Ok so I really wanna get the relocation brackets for my Z28. But my dad who has been a mechanic for 30+ years told me if I do that modification, I'll have to get my rear end realigned. He hasn't really worked on a lot of 4th gen f bodies and I haven't read anything about that though so I was wondering if it was true? Thanks for any help.

 

I would say no. For one, relocation brackets will not change how the rear end sits in the car, but how some of the forces of accellerating and braking are applied to the chassis. For another, there are no adjustments to make on a stock rear suspension anyway, so there is not much to align. Now, if you got new adjustable LCA, panhard bar etc, that would be different.

 

well my plan was to get adjustable lca's and an adjustable panhard bar. so after I get that, what do I need to get done to the rear end exactly?

 

Honestly, nothing.
Adjustable LCA's are really for fitting larger wheels/tires(adjust axle front to back). If you are on stock wheels/tires just adjust them to the stock length and put them in. If you don't plan on putting huge slicks on then you really don't need the LCA's to be adjustable. - actually you really don't need aftermarket LCA's at all, unless you are trying to get the absolute best out of launching. Same goes for the relocation brackets.
The adjustable PHB is for centering the rear end left-to-right. Some cars come from the factory with the rear pushed a little to one side or the other. And when lowering the rear gets pushed to the drivers side because of how the PHB geometry works. You can adjust it back to center then.
You don't need any special tools or alignment rack for any of this.
What are you looking to do exactly with these mods? What do you want to get out of the car?

 

I really just want to tighten the rear end up. I've got terrible wheel hop so thats why I was thinking about the relocation brackets. Plus it helps the launch so I figured that would be nice too.

 

However, if you get your car on a 4 wheel alignment rack, and the rear in your car shows anything but a "zero" thrust angle, which many do (mine included), by adjusting the length of these arms, you can get the thrust angle to "zero". Will it make a HUGE difference in the way the car drives? The jury is still out.....

 

ok I've got 315's in the back now. Tell me if I got this right, you're saying I should install the adjustable lca's,then put it on a 4 wheel alignment rack, and adjust them to a zero thrust point angle?

 

Yes.

If you've got 315s on the back, clearance is probably at a minimum. Do you already have an adjustable panhard bar, and the rear end centered under the car? If not, I highly recommend that, too.

 

Na I dont have that yet but that was apart of the plan. Would I be correct in thinking that I have to put the car on a 4 wheel alignment rack to get the rear end centered?

 

here's what i think you should do,
- pull one oem lower control arm (LCA) off the car and then adjust your new adjustable LCA to be the same length, then install. Do same for the other LCA. This way nothing changes from the oem setup,
- do same for the panhard bar (PHB) with the new adjustable one.

with the adjustable stuff on the car, visually look at your wheel placement forward and back in the wheel wells. if either side needs to move then you can do that with adjustable LCA's however you would be affecting the rear end thrust angle. You want thrust angle to be 0°. If you adjust your LCA's or PHB from the oem length then it would be a good idea to have alignment checked and you want to go to a shop that can do 4 wheel alignment, and you will have to specifically request that. when they see a solid rear axle car they assume it's non adjustable and only align the front wheels, so you need to tell them you have adjustable suspension on the rear and to specifically set thrust angle to zero while maintaining acceptable fore/aft wheel placement and keeping the rear centered. I also believe that if you adjust any of that, you should also have your drive shaft pinion angle checked. You didn't mention torque arm, i want to say i've read a few experiences on here that aftermarket torque arms and new torque arm bushing also greatly helps with wheel hop and traction. And if you get a new tq arm then also get adjustable so you have the ability to properly set drive shaft pinion angle.

and for your initial question about using LCA relocation brackets and then needing an alignment, no that is not true. Pretty sure the relocation brackets compensate for rotation, the relocation holes are not straight down they are slightly forward to account for the slight rotation that happens when the control arm length from oem does not changed- because the rear should not move forward when using the lower holes which would also affect pinion angle along with pushing the slip yoke further into the transmission which is bad. ...on second thought i just looked at mine and i can't tell, i had the impression the relocation holes were forward a little. in any case, nothing changes or if it does it's so little and it's an even change on both sides it would not require a rear wheel alignment.

 

No.


You install the PHB on the car, set at roughly the length of the OE part. You then get a couple of plumb bobs on fishing line, or if you don't have two, use 2-3 good sized hex nuts, tied to a 16-18" length of fishing line, to simulate the plumb bobs. Tape the plumb bobs or hex nuts to the rear quarter panels of the car, locating them down the CENTER of the rear wheels.

Using the line as a guide, measure the distance from the line, to a fixed point of the rear rim, such as the bead, or if your wheels have identical hub caps, you can measure to them. Either way, you adjust the length of the PHB, until the distance from the fishing line to the wheels is equal on both sides of the car. This should be done with a half tank of gas in the car.

 

that's not always true. if you want to improve the handling of the car (as opposed to drag racing), then LCA's with either rod ends or roto joints will help a lot with rear axle articulation, and help prevent it from binding up during hard turns.

 

Absolutely!


I had a set of the "roto-joint" LCAs on my car for a while, and noticed a benefit from being able to set the thrust angle to "zero", as well as the reduced bind. However, the roads are pretty rough where I live, unfortunately, and I would up taking them off, due to the increased transmission of road shock from the bumps. One of these days, I'm going to get some ambition and take a picture of them, and list them in the "parts for sale" section...

 

The roads around me are pretty rough too so should I get the rod end/roto joint LCA's or not? Because Founders has poly/poly, rod/rod, and poly/rod for around the same price. So I'm just tryna figure out what's best for a daily driver.

 

Are all the Founders LCAs you mention of the adjustable variety? If so, for a DD, I'd get the poly/poly.


Just my $0.02 worth.....

 

Or you could just use the stock LCA's and get the same effect. As far as handling goes in my opinion, the handling effect is the same between stock and a bind free LCA while the noise absorbtion is better on the stock LCA . Best of both worlds if you ask me is a stock LCA.

Sorry everyone, I am still on my high horse about aftermarket LCAs being overhyped and misunderstood and I will stand by it until proven otherwise. 90-95% of most people on here will be fine with stock LCAs if symptoms are fixed the right way.

 

See, I have to agree with you here. I have roto-joint LCA's (non adjustable) and noticed no real handling difference. Maybe, MAYBE the rear is sharper to respond to input, and that's it, and I think I have a pretty sensitive butt dyno.

 

@leadfoot, yea I was going to get all adjustable. So the poly/poly isn't going to bind up compared to the other options?