[crocodile110]

How are you getting on with the ohlins, still pleased with the upgrade? I emailed Ohlins Europe directly and they said the kit wasn’t available for the f31, even thought it is clearly is available. I’ll shoot center gravity a email to enquiry about the kit.

[Watsey]

Loving the R&T. Ohlins doesn't officially offer it for the F31, only the F30, but as the rear spring rates are ~100% greater than OEM and the additional weight of the F31 (~60kg from memory) will all be at the rear of the car I was happy to proceed.

Here are some observations in terms of the R&T with my specific suspension/wheels/tyres setup :

Being able to set ride height independently from spring preload is a good thing, and allows for a more precise setup when done by a specialist such as CG. Weight distribution is 48/52% F/R, and corner-weighted to within 4KG. The car feels much better on the road.

Ride control is good. They keep up with the road well, good control of bump and rebound (and the OEM 403s are a reasonably heavy), and the car 'lands' nicely after big bumps in the road.

The front springs are slightly softer than I'd like. Bearing in mind that the car has 12mm front spacers and is running 235/40 front tyres, I had had to judge the ride height carefully in order to avoid any rubbing of tyres on a moulded protrusion inside the lip of the front wheel arches over big suspension inputs. CG advised that the front spring preload should be increased by 2 to 3 turns (I opted for 2), and this has made a nice difference in terms of a firmer front end. Ohlins can provide springs to pretty much any spring rate, so you may want to talk to CG about that.

Front adjusters are very easy to access. Rears are slightly more difficult, but this is common on several of the adjustable dampers for this car (Ohlins; ACS/KW).

The ride can be nadgety at slow speeds on crappy roads, but that's to be expected. At higher speeds (road and track) the ride quality loosens-up, the control is still excellent.

Very happy with them, and I don't miss adaptive one bit.

[ryanwarriors9]

Hi Guys

This set up looks amazing but unfortunately i have no where near that budget and i wont be tracking my car etc.

I too have EDC and looking to do away with this as i hate it. I have a couple of knackered shockers so seems like the right time to replace everything.

What delete kit did you purchase?

I am looking at the Bilstein b14 PSS which they dont do for EDC so my options are code out or get the delete kit

Any advice would be great would any other parts be required? its just basically a swap for OEM to the b14 for me.

[crocodile110]

Originally Posted by Watsey

Loving the R&T. Ohlins doesn't officially offer it for the F31, only the F30, but as the rear spring rates are ~100% greater than OEM and the additional weight of the F31 (~60kg from memory) will all be at the rear of the car I was happy to proceed.

Here are some observations in terms of the R&T with my specific suspension/wheels/tyres setup :

Being able to set ride height independently from spring preload is a good thing, and allows for a more precise setup when done by a specialist such as CG. Weight distribution is 48/52% F/R, and corner-weighted to within 4KG. The car feels much better on the road.

Ride control is good. They keep up with the road well, good control of bump and rebound (and the OEM 403s are a reasonably heavy), and the car 'lands' nicely after big bumps in the road.

The front springs are slightly softer than I'd like. Bearing in mind that the car has 12mm front spacers and is running 235/40 front tyres, I had had to judge the ride height carefully in order to avoid any rubbing of tyres on a moulded protrusion inside the lip of the front wheel arches over big suspension inputs. CG advised that the front spring preload should be increased by 2 to 3 turns (I opted for 2), and this has made a nice difference in terms of a firmer front end. Ohlins can provide springs to pretty much any spring rate, so you may want to talk to CG about that.

Front adjusters are very easy to access. Rears are slightly more difficult, but this is common on several of the adjustable dampers for this car (Ohlins; ACS/KW).

The ride can be nadgety at slow speeds on crappy roads, but that's to be expected. At higher speeds (road and track) the ride quality loosens-up, the control is still excellent.

Very happy with them, and I don't miss adaptive one bit.

Thank you for the detailed response, it’s a huge help, I briefly spoke to cg on email this afternoon and they confirmed as you did, officially ohlins have only tested on the f30 so recommended for that platform only,but it will work on the f31 as you guys have proved.

When you say “at higher speeds the ride quality loosens up, the control is still excellent” what do you mean by loosens up? Excuse my ignorance I’m not the most savvy with tech talk and suspension, or anything for that matter ha

Thanks for your help

[Watsey]

My car has a pretty firm suspension setup now - the Ohlins springs have a much higher spring rate than OEM and the ACS springs that I ran for 18 months or so, and the dampers are set at 9 off full stiff (from a total of 32 clicks on the front).

At slow speeds on poor tarmac the secondary ride (surface imperfections) can be quite busy. Suspension inputs tend to be short and sharp as it is predominantly dealt with by the springs. The damper isn't really coming into play so the ride quality feels harsher.

At higher speeds, when the mass of the car is moving around more by larger undulations, the dampers play a much bigger role in controlling this primary ride - the ride quality improves as the dampers do their thing in smoothing the body movements. This is what I mean by the ride loosening up, but the body control is still very good.

[Mr Whippy]

Those rear rates look huge vs OE, but I bet OE go as high after a reasonable amount of compression.

I thought over 2hz steady state ride rate for a road car was generally considered bad, and not needed unless you need to combat aero induced loads (ie bottoming out suspension at high speeds etc)


Or you’re focussed on a really low ride height but then kinematics might be way unoptimised then (why touring cars etc raise the suspension pickups and run sensible geometry deflections)


I think as long as people are happy then great, but as much as no one in tuning talks about spring rates, no one even mentions OE kinematics, like they don’t exist or something.


Until you do a full analysis before/after of kinematics and roll rates, how do you know what the heck you’ve done?


For all you know for example, static camber at front might go more negative under bump and need some roll and steer to bring it in.
Adding more static negative might mean too much under bump and steer, then stiffening might mean back to ok levels, but then less roll might change roll centre height and mean more weight transfer and more understeer.



It’s certainly a cool project and wish you the best of luck getting it nice for your needs.
Indeed you should be praised for seeing the marketing crap from most tuners as just that, with their ‘secret’ spring rates nonsense, and doing a decent upgrade.


But now you’ve scratched the surface you’ll find it goes much much deeper

Enjoy!

[52172]

What are the front spring rates on the Ohlins?

[Watsey]

Originally Posted by 52172

What are the front spring rates on the Ohlins?

Hi. I've seen your post in the main technical forum (Suspension etc) and have replied there.

[cfm56d7b]

@Watsey, Pulitzer Prize is overdue for this write up and subsequent replies. Simply great.

[Watsey]

Originally Posted by cfm56d7b

@Watsey, Pulitzer Prize is overdue for this write up and subsequent replies. Simply great.

You're welcome. I've enjoyed loads of great advice from the forum over the years, so I'm very happy to help where I can.

[dr.roro]

Watsey Based on your experience so far, what do you think about going with 60/140 or 70/140 (N/mm) on a F32 435i RWD?

[Watsey]

Originally Posted by dr.roro

Watsey Based on your experience so far, what do you think about going with 60/140 or 70/140 (N/mm) on a F32 435i RWD?

It's a difficult one to try and gauge, as the weight and weight distribution of the F31 and the F32 are different. I don't know what the difference is in terms of engine weight, but the following info/experience may be useful.

It seem that Ohlins based its R&T development work on a 320d for the F series cars. The 20d isn't a particularly heavy unit.

I found the front spring rate (70N/mm) for the R&T to be too soft for the 30d so ordered 90N unit springs and had these fitted instead. Front ride/control is now much better - there's far less wallow (although wallow is relative - even with 70N springs it was much reduced compared to BMW OEM M-Sport suspension). I am happy with the F/R spring rates now - the car feels evenly planted.

As the N57N engine has an aluminium block the weight of the 30d may be similar to the 35i in which case, assuming that you are opting for R&T to get a 'tighter' setup, 90/140 springs F/R may also suit your car.

[Jrcleveland1990]

Interested in showing photos of the orientation of the sway link tab.? i installed mine at the wrong angle and broke my sway link