240Z2NV Posted December 29, 2007 Share Posted December 29, 2007 After using the Search function, I was unable to get my specific question answered, so here it is: What is the specific location for a properly installed loop? [e.g. more towards the front of the shaft, dead center, or toward the diff] Thanks.... Quote Link to comment Share on other sites More sharing options...
elks240 Posted December 30, 2007 Share Posted December 30, 2007 2.4 DRIVELINE ( Drive shaft loop 6 inches from the front U Joint) On any car in which the driver sits over or in back of the rearend center section, a suitable protective shield of .120-inch (3 mm) minimum thickness steel plate must be installed for those units with universal joints securely mounted to the rearend center section and the bellhousing adapter. Where possible, couplers are recommended in place of U-joints. For straight couplers, the minimum requirement is .063-inch (1.6 mm) aluminium which must contain an inspection cover for removal and inspection of the coupler, securely mounted to the rearend center section and the bellhousing adapter, or as noted in Class Requirements. 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 f or support of the driveshaft in event of U-joint failure. Recommended the loop be round rather than oblong to minimize loading on loop. Open drivelines passing any part of the driver's body must be completely enclosed in 1/8-inch (3.2 mm) minimum thickness steel plate, securely mounted to the frame or frame structure. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 30, 2007 Share Posted December 30, 2007 I'm placing mine in the middle of the driveshaft, but the reasoning is because the Z driveshaft is relatively short. A loop in the middle, if tight enough will guard for failure at either end, but I have an advantage: My entire drivetrain is solidly mounted, thus I can use a perfectly round loop that has only .200" clearance between it and the driveshaft tube. On those cars using rubber (or flexible) mounts, the clearance must obviously be larger, which will cause a little more ruckous should either joint fail. Quote Link to comment Share on other sites More sharing options...
Guest TeamNissan Posted December 30, 2007 Share Posted December 30, 2007 You shouldn't just copy paste race rules with even listing a source. Or quotes for that matter....... 2.4 DRIVELINE ( Drive shaft loop 6 inches from the front U Joint) On any car in which the driver sits over or in back of the rearend center section, a suitable protective shield of .120-inch (3 mm) minimum thickness steel plate must be installed for those units with universal joints securely mounted to the rearend center section and the bellhousing adapter. Where possible, couplers are recommended in place of U-joints. For straight couplers, the minimum requirement is .063-inch (1.6 mm) aluminium which must contain an inspection cover for removal and inspection of the coupler, securely mounted to the rearend center section and the bellhousing adapter, or as noted in Class Requirements. 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 f or support of the driveshaft in event of U-joint failure. Recommended the loop be round rather than oblong to minimize loading on loop. Open drivelines passing any part of the driver's body must be completely enclosed in 1/8-inch (3.2 mm) minimum thickness steel plate, securely mounted to the frame or frame structure. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted December 31, 2007 Share Posted December 31, 2007 Kind of depends on your set-up as well. The rules above say near the front probably because if the car is rolling the driveshaft is spinning. If you lose the rear u-joint you can simple put it in neutral and it will stop spinning. Also depends on how it's joined. For example my old Datsun comp 5-speed used a bolt-on driveshaft at either end where the T56 used a slip in front. On the datsun tranny your screwed either way but for the T56 if you lose the back end the driveshaft will simply fall out. If you lose the front it will flail everywhere and if your luck hit the ground and launch you. In this situation you definitely want it near the front and I would consider making it large enough so that the driveshaft could slip out if the rear u-joint failed. That's just my initial thoughts as I have yet to install one. More discussion is welcomed as I'm about to this point in my build. Cameron Quote Link to comment Share on other sites More sharing options...
tube80z Posted January 2, 2008 Share Posted January 2, 2008 If you lose the front it will flail everywhere and if your luck hit the ground and launch you. In this situation you definitely want it near the front and I would consider making Don't you watch Mythbusters!? Quote Link to comment Share on other sites More sharing options...
heavy85 Posted January 2, 2008 Share Posted January 2, 2008 Don't you watch Mythbusters!? "They decided to slow car down to 15mph. This plan was successful -- the driveshaft hit the hole square-on and popped the car up about 1-2 feet, driving the driveshaft up through the trunk. It wasn't particularly dramatic, and not nearly enough to qualify as "pole vaulting." OK so maybe it wont 'launch' you but your day would still suck. Cameron Quote Link to comment Share on other sites More sharing options...
elks240 Posted January 4, 2008 Share Posted January 4, 2008 You shouldn't just copy paste race rules with even listing a source. Or quotes for that matter....... This is from the 2007 NHRA general rules page 206-207 there is even an illistration for you. Are you happy now . Quote Link to comment Share on other sites More sharing options...
blueovalz Posted January 4, 2008 Share Posted January 4, 2008 I am! I had no idea what the quote applied to. It does my heart good to know that there are folks concerned for my happiness. :biggrin: Quote Link to comment Share on other sites More sharing options...
240Z2NV Posted January 6, 2008 Author Share Posted January 6, 2008 My appreciation goes out to all of you who gave thought to this. I will mount it toward the front. Kind of my plan; but, my mechanical insecurities begged for support [agreement or consensus]. Thanks! Quote Link to comment Share on other sites More sharing options...
Dudeboy Posted January 6, 2008 Share Posted January 6, 2008 A drive shaft loop is one of the next items on the list I need to get as well. Has anyone ever utilize two drive shaft loops ? What is the gurantee of one loop bolted in the right place for security ? But maybe bolt in two ? Quote Link to comment Share on other sites More sharing options...
240Z2NV Posted January 6, 2008 Author Share Posted January 6, 2008 They are pretty low-tech with regard to the possibilites of "failure". I got a generic Summit Racing unit. One could easily be made, and I have seen better designs; but, this was a purchase very, very early in the project, and I was just going crazy buying up all kinds of $hit at the beginning. My enthusiasm created many pitfalls. Didn't follow the best advice that I have ever gotten on this project [Tim240Z], and that was "buy items AS YOU GO, WHEN you NEED them". If you follow in my footsteps [hopefully not] you will end up with TONS of boxes filled with parts, and have to repeatedly search for stuff as the need arises. It is difficult to stay organized, and you will very likely overspend. Quote Link to comment Share on other sites More sharing options...
elks240 Posted January 7, 2008 Share Posted January 7, 2008 A drive shaft loop is one of the next items on the list I need to get as well. Has anyone ever utilize two drive shaft loops ? What is the gurantee of one loop bolted in the right place for security ? But maybe bolt in two ? There is nothing wrong with putting in 2 loops, it will just help keep the rear from slinging around if you bust the rear U-joint. I have broken the rear at about 40 MPH and it was loud and banged up the bottom of my car till it came out and tranny fluid went everywhere. So there is nothing wrong with additional insurance. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.