Weld-In Rear Alignment Adjustment - Worth It For Me?

[Panici]

Thanks in advance for the read, I was a little long-winded here but it's all relevant.

--

I now have my subframe out for the 2nd time; Contemplating the pros/cons of welding in adjusters.

There are now serrated adjusters on the market, and modified as moatilliatta has done they seem like a good solution.


But my question remains, is it worth it for my car?

• The car is mildly lowered in the rear with H&R Sport springs and thinner spring pads, and I have no plans to go with a lower ride height (even if I go with a better suspension setup down the road).
• I don't care about tire wear, I don't put enough mileage on the car for it to matter.
• The car will see occasional track time just for fun, and I don't care about lap times or maximizing traction. It's set up primarily as a comfortable street car.
• It's a PITA to set the rear alignment even with the best of the adjusters. Would have a hard time finding a specialty race shop who would even touch an alignment with a custom setup.
• Stories of other's E30s losing adjustment mid-corner are no-bueno, could result in a crash.

My main concern is keeping the car's fun-to-drive feeling now that I've more then doubled the original power.
To me this means having a chassis that acts predictably as it crosses the limits of traction.

My goal is to do this without making the suspension harsh, which means sticking with softer springrates, and therefore more dynamic toe/camber changes in the rear as it squats under power.


How much would an adjustable static rear alignment really do for me with my specific use case?



As everyone likes pictures, here are moatilliatta's modified rear IE adjusters from the thread HERE:



And my current ride height. Happy with the rear, and I would actually like to raise the front up slightly if I ever make the jump to coilovers.




(Wheel spacers were not installed in this 2nd picture)

[jbontke]

I welded in lower control arm adjustment to my subframe. Used Gargistic kit that came with the eccentric bolts. Currently using Bilstein and H&R race springs. I switch from the eccentric bolts to the shim kit with the bolts. Its very hard to get in there and adjust the shims and tighten the bolts. I was able to get to 3 degrees of negative camber at best. Much better than it was before. I would have liked to get closer to 1 degree of negative camber.

I plan to use the serrated kit on my next go around, it looks to have more adjustment than the eccentric/shim kit. Other option would be a subframe riser to move the subframe away from the car, make room for adjusting the toe/camber and recover some camber.

The H&R Race springs came on the car, I would have preferred the H&R sport springs and larger sway bars. I have a set of style 5s that may cause me to lift the car with different springs when they go on.

Handling: the car stays planted. Usually the front slides in a corner if I am too hot on entry, blip the throttle and the rear comes around. It feels predictable. I am using a hard (7 yr old) 195 tire on 14" wheels. With the ok tires, I cant complain. The car can outdrive my skill level.

[TobyB]

So: worth it?

Good question. I have found the BMW curves to be really good as you lower the car: as in, as you lower, you gain about the right amount of
camber for your intentions. Low car= track car, mid- height is good for sporty street, and almost stock is comfortable for commuting.

It's quite possible to do the camber adjuster and leave the toe adjuster out. Again, BMW gives you just a little toe- in, so it's very stable,
increasing slightly as you lower. If you want to add camber without lowering the car, this is perfectly valid, and works great for
'hey, I'm going to hit 6 tracks this summer, and don't want to wear the outside edges off my tires' but you don't want to get into the
alignment hassle of toe adjustment plates.

The toe adjustment is really only a big help when you want a 'pointy' car. Otherwise, most of us set it pretty darned close to factory, and then ignore it.
I WOULD add that the serrated adjuster is a bad idea here, (incidentally where it's most needed,) as it's far too coarse to allow the tiny adjustments in toe that you'll
want. The inner camber adjustment can be made in clicks with no ill effects.

So: in your shoes, I'd try the inner camber adjustment without the toe. Get it aligned once to make sure nothing's off, and then mark
the inner adjusters. Then start playing with moving them a notch or 2 in either direction.
Oh- when you install them, don't center the slot on the factory position, set them so that you can ADD a lot more camber (slide the trailing arm lowr)
than you remove. It will probably mean you put them as low as they can go, bumped into the subframe. You seldom want to take out more
than a degree, but adding 3 is... wonderful.

As to rear ride height, you're sitting pretty high. you might want to play around with lowering a bit to see what it does for handling.
That said, a bit of front rake, as you have, makes the car turn well without being unstable or too quick to transition.
If you keep it at this height, being able to increase rear camber will certainly help acceleration out of a corner, and ultimate rear grip as well.

just my opinions,
t

[Panici]

So: worth it?

Good question. I have found the BMW curves to be really good as you lower the car: as in, as you lower, you gain about the right amount of
camber for your intentions. Low car= track car, mid- height is good for sporty street, and almost stock is comfortable for commuting.

As to rear ride height, you're sitting pretty high. you might want to play around with lowering a bit to see what it does for handling.
That said, a bit of front rake, as you have, makes the car turn well without being unstable or too quick to transition.
If you keep it at this height, being able to increase rear camber will certainly help acceleration out of a corner, and ultimate rear grip as well.

Appreciate the info Toby.
Glad to hear that the BMW curves are really good as ride height is reduced. That was one of my concerns with dynamic camber/toe as the rear squats under acceleration.

I'm surprised that you recommend more rear camber, I've read about a lot of folks adjusting to take camber out. But perhaps they are running much lower rear suspension then I am.

Noted about the rear grip, not a big concern as the car isn't a track toy. Fun to steer with the right foot anyways.

Based on the above I'm leaning towards leaving the subframe without adjustment.

[hopeful]

So: worth it?

Good question. I have found the BMW curves to be really good as you lower the car: as in, as you lower, you gain about the right amount of
camber for your intentions. Low car= track car, mid- height is good for sporty street, and almost stock is comfortable for commuting.

It's quite possible to do the camber adjuster and leave the toe adjuster out. Again, BMW gives you just a little toe- in, so it's very stable,
increasing slightly as you lower. If you want to add camber without lowering the car, this is perfectly valid, and works great for
'hey, I'm going to hit 6 tracks this summer, and don't want to wear the outside edges off my tires' but you don't want to get into the
alignment hassle of toe adjustment plates.

The toe adjustment is really only a big help when you want a 'pointy' car. Otherwise, most of us set it pretty darned close to factory, and then ignore it.
I WOULD add that the serrated adjuster is a bad idea here, (incidentally where it's most needed,) as it's far too coarse to allow the tiny adjustments in toe that you'll
want. The inner camber adjustment can be made in clicks with no ill effects.

So: in your shoes, I'd try the inner camber adjustment without the toe. Get it aligned once to make sure nothing's off, and then mark
the inner adjusters. Then start playing with moving them a notch or 2 in either direction.
Oh- when you install them, don't center the slot on the factory position, set them so that you can ADD a lot more camber (slide the trailing arm lowr)
than you remove. It will probably mean you put them as low as they can go, bumped into the subframe. You seldom want to take out more
than a degree, but adding 3 is... wonderful.

As to rear ride height, you're sitting pretty high. you might want to play around with lowering a bit to see what it does for handling.
That said, a bit of front rake, as you have, makes the car turn well without being unstable or too quick to transition.
If you keep it at this height, being able to increase rear camber will certainly help acceleration out of a corner, and ultimate rear grip as well.

just my opinions,
t

I plan on doing the subframe risers and the eccentric adjustment route. After reading about this (primarily that it is the toe adjuster that moves and not the camber), then your comment about setting the toe and forgetting it. I'm starting to wonder if maybe the toe adjuster is a mistake.



(https://www.e30sport.net/tech_articl...ves/page-3.htm)

From the toe curves mentioned on the 15deg rear sweep arms we have, we're talking about 1/64 toe IN for every INCH in compression past horizontal.



Panici as a side note, contact me if your thinking of going only camber correction, I may have half an eccentric set to sell you .

[moatilliatta]

What is your current alignment?

[Panici]

Panici as a side note, contact me if your thinking of going only camber correction, I may have half an eccentric set to sell you .

Pretty happy with my fixed rear setup at the moment.
Handles very predictably on the street at least.

Planning on a shakedown run at the track this spring. Need to finish off this set of old tires before the new ones go on!

[hopeful]

What is your current alignment?

To keep things interesting I'm going to assume you were asking me, I don't know. I haven't put it on a rack and possibly won't. I'm betting however you have. What was toe measurements lowered? The earlier chart assumed the control arms were starting from a horizontal, which is no likely to be true.

I plan on doing this work definitely for this summer, I guess I'll just have the subframe out and gauge what it's doing and go from there.

[reelizmpro]

H&R recommends camber correction for their Race springs only and even without it the rear negative camber isn't too bad. So it's not needed unless you are going very low.

[moatilliatta]

Bent rear suspension parts seem to cause more issues than lowered cars.

IMO, its worthless to weld on any adjuster if you don't know where you are to begin with.