40thgtfl

I am having my hooker long tubes installed on thursday and i was wondering, should i go ahead and replace the spark plugs as long as they are down there? the car is an 05gt with 40k miles on it. im sure i could get the labor for free.. if so is there any particular plug i should think about?

mac10chap

i am in the same boat you are...i am in the process of replacing the plugs and it seemsthat autolite HTO's are what most are recommending.

as far as getting labor for free on plugs, jump on that. i have heard of dealer quotes of around $200 just to replace plugs based on the difficulty of removal and possibility of breaking them off and having to drill them out and all. all in all, compared to other plugs, they are quite a pain in the ***.

SuperSonic05

sounds like a good idea to me

kcmarti

Down where? The headers and plugs, although they are both in the heads, are not in the same location. Nor does installing headers necessitate pulling plugs. In fact, changing the plugs would interfere with the header install - changing theplugs requires a hotengine,replacing the stock manifold with headers requires a cold engine. The free part is good though.

SCCAGT

The spark plugs are not on the side of the heads. So its not something they "could do while they are there". The spark plugs are on the top of the heads. But if they will actually do it for free, then its a no-brainer.

modaddict

I agree if it's 'free' then why not but it is not rocket science to change plugs on these cars...

Also - N/A guys need not think about the HTO's.

40thgtfl

well, they said they would have to lift the engine a bit.. i dont know. we shall see if they will do it for free

mac10chap

ok, not to steal this the thread, but you mentioned that N/A guys dont consider HTO's...then what do you recommend??? I was told that FI, NO2, and even stangs with full bolt-ons should get them. why should we not consider? is it just overkill or can it hinder performance or what? I am curious now???

kcmarti

You should use the stock HT plugs for a stock engine. This should expalin it somewhat:

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 500°C–850°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 “cold plug�, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A “hot plug� 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 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.

mac10chap

Sooooooo, ummmmmmmm...HT1's???[sm=smiley24.gif]