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

 

go umi go w/byunspeed http://www.byunspeed.com/product_inf...oducts_id=3305 the mount or the actual arm ?<edit> ah.. vs. was wondering why I'd went with BMR and this for the below poster to get the stress off the A4's tailshaft

 

If you go to the track at all then I would go more for the cross brace mounted torque arm rather than the tranny mount. Reason being is no matter how little torque you have really doesn't matter, but shock to the drive train which stresses/breaks components.

 

I can get a tranny mounted TA and then later get a crossbrace for it cant I?

 

dont waist ur money on the Edelbroke arms they are weaker than stock

 

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.

What happened?

 

well, it wont be a short tunel mount but you can use the trans crossmember mount that is pitured above with a full lenth tq arm, and it will be off the trans and adjustable. i built my own mount for my stock arm like that one after breaking the tailshaft twice...

it bowed in the middle and wrapped around the driveshaft

 

you can get the relocation brkt to get it off the A4 tailshaft later...I'm slow at posting whilst eating nachos

 

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.

 

I went with the UMI trans mount TA and later added the relocation crossmember! Before that I had the tunnel mount TA and absolutley hated it for a street car.

 

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.

 

Even on a stock torque arm I wouldn't use the crappy stock rubber bushings. I swapped mine out for a poly bushing long ago. Soon I will install my adj tunnel mount TA. That's the only way to go IMO.

 

If your car has a stock stamped TA and is also lowered, you'd be better off with the rubber bushing. Otherwise it will bind like crazy with a poly one, and will probably break the TA sooner than later.

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.

 

You misunderstood me. You need to think about the torque arm, drive shaft and differential traveling up and down as one. The only pivot points for those three components are at the front with the drive shaft u-joint and tranny to torque arm mount. Yes I do agree that if there is excessive play at the torque arm/tranny mount the pinion angle will be compromised, but I am not typing about that. An entirely different force comes into play to make that happen. My point is it doesn't matter at what position the differential is in whether up into the chassis or down at full travel, the pinion angle will stay fixed as long as the torque arm to differential position is not compromised by flex.
Okay.. you say it "points up." What causes the violent reciprocation of the entire differential housing? Could it be it has absolutely no load points because the lower control arms are sitting at a higher point at the differential mounts than the chassis mounts and are pretty much useless transferring load?

 

How do you run the risk of damaging the trans by running a tunnel mount tq arm? I run one and it seems there is alot less stress on the trans now!

 

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.

 

Yeah, thats what I meant.

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.

 

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