View Full Version : Wich Plugs????

05-12-2007, 10:23 AM
what is the best plug to use for a 04 cobra that is ported and has a 2.8 upper with a 4lb lower:) also what should the gap be i have tr6's now but i was told to go to a colder plug (NGK BR7EF)

05-12-2007, 05:20 PM
I have been told that the plugs you have now are the best.

05-12-2007, 06:02 PM
NGK TR6, gapped at .032...shouldnt have any issues there...if you do, then regap to .028, but i doubt that'll be necessary :thumbsup:

05-13-2007, 12:19 AM
plus 1 on the NGK plugs, you really should change those plugs with the increased boost

05-13-2007, 09:39 AM
NGK TR6 are the way to go :thumbsup:

05-20-2007, 12:38 PM
what waqs the gap that you set them atNGK TR6 are the way to go :thumbsup:

Big T
05-20-2007, 12:56 PM
I use ngk tr6 at .035. I used to have a 2.7 upper and 2# lower with ngktr6 at .035. I was told to change them about every 6-12 mos. to keep your car running good with the extra power and boost.

05-21-2007, 06:43 AM
2.8 upper and 2# lower.. TR6 with 035 gap.. 516 HP with stock injectors and MAF.

05-25-2007, 10:05 PM
Why are the TR6's so good?

05-28-2007, 09:38 AM
I also recommend the TR-6s. They are a perfect plug with the added boost. we install these on almost everyone of our boosted Terminators.

05-29-2007, 04:33 AM
yeah tr6's are good plug. Start at .035 gap if your experiencing blowout then you can pull the gap down even tighter but .035 should be perfect with your application

05-29-2007, 06:25 PM
blowout what is that. this the first im hearing of 'blowout'. i just put mine in this weekend and gap them at .032 should this be allright .yeah tr6's are good plug. Start at .035 gap if your experiencing blowout then you can pull the gap down even tighter but .035 should be perfect with your application

05-30-2007, 12:10 AM
yeah .032 will be fine.
Basically blowout is where your plug gap is to large for the amount of cylinder pressure and the spark gets "blown out" before it can ignite the fuel/air.

This is a common problem where people maintain the stock gap of .044-.045 and put a smaller pulley on and up the boost. Basically the car will spit and sputter and stumble.

There are however aftermarket coil on plugs like the granatelli and weaponx cop's that you can put on the car and run bigger gaps like near stock gaps even at higher boost levels. Some people with the weaponx cop's have reported being able to use .042 gap at close to or over 20lbs of boost. The more gap you can run the better.

I had a friend with 03 convert who went to a tuner on this board <against my advice lol> and had them do bunch of mods kb/plugs/tune/pumps the works well they didnt do the plugs like they said they did and left factory platinum plugs in the car and tuned it with those, the car literally would not pull past 4k rpm because it would break up and fall on its face and they tuned the car and said here ya go! Needless to say he listened to me and we put good plugs in it pulled gap to .035 and had it retuned somewhere else and made all diff in world!

05-30-2007, 05:37 AM
NGK TR6 (Ix irridium) or Denso irridium plugs are both good plugs. The irridium plugs have a smaller surface area to concentrate the electrical charge and provides a higher intensity of spark compared to those that have a broad electrode. Note: if you have issues with colder than stock plugs, it is related to the factory coil packs since they sometimes do not perform well when matched to much colder plugs. Colder plugs have the insulator and electrode tip further in the spark plug body where as hotter plugs extend the electrode and insulator further out. No matter which brand of plug you use they will eventually fail from deposits of combustion. Even if the plug claims it will last for 100k miles, it's performance will not. The effects of a small air gap on the plugs will reduce the intensity of the spark so you do not want too small a gap especially if the surface area of the electrode is large in diameter. If you have too much gap, it will take more time for the coil to build up the voltage to breach the gap along with the associated issue of blow out under higher compression.

blow out: The arc itself is classified as a plasma which does have some fluid like properties. The spark or arc can be viewed similar to a stream of water flowing out of a faucet. If you blow on the water stream that would sumulate the effects of compression on the spark. The harder the air flow on the water stream to the point where it is dispersed from a solid stream is the same as when high compression forces the arc to disperse resulting in loss of arc across the gap.