Does anyone have one of these or any comments on it? I was thinking about getting one. I have the Spohn one now, but I want to use Hooker Super Comps so I have to use the factory crossmember to retain some ground clearance.

Any one have any pics of one installed?

Thanks

Steve

 

Depending on how much power you're putting out you may prefer to stick with the Spohn or another model that lifts on the frame. Lifting on the tranny can result in structural failure of the tail housing. Just something to think about.

 

I have tought about that and I agree to a point, however, there are some 9 and 10 second cars out there using the stock torque arm or ones mounted to the trans tailshaft.

I was curious is anyone had one of these and what they thought about it.

 

OK the TA does not lift the car. It's too long. If that was the only thing holding the rear suspension, and you hooked up all the way 0 slip on the tires in first gear with 3.73s you would have 900 lbs pushing on the trans if you where making 400 ft-lbs. Take into account that you have LCAs handling a lot of load that 900 lbs. drops way down to 300 lbs. Now take into account slip that's a max 250 lbs pushing on the end of the bar. The reason it is so long is so it doesn't take a lot of force to keep the pinion from rotating back. Aftermarket pieces just take a lot of flex out of the TA and give you pinion angle adjustment.

[This message has been edited by ATOMonkey (edited August 17, 2001).]

 

Ladder bars do the same thing as the torque arm but don't rely on a LCA. Ladder bars are only 33" long so you don't really need the length.

------------------
Follow my racing progress on Stephen's racing page
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87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block

Best ET on a time slip: 11.242 altitude corrected to 10.89
Best MPH on a time slip: 121.52 altitude corrected to 125.89
Altitude corrected rear wheel HP: 497.9
Best 60 foot: 1.546

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

It's not a static problem. There's at LEAST 3 times the static force in a dynamic scenario if not more. Cars are dynamic. You simplified the problem so far that your results are bogus. Also, the tail housing would likely break from fatique due to the contant up/down cycling of the force from the torque arm. This is even more of a concern since aluminum fatigues quickly.

 

I understand that dynamic loading is much higher than static loading due to the nature of impacts. However, the dynamic load is applied for a very short time therefore possibility of failure from dynamic loading is reduced. Also, tailhousings do not crack from torque arms, they crack from excess torque delivered by the transmission along with cycles applied to it. I'm sure you're aware that aluminum will fail because it has no peak cycle limit like steel. Many vehicles that do not come equiped with TAs also fail tailshaft housings.

I also agree that mounting it to a location other than the trans would also be advantageous as that point would not move as much as the transmission. As for it being a necessity to move the TA mounting position I will have to disagree.

Yes you will reduce the total amount of stress being applied to the tailhousing by moving it, but I believe that the stresses delivered by the output shaft far outweigh that of the TA.