shortdog

iTrader: (1)

If your tune is right, you will not foul out plugs. I drive around with 8s in my car, but will be switching to 9s when it gets warmer. I won't know the effect it'll have on my n/a performance until I hit the track.

Kierstyn, if depends how much power the car is n/a.. A h/c car with a higher compression than stock can use 7 plug or higher.

kierstyn

iTrader: (5)

Yeah the car is a h/c forged 355 lt1 going with the 150 pills and maybe bump to 175 before long. Before anyone asks it is full suspension on a moser 9in.

Robert56

iTrader: (2)

Yea, true, the 7 may give a slightly better safety blanket, but likely under 150 the br6 would do fine. Myself, I would give the 7 a try, and see if that is what your car likes? They really are not that much and HSW carries them all. I have found that the 7 works great for me on the street. The br6 may perform equally as well for your set-up?

Run a new br6 on a hard 1/4 pass, and pull it, or them. Look at the porcelain for a chalky like look, which is what we are after. If it is glazed over (shiny) that is sign of getting hot and the glass beads have melted. If it's shiny with spots, the A/F ratio may be off. But it needs to be a fresh plug and pulled right after the run. There are 3 sections that get colored on the porcelain, the deepest Fuel Ring is what your after. At WOT the fuel ring will start at the top and clean off 1st and 2nd sections before appearing at the bottom. But if your drive back to the pits the porcelain will turn gray, so thus the need to pull right after the WOT pull. One thing to point out, it sometimes takes a couple passes to get the fuel ring readable, so if you don't see it after the 1st pass, make another. Some idling prior to the run will color the top 1st section, but the WOT pull will wash it clean. Now if you idle a lot, in excess prior to your run, you can also glaze the plug at this time. Glazing can cause a short which leads to a misfire, and can sometimes be heard popping out the exhaust. If glazing shows it's ugly head replace the plugs right away before potential issues appear.

You can also look at your timing mark at this time. Basically, you want it just below the 90 degree turn in the ground strap towards the threads. The timing line should be blue, however, NGK plugs often have that gold colored plating so it may be hard to see your timing mark at first. As the timing is advanced the timing line will head towards the threads and can even disappear. So it's better to start with the rec 2 degrees pulled per every 50hp of spray. Then if the line is to far toward the end of the ground strap, you can start adding timing back in 1 degree increments until you get it on the other side of the 90 bend. Some like it just prior to the weld (dedicated racers), but myself being a little more conservative like to get it mid way between the weld and the 90, better/safer IMO, for a street/strip ride.

It does take some effort to dial in the correct plug and tune, but worth it in the end. Sure many just go for the rec, one step colder, good gas, pull 2 degrees rule, a/f ratio mid 11s and go for it. It can work fine for smaller hits on unmodified motors. However, we can make more power and do it knowing we are safe, if willing to put the extra time and effort into the tune. I am guilty myself and have set-up numerous kits with out reading the plugs, but once we get to the 150hp and above we must have advanced tuning knowledge if we want our motors to live a long life. The cylinder pressures at 150 and above become so extreme that if one area goes afoul, we could have problems if the tune is not spot on. Having a good tune is probably the biggest safety component we can apply.


TJ, I agree, and especially the LSx platform can run leaner than motors of past. Low to mid 12s is a much more realistic A/F ratio to shoot for on a sprayed LSx, compared to the old standard blanket statement of mid 11s.

Robert

ATVracr

iTrader: (5)

To much timing.
IMO

TJ

iTrader: (10)

yes. closer to the threads=higher than ideal timing.

Robert56

iTrader: (2)

Each person is going to have to decide what they want in the real world, and this is more of a general starting point rather than an absolute. Mostly just trying to give a perspective on reading a plug. I think that once a person sees the actual timing value compared to the timing mark, they will understand what we are looking for. Where would you say the timing line should be, for a dedicated racer, and for a street/strip set-up, both running a 150hp shot?


That's why I suggested to use the 2 degree per 50hp rule. then they can note where a good starting point would be. I do realize that the LSx likes a lot of timing pulled, compared to some other engines. On the other hand, when guys are asking the vendors about timing pull on stock motors, they all say no timing pull is needed on 150 and below. So I contend that many will see their timing mark closer to the threads, and this is a non projected plug too. This may be where the confusion comes from, the #7 has the 90 into the weld before you could leave the 90.

I am trying to find one of my pictures with a good timing line to make it more realistic, but can't find the one I want. I may have to take another picture, as I have my own plugs all the way down to 14 degrees total, and various size shots, for insight. Maybe we should just say mid point on the 90 is target for a 150?
Robert

BAKED

iTrader: (14)

Robert, I have to disagree with you too on the timing mark. I like mine to be just before the bend. Once it creeps into or past the bend it's time to back it off a little.
Guys you need to also remember that when you make a jet chance or a fuel pressure change, you need to adjust the timing accordingly. When you lean it out you need to pull more timing. You can always put it back in if the plugs shows that it wants more.

When looking at the fuel ring that Robert was speaking of I personally like to see a very light, thin grey ring at the base of the porcelain. The cleaner, the better in my opinion. I don't care if your wideband is showing 14:1 if the plugs are still have a thick, dark, fuel ring then it's rich. Trust your plugs. They are your only window to inside your motor to tell you what is really going on inside.

Another thing, trust your time slips. If you are tuning at the track (where you should be) then take note of your time slips and what jetting/FP/timing were all set at. This will allow you to go back and see what produced the most power. Look at the MPH, it tells the story on how much power you are making.

When you spray big shots (300+) it is a full time job at the track. I don't even race my car in a class most of the time and it still wears me out. You stay really busy going over everything and are constantly thinking. It's not as easy as some people would like to think, that's for sure.

89ROC-Z

iTrader: (11)

Great info here for a newb to nitrous like myself. Quick question regarding the projected / non projected plugs. Currently i'm running accel 276s shorty plugs http://www.jegs.com/i/Accel-Spark-Pl.../276S/10002/-1 to fit with my headers, and i'm getting a wet kit today. Would these plugs be fine for a 125 shot of n2o since they are non projected? Regular length plugs will not fit, so does anyone know of a good nitrous plug that is shorter than the tr6?

thanks

Robert56

iTrader: (2)

That's fine to disagree. However, your talking timing for a 300 shot. We are referring to a 150hp shot. Of course your going to pull more timing, right? What your saying to these guys is to run around with a street/strip tune set-up like a 300 race tune? I have a whole different tune when I run a 300 hit compared to what we have been talking about IE: Plugs, Fuel, Timing, ON/OFF Rpm, Tire Pressure and on and on. That's why I asked ATV the difference between a street/strip tune and a dedicated race tune, which he runs also. Now don't get me wrong, your input is correct, and good, just pointing out that all tunes will not be the same. Then again, maybe I just run too aggressive of a tune all the time?
Robert

BAKED

iTrader: (14)

I think that you misunderstood what I was saying....

Even if I were only spraying a 150 shot, when I pulled the plugs at the end of the track I would want the timing mark before or right at the bend. With a 150 shot I would be running a different heat range plug that is better suited for that size shot.
I have my electronics setup to pull the timing when I activate the kit(s) so I run around on full timing and when I want to spray I just flip the switch. No aftermarket box either.

Basically what I'm saying is that when I tune a nitrous car, whether it be a 100 shot or a 400 shot I want the timing mark to be before/right at the bend. If you have a street/strip setup that you are wanting to run around on a nitrous tune then I would have enough timing pulled to get the timing mark where I wanted it. No compromises, Better safe than sorry IMO

TJ

iTrader: (10)

that picture in that link is not the plug you want for a ls1 type cylinder head.
they use a longer reach .708(most heads)
the image looks like an old school ford or chevy plug for a stock head.
whats your setup and maybe i could get you in the right direction.
i never ran the accel plugs in anything. just one of those things my brain tells me to stay away from so i listen to it.

TheGovernorZ06

I drove many miles w/ a br7ef and never had any problems.... i prob will do a br6ef as my daily driver plug w/ the 1st stage...when i do 2 stages ill swap over to a br7ef

89ROC-Z

iTrader: (11)

Sorry bout the confusion. I'm running those plugs in my old TPI, and am putting nitrous on it (building a 408/402 lsx). I need to find a short style n2o plug for the tpi but have br6ef chosen in the hsw kit

TheGovernorZ06

guys, w the 4177 br6ef plug what would u gap it at at say 100shot dry?

this is on my ls1...thanks

TJ

iTrader: (10)

the br seires plugs arent for the tpi, you will need a short reach plug for the tpi style head, unless its aftermarket.

89ROC-Z

iTrader: (11)

damn. i'll pm nick and dave and see what they think will work. thanks for the heads up tho!

pink_bits

im a newbe can we get some pics of what the plugs should look like please....

shortdog

iTrader: (1)

4177 is a projected tip, so I'm assuming you meant 3177. Plug gap at around .035 is ok.

TJ

iTrader: (10)

which/what plugs?
the pics of the cylinder head chamber on the 1st page says it all.

Robert56

iTrader: (2)

OK, thanks for the clarification. Again, all your input has been good. I guess I just run a little more aggressive than you guys. here is what i think I am trying to say. You can be more aggressive when running a 150 shot or less, so being on the down side of the 90 doesn't mean instant death. I too agree when getting to a 300 area, due to the cylinder pressures being so damn high, the top side of the 90 is correct. There are so many factors that play into what will work for each car. My car, in street/strip mode and under a 200 shot works great with the mid 90 area. Now would a 14 1/2 comp racing motor work there, it's unlikely. Again though, I am talking in general terms and not telling anyone to run any certain amount of timing. I don't have the time right now, but maybe later I can go into how I decide what the final timing will be, on any given set-up. As you know, there are things to look at to say whether this combo makes the most power with 12 or 18 degrees of timing, along with MPH increase or decrease. Here's a for instances;

Running a 150/175hp shot in dual stage, my combo liked 18/20 degrees, anymore and there was no power gain, and topped out at like 130mph. My timing mark was always around the mid point, and BR7 plug. Depending on gas, I would sometimes go even lower than the 18 for safety. For the time period i ran this size, it worked well. My compression is only 11.25, and a small cam, so it wasn't a very radical combo. Could I have run closer to stock timing, and had the timing line closer to N/A, with out issues, I truly believe so. That is where a lot of guys are running their street/strip cars, and I contend that a timing line mid point or lower is not always incorrect, maybe not optimum, but incorrect no. Now with that said, that is why I always state that max timing n/a power, does not always mean max power on the spray. A stockish car may get away with stock timing and small spray, but doesn't need it to perform at it's best, and sometimes will perform better with the timing pulled. Now would telling someone to run on the top side of the 90 like you do, be wise, yes I think it would. Like you said, better safe than sorry. We can always add some back if need be. I think I will be more careful on suggesting a starting point, to be sure no one gets into trouble from the get go.
Robert