Are there any real diffrences between these from BMR or UMI? How many of you guys noticed a nice difference?

 

Yes, did noticed a difference. But my car had the LCAs at the wrong angle to start with. I have stock springs, but the rear is just sagging, so my LCAs were angled the wrong way...axle higher then chassis.

With the brackets, now the axle is lower then chassis side, so helps keep the tires pinned.

I do "feel" the difference..feels like the cars is "digging" in more.

 

Schweet! I have my car lowered a lil, not slammed but it's a lil lower than stock, maybe an 1" or so. It was lower but I've been puting her on a diet and she's coming up a lil. I never paid any attention to whether or not the body mount where the control arm bolts up was lower than the axle mount. I'll look at that. Are ther different settings on the relocation brackets?

 

Most of them have different settings. Mine had 2...I just used the lowest hole possibly. Just remember to do the final tightening with the rear suspension "preloaded".

 

BMR and UMI are two damn good companies, You won't be wasting your money...
A nice improvement with the wheel hop after I lowered the car.

 

I checked my car last evening and I noticed that my axle mount was higher than the body mount as well. I wonder if GM set em up to be level at stock ride height. It seems to me that when they become lower on the body that instant center would be eliminated. There isn't any place for our " imaginary lines" to intersect.

 

Hard to say without access to the OE dimensions. But I wouldn't be surprised if they were either level or slightly downhill going from the axle to the chassis with the car at curb weight but otherwise unloaded. Not the best for launch, but GM has bigger concerns with axle steer, which is also affected by the LCA inclination.

Even though it's generally better for launch, uphill toward the chassis is a vehicle roll oversteer effect, which is not something that GM or most any other mfr is comfortable with. Your lowest-common-denominator buyer (whose pulse and net worth are both positive numbers, with the jury still out with respect to his driving IQ) cannot be expected to cope very well with that condition.

I'm assuming that you mean "Side View Instant Center", and there is such a thing for a torque arm suspension. But its construction is quite different from the 4-bar linkages that are relatively obvious. It involves the torque arm inclination from the axle center to its chassis attachment point and the specific chassis attachment point location in addition to the LCA inclination. LCAs that are moved to a more downhill toward the chassis inclination drops the IC and probably moves it rearward a tiny bit as well.

In particular with the later LS1 cars, the ones with the brake hop issue, more anti-squat (what the IC location affects) means more anti-lift, which means brake hop will be more likely and could be expected to occur sooner. Just something else that GM would tend to tune away from.

It might have even been intentional to hold the amount of anti-squat down to a lower value than what could have physically been done - as a means of reducing warranty costs. The harder that you can launch, the more likely it is that you'll break something. Nobody wins when the customer and the service dep't get into an argument over whether drivetrain parts breakage is going to be covered. Simply letting the rear tires spin more easily is kind of like the fuse or circuit breaker in your household wiring in this respect.


Norm

 

Understood Norm, good post.

 

Check out hotparts. They're a sponsor here and they have some good LCA relo-brackets (J&M). They were less expensive then the others.

 

i have all BMR products...they are all great quality.

and it's nice to have a choice in colors...even if its extra $$


with lca and relocation brackets....my car just squated and ran...very nice improvement over stock