Discussion in 'Engine & Performance Modifications' started by Mr MoPar, Jun 7, 2009.
Can't get a hold of you on the phone Mr Mopar. Can you pm me a diff #
What is concidered safe air inlet temps?
I'm using NGK LZTR6AIX-13.
Very good question and I've gotten a different answer from everyone I've asked. Some say 150, others say dont go over 220, I just want them as low as possible. Theres a formula that says for every 10 degrees higher the air charge its 1% of hp lost. Several trustworthy sources have said it's has proved consistent time after time on the engine dyno.
Hmmm. I'm using NGK LTR6IX-11
I heard anything below 200. I run an intercooler and my stay around 120 under boost.
The plugs I use are NGK LTR6A-11
Are you guys running Platinum, or Iridium plugs??? I notice there's no Z in your part #.
The NGK LTR61X-11 is an iridium plug, not sure if they are listed for the 6.1, but they are commonly used of 6.1 forced induction, and they work just fine. They are two steps colder than a stock plug. These are the ones I always use on a 6.1 Hemi.
This was posted by Sharadon on another discussion;
"These are 2 ranges colder than stock and have the same dimension's as a stock plug. NGK LTR61X-11. Stock # 6509. I tried to find a TR7, but no luck unless the plug was shorter."
tim - what about the ngk 2315 plugs for a blown 6.1?????
I think those are actually 3 ranges colder than stock
Kris, what plugs are you running?
2315's 1 stage colder than Stock Iridiums
same plugs i run as well kris / ken........
Im new to this forum and thought id chime in about the spark plugs.
NGK LZTR7AIX-13 stock # 5107 are 2 ranges colder for the 6.1
I will write down the part numbers and have Denny at Sharadon tell me which are which and then post up the info.
Yep, here is what I have come up with so far, but I am still digging.
In the NGK number the last two digits refer to gap. 13 = .050 and 11 = .044 gap
The heat range is indicated by the number AFTER "TR". 5 is stock, 6 is one step, 7 is two steps colder.
There are differences in construction and I am trying to track that down. But, an "LZ" is not a "laser" plug.
Here are the numbers I have right now, info direct from NGK.
NGK LZTR5A-13 â€“ 5 â€“ v power, .050 gap, standard plug, extended body
NGK PLZTR5A-13 â€“ 5 â€“ double platinum, .050 gap, extended projected tip
NGK LZTR6AIX-13 â€“ 6 â€“ ix iridium, .050 gap, extended shell, extended projected tip, projected core nose
NGK LTR6IX-11 â€“ 6 â€“ ix iridium, .044 gap, projected tip
NGK LTR6A-11 â€“ 6 â€“ number not found
NGK LTR71X-11 â€“ 7 â€“ ix iridium, .044 gap, projected tip
Here is some other very good information as well from NGK.
The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500Â°Câ€“850Â°C. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.
The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a â€œcold plugâ€, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A â€œhot plugâ€ has a much slower rate of heat transfer, which keeps the firing tip hotter.
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75â€“100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70Â°C to 100Â°C from the combustion chamber.
The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK nor the same in Autolite. Some manufacturers numbering systems are opposite the other, for domestic manufacturers (Champion, Autolite, Splitfire), the higher the number, the hotter the plug. For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.
Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single precalibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage
The only thing we found the plug techs agreed on was that for performance issues, a fine wire center electrode will provide a stronger spark from the existing voltage. However, fine wire electrodes will not survive in many modified motors.
NGK LTR6A-11 – 6 – number not found. The number is correct but hard to find. They are a copper plug.
NGK Plug Chart
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