's in my car.. gapped them out to about 34 thousandths. Immediately noticed the car started better. I run pretty rich, i think boosting I'm hitting around 12.2 right now. I haven't noticed any issues, but I did notice on a 100+ mph run that my EGT flashed a warning light at me. I didn't catch the temp, but I believe it was in excess of 800C. So now I"m wondering on these plugs. I'm running 8 psi constantly as of right now, and half thought about bumping up for lapping days where I'll be well above 100 mph. So now I'm debating on what plugs to switch to and if I need to get away from these plugs or not.

 

[igdrasil]

Well...FM says it promotes a better burn in the chamber. I would say it starts the flame-front more centered or more closer to the piston, which I think is a bad idea.

What we dont want is the flame front to touch the piston!!!

As heats builds up, it tries to burn the fuel near the piston area (which is not supposed to), if it reaches it, it starts to heat the piston up and eventually, melting it.

Thats what happens when you run lean!

So...thats only my visualization. My opinion.

 

[TurfBurn]

Any idea what kind of EGT you had? What AFR were you running, and do you know what your timing is at? Sorry, full of questions .

Thanks!

 

[igdrasil]

Any idea what kind of EGT you had? What AFR were you running, and do you know what your timing is at? Sorry, full of questions .

Thanks!

 

[TurfBurn]

Uh that'll do it! LOL.. how do you operate that gauge? i Have the same one, but have no idea how to set the warning and recall the memory since I dont' have a manual for it!

thanks!

EDIT: Got it now.. simple enough press the memory button for the recall, press it again to go back to operation, hold it in to reset. other "knob" you just turn to set the warning level.

 

[CustomMSP]

LinuxRacer,

How is your car doing with these plugs?

 

[PaulMP3]

Hmm... interesting... I put the ZFR7F's in my car.. gapped them out to about 34 thousandths. Immediately noticed the car started better.

I also noticed my car ran better and seemed more responsive "off boost" in boost i couldnt feel a difference.

Im gonna check my plugs and adjust my timing map then take it back up to 10-12 psi and see if it miss-fires again. In my case it only happened a few times but it felt like the car lost all power so i would let off imediatley, also it happened right around 6000rpms every times, i think it might be cause im pulling to much timing in that area.

I might try these ones soon.
From NGK:
"I would highly recommend the BKR7EIX stock number 2667. These are available colder if you need them. However it's up to you to determine the correct heat range for your application. This spark plug will give your the performance of the OE style yet be cold enough for your application. Set the gap .002" less then the factory recommended gap."

 

[midnightracr]

Paul, How does the 12psi feel? When did you start running this much boost? I remember you were only running 8 there for a while

 

[midnightracr]

Also I talked to Nick from WagnerMotorsports (when I was ordering my turbo kit) & he said for me running only 8psi the Mazdaspeed plugs would be plenty good for 8psi & to only upgrade to the colder plugs for when i'm boosting 12 or more

 

[brentw1584]

Ive read this forum and iam kinda debating on the diffrent plugs to get. I have the bk7e or whatever they are. my question is should i switch to the zfr7f-11 iam boosting aroun 8-10psi

 

[TurfBurn]

I respect Igradsil as he certainly knows his stuff, so the fact that he had problems when running these plugs worries me some. He also seems to have done the most thorough overall comparison... but the only thing that bothers me is that 900C is pretty freakin hot regardless of what plug or system you have. I'm not planning on ever exceeding 800 frankly. So I don't know if the plugs can be blamed. I may get some of the bk7e's and I'll report back with the exhaust temps I get in 4th gear at 70 mph under full boost with as many factors as possible controlled. Based off that we can see if it's the plugs or not. This is a major concern for me because on a hot race track doing 100 mph I don't want any problems and I need to keep my temps down. As of now I did 100+ mph with the Z series plug in 4th gear in 55 degree weather after driving for 30 odd minutes at good speed and only peaked out under 8 psi load at 730C.

The simple version of this all is that we need to know what temp we get in one condition with one plug and then what happens with another plug. Anything else is just jumping to conclusions.

 

[LinuxRacr]

LinuxRacer,

How is your car doing with these plugs?

I'm kickin' ass!

 

[LinuxRacr]

I just went back and read Igrdrasil's responses....DAMN! You all need to keep in mind that I have the J&S Safeguard helping me out.

 

[PaulMP3]

I'm not planning on ever exceeding 800 frankly. So I don't know if the plugs can be blamed. I may get some of the bk7e's and I'll report back with the exhaust temps I get in 4th gear at 70 mph under full boost with as many factors as possible controlled. Based off that we can see if it's the plugs or not. This is a major concern for me because on a hot race track doing 100 mph I don't want any problems and I need to keep my temps down. As of now I did 100+ mph with the Z series plug in 4th gear in 55 degree weather after driving for 30 odd minutes at good speed and only peaked out under 8 psi load at 730C.

Where is your EGT probe mounted???

 

[jurgs01]

I have run the BKR7Es and the am currently running the ZFR7Fs, and my MSP runs much smoother with the extended-reach ZFR7Fs. My car does run extremely rich, so that may have something to do with it. I am running about 9.5 psi, and the plugs feel very responsive through all RPM ranges, especially when the turbo kicks in. No cut, no detonation.

 

[TurfBurn]

Where is your EGT probe mounted???

in one of the turbo manifold runners.. about 3" away from the block...

 

[PaulMP3]

in one of the turbo manifold runners.. about 3" away from the block...

Wow.. and the highest reading you get is 730C. I know Igdrasil has his after his turbo in his DP so 900 is realll hot there.

Mine is right in the collector, right near the turbo flange, and i get readings as high as 880c. I always thought my readings were somewhat high, but even with my FMU running 5psi and keeping my AFR below 12 i got numbers close to 900c, since installing xtra injectors and running up to 12psi i actually get slightly lower temps. 5th gear WOT runs seem to put out the highest temps, probally just cause i can stay in boost longer, larger load.

Im gonna be pulling my mani/turbo/DP off soon, i better recheck the location of the probe to be sure it is centered in the collector.

I also read on Probetalk.com that the collector can be the hottest point because of the pressure from the turbo restrcition.

It seems everyone has a different opinion on EGT placement.

maybe i will have wagner weld me a new bung on one of my runners to check differences in temps.

here is a pic of my location.. you can see the EGT next to my o2 sensor in the collector area.

im gonna keep these extended reach plugs in, and add some timing back in this weekend. hopefully i can stay at 12psi with out that issue. 8psi feels to slow

 

[PaulMP3]

Paul, How does the 12psi feel? When did you start running this much boost? I remember you were only running 8 there for a while

im back down to 8 psi for now...

i was running 12psi (more like 10.5 but i got 12psi in 4th and 5th gear )for a few weeks, the car felt really fast, i still feel i could get some more power out of it with some better tuning (timing mainly). im gonna take it back to 12 this weekend, hopefully all will be well again. It is a blast to drive like that, 8psi is starting to feel slow (rofl2)

 

[igdrasil]

hey people, remember that the 900c was a flash! I kept my eye on the gauge and I couldnt see the needle jumping at all, but the warning was there.

Dont blame the plugs, but I do believe they are not good for high boost apps 12psi or over if you dont have good engine management and are sure of fuel octane in the tank.

I just showed the plugs to let you guys see how they look when it experiences lean situations and detonation. I will be doing a cylinder leak test tomorrow and fixing my turbo because the detonation ****** it.

But let me tell you one more thing: I felt it better with those plugs, Im even thinking on continuing using it now with the MPI.