Is this legal for a drive shaft safety loop ?

[85tr]

I welded a loop to the stock brace and reinforced it on the backside just wondering if I well get hell going through tech ?

 

[BBCTURBO11]

Wouldn't know but it looks damn good to me !
I think a saw one like that advertised on a g-bogy web site.


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[Major Nutz]

I've never had a tech look for a loop!

 

[85tr]

Neither have I running as fast as 12.5's but for a local buick meet we are going to a track that checks every car faster than 13.99 and I would hate to miss the turbo thunder event because of a safety loop.
Thanks for the replies guys.

 

[QwikStop]

That's what I'm going to do. Looks real nice and should be acceptable as a bolt in safety loop, I see no difference in this and one your able to buy via any vendor. In the event that you have a ujoint failure the loop is suppose to surround the drive shaft and keep it from falling and digging into the pavement preventing the vehicle from catapulting forward.

 

[pacecarta]

nhra wants it to be constructed of minimum 1/4" thick steel and minimum 2" wide and mounted no more than 6" from the transmission ujoint , stock location is fine but ..
although not specified the attachment points should be through 1/4 steel, although the loop looks fine it appears the loop isnt welded to the base metal only to the thinner metal of the original brace (thats a floor brace by the way meant to prevent sag) , and the lower steel isnt extended to the mounting holes area , it could be torn apart and away and become useless in a ujoint failure
heres the rule
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 minimum thickness and 2 inches wide, or 7/8-inch x .065-inch welded steel tubing, securely mounted and located within 6 inches of the front universal joint for support of the driveshaft in event of U-joint failure.

as to when they want a loop ,
Driveshaft loop required on all cars running 13.99 (*8.59) or quicker and utilizing slicks; except vehicles running 11.49 (*7.35) seconds or slower equipped with street tires.

heres link to general rules 2010 which havent changed
http://www.nhra.com/UserFiles/file/Unleashed/2011 NHRA Rulebook General Regulations Section.pdf

 

[QwikStop]

nhra wants it to be constructed of minimum 1/4" thick steel and minimum 2" wide and mounted no more than 6" from the transmission ujoint , stock location is fine but ..
although not specified the attachment points should be through 1/4 steel, although the loop looks fine it appears the loop isnt welded to the base metal only to the thinner metal of the original brace (thats a floor brace by the way meant to prevent sag) , and the lower steel isnt extended to the mounting holes area , it could be torn apart and away and become useless in a ujoint failure
heres the rule
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 minimum thickness and 2 inches wide, or 7/8-inch x .065-inch welded steel tubing, securely mounted and located within 6 inches of the front universal joint for support of the driveshaft in event of U-joint failure.

as to when they want a loop ,
Driveshaft loop required on all cars running 13.99 (*8.59) or quicker and utilizing slicks; except vehicles running 11.49 (*7.35) seconds or slower equipped with street tires.

heres link to general rules 2010 which havent changed
http://www.nhra.com/UserFiles/file/Unleashed/2011 NHRA Rulebook General Regulations Section.pdf

Damn good info, i guess a safety loop could be constructed and bolted in the factory location dont you think?

 

[pacecarta]

or.... you could buy one from fullthrottle , gbodyparts or metco that bolts in place of the stock brace

http://metcomotorsports.com/proddetail.asp?prod=MDL2000

 

[QwikStop]

Cool, didnt realize they sold them that way, thats what ill do, thanks

 

[StageII86]

In my opinion, the metco is the best choice for our cars because it is totally round. The other more "squared" loop designs I've had DS interference problems with.

 

[85tr]

Pacecarta thanks for all the input ! the steel is thick enuf and there was plenty of penetration to connect the top loop to the bottom plate . I guess I will pick up some more flat stock and weld the bottom plate across the mounting holes and connect all the short passes together. The track I am running at will not let any car run faster than 13.99 without on no matter the tire.

 

[coach]

I think if you add plate to the bolt hole areas you'll be fine. The loop is strong, but it would rip the bolts right thru the thin metal if it let loose.

 

[85tr]

That was the plan but I made this out of scrap I had lying around and didn't have quite enuf so I half assed it. Thanks for the help and opinions everyone.

 

[SS/GN]

I have one like that and was told it was ok. I actually made a couple before you could buy them. If any one is interested I have one left $30 with factory hardware.
Thanks

 

[turbofabricator]

I run a drill and tap the factory inserts to 3/8-16 so I can use better stronger bolts. The factory bolts are 8mm x 1.25. And are too short for good thread engagement with 1/4" steel. At a minimum be sure to use longer 8mm bolts. I had a friend blow a trans up many years ago and it busted the drive shaft in half which BEAT through the car body and ripped the threads out of the nutplates in the body (because he used the short bolts) and it twisted the safety loop into a pretzel. That convinced me to step up to a stronger 3/8" bolt in every car I put a loop in. It is best to weld it to the cross member. However, he is the only one I know that has lost a driveshaft like that in a Buick. The trans builder pumped the line pressure to the moon and it literally blew the case apart.