The nhra rulebook on http://www.nhrssportcompact.com was that to runn 1.99 and quicker, you need all-metal screw-in valve stems.

What's a screw-in valvestem? I took my slicks to discount tire this morning to have them mounted and I requested an all-metal valvestem. Are all "all-metal" valvestems "screw-in"? If not, does anyone have a pic/some info on a screw-in valvestem?

 

anyone? I gotta find out before I go back to the tire shop tomorrow to pick up my slicks and bogarts!

 

Here's a regular rubber valve stem on the top row.
The metal, screw-in ones are in the middle row. The bottom are truck stems.



They mounts from the inside of the rim like the rubber one, and are threaded with a nut on the outside. The rubber o-rings seal it. I guess at 100+mph, the last thing you need is a rubber valve stem failing on ya

I use the low profile metal ones 17-559 (they're nice shiny chrome too! )

I get mine all day long from PepBoys or Autozone/Advanced Auto for about $3 for a pair.

Print these pictures out and take them to that stupid tire place.

And while we're at it.. this is what "stick-on weights" look like.

It seems like tire places don't know what they are.

 

Awesome... preofessornate, you're my hero.

The middle row is all screw-in ones? Even 17-559 (it doesn't appear to have a bolt on the bottom to me). I ask because it looks to me like that's the ones they put in.... so I should tech ok at the track with 17-559?

Thanks again for your awesome post

 

Yeah, 17-559 is like a t-bolt (or a bolt without a hex head.) You can see the nut in the middle of it. Actually in the picture, the second, optional oring is sitting on top of the nut. That one isn't used (just depends on the hole size).

If it's metal on the outside, and it's mounted solid (you can't wiggle it) then it's probably the right one.

Have fun at the track!