Yeah, there is a difference in the gaps between the ts and tsx. One thing to keep in mind is that there is no such thing as a pre gapped plug. They had “pregapped” plugs when I started driving in 74, but any basic automotive 101 type schooling will point out the fact that there is no such thing as a pregapped plug. If one prefers to listen to what GM claims about its product, GM tells you to “gap to specifications” right on the side of the tsx box, along with any other plug they sell.
If one insists to refer to plugs as pregapped, the ts is pregapped: 7 of them are @ .045 and 1 is @ .043. And the 1 tsx plug I measured is @ .059. Does that mean that the other 7 that I didn’t measure are pregapped @ .060?
In addition to the tsx‘s approximate .060--a gap that has long been considered an incorrect gap for performance--it’s a totally different plug than the ts. The tsx’s overall length is shorter; also, the porcelain surrounding the center electrode is shorter, and the overall electrode protrusion on the tsx is shorter. In other words, the ts sits deeper in the chamber. My guess is that the tsx is a hotter plug. Whether that good or bad is something that’s out of my realm. If you look at the timeline for the ts-tsx applications, however, it seems that the tsx was introduced as one-step-further into emission control.
After researching the difference in the plugs, and applying mechanical aptitude and internal logic to the matter, my hunch was that the ts is the better selection. The hot-cold factor notwithstanding, the electrode is less shrouded than the tsx, and it would seem that the unshrouded electrode would offer a more intense spark in the firing chamber.
I hate to go on hunches or, worse, blind guesses drawn from whatever ill-documented google source, so I always fish for documented, expert sources. Here’s a comment about plug selection from one of the few folks of whom I consider an expert when it comes to Pontiac performance. Seeing that the tsx was dominant on the market when the article was written, you would think that this expert would recommend the tsx over the ts.
Myself, I’ll stay with the ts because it’s a recommendation from one of the kings of Pontiac performance‘s--not my--recommendation.
http://home.comcast.net/%7e69bird3/jhand15.htm
MERV QUOTE: I hate to go on hunches or, worse, blind guesses drawn from whatever ill-documented google source.
And then you say:
my hunch was that the ts is the better selection
I think you are hunching there Merv! Unhunch yourself! To hunch or not to hunch, make up your mind.
Why go with your quesses and hunches when you can go with facts. I think I'll use your description to show a fact.
MERV QUOTE: The tsx’s overall length is shorter; also, the porcelain surrounding the center electrode is shorter, and the overall electrode protrusion on the tsx is shorter. In other words, the ts sits deeper in the chamber. My guess is that the tsx is a hotter plug. Whether that good or bad is something that’s out of my realm.
It is designed specifically for HEI that's why it looks different.
To help show another common misconception, I'll use another MERV QUOTE:
If one insists to refer to plugs as pregapped, the ts is pregapped: 7 of them are @ .045 and 1 is @ .043. And the 1 tsx plug I measured is @ .059. Does that mean that the other 7 that I didn’t measure are pregapped @ .060?
When I say the plugs are pre-gapped at .045 it doesn't mean that they are ready to slap in and all the gaps are perfect. It means that the electrode is made to be gapped at .045. Get it? It's not made to be gapped a .030(or narrower) like the original plugs. So when you gap the TSX the top of the electrode is straight not bent up on an angle to get a gap it wasn't designed for. ALWAYS CHECK YOUR PLUG GAPS. Pregapped doesn't literally mean perfectly gapped and user ready. No plugs are.
I like to keep things simple so here's the low down again.
TSX have the design made for HEI ignition. AC redesigned their TS specifically for HEI. The redesign was called TSX. Go figure! AC engineers came up with this design in 1980 through research of what type of improvements they could make with their plugs to work with the 'new' high energy style ignitions. They were a few years late. Better late than never. Lucky for us, if correctly informed, we have the better plugs to choose from.
If you want the cooler one you get R44TSX. The R45TSX is the most highly recommended and widely applied plug in AC history. Come on out into the post 1980 world and use the technology!
