Thread: what plugs to buy?

my only performance mod is a DIY 3" FWI. i have not messed with t-stat or plugs or wires yet. i'm wondering what you guys recommend for my N/A vehicle for plugs????

When I was N/A I ran AL605s. You don't want to go too cold on plugs, and the AL605s seemed just right for a N/A engine.

Keep in mind these are copper core plugs and will need to be changed every 10k miles or so. But they're dirt cheap.

I was gonna say that too...I got AL's in the DD...might as well buy a 180* T-Stat when you get the plugs too...just ask for it at the auto parts store

can you explain the physics behind the colder t-stat? i know that a lot of people do this, and my friend that is in an engineering program told me that the idea behind it sounds like it should work but really doesn't. i just don't understand the whole system, and i would like to...thanks

These engines love cheap copper plugs. I run 606's since im mostly stock for now, soon will be 103's

Originally Posted by vailskier3

can you explain the physics behind the colder t-stat? i know that a lot of people do this, and my friend that is in an engineering program told me that the idea behind it sounds like it should work but really doesn't. i just don't understand the whole system, and i would like to...thanks

Keeps the engine cooler which reduces the temp of hot spots which in turn reduces knock. I noticed a big difference in knock when I went to a drilled 180*. You don't have to get a drilled, and it has its own set of pros and cons.

X2...plus a colder engine is a happier engine...well for a 180*...I got a 160* but that is just me...

so does it make the fan run more often, or it just allows more coolant flow?

Originally Posted by vailskier3

so does it make the fan run more often, or it just allows more coolant flow?

It opens at a cooler temperature. It does not affect fan operation.

One thing to note about a colder happier engine. Gasoline is most efficient at 195*, thus that's why cars run with 195. If you want efficiency, you want a hotter temp. If you want HP, you want colder. I would guess you want HP, so go with the 180*. I ended up putting a 195* back in my GP because it's my DD. My Impala has a 180*.

I still got 33MPG on the highway with a 180*. I don't see how it affects efficiency. I understand the theory, but just can't see it in practice.

so should i side gap these AL 605's, and should i do wires while i'm at it, or just change the plugs. my baby just changed over 40k today, and i'm pretty sure she could use new plugs. i don't really see how new wires could make THAT much of a diff, but since i'm a noob i thought i'd ask...

thanks guys, and sabre CONGRATS ON THAT BOOST!
in about a year or two i hope to add that lovely mod to my sig...

I have 605 coppers in my 99 grand prix 3800 and it runs well. However, in my opinion it ran better on NGK TR55 spark plugs. They are roughly the same heat range TR55~Autolite 605. Regular gapping around .055 to .060 should be good.

anyone done the side gap with AL605's? i'm curious if you notice a difference not necessarily with performance but KR. i don't have any way to scan for it, but i assume that if other people get good results, then i would as well. just curious...