Broke my torque arm
search around a little, the eddy is known to break under power, i have a BMR trans mounted piece and it was a night and day difference over stock. i've seen broken UMI ones where the mount goes on the trans as well
Ok, I found these...
edelbrock
http://store.summitracing.com/partde...5&autoview=sku
UMI
http://store.summitracing.com/partde...5&autoview=sku
edelbrock
http://store.summitracing.com/partde...5&autoview=sku
UMI
http://store.summitracing.com/partde...5&autoview=sku
vs. 
was wondering why I'd went with BMR 
and this 
for the below poster to get the stress off the A4's tailshaft Last edited by ScrapSilicon; May 21, 2009 at 01:04 PM.
Wow, this is gonna get more expensive than I thought. I cant find a stocker near me so I guess Im gonna bite the bullet and get an adjustable TA. Id like to keep it tranny mounted due to my car being lower on power, under 400 ponies, and to keep cost down. I just cant spend 400-600 bucks on a chassis mounted torque arm right now.
What would you guys use?
What would you guys use?
What happened?
I don't think so. You can get a torque arm and then a drive shaft loop that bolts to the cross brace mounts, but I don't think you can attatch the two together? Not real positive on that. Just for more FYI, if you get the cross brace mounted torque arm you can get a drive shaft loop on the torque arm so now you are killing three birds w/ one stone. ?
?it bowed in the middle and wrapped around the driveshaft
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Verdad Gallardo Ok, I decided to go UMI, its 50 bucks cheaper than the BMR and Im on a strict budget to get my car on the road. Pics above steered me way away from edelbrock suspension parts. When my car actually makes a little power Ill get the relocation bracket.
Thanks for all the replies guys.
Thanks for all the replies guys.
TECH Regular
Joined: Dec 2005
Posts: 444
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From: Kailua-Kona, HI
What you've stated is an interesting theory and all, however the pivot point between the drive shaft and yoke are not compromised no matter how into or out the chassis the differential sits. That is because the torque arm to differential is a fixed point. The only part of the differential, drive shaft and torque arm that changes angle is at the torque arm and tranny mount. Think about it. If what you said was correct the pinion angle would be changing constantly during normal suspension travel (ie over every bump/dip in the road).
The only time the pinion angle will change (and hopefully in a very minuscule fashion) is when there is extreme load (ie shock to the drive train) on the differential which forces the diff. in an upward fashion. This is where stress fractures can take place with the stock stamped steel torque arm which inevitably leads to breakage.
I blame wheel hop more on the angle of LCA's rather than pinion angle.
The only time the pinion angle will change (and hopefully in a very minuscule fashion) is when there is extreme load (ie shock to the drive train) on the differential which forces the diff. in an upward fashion. This is where stress fractures can take place with the stock stamped steel torque arm which inevitably leads to breakage.
I blame wheel hop more on the angle of LCA's rather than pinion angle.
Actually the torque arm to the differential is NOT a fixed point. It is fixed at the axle mounting point but it is not at the tailshaft of the trans, otherwise the rear axle would not be able to move at all.
Remember? There is a crappy rubber bushing in the torque arm mount on the rear of the tranny? Well when the car is lowered, it changes that angle right there at that point and also changes your pinion angle. That bushing allows a small amount of movement up, down, and forward and backward. When you buy an aftermarket adjustable TA, most often the mounting points will be fixed but it will have a slider on it for this same type of movement.
You can call it a theory all you want, but you are talking to someone who has measured the angle at stock ride height, measured it after lowering, and then set it to the desirable setting after buying an adjustable TA.
I know for a fact that lowering the car alters the pinion angle.
It is simple geometry really, no question about it.
The wheel hop comes from the yoke of the rearend pointing up under load as you mentioned, and when the pinion angle is set correctly it will do the opposite, turning the yoke towards the ground resulting in bite and traction.
Lowering the car will have an effect on instant center as well as pinion angle.
Actually the torque arm to the differential is NOT a fixed point. It is fixed at the axle mounting point but it is not at the tailshaft of the trans, otherwise the rear axle would not be able to move at all.
Remember? There is a crappy rubber bushing in the torque arm mount on the rear of the tranny? Well when the car is lowered, it changes that angle right there at that point and also changes your pinion angle. That bushing allows a small amount of movement up, down, and forward and backward. When you buy an aftermarket adjustable TA, most often the mounting points will be fixed but it will have a slider on it for this same type of movement.
You can call it a theory all you want, but you are talking to someone who has measured the angle at stock ride height, measured it after lowering, and then set it to the desirable setting after buying an adjustable TA.
I know for a fact that lowering the car alters the pinion angle.
It is simple geometry really, no question about it.
The wheel hop comes from the yoke of the rearend pointing up under load as you mentioned, and when the pinion angle is set correctly it will do the opposite, turning the yoke towards the ground resulting in bite and traction.
Lowering the car will have an effect on instant center as well as pinion angle.
Remember? There is a crappy rubber bushing in the torque arm mount on the rear of the tranny? Well when the car is lowered, it changes that angle right there at that point and also changes your pinion angle. That bushing allows a small amount of movement up, down, and forward and backward. When you buy an aftermarket adjustable TA, most often the mounting points will be fixed but it will have a slider on it for this same type of movement.
You can call it a theory all you want, but you are talking to someone who has measured the angle at stock ride height, measured it after lowering, and then set it to the desirable setting after buying an adjustable TA.
I know for a fact that lowering the car alters the pinion angle.
It is simple geometry really, no question about it.
The wheel hop comes from the yoke of the rearend pointing up under load as you mentioned, and when the pinion angle is set correctly it will do the opposite, turning the yoke towards the ground resulting in bite and traction.
Lowering the car will have an effect on instant center as well as pinion angle.
TECH Regular
Joined: Dec 2005
Posts: 444
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From: Kailua-Kona, HI
Did I mention that I hate Torque Arms?
I've used multiple aftermarket ones, and they are all noisy unless they are trans mounted.
Tunnel mount is the way to go, but the risk of damaging the trans is too sever for me.
The wheel hop comes from the yoke of the rearend pointing up under load as you mentioned, and when the pinion angle is set correctly it will do the opposite, turning the yoke towards the ground resulting in bite and traction.
There isn't. Perhaps he mistakenly put that and meant a transmission mounted torque arm which displaces the load onto the tail shaft of the transmission. Many f-bodies, especially those with greater torque have snapped tail shafts because of the extreme shock while launching running a tranny mounted torque arm which also runs a greater risk of pinion angle problems. It's like a LTCC vs. opti. Like the LTCC having to depend on an opti, with a tranny mounted torque arum you still have to rely on the stock locations of the transmission mount, torque arm bushing and engine mounts to channel load to the chassis. A tunnel/cross brace torque arm is the absolute way to go since it transfers load to the chassis w/out having to be channeled through a bushing and transmission mount.
Last edited by SS RRR; May 22, 2009 at 12:56 PM.
TECH Regular
Joined: Dec 2005
Posts: 444
Likes: 0
From: Kailua-Kona, HI
There isn't. Perhaps he mistakenly put that and meant a transmission mounted torque arm which displaces the load onto the tail shaft of the transmission. Many f-bodies, especially those with greater torque have snapped tail shafts because of the extreme shock while launching running a tranny mounted torque arm which also runs a greater risk of pinion angle problems. It's like a LTCC vs. opti. Like the LTCC having to depend on an opti, with a tranny mounted torque arum you still have to rely on the stock locations of the transmission mount, torque arm bushing and engine mounts to channel load to the chassis. A tunnel/cross brace torque arm is the absolute way to go since it transfers load to the chassis w/out having to be channeled through a bushing and transmission mount.
I would rather run a trans mounted unit for ride quality and noise issues, but the tunnel mounted unit provides greater traction and takes the stress off of the trans tailshaft.
No biggie, I thought that is what you meant. I was just tryin to clear things up so somebody don't read this thread and think tunnel mt. tq arms are hard on trannys.
Well I went up to summit and they dont stock UMI, it comes straight from the factory. I went ahead and got the BMR. I like how it has the tube end instead of the thin flat one on the tranny side.
Gonna put it on in the morning and see if it cured my horrible wheel hop.
Gonna put it on in the morning and see if it cured my horrible wheel hop.
http://www.exoticperformanceplus.com...php?service=58
Here is a link to what happened to one guys torque arm who limped his car over to my shop. His rear springs almost fell out. Bob
Here is a link to what happened to one guys torque arm who limped his car over to my shop. His rear springs almost fell out. Bob