PDA

View Full Version : Do I need rim screws or tubes?



IMSHAKN
09-09-08, 11:30 PM
Currently I've got a set of 15 8.5" welds with a set of 26x10" MT ET Drags mounted up. Anyone have any opinions on whether I should run screws, tubes, or both? Right now I'm running NA so I'm curious if either are needed. Some say I need them others say they've done it for years the way I've got it set up. Opinions please.

AZSonicSnake
09-10-08, 01:51 AM
i ran on a set of et drags with neither screws or tubes. granted i feel far safer with both of them, but then again, i am wackin em from 6k+. i seriously think you will be fine on them. just don't get too low with the pressure. keep it about 14psi.

IMSHAKN
09-10-08, 11:51 AM
That was the plan, figured that keeping them around 13-15psi would keep them a bit more stable on the top end since the rim is a tad bit more narrow than M/T recommends and that I'd lower the chances of breaking the bead. I'll put a mark on the tire and rim and see just how much the tires are moving around.

Anyone else have opinions on this?

TorchedMach1
09-10-08, 01:14 PM
I ran my ET Drags for a while without tubes or screws. You should be okay on the motor, but definitely need to get it done before you have a power adder. After seeing a video of my car launching on the bottle, and seeing how wrinkled the tires get, I won't run my ET Drags without screws and tubes again. But I was cutting a 1.4x 60'.

AZSonicSnake
09-10-08, 07:30 PM
yeah, if mine do this, i would love to see a shot like this of jay's tires on a launch... :woot1:

http://farm3.static.flickr.com/2039/2214970605_3159aa0f6a_o.jpg

IMSHAKN
09-10-08, 07:36 PM
Well I suppose after the 26th we'll see if I need them launching at 6k...god I'd hate to break a bead and have a tire go...hmm. I should be good though I hope. :redface:

5.0Stanger
09-10-08, 09:18 PM
I've run without tubes and screws. I've, also, run with tubes and screws.

It's not a 'If I have this much power, I should run the tires like this, thing.' If you think you'll be safewith no tubes and no screws, then run it like that. I've run insanely low pressures with no tubes. I've never had a problem. That doesn't mean the next guy will treat his tires exactly like I do and fare the same. The bias-ply construction of the tire, itself, causes it to feel unstable at speed. That could be so, if you run radial tires on the front with the slicks on the back. The two types of tires always fight against each other.

The whole deal with the tubes is to make the whole contact patch of the tire touch the track. During the launch, having no tubes will allow the middle of the contact patch to curl inward (toward the inside of the wheel). The screws are there to keep the tire from changing it's position on the wheel. This is important, because running a tube with no rim screws can allow the tire to move the tube. If the tube moves far enough, you could end up with a broken valve stem. Thus, causing a serious accident, should it happen at speed.

If you're going to run sans-tube, find the air pressure your car runs it's best 60-foot time at and make sure you check the tire pressure before each run. That's what I've done and had no trouble.

If you're going to go the whole tube/rim screw route, make sure your wheels have the valve stem holes where a race tire tube's valve stem will come through without the tube being pulled to one side of the wheel. Trust me, most DOT tubeless wheels have the stem located so it's easy to fill the tire, not for keeping the a race tube centered on the wheel. Ignoring this point will cause your slicks to wear unevenly, possibly causing a leak or worse. Yes, I've done this, as well. Also, remember to put a little liquid dish soap (Dawn, etc.) in with the tube. This will help keep the tube from sticking to the tire. I've heard of putting baby powder in with the tube, too.

I hope this helps you make an informed decision. I'm not trying to come off like a know-it-all or some sort of tool. I'm just giving my insight, based on experience. Good luck.