Best Spark Plug for Cam Only LS3
11-06-2012, 06:09 PM
#21
WellI had the tr6's so I threw them on. I did a wot with them and then inspected them. What I went off off was the color band you can see on the ground strap. With the stock heat range they were close to the base, indicating it was on the hot side. With the ngk tr6's, the mark is now closer to the middle of the strap indicating a proper heat range. I noticed the car idles very well with the ngk's and seems to rev up smoother. Also less exhaust popping on decel. Only thing now is, I did a 3rd gear wot test on the fwy today while data logging. I figured it was warm and if I would see any detonation it would be then. I got no knock and the car felt great BUT the timing at wot was 31.9* when I had tuned it at 28*. Im guessing the ecu sees no knock and is advancing the timing? Iat' were low, 90's*, but I have that table tuned out anyway.
12-02-2012, 07:26 AM
#22
Glad those plugs helped you out! I try to tell everyone that even stock cars can benefit from a colder plug. There is no benefit running a TR5 or TR55 over a TR6 unless you have a 9:1 engine that makes no heat. Some guy's I recommend a heat range 7 plug to.
On the timing start looking at some of the timing correction tables. There are alot of other tables that add/subtract from the main spark tables. Sometimes wheen dealing with ignition timing and logging it's best to log all the ignition advance PID's to pinpoint which feature is adding the timing over the main table.
On the timing start looking at some of the timing correction tables. There are alot of other tables that add/subtract from the main spark tables. Sometimes wheen dealing with ignition timing and logging it's best to log all the ignition advance PID's to pinpoint which feature is adding the timing over the main table.
12-12-2012, 09:39 PM
#25
Thanks to working nights and nasty Folgers coffee, I researched and solved my spark plug dilema...I hope. Lol. For those who may find this useful....If you read this thread I changed my Autolite 103's because they looked fouled. Turned out it wasn't because they were too cold, it was because of octane booster that was in the gas tank when i installed the new motor. Anyway. I changed to NGK tr6's but started seeing slight hints of detonation, very light black specs on the porcelain, nothing crazy but they shouldnt be there and the first thread or two looked like they were getting hot, even though I always had good air fuel ratio readings (12.8-12.9 wot). So before I messed with the tune or went to a colder plug I looked into it. The tr6 plugs have almost an entire thread exposed into the combustion chamber, they're a thread longer then the 103's. This reduces its ability to dissipate heat into the cylinder head allowing the plug to get too hot. The Autolite 103 does not expose any threads and it is actually closer to a NGK heat range 7 (br7ef), then a tr6 in the 6 heat range, which is one lower then stock. Its design is slightly colder. In fact, the Autolite 103 appears on the cross reference for both NGK tr6 and BR7EF. Autolite usually has two plugs per other manufacturers heat range. No wonder the car ran good from the get go with them even when they looked fouled and especially since the car was tuned with them (obviously allowing for a bit more timing). So, in short, follow your gut because now I'm going back to the 103's. Posted this in case you're ever trying to decide on one of those plugs.
I should have some old Autolite 103's at home. I will try to get pictures comparing the threads to the NGK tr6.
I should have some old Autolite 103's at home. I will try to get pictures comparing the threads to the NGK tr6.
12-12-2012, 09:41 PM
#26
NGK (nickel) vs Autolite 103 (dark) thread depth. NGK is half a thread longer. Tried to compare as best as possible from where the tapered seat begins, which is where it meets the head. NGK is longer. I know the Autolites sit flush in the combustion chamber, I checked it when I got the heads new. So that means the ngk must protrude which doesnt help it dissipate heat.
Camera angle might throw off the line but theyre as close as my eyes allow.
Camera angle might throw off the line but theyre as close as my eyes allow.
12-12-2012, 09:46 PM
#28
I tried Autolites, Champions, and NGK's with the same tune. Only the NGK's had these black speckles on it. May be signs of slight detonation even tho the data logger isnt picking it up. To me it looks like the plug is on the hot side. Also with the Autolite 103's, my afr went to 12.7 vs 12.9 with the TR6.
12-13-2012, 12:02 AM
#32
When you use Autolite's heat range reference chart, the 103 shows up as the replacement for the TR6 and BR7EF plugs. Under Autolite the heat range is D14. It is slightly colder then the TR6.
BR7EF reference,
http://www.autolitecatalog.com/Compe...=br7ef&em=True
TR6 reference,
http://www.autolitecatalog.com/Compe...pn=tr6&em=True
As you can see, the 103 is the coldest plug in that heat range.
BR7EF reference,
http://www.autolitecatalog.com/Compe...=br7ef&em=True
TR6 reference,
http://www.autolitecatalog.com/Compe...pn=tr6&em=True
As you can see, the 103 is the coldest plug in that heat range.
12-13-2012, 12:29 AM
#33
There is absolutely no difference......using gaps from the factory .060 down to .040.....at least not on my stock engine or my 427ci. No gas mileage difference, no performance difference, no acceleration difference.
So I figured from about 2004-----on till the present.......to use a middle gap at .050 and NGK plugs. My 427ci performed identical to everything I tried and I've used it since 2002....till I reached 173,000 miles and a friggin rod finally snapped at 150mph 5 months ago.....LOL
People put too much thought into spark plugs.....like they do with motor oil. Or when people buy special, super duper, magical spark plug "wires" thinking its going to help performance on a 400-500 RWHP engine. A plug is a plug, a wire is a wire......until you use nitrous, boost or go BIG power like 650 RWHP++
If you're N/A.......NGK, AC Delco, or whatever......gapped .050.......thats all you can do for peak performance. These LSx engines are absolutely NOTHING special, they are regular ole' Chevy V8 engines. People treat them like exotic engines.....its hilarious.
But hey....some people like to chase that elusive .0000001 RWHP......thats cool.
.
12-13-2012, 12:42 AM
#34
Im not chasing nor expecting hp gains from plugs but I do want to avoid detonation and plugs play a big part of it. Even an ol' Chevy motor needs the right plugs to run right. Every combo is a bit different. If you can live with a hot plug with signs of possible detonation on them, then go ahead. I dont mind investing another $16 in plugs to find the best one for my motor. I would like it to last me a long time. Maybe a tr55 at .050 worked for you, not happening here tho. Choosing plugs is part of tuning. I wish there was a "one plug that works for all" but there isnt. Anyway thats a fact so no use debating that.
12-13-2012, 05:19 PM
#38
After talking to and NGK guy at a show, here is what I was told: A spark plugs job is to stay clean and ignite the air fuel mix without overheating or causing pre-mature ignition due to plug overheating.
The plug has to be hot enough to stay clean but cold enough not to cause pre-ignition. Spark plugs that are too hot can also wear excessively due to heat erosion.
In my car, I have successfully run both TR5s and TR6s. The TR5s stay cleaner, and you can see more heat in the electrode as you might expect, but I have never experienced pre-ignition. My car is 10.8:1. On nitrous I run BR7s and they look excellent after a pass.
As for the copper vs. iridium thing, I will say this: A clean iridium plug will deliver a better spark than a dirty copper plug for sure. Not only will the iridium plug wear longer but the anode stays cleaner by design.
If you plan to change your plugs often for whatever reason I can see using a cheaper plug for sure. I do.
Also, why the small gap? Most guys are running .045" no problem. The only reason to close the gap is because you are making so much cylinder pressure that your spark is failing. I do not see that happening with your cam only LS3. When you close your gap, you actually get less spark energy. This would certainly greatly overshadow any gain you feel you are getting from a copper plug.
The plug has to be hot enough to stay clean but cold enough not to cause pre-ignition. Spark plugs that are too hot can also wear excessively due to heat erosion.
In my car, I have successfully run both TR5s and TR6s. The TR5s stay cleaner, and you can see more heat in the electrode as you might expect, but I have never experienced pre-ignition. My car is 10.8:1. On nitrous I run BR7s and they look excellent after a pass.
As for the copper vs. iridium thing, I will say this: A clean iridium plug will deliver a better spark than a dirty copper plug for sure. Not only will the iridium plug wear longer but the anode stays cleaner by design.
If you plan to change your plugs often for whatever reason I can see using a cheaper plug for sure. I do.
Also, why the small gap? Most guys are running .045" no problem. The only reason to close the gap is because you are making so much cylinder pressure that your spark is failing. I do not see that happening with your cam only LS3. When you close your gap, you actually get less spark energy. This would certainly greatly overshadow any gain you feel you are getting from a copper plug.
12-14-2012, 01:47 PM
#39
After talking to and NGK guy at a show, here is what I was told: A spark plugs job is to stay clean and ignite the air fuel mix without overheating or causing pre-mature ignition due to plug overheating.
The plug has to be hot enough to stay clean but cold enough not to cause pre-ignition. Spark plugs that are too hot can also wear excessively due to heat erosion.
In my car, I have successfully run both TR5s and TR6s. The TR5s stay cleaner, and you can see more heat in the electrode as you might expect, but I have never experienced pre-ignition. My car is 10.8:1. On nitrous I run BR7s and they look excellent after a pass.
As for the copper vs. iridium thing, I will say this: A clean iridium plug will deliver a better spark than a dirty copper plug for sure. Not only will the iridium plug wear longer but the anode stays cleaner by design.
If you plan to change your plugs often for whatever reason I can see using a cheaper plug for sure. I do.
Also, why the small gap? Most guys are running .045" no problem. The only reason to close the gap is because you are making so much cylinder pressure that your spark is failing. I do not see that happening with your cam only LS3. When you close your gap, you actually get less spark energy. This would certainly greatly overshadow any gain you feel you are getting from a copper plug.
The plug has to be hot enough to stay clean but cold enough not to cause pre-ignition. Spark plugs that are too hot can also wear excessively due to heat erosion.
In my car, I have successfully run both TR5s and TR6s. The TR5s stay cleaner, and you can see more heat in the electrode as you might expect, but I have never experienced pre-ignition. My car is 10.8:1. On nitrous I run BR7s and they look excellent after a pass.
As for the copper vs. iridium thing, I will say this: A clean iridium plug will deliver a better spark than a dirty copper plug for sure. Not only will the iridium plug wear longer but the anode stays cleaner by design.
If you plan to change your plugs often for whatever reason I can see using a cheaper plug for sure. I do.
Also, why the small gap? Most guys are running .045" no problem. The only reason to close the gap is because you are making so much cylinder pressure that your spark is failing. I do not see that happening with your cam only LS3. When you close your gap, you actually get less spark energy. This would certainly greatly overshadow any gain you feel you are getting from a copper plug.
12-14-2012, 03:26 PM
#40
An iridium plug will not outperform a copper plug, it just lasts longer. You cant compare a dirty plug either. Any plug will outperform it then. Unless you have plugs made of silver, copper is the best conductor. Also I understand heat ranges just fine. Heat range is how fast the plug dissipates heat, not how hot the spark itself is. Also, NGK tr6 have a .038 gap out the box. .035-.038 is a gap that many feel gives good performance on moddified cars. In my case it probably wont make a huge difference, just a gap size that I have success with before with those Autolites. Just sticking to whats worked....for me.