View Full Version : Spark Plug Dilemma


jallen100
07-31-2012, 02:24 PM
98 ls1

So I put a set of TR6's in my car about a week ago in preparation to spray the car. I took it out racing that weekend and by the time I made it out there, ther car did not want to idle. I figured it would be a little rich but not rich enough that the car would not idle. The plugs that were in it were old Autolites and I could not read the numbers. So my question now is, do I go with a TR5 or try a TR4 until I am ready to spray the car? I pulled the number 3 plug and it actually looked a little lean to me but my tailpipes are charcoal black now. All teh fouled plugs that I have ever seen had a smell of fuel on them and it was obvious that they were fouled. Other than the car not wanting to idle now, it runs like a champ. It did lay down a little on the first pass but after that pass cleaned everything out it left like a beast on the 2nd pass. I just dont want to get the car to lean but I would think 2 steps hotter than the TR^ would not do that since the 6's are fouling.

Any Thoughts? And yes I know I need to get the tune looked at and that is why I am not spraying it yet.

versz
07-31-2012, 03:11 PM
Im running TR55's in mine. I love it. This is the second thread I've seen in a week about TR6's being trouble.

RPM WS6
07-31-2012, 03:27 PM
I don't know what sort of modifications are done to your car (other than N2O), but the TR55s would be the stock replacement heat range. Unless you have an extreme NA setup, I would use the TR55s when you are not spraying.

Unless you spray the car often, in which case it would be a pain to constantly swap plugs, so then the TR6s should be OK but won't last as long. Lots of people use TR6s full time and don't have the issues that you experienced, so I wonder if something else may be going on.

jallen100
07-31-2012, 03:48 PM
Well I know that the car is tuned rich for the spray. That is how the previous owner had it set up. I guess its just to rich for normal driving on the tr6's. I really need to get the car tuned properly for the nitrous, which I plan to do. In the meantime I still wanna be able to drive it around without fouling the plugs. I think the TR6's will be ok after the tune but they suck right now. So That was really the question. With the car already being rich, do I go to a stock heat range to prevent fouling or should I go 1 step hotter? Im just concerned about going lean if I go to a hotter plug than stock even though the car runs a little rich.

Neal@NitrousOutlet
07-31-2012, 04:13 PM
just a question but how much are you looking to run nitrous wise?? We usually dont recommend running TR6 plugs with nitrous.

zracer323
07-31-2012, 07:58 PM
I would definitely run a non-projected tip plug with nitrous. I run ngk br7ef in mine.

Camaro_94
07-31-2012, 10:54 PM
just a question but how much are you looking to run nitrous wise?? We usually dont recommend running TR6 plugs with nitrous.

I have one of your kits on my Z06, why don't you recommend the TR6's, and what would you recommend instead?

jallen100
08-01-2012, 10:44 AM
just a question but how much are you looking to run nitrous wise?? We usually dont recommend running TR6 plugs with nitrous.

I was going to start with a 100 shot for now and work up to 200. I dont know how well I like the kit that is on it now and will be definitely putting a Nitrous Outlet kit on it probably this winter.

Neal@NitrousOutlet
08-01-2012, 11:17 AM
I have one of your kits on my Z06, why don't you recommend the TR6's, and what would you recommend instead?

The TR6's are projected tip spark plugs. The strap that runs over the electrode is on a projected tip spark plug can not dissipate the heat out of the strap as fast as the non-projected tip plugs. This makes them better suited from the high heat in the cylinders thus creating a better "cushion" than the TR plugs.


I was going to start with a 100 shot for now and work up to 200. I dont know how well I like the kit that is on it now and will be definitely putting a Nitrous Outlet kit on it probably this winter.

We would be honored to help you out. Thanks for keeping us in mind. Whenever you are ready just give us a call.

Fbodyjunkie06
08-01-2012, 06:19 PM
Never use a projected tip plug on a power adder.

NGK makes a BR6 and a BR7. I'd use one of those.

BriancWS6
08-02-2012, 10:58 PM
You have something else going on. I ran TR6 plugs with bolt ons for thousands and thousands of miles. Not once did they foul or ever make the car perform poorly. I ran TR6s with my heads/cam setup for years as well, no issue. I built a forged 347 for a customer/buddy about 1 1/2 years ago, and installed TR6s in his car. It's been perfect all along.

TR55s are the stock heat range for these cars. A lot of people think the only time to go a step colder is if they are running nitrous, or boost. That's not true. Another time to go colder on plugs is when you have increased power a good bit over stock. An old rule of thumb is go one step colder when BHP has been increased by 100.

If you understand how a spark plug works, and what's actually different in a colder plug, it makes more sense. It has nothing to do with the intensity of the spark. It has to do with how far into the plug the porcelain around the center electrode goes up into the plug. This factor determines the rate that the plug is able to dissipate heat. A colder plug will allow for cooler temps in the combustion chamber by allowing heat to be more readily transferred from the plug to the head.

Fbodyjunkie06
08-03-2012, 09:18 AM
You have something else going on. I ran TR6 plugs with bolt ons for thousands and thousands of miles. Not once did they foul or ever make the car perform poorly. I ran TR6s with my heads/cam setup for years as well, no issue. I built a forged 347 for a customer/buddy about 1 1/2 years ago, and installed TR6s in his car. It's been perfect all along.

TR55s are the stock heat range for these cars. A lot of people think the only time to go a step colder is if they are running nitrous, or boost. That's not true. Another time to go colder on plugs is when you have increased power a good bit over stock. An old rule of thumb is go one step colder when BHP has been increased by 100.

If you understand how a spark plug works, and what's actually different in a colder plug, it makes more sense. It has nothing to do with the intensity of the spark. It has to do with how far into the plug the porcelain around the center electrode goes up into the plug. This factor determines the rate that the plug is able to dissipate heat. A colder plug will allow for cooler temps in the combustion chamber by allowing heat to be more readily transferred from the plug to the head.

Nailed it, great information!

jallen100
08-03-2012, 11:51 AM
You have something else going on. I ran TR6 plugs with bolt ons for thousands and thousands of miles. Not once did they foul or ever make the car perform poorly. I ran TR6s with my heads/cam setup for years as well, no issue. I built a forged 347 for a customer/buddy about 1 1/2 years ago, and installed TR6s in his car. It's been perfect all along.

TR55s are the stock heat range for these cars. A lot of people think the only time to go a step colder is if they are running nitrous, or boost. That's not true. Another time to go colder on plugs is when you have increased power a good bit over stock. An old rule of thumb is go one step colder when BHP has been increased by 100.

If you understand how a spark plug works, and what's actually different in a colder plug, it makes more sense. It has nothing to do with the intensity of the spark. It has to do with how far into the plug the porcelain around the center electrode goes up into the plug. This factor determines the rate that the plug is able to dissipate heat. A colder plug will allow for cooler temps in the combustion chamber by allowing heat to be more readily transferred from the plug to the head.


I agree that something else is amiss. I bought the car and it was tuned this way for the spray. My assumption is that they just had the tune set fat all the time for the nitrous as the car didnt get street driven much at all. I have no plans on spraying the car until I get the tune looked at but I would have thought that the TR6's would not have fouled out like they did. I put the TR5's in them and it cleaned up a bunch but it is still to rich for that heat range. Again this is just a temporary issue until I can get time to get it on the dyno and get it tuned. Hopefully after that, this spark plug deal will be straightened out and I can put the BR6 or BR7 in it.

oldmano2z
08-04-2012, 11:52 PM
not to jack the thread but would a one step colder plug on a stock ls6 help with spark knock ??

RPM WS6
08-05-2012, 03:06 AM
not to jack the thread but would a one step colder plug on a stock ls6 help with spark knock ??

I think the bigger question is, why is your stock LS6 detonating in the first place? Carbon build-up, wrong fuel octane, etc.?