BMR Torque Arm Relocation.. higher or lower..?
06-25-2008, 08:00 PM
#1
BMR Torque Arm Relocation.. higher or lower..? Bit of a dilemma, should I mount the instant center higher or lower or just bust guesstimate to stock location?
Which is better for traction?
Which is better for traction?
06-26-2008, 12:08 AM
#2
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The instant center is a 2-dimensional measurement. When you mount the torque arm using the higher holes, you move the instant center forward and up. When you mount the torque arm using the lower holes, you move the instant center back and down.
The higher (and/or more forward) the instant center, the more weight transfer you'll get. The lower (and/or more rearward) the instant center, the less weight transfer you'll get. For a good launch, you want as much weight transfer as you can get without putting the car on the back bumper.
Unfortunately, the best instant center location depends on a number of factors. For example, a stick car usually likes a lower and longer (farther from the rear axle housing centerline) instant center while an auto trans car likes a higher and shorter instant center. Also, the bigger the tire, the longer the instant center should be.
How aggressive is your clutch? How stiff are the rear shocks set in compression? How stiff are the rear shocks set for extension? How are the front shocks set in extension? How sticky is the starting line? All these factors determine the best instant center location.
Fortunately, the BMR Torque Arm Relocation Bracket has multiple hole settings, so you can tune your suspension at the track.
Based on the info in your sig, I would recommend setting the torque arm with the bolts in the 3rd hole from the top. Then, go to the dragstrip and have some fun.
The higher (and/or more forward) the instant center, the more weight transfer you'll get. The lower (and/or more rearward) the instant center, the less weight transfer you'll get. For a good launch, you want as much weight transfer as you can get without putting the car on the back bumper.
Unfortunately, the best instant center location depends on a number of factors. For example, a stick car usually likes a lower and longer (farther from the rear axle housing centerline) instant center while an auto trans car likes a higher and shorter instant center. Also, the bigger the tire, the longer the instant center should be.
How aggressive is your clutch? How stiff are the rear shocks set in compression? How stiff are the rear shocks set for extension? How are the front shocks set in extension? How sticky is the starting line? All these factors determine the best instant center location.
Fortunately, the BMR Torque Arm Relocation Bracket has multiple hole settings, so you can tune your suspension at the track.
Based on the info in your sig, I would recommend setting the torque arm with the bolts in the 3rd hole from the top. Then, go to the dragstrip and have some fun.
06-26-2008, 07:35 AM
#3
So here's the setup at the moment suspension wise, only the springs are stock.
Stock Springs
Bilstein Shocks
35mm Front Swaybar
25mm Rear Swaybar
non-adjustable torque arm
LCA relocation brackets
Boxed LCA's
Panhard bar with panhard relocation
17x11 rims with 315 tires
track is usually not that sticky when I go.
I know the front swaybar hurts drag traction, but I love the way it handles and feels on the road as the car is primarily a street car and occasional drag.
So what you suggest is up and forward but I have a stick so down and away? kinda confused at that.
Stock Springs
Bilstein Shocks
35mm Front Swaybar
25mm Rear Swaybar
non-adjustable torque arm
LCA relocation brackets
Boxed LCA's
Panhard bar with panhard relocation
17x11 rims with 315 tires
track is usually not that sticky when I go.
I know the front swaybar hurts drag traction, but I love the way it handles and feels on the road as the car is primarily a street car and occasional drag.
So what you suggest is up and forward but I have a stick so down and away? kinda confused at that.
06-26-2008, 09:11 AM
#4
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So here's the setup at the moment suspension wise, only the springs are stock.
Stock Springs
Bilstein Shocks
35mm Front Swaybar
25mm Rear Swaybar
non-adjustable torque arm
LCA relocation brackets
Boxed LCA's
Panhard bar with panhard relocation
17x11 rims with 315 tires
track is usually not that sticky when I go.
I know the front swaybar hurts drag traction, but I love the way it handles and feels on the road as the car is primarily a street car and occasional drag.
So what you suggest is up and forward but I have a stick so down and away? kinda confused at that.
Stock Springs
Bilstein Shocks
35mm Front Swaybar
25mm Rear Swaybar
non-adjustable torque arm
LCA relocation brackets
Boxed LCA's
Panhard bar with panhard relocation
17x11 rims with 315 tires
track is usually not that sticky when I go.
I know the front swaybar hurts drag traction, but I love the way it handles and feels on the road as the car is primarily a street car and occasional drag.
So what you suggest is up and forward but I have a stick so down and away? kinda confused at that.
06-26-2008, 04:47 PM
#6
there's a definite change in the feel of the car...
I'm not sure if it's positive or not though, have to test at the track
on the install.
Found out the hard way that I had to install the bushing first in the bracket before attaching it to the torque arm. M6 transmissions leave 0 space to tighten up the bolts.
Had to grind a bit of metal and bushing material off the back, my custom true duals had 1 pipe touching the back plate and a bit of the torque arm bushing.
Other than that, went fairly straight forward. The feel is different, but I can't pinpoint how it's affect my launches at the moment.
Lost the ability to mount up my rear O2 sim which had a mount spot in the stock bracket. Zip ties work wonders
The fact I could mount the torque arm up or down made little difference in my setup. I had to use the very top because of the bushing being relocated a bit back and was touching the exhaust now.
I'm not sure if it's positive or not though, have to test at the track
on the install.
Found out the hard way that I had to install the bushing first in the bracket before attaching it to the torque arm. M6 transmissions leave 0 space to tighten up the bolts.
Had to grind a bit of metal and bushing material off the back, my custom true duals had 1 pipe touching the back plate and a bit of the torque arm bushing.
Other than that, went fairly straight forward. The feel is different, but I can't pinpoint how it's affect my launches at the moment.
Lost the ability to mount up my rear O2 sim which had a mount spot in the stock bracket. Zip ties work wonders
The fact I could mount the torque arm up or down made little difference in my setup. I had to use the very top because of the bushing being relocated a bit back and was touching the exhaust now.
