Sway bar dumb question

[bmwlaguna]

Sorry, I'm a newbie. Does the base model 128i non-sport have a front sway bar? What size is it?

[The Wind Breezes]

Yes, and it's not very stiff. Why do you ask?

[bmwlaguna]

Originally Posted by The Wind Breezes

Yes, and it's not very stiff. Why do you ask?

Still looking at suspension options.

[The Wind Breezes]

Originally Posted by bmwlaguna

Still looking at suspension options.

Well, what do you want to do with the car? What are you looking for out of the suspension? The setup could vary drastically between, for example, autocross, track days, or fast driving on public roads. I'd forget about changing sway bars until you've got summer tires, aftermarket springs, dampers, bushings and additional front neg camber. Those things will improve the car's handling 100%. On the other hand there are few easier ways to royally screw up a car's handling with good intentions than adding sways. They should be used to fine tune the balance once you've got everything else worked out. Also, the rougher the road the less anti-roll you will want.

[chris_flies]

Non-sport 128i's have a small front sway bar and no rear sway bar.

Check out my build thread for what I have going on; the balance on track is sublime (for a histerically understeery platform as stock) and I haven't gone crazy with mods (cost-wise)...

[minirips2]

Yep, base 128i suspension is basically rubbish. Intended to keep pricing low to entice more people into the brand. As Chris flies and I found out, beefier front and rear sway bars make a huge difference, and adding the rear bar is something that should be done with the rear subframe completely lowered. You may be fortunate, being from sunny CA, and not have to re-tap or run a thread chaser into the holes where the sway bar bushing mounts go. Mine were a mess. So were the brake lines. If you decide to go that far, replace the rear subframe bushings with M3 bushings, or urethane. Between the M3 bushings and ECS sway bars (28mm front/15mm rear), I am amazed at the difference. Just the bigger front bar made a huge difference, but understeer was worsened by it until the rear bar went in.

[bmwlaguna]

Originally Posted by chris_flies

Non-sport 128i's have a small front sway bar and no rear sway bar.

Check out my build thread for what I have going on; the balance on track is sublime (for a histerically understeery platform as stock) and I haven't gone crazy with mods (cost-wise)...

Thx man. I'm wondering if I should go with the front e90/92 M3 or go with the thicker e93 M3- which did you go with?
This car will never see the track tho, so I'm trying to do a balanced approach.

[chris_flies]

Originally Posted by bmwlaguna

Thx man. I'm wondering if I should go with the front e90/92 M3 or go with the thicker e93 M3- which did you go with?
This car will never see the track tho, so I'm trying to do a balanced approach.

I've got the Eibach 28mm front sway bar, and ECS 15mm rear sway bar.

For a street-only car, I'd do the E92 M3 front sway bar, but I wouldn't do anything in the rear unless you get an LSD (expensive), as it'll pull more weight off of the inside wheel, and would lead to profane amounts of one-wheel peels and traction control intervention.