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      09-03-2012, 09:20 PM   #8
flinchy
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Drives: E82 135i
Join Date: Nov 2011
Location: QLD, Australia

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Quote:
Originally Posted by Rukuss
Quote:
Originally Posted by fboutlaw View Post
Done everything except for the rear lower link. That part requires you to change springs / struts, which I had done prior to swapping all the components.

Verdict: it's an amazing transformation. The e82 stock (non M) has a very soft suspension and play between every component in the suspension. Normally you'd get that play in all direction from your tires, but with run flats, they are so stiff you get little play. Thus the suspension has to take care of the compliance in our cars. If you switch to non-RFT, you will immediately notice that the car feels sloppy, which is because you've added a mode of travel to your car in all directions (x, y, and z), which are not tuned to match.

M3 / 1M cars are built for normal tires. They assume the suspension should provide the proper travel for your wheels, but the tires will take care of the comfort aspect. The parts are lighter and have better joints between all parts.

Now as a review, I did everything in stages, so I'll go stage by stage:

1. Strut tower bar
- This does nothing over stock parts. Only install if you need access to the top of your struts (certain adjustable shocks adjust at the top).

2. Front roll bar
- Limited roll side to side significantly over stock. Less understeer through corners. Car still very sloppy, hard to settle into a corner.

3. Rear subframe bushings, Rear roll bar
- Subframe bushings helped the subframe feel connected to the chassis. Before it felt like the rear wheels were floating under the car in all directions. Less roll in the rear of the car. Now you could feel the rear of the car, but honestly with the rear roll bar, it felt too stiff. I now had to be more careful into corners, and watch my corner speed, resulting in countless autox spins. The rear was now connected to the ground and the sloppiness of my driving was very apparent.

4. Front tension rod + wishbones
- Huge difference. You can now feel the road surface through your steering wheel. The added camber of the wishbones also adds to corner grip.

5. Rear guide rods + upper arms
- Huge difference. The rear of the car now really feels connected. I can push the car through corners and not have the rear tires flexing in unpredictable ways, letting me get into corner slides without feeling out of control (like before). Able to be very accurate with the throttle as it translates directly to the ground rather than building up stored energy in the suspension.

6. Rear toe arm
- Haven't installed yet. Sitting in my garage until my next alignment. I expect this will make the suspension react faster as it's way lighter than the stock part, but I'm honestly a bit sketched out the the adjustable arm instead of a forged aluminum part. We'll see next season.

So overall. If you're going to do it, do all you can. Leave out the rear camber link kit unless you are doing coilovers. And leave out the strut tower brace unless you need access to an adjustable pin at the top of your front shocks.

Once you're done, expect a better car. I just crossed 30k miles this weekend and the car is far superior now than it was at mile 0.
What's the cost for all these parts ^^^^?
$500-600 for the front tension rod and control arm (wishbone)

$250 for rear sub frame bushings (plus half a days labour)

$500(?) for front and rear sway bars

Most kits/parts seem to float around the $500 mark

Strut brace is $200-$250 for aluminium straight bar, $500ish for an m3 one (not worth it imo, WAY too exxy and eh not a fan), $500+ for a carbon fiber one (lighter stiffer an prettier hah)
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