E92 SE handling upgrades - where to start on a budget

[SoupAnxiety]

Hi all,

Where is the best place to start when trying to tighten up my E92 330i SE? It is my daily driver and I have no plans to use it on track, I want to reduce body roll and understeer.

I've looked at -

• Anti-roll bars
• Bushes, specifically Powerflex
• Control arms
• Shocks, specifically Koni STR.T / orange
• Springs, specifically the Eibach Pro-Kit

I have a budget of £250-600 for parts and a good independent mechanic for fitting on top of this budget. I know that I need to cherry pick from the above list but am not sure where to start to get to my goals of reduced body roll and understeer.

Thanks in advance :-)

[roofer]

What wheels does it have?

They're a nasty drive on big rims and hard suspension.

[helix402]

1. Anti-roll bars
2. Bushes, specifically Powerflex
3. Control arms
4. Shocks, specifically Koni STR.T / orange
5. Springs, specifically the Eibach Pro-Kit

1. Good idea, do your research and find the thickness of other models bars. I have had great success with choosing used arbs from other models. Thicker bars reduce roll without giving a bad ride. If you want to reduce understeer the theory is: a thicker rear bar will increase oversteer, thicker front will increase understeer. When I changed mine I was happy with my under/oversteer balance (no understeer) so I increased both bars by the same degree.

2. You may find Poly bushes too harsh. Why not go for M3 bushes? (Subframe)

3. M3 control arms can be fitted front and rear. They are all a straight fit, though some of the front ones increase the negative camber.

4. The Konis you suggest aren't the best quality, maybe Bilstein B6 or B8.

5. Top quality springs, just make sure you use dampers designed for lowered springs.

Also the camber and toe are adjustable front are rear, if you have your suspension set up by someone who knows what they're doing this too can have a remarkable effect.

[SoupAnxiety]

Thank-you for the replies. It is on 17" wheels, 225/45 non-run flat tyres all round.

helix402 -

ARBs - Based on the front / rear effects I should be looking for a thicker rear ARB, leaving the front alone? That way I will reduce under steer.

Shocks - I'm not interested in adjustable shocks, naively I thoyght Koni orange were like sports but not adjustable. I've found mixed reviews. My attraction to STR.T was price / performance - are they a bit underwhelming? I'd like Bilstein shocks but they come in at a lot more money, I'm guessing it's worth the jump in price?

For a budget of a few hundred quid which would be the best place to start? ARBs first, see if I'm happy then if not go for springs and shocks?

[helix402]

Here's some more info:

http://www.birdsauto.com/product-information/b3-dy...

http://www.turnermotorsport.com/t-tech-e90-e92-swa...

Maybe try a thicker rear bar for starters.

Edited by helix402 on Friday 6th March 21:19

[sixpistons]

helix402 said:

Here's some more info:

http://www.birdsauto.com/product-information/b3-dy...

http://www.turnermotorsport.com/t-tech-e90-e92-swa...

Maybe try a thicker rear bar for starters.

Edited by helix402 on Friday 6th March 21:19

Birds sell excellent stuff - I've got the B1 springs and dampers on my 1 series and it's transformed it. Not cheap though. If you want a cheaper option maybe consider the Bilstein B12 kit, which is basically Eibach pro springs and B8 dampers. I think its about 600 quid if you shop around.

If you're fitting thicker anti roll bars bear in mind a thicker one on the rear will tend to reduce traction if you don't have a limited slip by unloading the inside rear wheel more during cornering.

[Sohlman]

I used to have a 330i and was considering the same conundrum.

My thought was the Koni FSD kit which uses OEM springs and is a magnetic frequency response damper. Reviews are great. Lifetime guarantee and on budget. Also works with an eibach profit. About £650 for kit. Koni is often looked down on by BMW circles, but it is a very good product used by likes of Audi, Ferrari as oem.

[ftypical]

Given the age of the car, it's probably worth assuming that the dampers and all the bushes are not as fresh as they might be. Additionally, the front and rear geometry is some way off what it left the factory with.
Finally, what make of tyres are fitted and how worn are they?

All of these will make more of a difference to how the car handles than throwing aftermarket upgrades at it so understand what state your car is in already before deciding where to spend your cash.

HTH

[SoupAnxiety]

Thanks again for all of the replies. The Birds kits look amazing but are out of budget (sadly!).

The Bilstein B12 kit looks to be a good compromise, how stiff are Bilstein shocks? What attracted me to Konis was their fixed adjustment / cheaper price and reputation for balancing comfort / sport. I think the Koni STR.T shocks are out, they're perhaps too cheap and seem to get mixed reviews. Koni FSDs are meant to be the business and paired with Eibach Pro-Kit springs there is nothing between the Bilstein B12 Pro-Kit in price. In my head the Koni FSDs would be better suited to daily driving than Bilsteins - this could be horribly misguided though!

Looking at the ARB choices at the links the rear E92 M3 ARB would be a good fit with the Pro Kit springs, stiffer but not ridiculous. The point about it buggering up the handling worries me a bit. Would it be better to upgrade both front and rear to keep overall "balance" in play, I know that my original post mentioned understeer but I don't want to dial that out if a rear ARB upsets the back!

ftypical - it's a 2009/59 car with 133k miles (!) so your point is a valid one. I've had it in the air with my mechanic and the rear bushes do not appear to be split and there doesn't look to be any play. Rear bushes were on an earlier MOT advisory with the previous owner and may not have been replaced (and missed from the later MOT). Not checked the front so these could be worn. The shocks do not wobble around when rocked and my mechanic didn't find anything seriously wrong with the setup. It's sat on Goodyear Eagle F1 tyres all round which I put on in October with balancing, I check the pressure monthly. The tyres have plenty of tread left etc, I've not checked in detail if they are wearing evenly. Tracking seems spot on too. It seems Bits which I've not checked are alignment / geometry. There are no knocks / bangs / horrible noises from the suspension but with 130k+ I am realistic that things will need to be replaced.

Edited by SoupAnxiety on Saturday 7th March 21:35

[Monkey_boy]

This is a very interesting thread - I too am looking how to improve the ride quality and handling of my 56 plate 335i E92. It has 59k miles and am sure the right rear shock has gone, the car leans more on a left hand bend.

I am very interested in the Koni FSD shocks as they seem to improve the crashing over bumps in the road as well as reducing body roll. Also they will work with standard springs as don't want to lower the car. They can be bought for £534.

[ftypical]

That sounds more like a broken spring...

[Monkey_boy]

ftypical said:

That sounds more like a broken spring...

mm possibly, thought that was only common on E46's

[smashy]

Reduce roll and understeer £650 will get you A C Schnitzer Springs,excellant kit

[SoupAnxiety]

Monkey_boy - have you tried giving the sunken side of your car a wobble? Do the shocks bounce around or stiffen up quickly on the rebound? What is making you think the shock is gone (would like to see if I have the same symptoms on mine)? The Koni FSD kit looks good, I'm with you on lowering as I do not want to do it. I think at 133k my car is due new shocks and springs (despite no horrendous noises etc) and my logic with doing springs as well as shocks was that they all live together and getting all fitted doesn't take much more time than just one component.

I'm thinking the Bilstein B12 kit is the way to go, the 25mm / 35mm drop worries me slightly. Are spacers a bad idea to offset the drop? From the pictures it doesn't look to severe but I don't want to bottom out over speed bumps or have a chavtastic car.

[Monkey_boy]

SoupAnxiety I just went outside to push both rear sides down and they actually behave the same, no bouncing and come back up in the same way as far as I can tell.

the reason I thought perhaps the shock had gone is because the car leans more going round a left bend that a right hand bend. Perhaps a spring is broken. When I replaced the brakes all round recently I didn't notice any spring damage, but then I probably didn't look that hard. Also when I flooring it the car pulls slightly to the right - perhaps suggesting that the left rear has more purchase and the right rear is giving way, maybe my thought pattern is flawed

[SoupAnxiety]

It could be that a shock is on the way out. Bit of a silly one but have you checked tyre pressures? I checked mine three months ago, noticed my car was sitting lower on the drivers side and it turns out last week I was 8 psi down on both tyres on the drivers side! If the shock doesn't wobble around too much it might still be on the way out. Your mileage isn't that high but the age of the car will contribute. Might be worth using it as an excuse to buy fancy shocks and new springs

[Monkey_boy]

well that was my thinking too, it is 8.5 years old and could say to my wife it's cheaper than a new car

Been reading this from birds and it makes for very interesting reading! BMW using thinner antiroll bars to gain extra purchase due to no LSD. Although ~£1300 for the kit is a bit rich really.

http://www.birdsauto.com/product-information/b3-dy...

.. not checked pressures for a while but usually check regularly.. I have a look

[SoupAnxiety]

The Birds kit would be the dogs bks but is very pricey. The Bilstein B12 kit is on my list, £700 with one days labour for installation. If I'm still upset with the handling might look at thicker ARBs (as the springs will cope). I've come from a hot hatch and miss the handling of it, I accept limitations of the E9x when balancing comfort but the roll is bizarre. Logically the car could still be comfy and not roll! Is yours an M Sport?

[Monkey_boy]

Well my E92 is an SE, but because it's a 335i it has M-sport suspension I believe. Ah yes I know what you mean about hatch handling, When ever I have a Golf hire car etc for work I always think, wow this thing handles great and is so nibble and chuckable.. I'd love the new RS3 as I think that would tick all the boxes.. should start saving

When are you looking to get your suspension bits?

[SoupAnxiety]

I've changed from a Suzuki Swift Sport as my daily car, the E92 is a brilliant car in every way and I've warmed to it but still have some way to go to love it. The handling does make me a sad panda - roll is really unsettling.

I'm trying to find the best price on the B12 kit, it's coming in at £700 on eBay / Larkspeed / Amazon / anywhere which I can find.

Get the bits whenever I can and take the car to an independent mechanic (who has been a life saver) as the E92 looks to be a royal pain in the arse to do with axle stands at home. Hopefully May / June / July this year - I should have my E30 back on the road next month which can act as my courtesy car!

I'm saving for a wedding whilst overpaying the mortgage so the only way I'll get it done sooner is if a shock / spring fails so that I can justify the suspension upgrade as a "necessity" (!). The insurance still puts me off as I know I'll be setting myself up for a hike when declaring this!