135 upgrade plan - need help

[vtb]

Hello overthere.

Got couple of questions about changing the suspension of my 135.

Background:

Mostly intown use. with speed not over 140 kmh, curvey roards, 6 month a year is a winter (no snow but close to mud on road)

Now my 135 is seems to be understeer. and it's likes to try to loose grip when trying to acselerate in the long curve.

Also when i make S-turn the springs seems not to be stiff enough.

Ways to improve handling
(as i think about it) and my related questions.


1. Change sway bars.

Well a lot of ppl says it cool. I saw the video of mwerks 135 with H&R rear sway bar installed - and it seems to me this the effect i would like to achive.

At **********s there are two different choises
1. H&R sway bars
2. UUC swaybarbarian sway bars

Questions:
1. Which is better?
2. Do i need to buy front and rear sway bars or should i buy only rear one?

2. Replace stock coilovers and springs with aftermarket parts.

Well - again - im in town. with not so-good roads (i.e. 19" rims are suicide). but i go to the track at the weekend. So as i found there are basically 3 options to choose from

1. Leave stock coilovers but put shortened springs (0.5" lower)
2. Install BMW Performance pack
3. Install H&R street performance coilovers

as i think about these choices 1 and 3 are the candidates. But i have questions

1. Which way is better
2. If to go with H&R - does this kit come with springs?

3. Replace Runflat tyres and stock 264 rimms with aftermarket

Weight of stock 18" 264 rimms with Bridgstone Potenza RE50 is (roughly)
48 lbs front
52 lbs rear.

Rimms itself weights
24 lbs front
26 lbs rear

So first step is to lower the weight of rimms

I think about two options
1. Breyton GTS-R - 17.2lbs front (18x7.5J), 17.8lbs rear (18x8.5J)
2. OZ Ultraleggra - 18.6lbs any (18x8J)

And the second step is to change Runflat tyres to normal ones

I think Yokohama S.drive

Questions
1. Can anyone give me the weight of Yokohama's?
2. which rims are better in terms of durability?
4. Should i go to 7.5J front, 8.5J rear setup, or maybe it's better to go for 8.5J all-around setup?

4. Install Quaiffe LSD
That's important but not the first thing to do.

So at the mid-stop - i need an input from ppl who already changed their suspension - to help me to understand if i'm moving in right direction.

Thank you in advance.

[atr_hugo]

vtb - very well reasoned post. I think you'll get good responses.

[mikeo]

1. Change sway bars.
Recommend trying front bar first then add rear. Rear only has resulted in oversteer on the track/street (rear end comes around when accelerating out of corner). Both H&R and UUC are good quality and the UUC is adjustable. Hotchkis makes a 38mm front bar which is the largest diameter bar on the market.

Others here can address your remaining questions.

[EspressoBoy]

I hope so, I would like to read about this on. Sorry I don't have any info for you. But just posting it will bring it back to the top of "new posts" *smile*

EspressoBoy

PS
mikeo just beat me to the punch... lol see the time is the same...

[BMW F22]

H&R sway bars are very popular with the BMW crowd and it what I usually recommend getting. Most people would never adjust their sways so UUC may not be worth it. You can get either the front or rear or both but it's the rear that is usually changed first.

As for the suspension, if it's a coilovers set then it will come with springs and shocks. I should also note that BMW cars have understeer "built in" so while these mods will help decrease it, I don't think you can completely get it for it. Let me know if you have any other questions.

[modbargains]

Hello vtb,

1) UUC SwayBarbarian Sway Bars
- Front 27mm 2-Way Adjustable
- Rear 19mm 3-Way Adjustable

I would suggest going with the UUC SwayBarbarian Sway bars, they are also adjustable, 3 way in the front and 2 way in the rear. Getting both front and rear sway bars will be the best option, you will be able to dial in the front and rear characteristics to exactly how you want them.

2) KW Variant 1
- 1.2-2.1 in Front
- 0.9-2.0 in Rear

For a complete suspension replacement, I strongly suggest that you do with coilovers, whether they be basic entry level or full track systems. We carry H&R Street Performance Coilovers and they are a great product, however I strongly suggest that you look at the KW Variant 1 coilovers also; for not much more you will get the BEST coilover out there the daily driver and weekend tracker.

3) Wheels / Tires

As for wheel and tires, between the two choices that you are looking at the OZ wheels would be the more sound decision in terms of quality, durability, and finish. Running a staggered set-up is more ideal, if you can I would advise that you do 8.5 up front and 9.5 in the rear.

Yokohama S. Drive tires are a great tire for daily driving, you will get good life out of them.

4) LSD

As for the limited slip differential, we can help you out with this also

[ocinek]

You forgot some very CHEAP and important parts that will dramatically improve your handing.
-M3 front lower wishbones
-M3 front tension rod

They are larger & stiffer material bushings which will yield more responsive steering and also give you some more negative camber. I have done this all before with my E46 and the sway bars together with bushings make the biggest difference in terms of steering response (aside from coilovers of course). I will be going down this path and the above are my first choices. Good luck with your suspension journey!