Improving the Handling of E46 318i valvetronic

[The Mixmaster]

Dude

As far as I know, Sachs Performance system (springs and shocks) is the cheapest at approx $1100.

The adjustable Bilstein PSS9 system can cost as much as $3500. In between, should be Eibach system and BMW sports suspension system.

 

[ryan]

I believe it's hot bits

Will reply again when my brain starts to function properly.

 

[quiksilver]

SInce ur budget is limited, change to a sports suspension first. Like DJ mentioned SACHS is one of the most value buy @ $1K+. After that, u can consider changing anti-roll bars. Strut bars I wld give it last priority or no priority as it gives least bang for the $$ u pay.
:roll:
If u still got $$ leftover, go for 18" rims!

 

[TobyNik]

Dude

As far as I know, Sachs Performance system (springs and shocks) is the cheapest at approx $1100.

The adjustable Bilstein PSS9 system can cost as much as $3500. In between, should be Eibach system and BMW sports suspension system.

Dude

I think qoyogi is a babe lah.....



Anyway, back to the handling topic.

My suggestion:
- Lowering with BMW sports suspensions would likely cost more than SACHS but ride height may be a tad higher than most lowering sets. But since you are not too concerned about looks, then its ok lah! And being on 17s will probably still look quite alright. But on 18s, not so nice to look at lor......

- Lowering to some after market sets and go on 18s. This is good but sacrifice a little bit of "pick up" cos of slightly higher rolling resistance and perhaps weight as well. But sweeeet cornering man!

- Anti roll bar change to better and thicker ones. Yes, I agree

- Strut bar. If you have budget, go for it. But make sure you install properly with lotsa lubrication to prevent the thing from creaking


By the way, lowering with sachs is not so bad that you have to "crawl" over humps. MOst times, I do that just to "preserve" my shocks from getting shot sooner than they can last.

Cheers! :wavey:

 

[Racebred]

Well, I think I have written something about this in the old forum, but let me try to contribute a little especially for those who have the luxury of improving their ride handling from ground up, and probably this can be a resource of some sort for future similar questions:

1. First thing is to move backwards. What is your objective in improving the ride handling? Serious Motorsports, Occassional Motorsports, Very enthusiastic street driving, Merely improving stock handling, Looks. Deciding which of these 5 objectives will subsequently tell you which replacement parts you're looking for, and money you will spend.

2. For serioius motorsports, you'll be looking to change to 2 way adjustable coilovers. These will let you adjust the bump and rebound settings as well as ride height. You can import many kits on your own but a good buy easily available will be KW Var 3. What you're adjusting is the low-to-medium speed shock absorbing aspect of the shocks. These should take care of accel squat, braking dive, and cornering roll. KW makes very good damping rates for high speed shock absorption. This is not adjustable and takes care of your cruising ride comfort; how it handles bumps, dips and other imperfections on the road. So it's both sporty and comfortable, but expensive.

Anti-roll bars are next. A rule of thumb for ARB rates will be to look at the diameter. For serious motorsports, you'll want to dial out all the understeer inherent in the E46 chassis. This will make your car more twitchy at the limits. Some even want to dial in a little oversteer depending on how they like to drive on the track. Comparing the various ARBs diameters in the market for E46 - Racing Dynamics, Hamann, Eibach, UUC, ACS etc - will tell you for what purpose they are designed to do. There's an E30 here with the thickest rears (M3), and the thinnest front (316i) to achieve superb handling on the track. You get the idea here.

Strut bars reinforce the chassis to prevent flex. The cabrios will benefit most from this. If the car is not driven at 100%, usually the effects of the strut bars front and rear are not felt. For installation of the rears, the boot carpet must be cut with 2 holes for the strut bars to go through.

Camber plates, and other adjusting kits for castor/toe, to let you adjust to suit your track.

Tyre profiles should be as low as possible. I see 19" as optimum. 20" is more for looks.

2. For Occassinal motorsports and enthuastic driving on the road, people choose to go for less hardcore coilovers, like PSS9, KW Var 1 and 2, etc. If adjustable, these let you control the rebound settings and ride height only. Less hardcore will go for complete Spring/shock set upgrade. A popular one here will Sach sporting or performance sets. Other brands like KW also carry complete sets. Generally they cost about half of coilvers.

ARBs are also changed, but any aftermarket ones will do, if you're not that particular about the minute differences between the few brands.

Strut braces are optional. most dont go for rears due to practicality.

Tyre size should be about 18". 17" still carry a little more tyre-flex than desired.

3. For ppl who just want to improve their ride handling over stock, they can either get a spring/shock set upgrade like Sach, or mix and match their springs and shocks separately.

Changing to wider tyres and at least 17" will help. ARBs are still important in this category, but could be optional. Strut bars are not needed.

4. For Looks only, just a set of lowering springs which the manufacturer has stated that it's compatible with stock shocks, like Eibach, will do. Maybe a strut bar so when you open bonnet you can show ppl, but i dont think the effects will ever be felt.

So for Justine's qn, first you must determine which category you are aiming to go to, and we can then see what are the options open to you in terms of what to buy and how much to spend.

 

[TripleM]

Goyogi..

For you case...suspension is no.1 priority then if u want a flatter and tighter cornering, comes the ARB to complement the mods

AFAIK, Sachs offers the best value for money. U get reasonably good handling and comfort so it's just perfect for you.

Now, having said that...
Where to get em? Plenty of places offering this
1. BVO
2. Juzz4Cars
3. Stamford tyres
4. Autovox...To name a few

ARB is the difficult one to get unfortunately for E46 318 model..
U can forget bout sourcing from the US as this model doesnt exist there hence no suppliers. UK and continental Europe are probably your best options. Maybe can also try Australian websites?

Strutbar...leave it to the last one..

Cheers

 

[g0yogi]

Hey guys, thanks so much for the valuable feedback. Ryan, I think all this info deserves to be preserved in the knowledge database...

I believe it's hot bits

Ah i c...sounds rude doesn't it... hehehe!

Lowering to some after market sets and go on 18s. This is good but sacrifice a little bit of "pick up" cos of slightly higher rolling resistance and perhaps weight as well. But sweeeet cornering man!

Mmm...one thing I am rather particular about is not losing any low end torque, so I guess that option is out. Need it to get myself out of trouble, hehe! :twisted: That's why I haven't upgraded my air filter...

RB - very comprehensive answer! Thx for the effort. Hehe, what I aspire for and what my budget allows for are 2 different things... :| So while it would be nice to aim for the "enthusiastic street driving" category, my budget prob allows only "improving handling over stock".

It seems quite unanimous that suspension is the first priority, but has anyone tried just changing the ARB to say, UUC ones and not touching the suspension ?

ARB is the difficult one to get unfortunately for E46 318 model..

Jack, I think the UUC sways would fit - I asked Wilson. Terima kasih ya for the info on workshops.

Has anyone tried mixing and matching reasonably priced springs and shocks ? I heard that the Eibachs are cheaper than Sachs. Anyone used Eibach b4 ?

cheers! :wavey:

 

[SMYUEN]

Racebred,

Hey bro..

Nice summary for someone like me who is still trying to understand the world of suspension upgrades.

For me, I am more than happy with my current stock suspension in terms of the balance between handling and comfort. But I do feel my car will look a bit better if slightly lowered, especially after the AC body kit has now been stuck on.

Does that mean I should consider Eibach just for lowering? Main thing is, will the subsequent comfort and handling be altered?

Very concerned NOT to worsen the comfort too much..

Cheers!

 

[ryan]

Heheh...those crazy japs (or issit aussies?)

Yep, already added some stuff into the knowledge base Thanks for the prompt. Will be editing it again as im still suffering from brain-fart.

:laughlik:

Hey guys, thanks so much for the valuable feedback. Ryan, I think all this info deserves to be preserved in the knowledge database...

I believe it's hot bits

Ah i c...sounds rude doesn't it... hehehe!

Lowering to some after market sets and go on 18s. This is good but sacrifice a little bit of "pick up" cos of slightly higher rolling resistance and perhaps weight as well. But sweeeet cornering man!

Mmm...one thing I am rather particular about is not losing any low end torque, so I guess that option is out. Need it to get myself out of trouble, hehe! :twisted: That's why I haven't upgraded my air filter...

RB - very comprehensive answer! Thx for the effort. Hehe, what I aspire for and what my budget allows for are 2 different things... :| So while it would be nice to aim for the "enthusiastic street driving" category, my budget prob allows only "improving handling over stock".

It seems quite unanimous that suspension is the first priority, but has anyone tried just changing the ARB to say, UUC ones and not touching the suspension ?

ARB is the difficult one to get unfortunately for E46 318 model..

Jack, I think the UUC sways would fit - I asked Wilson. Terima kasih ya for the info on workshops.

Has anyone tried mixing and matching reasonably priced springs and shocks ? I heard that the Eibachs are cheaper than Sachs. Anyone used Eibach b4 ?

cheers! :wavey:

 

[Racebred]

Now if looks are out of the question (meaning you dont mind truck-like wheel arch clearance and fat tyres), and i have only one thing to mod, it'll be anti-roll bars.

You can probably start from here. All anti-roll bar upgrades are the same if you're not pushing 10/10ths at the track. The only other factor to consider is availability and price then. Below are the various sizes and brands of ARB you can buy.

Sports Stock 24mm/20mm
Eibach 27mm/21mm
UUC 25.4mm/23.8mm
ACS 27mm/23mm
RD 27mm/24mm
Dinan 24mm/22 mm
Hamann 27/24mm

Our forumers have eibach, ACS, and I have Hamann fitted. They are all good stuff. Going by the thickness upgrade, Eibach is probably the most conservative, dialing in more understeer into the car for stability. For sharp handling, all the others are there, except for UUC, which goes for the most neutral handling.

ACS is the most expensive probably at about 1.3k, Dinan and RD need to special import from USA no point, Hamann is sold by Phoenix Enterprise (Mine was sold at $780 with install), Eibach cost about $600+. These prices were quoted at Euro 1.6 coz that's how long ago I started searching for ARBs. Do a little adjustment to 2x for current prices.

During install, take note that you should lup a shitload of grease on the bushings to prevent screeching noises when you roll over humps. Anyway I reckon almost all of them are made by Eibach anyway, only marketed under different brands and specced differently.

I'd recommend Eibach, cheapest. I dont know how much UUC cost, maybe wilson can advise.

For shocks and springs, if you just want to improve turn in, consider these routes, keeping in mind replacement costs:

1. Sach Performance Set. I think they cost over a grand. since they come in a set, they are a good match between spring and damping rates. Bad point is that Sach shocks have a terrible lifespan. They die off at pretty low mileage and you have to replace them.

2. Eibach springs only. Putting in eibach springs only is ok. with low-profile tyres, the handling is improved tremendously. I've gone on this route before. It should cost probably from $400-$500. This can be standalone, mated to your original shocks. Only thing is that your shocks will wear out a little faster than normal. You can also try KW springs. Springs last forever, so they are pretty value for money.

3. After eibach springs, add on aftermarket shocks. You can get Monroe, Bilstein, Koni, KW. Bilstein offers the best comfort, and Koni is rock hard. Monroe has terrible high-speed damping. Bilstein has been tried and tested, to be a good match to the Eibach springs. Back in the friendly Euro days, each Bilstein damper cost less than $100. I recommend that you keep your original shocks first, use until they wear out, then spend money on the shocks. makes more economic sense.


4. Salvage used coupe shocks and springs and put them in your car. Best is to get 318ci suspension, but 6 cylinders will do too, except that since your engine is lighter than the 6 cylinders ones, your front will end up sitting about 1 finger higher than if you were a 6-cyl. (but still lower than stock) I've gone on this route also too.

Steps 2,3,4 will probably save you a lot of money, and tremendously improve your handling over stock.

If you dont want to spend any more money, i'd say give the strut braces a miss.

Dont need to spend money on PML to get their M-technik springs/shocks/antiroll bars. Axl was on this on his car, it's good but it cost way too much.

Installation wise, shouldnt be more than $80 for one set of springs, or one set of shocks, or one set of anti-roll bar.

What tyre size are you on now?

 

[Racebred]

SM,

if you want to lower your car further still, and only want to spend money on spring only, then consider eibach and KW. I think Sam lowered his coupe once, it became way too low and he had to remove it.

Take note of the specifications of the lowering springs, lower by how many mm, and see if your front bodykit can take it or not.

handling wise, it'll still improve slightly over your cabrio springs, but i wouldnt say its very significant. it's mostly for looks only. But your ride comfort will definitely suffer and you'll feel every bump on the road.

if you're concerned about comfort, unlike justine, i'd say you dont touch your suspension at all. BMW Sports suspension is good enough already.

if you want sharper handling, change your anti-roll bars and strut brace ASAP. Put in the rear struts if you can afford to lose the luggage space. trust me your handling will improve tremendously since you are already on 18"

 

[piggyboyz]

Goyogi..

Actually, thw way to go is the ARB then suspension, not the other way round...

A lot of ppl might not believe until they tried but by changing the ARB, the setting is firmed up straight away without the harshness of a lowered suspension.

For lowered suspension, the geometry of the car changed and unless u get someone who knows what they are doing, the original stting of the car's camber and toe will be affected, which can be undesirable...

Worst still, some of the aftermarket suspension, like SACHS, are known for failing after a year or two, something u won't get if u change ARB since it's basically a stiffer torsion bar...

I would recommend a ABR for occasionally spirited driving and when it's time to replace the shock, find a set of coupe spring, which is slightly stiffer and u r done with it...

 

[wilman2772]

Hi Justine!

Wow!! So many ppl respond to you eh......

I'll join in as well

Your stock anti-roll bar for the front is 22.5mm part no. 31 35 1 094 539, the rear is 15mm part no. is 33 55 1 094 544

My 320i stock anti-roll bar is front 23mm & rear 18mm.

So, by changing ARB alone will sharpen your handling immediately liao, just like wat piggy says!!

Too thick in the front will give you more understeery, I personally prefers neutral towards oversteery......that's why UUC swaybars will suit my driving style.

Let me know if you want the UUC Swaybar yah?



'The Great White'

 

[piggyboyz]

Your stock anti-roll bar for the front is 22.5mm part no. 31 35 1 094 539, the rear is 15mm part no. is 33 55 1 094 544

'The Great White'

Bro, valvetronic is having the same ARB as the 320i these days liao...

It's 24.6mm frt, 31 35 1 095 272

 

[wilman2772]

Bro, valvetronic is having the same ARB as the 320i these days liao...

It's 24.6mm frt, 31 35 1 095 272

Oops....izzit?? So good ah?? Since which year production har?? I dun have her chassic number, so just check the ETK under 318i N42 YOM 2002 June......

Thanks for the info!!

'The Great White'

 

[SMYUEN]

Hi racebred,

Thanks for reply.

So i guess i would consider Eibach. Who should I get from?

Whats the difference between ARB and strut braces? very confused oredi....

 

[Racebred]

ARB is at the bottom of your car, cannot see. Strut bars are in your engine bay and boot, can see. ARB distributes the forces amongst the 2 sides of your suspension. SB reinforces the structural rigidity compromised by the 2 big chasms which are your engine bay and boot. so they do different things.

 

[SMYUEN]

Hey RB,

Thanks man.. Now I understand.

I dont really want to spend too much but wouldnt mind something for my car.
Any suggestion for:
1. ARB
2. Strut bar - only engine bay. Will not put in boot.

Cheers!

 

[TripleM]

Hi bro
There are plenty of choices for your ride with regard to ARB n Strut Bar.
Given that you are quite a fan of AC, u can get the whole set from PML ( not sure if there is any disc or not) or perhaps Autovox.

If not, you can go for UUC set which I think probably better in terms of weight savings and its unique material.

I hv test-driven a car fitted with AC ARB and the cornering is really flat even on soft setting. I am currently on UUC and it's fantastic (bout 4 kg lighter than my stock one and happy with it)

Assume if you wanna do step by step, I suggest u just go to do ARB first..SB can come a bit later.

U can also check out Breyton or Racing Dynamics stuff, both are available at AutoVox

Gd luck bro

JacK

 

[SMYUEN]

Hey Jack,

Thanks man for the suggestions!

Will go check it out....

Cheers!