[Dmitry83]

Hi, All,


Happy to move here from great E84 X1 forum (thank you, Guys, for your hospitality!)

Nice to meet you all and here is my car- it is a 320i with 328i ECU and standard suspension.

Now having passed a thousand kilometers, got rid of P7 Runflat, replacing with PSS, and got used to a lighter steering, I started investigating the ways to add some more stability at turn-in and a bit of oversteering instead of neutral turning.

As far as I could understand from the forum experience and opinions, It makes sence to consider on thicker sway bar in the front (M-technic, H&R?) and stiffer rear shocks (Bilstein B6/Koni Sport?).

So what are your opinions on that?

Is the front camber adjustable on F30?
Should I increase it to get the better corner grip in front?
What is he maximum rear camber which will not cause the rear "overgrip" and loose the front that way?

Thanks in advance,


Dmitry

[oceanview]

Depending on how much you want to spend.
Easiest and cheapest change is a strut bar. I just did that a week ago. Steering improved so far. Strut bar cost will be around 140$ install time 1 hour (DYI).

If your satisfied with that change fine, otherwise you could change other things like sway bar. Install time (i read somewhere here) about 8 hours.

The best for more dynamic and fun will be a LSD (Limited Slip Differential). I just had a Quaife installed and so far I just love it. Understeering is gone, fun has come.
Quaife also has an LSD for X Versions F30.
You will look at about $3000.- for that.

I can't answer how changing dampers/springs will affect steering. But sure there are some experienced folks here, who can answer that.

[Bee Pee]

Front camber is not adjustable.

You can change parts to add more camber.

Oem parts

1. Hub swivel bearing -0.5 deg
2. Fit f8x m4 lower control arms -1 deg

Non oem parts

3. Adjustable camber plates up to -3 deg

I have items 1 and 2 fitted on my m135i along with H&R springs and arbs. Steering weight has increased. Car turn in is more direct and much less steering vagueness around centre

BP

[963mw]

Originally Posted by oceanview

Depending on how much you want to spend.
Easiest and cheapest change is a strut bar. I just did that a week ago. Steering improved so far. Strut bar cost will be around 140$ install time 1 hour (DYI).

If your satisfied with that change fine, otherwise you could change other things like sway bar. Install time (i read somewhere here) about 8 hours.

The best for more dynamic and fun will be a LSD (Limited Slip Differential). I just had a Quaife installed and so far I just love it. Understeering is gone, fun has come.
Quaife also has an LSD for X Versions F30.
You will look at about $3000.- for that.

I can't answer how changing dampers/springs will affect steering. But sure there are some experienced folks here, who can answer that.

Which strut bar did you end up going with? I can't seem to understand the differences between different brands' strut bars. Thanks

[Dmitry83]

Originally Posted by oceanview

Depending on how much you want to spend.
Easiest and cheapest change is a strut bar. I just did that a week ago. Steering improved so far. Strut bar cost will be around 140$ install time 1 hour (DYI).

If your satisfied with that change fine, otherwise you could change other things like sway bar. Install time (i read somewhere here) about 8 hours.

The best for more dynamic and fun will be a LSD (Limited Slip Differential). I just had a Quaife installed and so far I just love it. Understeering is gone, fun has come.
Quaife also has an LSD for X Versions F30.
You will look at about $3000.- for that.

I can't answer how changing dampers/springs will affect steering. But sure there are some experienced folks here, who can answer that.

Hi and thanks for your input.
Had you installed a front strut bar or the rear- in the trunk?
And what about the sway- which one will bring more grip to the front-the stiffer front one or the rear one?
Thanks.

[Dmitry83]

Originally Posted by Bee Pee

Front camber is not adjustable.

You can change parts to add more camber.

Oem parts

1. Hub swivel bearing -0.5 deg
2. Fit f8x m4 lower control arms -1 deg

Non oem parts

3. Adjustable camber plates up to -3 deg

I have items 1 and 2 fitted on my m135i along with H&R springs and arbs. Steering weight has increased. Car turn in is more direct and much less steering vagueness around centre

BP

Hi, thank you very much- very interesting, as I've used M3 lower control arms on my former 120i E81 (3 door) + M3 cabrio front sway bar, and the result was amazing.
Had just found and read a thread on the Hub swivel bearings- cool stuff with -0,3 degree correction. I think it is better for me to reach around -1,0 or so with front camber, as I will not track the car, than going for the M4 control arms which will provide -1,5 degree in total.

[Dmitry83]

I've found those control arms partnumbers are 31122284529 & 31122284530 with price around $360 for the pair, which equals the negative hubs.
But as per the E90 M3 experience, will try to look for TRW offer- they made the E90 ones, as the ///M stamp had been shaved off after cast was made to sell the arms in TRW packaging. The price was 60-65% lower than those for OEM.
More to the camber increase, I remember those M3 E90 arms on my E81 made the front suspension completely silent and rubbery-tight.

Bee Pee, what is your opinion on their ride quality influence on F30?
At E81 this M3 parts had removed the wobbling clanking on the potholes, but did not make the suspension too stiff.
However I've also tried the upper control arms, and is was literally a disaster. Having passed like a mile, I've called to a service with the request to replace those with my old OEMs back due to terrible hardness.
(Then those arms after 2 years dusting in my garage were fortunatelly sold to a M3 owner, whose parts were worn out.)

And one more question- did you install the Hubs and the Arms together or one mod after another?
What do you think of increasing negative camber on car's ability to keep the straight line way? To my understanding if keeping the rear negative camber at reasonable level like not more than -1,5 degree (and it should not bee to much not to increase the rear grip i.e. understeering at the front), than -1,0 degree at the front should not make the car too nervious at the straight.

Thanks.

[.BMW.]

Are your 400 wheels square or staggered?

The easiest way to reduce the understeer would be to increase the grip the front tires can provide. If your car is RWD and with staggered wheels, 245 front and 255 rear tires will help a lot, or even 245 square on the staggered wheels.

But this alternative might be a bit late since you already have changed your tires.

[Bee Pee]

Originally Posted by Dmitry83

I've found those control arms partnumbers are 31122284529 & 31122284530 with price around $360 for the pair, which equals the negative hubs.
But as per the E90 M3 experience, will try to look for TRW offer- they made the E90 ones, as the ///M stamp had been shaved off after cast was made to sell the arms in TRW packaging. The price was 60-65% lower than those for OEM.
More to the camber increase, I remember those M3 E90 arms on my E81 made the front suspension completely silent and rubbery-tight.

Bee Pee, what is your opinion on their ride quality influence on F30?
At E81 this M3 parts had removed the wobbling clanking on the potholes, but did not make the suspension too stiff.
However I've also tried the upper control arms, and is was literally a disaster. Having passed like a mile, I've called to a service with the request to replace those with my old OEMs back due to terrible hardness.
(Then those arms after 2 years dusting in my garage were fortunatelly sold to a M3 owner, whose parts were worn out.)

And one more question- did you install the Hubs and the Arms together or one mod after another?
What do you think of increasing negative camber on car's ability to keep the straight line way? To my understanding if keeping the rear negative camber at reasonable level like not more than -1,5 degree (and it should not bee to much not to increase the rear grip i.e. understeering at the front), than -1,0 degree at the front should not make the car too nervious at the straight.

Thanks.

M135i come from the factory with -0.5 swivel hub bearings so I've just added M4 LCA. You will need to get your alignment rechecked once LCA are fitted and I'm running with 0 degrees toe at the front and the car tracks straight no problem.

If keeping stock suspension, your ride will be fine.

F30 have 8" front wheels so as suggested above, switch to Mich Pilot Super Sport tyres with wider 245 fronts then you will have made some subtle changes that give you the improvements you are wanting.

[Dmitry83]

Originally Posted by .BMW.

Are your 400 wheels square or staggered?

The easiest way to reduce the understeer would be to increase the grip the front tires can provide. If your car is RWD and with staggered wheels, 245 front and 255 rear tires will help a lot, or even 245 square on the staggered wheels.

But this alternative might be a bit late since you already have changed your tires.

Yes, it is staggered, replaced with PSS of stock width.

[Dmitry83]

Originally Posted by Bee Pee

M135i come from the factory with -0.5 swivel hub bearings so I've just added M4 LCA. You will need to get your alignment rechecked once LCA are fitted and I'm running with 0 degrees toe at the front and the car tracks straight no problem.

If keeping stock suspension, your ride will be fine.

F30 have 8" front wheels so as suggested above, switch to Mich Pilot Super Sport tyres with wider 245 fronts then you will have made some subtle changes that give you the improvements you are wanting.

Thanks, Man.
I would prefer to avoid 245s at the front and stich to an idea of M-Lower Control Arms for the following reasons:
1) With Winter sqare setup of 225/50/17 (I'm using T-speed category studded Michelin X-Ice North 2, which are enough stable not to loose totally the steering quality and joy) I will keep negative camber
2) Compared to Hubs, the Lower Control Arms will bring the good quality stiff solid bushings and ball-bearings
3) I don't actually like the fit of 255/40/18 at the 8,5' rears (tires are very wide and the walls are exactly upright with a rim inside for around 10mm), so for 8' wheel 245 Michelin PSS will be a "SUV-look as well"
4) LCAs are 30% cheaper compared to Hubs

So First of all I will do the alignment which is at least not bad to do at last as 20000km are passed with factory alignment. This will let me see what camber is there at the front now. Subjectively comparing to the rears, it is definitely not a 0,00 degrees, but some negaive camber. Then it will be clear weather I get a reasonable camber increase with LCAs or it will be too much and should be done with Hubs only.

[oceanview]

Originally Posted by Dmitry83

Hi and thanks for your input.
Had you installed a front strut bar or the rear- in the trunk?
And what about the sway- which one will bring more grip to the front-the stiffer front one or the rear one?
Thanks.

I've installed the front strut-bar from German manufacturer Wiechers
http://www.wiechers-sport.de/en/shop...ne-oben-detail
(Website is in English)
For my F31 there is no rear strut-bar. But for the F30 the also have rear strut-bar in the webshop listed.

As far as I know the 335i has a thicker sway bar (at least in front) as the 328i. I read in the forum here somewhere that 328i owners replaced for the original with a 335i sway. But in the meantime there are many aftermarket sway bars for front an rear. I will not change mine, it's quite a lot of work to do on the F30/F31!

But again, understeering in my car has gone with the Quaife LSD installed. Cornering is fun now! The LSD will add more traction AND solve understeering. (Naturally if you are driving too fast into the corner, the car will still understeer, but if you have the right speed at entering point and then you accelerate in the corner, thanks to the LSD the car turns into to corner)
It's an expensive tune, but it will give you the best effect for cornering, because you can control the car with your right foot :-)

[cracing]

anyone knows an option for rear camber adjustment?

[Bee Pee]

Originally Posted by cracing

anyone knows an option for rear camber adjustment?

Yes, the rear arms can be adjusted where they fit to the bodywork to tweak rear camber. Any good alignment shop will know how to adjust rear camber up or down.