NHRA approved driveshaft loop ?

[SCrazy]

Keith: Thanks for the info and the sanity check....I definitely be making an upgrade.

Originally Posted by VicRattlehead

that is NOT NHRA legal. here is what it says.......

In place of a crossmember, in the vicinity of the front universal joint, all cars in competition using open driveshafts, must have a retainer loop 360-degrees of enclosure, 1/4-inch (6.35 mm) minimum thickness and 2-inches (5.1 cm) wide, or 7/8-inch (22.2 mm) x .065-inch (1.65 mm) welded steel tubing, securely mounted and located within 6-inches (15.2 cm) of the front universal joint for support of the driveshaft in event of U-joint failure



notice the red piece of driveshaft in the lower left side of the picture...



http://www.competitionplus.com/index...at-htranspired

this right here is why i believe NHRA should make EVERYONE have 2 loops, one front one in the rear, and anything faster then 8.99's should have the tunnel. I was at the start line when Barb made this pass. this car is a brand new 120k chassis, was just finished in time for the nmra/nmca joliet race last month. there was nothing that showed that she was in trouble, even through everything, she kept that car right down the middle of the track.

[CMac89]

I just finished putting one in today. It took a little bit of smoothing out with a flap disc on an angle grinder and I had to put a little more bend in a few spots, but for how cheap it was, it worked out well.

$20 from Jegs.

[Super XR7]

I also finished putting my loop in today. I am about ready for the event; just a few more things to do.

Mike

[Mike8675309]

that's a lot of nuts and bolts. I don't see any nyloc nuts either. Did you throw some loctite on those threads? Otherwise you may want to check them after the season to make sure none of them loosen up.

[CMac89]

The kit came with nuts, bolts, and lock washers. It has four pairs of holes, on each L-bracket to select which loop height you need.

[Mike8675309]

I personally do not use only lock washers in an application I would prefer never comes loose. They simply are not effective.
http://www.eng-tips.com/faqs.cfm?fid=1257

[CMac89]

They're not as effective as nylon lock nuts are, but they certainly aren't zero. The spring like activity will serve as an added restraint as opposed to having nothing there. If it was only a washer with a crack in it, then that assumes there isn't any elastic memory in the washer itself. In the very least, it slows the rate at which the mechanical vibrations loosens the nut.

Anyways, I'll just keep an eye on it, regardless.

[Mike8675309]

Check out this video showing a standard nut turning off a bolt when under vibration. then the next one showing a standard nut with a spring (split) washer.
http://www.boltscience.com/pages/junkertestplainnut.htm
http://www.boltscience.com/pages/jun...ringwasher.htm

I'm not sure I would be confident in saying a lock washer is better than nothing. In fact, information at the site above states:

http://www.boltscience.com/pages/vibloose.htm

As a result, a rationalisation of the variety of locking devices used by such major companies has occurred. For example, conventional spring lock washers are no longer specified, because it has been shown that they actually aid self loosening rather than prevent it.

I'm not arguing that you shouldn't use them. Just trying to share some information I've dug up over the last couple years that I've found makes use of lock washers questionable. I've still used them in various applications, often times just from the idea of peace of mind, even though info I've seen says that is the opposite of what they give you.

[CMac89]

It's cool, Mike. I looked at it as a conversation.

That's interesting stuff. Are the vibrations of the same magnitude in each test? I'm also a skeptic towards the split washers, but I have never assumed their effectiveness to be null. Thinking about it actually makes me agree with accelerating loosening of the nut or bolt. I give thought to many petty things, but not locking fasteners. Obviously nylocs aren't skeptical, once they're away from heat, at least.

They're annoying to tighten, though.

[Mike8675309]

yes, vibrations the same for each test. The company has something they call a junker which is a machine that is able to create shearing forces to duplicate vibrations over time but within a much shorter period. they've tested a number of fasteners and locking devices.

Their double nut test was pretty interesting as well.
http://www.boltscience.com/pages/twonuts.htm

[super red91]

Funny I read all this, I also just installed a Summit Racing brand loop just like the one Casey pictured. Had an issue with it hitting on my exhaust under load, nothing a large pry bar didn't help.

Mine however did not come with lock washers, just serrated nuts which had the washer built it. I'm not to sure how good I feel about that but I plan on checking them after awhile.

[super red91]

Also, just to poke fun on Mike

I read your sig 93 SC - before: 275hp/343tq 13.709 @ 104.25 After: 441hp/462tq Best so far 13.449 @ 111.59

I think you need to spend more time at the track and less time researching fastener vibrational loosening.

[neverfastenough]

I need to install one on mine. Your car in canton? Mine is in AK right now.

[CMac89]

Originally Posted by super red91

Also, just to poke fun on Mike

I read your sig 93 SC - before: 275hp/343tq 13.709 @ 104.25 After: 441hp/462tq Best so far 13.449 @ 111.59

I think you need to spend more time at the track and less time researching fastener vibrational loosening.

Yeah...........dork!!

[Mike8675309]

Originally Posted by super red91

Also, just to poke fun on Mike

I read your sig 93 SC - before: 275hp/343tq 13.709 @ 104.25 After: 441hp/462tq Best so far 13.449 @ 111.59

I think you need to spend more time at the track and less time researching fastener vibrational loosening.

Considering the length of time i've been willing to live with a non-functional trac lock it is important that other parts I've installed don't fall off waiting for me... thus the research.