raising trailing arm brackets

[hoveringuy]

It seems that everyone is correcting geometry in lowered cars by raising the subframe at the subframe bushing by 12mm, and then shimming the diff back down.


Has anyone raised the actual trailing arm brackets? The obvious concern is keeping proper placement, but with a jig that can be overcome.

[LowR3V'in]

why though?

[hoveringuy]

Because I have an extra subframe and all summer to do it.

If the point of raising the subframe is to raise the TA pivot point, why hasn't anyone just reworked the mounting bracket itself?

[cwlo]

Seems that the added height of the mounts would require them to be reinforced a bit, and the TA mounting bolt and nut prevent doing that easily.

[LowR3V'in]

edit: i thought u were talking about something else.

[hoveringuy]

So here's my plan:

1) Create a locating jig that references the bore of the subframe mounts as the datum. The height adjustment will come from sliding the jig up and down in that bore.

2) Either weld A "C" section into the right dimensions, or find something that's off the shelf and machine it.

3) weld that back unto a smooth subframe

The mount will clearly need to be stronger, since the pivot will be further off the subframe, but that's something I should be able to accommodate with thicker material, plus there are already gusseting kits for the stock brackets.

I could even plug weld a section of 1/8" plate over the subframe.

The eccentric slots would be tacked on as usual.

[e30davie]

I think your idea has merit. Sketch it up, go forth and fabricate!

My only concern is getting to the control arm bolts with them higher up, but potentially easier than with the whole sub frame raised.

Spacing it up, and then fixing the diff sounds like a lot of stuffing around.

[cwlo]

Instead of the slotted TA mounts, you should consider the DTM style adjuster. Can't remember who, but some vendor has it for $200 or so, and adjustment would be so much easier.

[LowR3V'in]

ok i get what ur saying now.
this is mine with 9mm raising bushing.
picture was taken from inside the car. i had to cut a hole.



But ya the current way to adjust camber/toe sucks.
my shit is beyond maxed out and it's still not factory.
on top of that it doesn't even seem safe because the trailing arm bushings are all cock eyed in the slots. i think that's a bad way of doing it.

[hoveringuy]

Huh.. How about that.

https://www.irp.lt/individual-racing-parts-product/rear-trailing-arms-dtm-style-adjustment-kit-needs-welding/

[hoveringuy]

I've punted on raising the mounts on the trailing arms. Although I could do it, it would involve fabricating a jig to properly locate the mounts which would cost a few hundred.
Doing so would create the same issues that raising the subframe has and also some additional ones, without solving any big problems.
So, I'm going to install the IE posi-lock adjusters and then see how much room I have left to raise the subframe with the bushings, if any.

For what it's worth, I measured the camber on the my spare trailing arm/subframe assembly and measured it at 1.5 degrees when the center of the hub is level with the TA pivot. Raising it an inch gave about 2.5 degrees, which seems to agree with previously published data.

My car currently rides with the rear fender 23" high, and the trailing arm rises about 5/8" from the TA pivot to the center of the wheel

[cwlo]

I'm running the slotted adjusters, and recently installed the condor subframe bushings that raise it up 10mm or whatever. I haven't had a chance to align it yet, and access doesn't seem that much less than before. I did end up modifying some cheap wrenches earlier to fit the outer adjustments though, as its really tight.

[LowR3V'in]

with the ie plates you can just weld them so both mounts are slotted up, no toe adjustment,
and then just raise the shit out of the arms. Mine are not even maxed plus they where welded with the stock hole in the center of the slots

Are u lowered allot?

hope this helps
with ie3 springs and with the as much neg. toe as it can give me
and the same with pos. camber i went to get an alignment.

it was -1.6*/1.4* camber which is juuuuuuuuuust on the line of stock.
only reason it couldn't get more camber because toe was maxed out binding the arm.

Toe was too out so adjusting it back will give more camber bringing it into stock range.
and that's with ie springs which i think are as low as anyone should be.

i've raised it at least an inch since then now it looks like straight up and down

[JimmyP]

Huh.. How about that.


https://www.irp.lt/individual-racing...needs-welding/

THAT is the way to do it.
Actually its improved on the original design in the 1st Gen Gruppe A training arm, there appears to be an additional threaded adjuster in this version that makes it much easier to adjust toe.

[AndrewBird]

Yeah, that DTM adjuster is awesome. Camber and toe adjustable from one side. I'm already thinking about how I could replicate it. I wonder if it's $230 per side or for both sides?