Yellow Bullet Forums banner

New NHRA "header tether" rule?

68K views 323 replies 129 participants last post by  JL Performance 
#1 ·
What is up with this rule? I have 2 welded on tabs on each collector and tabs on matching header primary tubes on each header and they are bolted on with FOUR 1/4 inch bolts. Is this not sufficient for a POSITVE collector retention device? I could even weld on tabs to the other 4 remaining tubes WAAAAY cheaper than the 200.00 to 250.00 bucks for the NHRA "APPROVED" abortion collector retention device! HERE: http://www.collectortethers.com/Collector-Tethers_c2.htm This is "REDICULUS" !!! I have a door car and have to take off the collector to install and remove tubes ONE at a time, so I can NOT weld the collectors on to get around this STUPID regulation! With 4 or even 8 quarter inch bolts my collectors would NOT come off even if I ""crashed"" at 150mph! WHAT IS IT WITH "NHRA"!!! Safety is #1 but this is a RIP!!!!!!:smt013
 
#134 ·
I cut and paste the following from the Class Racer Forum:

There is no SFI Foundation specifications or testing criteria for the tethers.
Therefore, I assume it is up to NHRA to approve any solution for compliance with the rule.

A similar design to the one they offer can use an aerospace band clamp that meets Military Specification MS21920.
There are several vendors for these clamps in various sizes:

http://www.herberaircraft.com/pdf/Ot...20bulletin.PDF

http://www.clampco.com/products/products.asp

As regards to the cable and ends, they can also be procured from a few companies and it would require the swaging crimping tool and gauge.
Some sources for the cable, ends and tools are as follows:

http://www.mcfarlane-aviation.com/Pr...?CategoryID=47

http://www.aircraftspruce.com/catalo...ntrolcable.php

For guidance on assembling, strength requirements and testing the cable, I suggest checking out the FAA Mechanics Handbook and read Section 2-41 of the handbook and on. The link for the handbook is as follows:

http://www.faa.gov/regulations_polic...frame_vol1.pdf

Additional specification, assembly and testing guidance can also be found at the following link:

http://thecableconnection.com/cable-specification.html

I believe if you document the cable assembly, show load testing that meets the FAA guidance and requirements as objective evidence, NHRA should approve it.
Control cable assemblies are used in commercial and private aircraft in a daily basis and I do not believe the threshold is higher for retaining a header collector in the event it comes loose.

They also claim a "Patent Pending", well the concept, system and design is not patentable. A patent search will show many of the same concepts and ideas with patents.
 
#139 · (Edited)
I too had some sticker shock when I initially seen these. So I researched the price myself using McMaster Carr. If a person uses what appears to be the exact same items it comes out to be $100-$120 (not including shipping or handling charges) to build a set of these yourself and that is if you already have the crimping tool. None of the pre-made assemblies use the same parts and if a person used a premade assembly of what looks like the same cable the costs goes up even more. And in the end you don't have a NHRA accepted piece. Of course it can be done cheaper or even much cheaper than that using lighter duty materials or non-stainless steel but it wouldn't be as nice or as strong not to mention the "NHRA Accepted" thing again... if it could even get NHRA's ok. I have no idea what NHRA's requirements are for strength for header tethers but these appear to be heavy duty looking compared to the way they could be built.

After adding the parts costs and labor of getting accepted, building them, packaging, the NHRA accepted collars and any other BS I personally don't think the price is un-acceptable. In the end it doesn't appear that there is any significant price gouging going on. Do I like it... hell no but I think the rule itself is unacceptable in its current form and it the real instigator of any discontent.

Header tethers.... I'm still on the fence but will probably just weld my collectors.

Scott
 
#147 ·
Mcmaster carr is usually he most expensive source for components. The stainless clamps can be easily bought in bulk for 2.50 a piece and the cables could be made and shipped for $60 for a pair using swivel style ends. Its designed to drag a maybe 2lb collector down the track, not hold the spaceshuttle down.

We control airliners with 1/8 cable. That says something. But even with 1/4 SS cable they can be fabricated for a very reasonable price.

But then again engineers didn't design these, and it shows.
 
#144 ·
- NHRA Accepted -

SECTON 20: GENERAL REGULATIONS, ENGINE: 1, 1.3 EXHAUST (Page 3) (2/4/2013) (7/16/2013)

All cars must be equipped with exhaust collectors

So according to this rule we are going to see collectors required on TF, and F/C as well? New ruling says ALL cars...

The rule itself does not bother me as much as the fact that it was initiated by racers to profit from fellow racers...
 
#146 ·
you guys are going to far with this , ho wmany tracks will actually enforce this ? i going to bet the only places where you will find this rule picked apart is at a divisional or national event . that said , how many guys actually have removable collectors ? im going to say 75% of use have collectors welded onto the header anyways .

some of you guys are just looking for some thing to complain about .

also , for the guys picking apart the pricing on the company making them , remember , they are running a business , they probably have alittle over head , and the packaging isnt free .....
 
#154 · (Edited)
I should be, if its a unibody car it's spot welded together. But it seems like mig or tig would be smarter, even if they are short tack beads.

Or maybe that was sarcasm...
 
#157 ·
The reason NHRA is doing the "NHRA Accepted" deal, is to make it easier on their tech guys. If we all make our own tether, then the Tech guys will have to climb under EVERY car and "inspect" it to make sure it will work. This was the easiest way to police it. Now, I still think it sucks, and I am most likely going to be welding my 6 month old stainless fab shops, but how else do you police this and the idiots that do not know how to do maintenance on their cars?
 
#173 ·
After looking at this... I will say I'm attaching the collectors to each primary with a 1/4 or 5/16 bolt... And will not be bothering with this. Other than a national event I highly doubt this will be looked at on a stock floor door car, dragsters, that would be a different story.

Zoomie style sould solve that though. I see alot of dragsters going to zoomie s in the near future
 
#175 ·
I know at my local track they won't look for it. I follow all the rules because i want to be safe i dont care what other people do i hope they are safe. I seen cars that shouldnt have past tech but they know the tech guy or gal.. So it looks like I have to get a set but it dose get old after while do this do that it only money right....
 
#177 ·
The rule is badly phrased. Multi-piece collector means a collector attached to a bunch of separate tubes -- yes, like the collectors for four tubes from one side of a v8. And yes, unless it's welded on, the rule states it needs a tether. In addition to the four bolts I already have -- with lock nuts, and that get checked all the time to be sure they're not loose...
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top