Driveshaft Safety Loop Q's

[intocarss]

You have to follow the rules. But in reality an X pipe will keep the DS from hitting the ground..How can the DS get passed the X

[TheJDMan]

Originally Posted by intocarss

You have to follow the rules. But in reality an X pipe will keep the DS from hitting the ground..How can the DS get passed the X

An X pipe MIGHT keep the drive shaft from hitting the ground or, more likely, the DS would simply rip the exhaust out from under the car. Regardless, the X pipe would do nothing to prevent the shaft from tearing through the floorboard. In any case an X pipe would never be considered an alternative for the DS loop by any santioning body.

[67Rally]

I still need to see if I want to connect the loop to my subframe connectors or run it straight back off the transmission mount.

But, if I ran it straight back from the trans mount, would the NHRA view two 1.5"x1/4" pieces of steel running parallel, but not connected to each other as good as one 2"x1/4" piece of steel. The ONLY reason I ask is that I already have some 1.5"x1/4" steel stock lying around. The loop itself would be 2"x1/4", and the plate that bolts to the trans would be something like 4"x3"x1/4"

Forgive my Microsoft Paint sketch. If I run a DS loop off the trans mount, this would be a top view with the transmission on the left of the picture. The DS would pass through the loop and out to the right.

[intocarss]

Originally Posted by TheJDMan

An X pipe MIGHT keep the drive shaft from hitting the ground or, more likely, the DS would simply rip the exhaust out from under the car. Regardless, the X pipe would do nothing to prevent the shaft from tearing through the floorboard. In any case an X pipe would never be considered an alternative for the DS loop by any santioning body.

I was never saying to use the X pipe in place of a DS loop

[gevette]

Let me give you my 2 cent experience with d-loops. Drag racing in the lat 80's I broke the front yoke at about 75 mph. It totally demolished the turbo 400 tail shaft and broke the mount dropping the engine and trans down; it ripped the Lakewood flat strap style loop out of the floor (bolted in the stock floor pan of my 67 Firebird). Luckily I was not hurt just my wallet. In 2002 racing the same car I broke a driveshaft at 160 mph. I had a tubular front loop and it was destroyed. The shaft can openered the floor but a double frame rail next to my leg saved me from major bodily damage. 3/4 of the shaft exited out the back of the car. The noise was horrendous and after that day I installed a full 4130 enclosure that went from front yoke to the rear yoke in addition to front and rear loops. Do not skimp on the loop!

[67Rally]

Just an update...I ended up making a driveshaft safety loop out of 1/4"x2-1/2" steel plate. I got the solid loop from Jegs, and the rest is bar stock. I mounted this between the T56 mount and the trans itself. I thought I'd get lucky and make a straight run back, but the loop needed to be about 1" higher than the front mount.

Jegs loop:


Bar stock:




Basic shapes:


This is what I came up with:




Here it is installed:





Notice the hack job on the exhaust H-Pipe. That's not my work, and yes I paid to have that done. When I get back from Jamaica, it's going to a real exhaust shop and I'm having them install a Magnaflow X-Pipe, with new pipe running from the new headers to the existing Magnaflow mufflers.