AC Schnitzer 335d x-drive springs

[DocSteve]

These don't seem as expensive as I thought they would be. Does anyone on here rate them for the F31 (touring)? It seems most people have had a positive experience, although I can't help thinking I need to get rid of the RFTs first before I do anything...

The car is/was meant to be a workhorse but I just can't resist analysing its capabilities beyond that and to me it feels like changing the springs would be worthwhile.

Thanks
Steve

[roofer]

Tyres first.

[335d]

I added the springs first to my F30 335d, and just replaced the runflats when they wore out. The improvement from the springs is huge, even while running on Potenzas which are probably the worst of the runflats. The turn in became so much sharper and the car handled far better than the sDrive M Sport F30s which I often had as loan cars.

I have since switched to MPSS tyres to complete the transformation. The tyres are also a large improvement, but a smaller step forwards than the springs in my view. So I would go for the springs first and then decide when to ditch the runflats. You might even decide to keep the tyres until they need replacing.

[DocSteve]

335d said:

I added the springs first to my F30 335d, and just replaced the runflats when they wore out. The improvement from the springs is huge, even while running on Potenzas which are probably the worst of the runflats. The turn in became so much sharper and the car handled far better than the sDrive M Sport F30s which I often had as loan cars.

I have since switched to MPSS tyres to complete the transformation. The tyres are also a large improvement, but a smaller step forwards than the springs in my view. So I would go for the springs first and then decide when to ditch the runflats. You might even decide to keep the tyres until they need replacing.

Thanks - that's very helpful. I do have the Potenzas on 18s and although I am tempted to ditch them straight away the are brand new and it seems like a bit of a waste.... I'll be looking at some point to get the Michelis if I can get around the load rating issue which seems to be a problem for me with these tyres when on 18s.

Quite why BMW persist with the RFTs I don't know - I heard that they had a long term contract with Bridgstone which I guess might explain it.

[JNW1]

DocSteve said:

335d said:

I added the springs first to my F30 335d, and just replaced the runflats when they wore out. The improvement from the springs is huge, even while running on Potenzas which are probably the worst of the runflats. The turn in became so much sharper and the car handled far better than the sDrive M Sport F30s which I often had as loan cars.

I have since switched to MPSS tyres to complete the transformation. The tyres are also a large improvement, but a smaller step forwards than the springs in my view. So I would go for the springs first and then decide when to ditch the runflats. You might even decide to keep the tyres until they need replacing.

Thanks - that's very helpful. I do have the Potenzas on 18s and although I am tempted to ditch them straight away the are brand new and it seems like a bit of a waste.... I'll be looking at some point to get the Michelis if I can get around the load rating issue which seems to be a problem for me with these tyres when on 18s.

Quite why BMW persist with the RFTs I don't know - I heard that they had a long term contract with Bridgstone which I guess might explain it.

I haven't fitted ACS springs to my F31 335d but I have moved from Bridgestone run-flats to conventional Goodyear AS2's (also on 18" wheels). The Goodyears are certainly better than the Bridgestones in terms of ride quality but I'd say the improvement is relatively minor and to be honest I didn't think the ride was too bad even on run-flats. However, the reduction in road noise - and hence the improvement in refinement - has been much more noticeable and come replacement time I'd certainly advise anyone to move away from the Bridgestone run-flats (which do appear to be the worst of the run-flats BMW fit as original equipment).

As I say, no experience of the springs but based on my experience with the tyre change - and the comments from owners on this and other forums - I'm quite prepared to believe that the springs make more of a difference than changing from run-flats. Therefore, in your position I'd do the springs first and move to conventional tyres when the run-flats need replacing.

[335d]

DocSteve said:

Thanks - that's very helpful. I do have the Potenzas on 18s and although I am tempted to ditch them straight away the are brand new and it seems like a bit of a waste.... I'll be looking at some point to get the Michelis if I can get around the load rating issue which seems to be a problem for me with these tyres when on 18s.

Quite why BMW persist with the RFTs I don't know - I heard that they had a long term contract with Bridgstone which I guess might explain it.

Can you remind me of the load rating issue you have with MPSS? It rings a bell, but I can't find it.

[DocSteve]

335d said:

Can you remind me of the load rating issue you have with MPSS? It rings a bell, but I can't find it.

Hi,

I can't seem to find many non-RFTs (MPSS included) that are load rated the same as the current ones. I think I have 225/45/18 Y91 at the front and 255/40 95 at the rear and can't see to find any MPSS for both of those axles (or Goodyear F1s either).

Did you find that insurance was an issue with the springs? I'm with Admiral.

Thanks
Steve

[Wills2]

roofer said:

Tyres first.

The suspension is by far and away the worst thing about the x-drive cars.

[tighnamara]

DocSteve said:

Hi,

I can't seem to find many non-RFTs (MPSS included) that are load rated the same as the current ones. I think I have 225/45/18 Y91 at the front and 255/40 95 at the rear and can't see to find any MPSS for both of those axles (or Goodyear F1s either).

Did you find that insurance was an issue with the springs? I'm with Admiral.

Thanks
Steve

With Admiral and have fitted springs and exhaust, called and they had no problem. Think there was a bit extra but can't exactly remember.

[Ady555]

I think one of the issues you guys have overlooked running 18" wheels, is the huge 45 profile tyres. There is too much flex in the tyres when cornering hard and it's just not the springs that are to blame. Put some 19" wheels on and you will see a massive improvement in the handling. Another thing to take into account, these big 3 series BMW's aren't sports cars, but the owners are expecting them to handle like sports cars. Yes the handling can be improved with springs wheels tyres etc etc, but what are you guys using your cars for???

[JNW1]

Ady555 said:

I think one of the issues you guys have overlooked running 18" wheels, is the huge 45 profile tyres. There is too much flex in the tyres when cornering hard and it's just not the springs that are to blame. Put some 19" wheels on and you will see a massive improvement in the handling. Another thing to take into account, these big 3 series BMW's aren't sports cars, but the owners are expecting them to handle like sports cars. Yes the handling can be improved with springs wheels tyres etc etc, but what are you guys using your cars for???

Not sure I agree with that! I think you'll find the general consensus is that the car will drive better on 18's but look better on 19's; the issue with the X-Drives is more that even on M-Sport versions you get SE suspension and it's simply too soft for fast road use IMO. Personally I don't expect my car to handle like a sports car (it's too big and heavy for that) but I do expect decent body control and reasonable roll resistance on a car which is after all marketed as a sporting estate (or saloon if you have an F30!). S-Drive versions of the 3 and 4-series show what can be achieved - as from the sounds of it do X-Drive versions when fitted with the ACS springs - and frankly I don't understand why BMW ever allowed the over-soft set-up to see the light of day on cars like the 335d.

[Wills2]

Ady555 said:

I think one of the issues you guys have overlooked running 18" wheels, is the huge 45 profile tyres. There is too much flex in the tyres when cornering hard and it's just not the springs that are to blame. Put some 19" wheels on and you will see a massive improvement in the handling. Another thing to take into account, these big 3 series BMW's aren't sports cars, but the owners are expecting them to handle like sports cars. Yes the handling can be improved with springs wheels tyres etc etc, but what are you guys using your cars for???

Not sure I agree, I had 19" and it was floaty mess, the sdrive M sport handles well the xdrive doesn't or at least mine didn't.

[smashy]

The standard suspension never mind with Xdrive is as bad as it gets suspension wise.A floating blancmange.Thank god for ACS i put their dampers on as well as springs otherwise I would have bought a real lemon. ...and before anyone asks I didnt test drive as I had had an SE one series with no problems so thought this would be a step up.

Edited by smashy on Monday 20th June 17:12

[DocSteve]

Right, enough messing around. I'm going to order these springs!

Thanks all for the advice; I think there's a bit of a wait on them but will update once they're fitted.

RE: what do I use it for - well it's intended as an all round motor for long trips, carrying stuff including bikes and also towing a track MX5. I do like to enjoy a good road and whilst I don't think it's terrible by any means considering the type of vehicle it does feel like it has the potential for improvement. The springs are not that expensive so I think worth a go....

[Wills2]

I can also vouch for ACS and team in Norfolk, if you can get them to fit them as well, they fettled my F10 M5 and know what they doing.

[Ady555]

Wills2 said:

Not sure I agree, I had 19" and it was floaty mess, the sdrive M sport handles well the xdrive doesn't or at least mine didn't.

Did you have it in Sport mode?
I still think you guys are expecting too much of what is essentially, a big heavy luxary premium brand rep mobile. There is a lot of weight to transfer from side to side when throwing it into corners, coupled with 45 profile tyres if on 18's, Not taking into account if you are running the correct tyre pressures. I still think running 19's is a vast improvement over 18's. The suspension on the 3 series is probably ok for a high percentage of its UK buyers anyway, it's only a selected few that buy a large car like the 3 series and want it to handle like it is on rails. That is why they have the M3 in their range. (i am not claiming that the M3 handles like it is on rails though.) But handles better than the car in question from the op.

[julian64]

I've seen a few of these threads now, and they are all very positive for the springs but very information light

Half the claims made for the swap in springs in the way the car handles can't be right. People claim damping improvement and cornering improvement and cornering feel which aren't directly spring linked.

One suspects that when someone buys new springs they automatically want to justify their purchase. I have driven a car with 18" wheels and AC springs and found it worse than my 20" wheels and standard springs in terms of harshness of ride. There was little or no difference in cornering feel which makes sense. I suspect there is an element of wheel size affecting the spring rate.

No one even seems to know what the spring rate is on the upgrade springs for any sort of comparison.

My advice would be to try and find a car with them and try it out rather than take advice on here. Be aware though that an F30 with adaptive suspension does feel a lot different to a car without so you must compare like with like.

[JNW1]

Ady555 said:

Did you have it in Sport mode?
I still think you guys are expecting too much of what is essentially, a big heavy luxary premium brand rep mobile. There is a lot of weight to transfer from side to side when throwing it into corners, coupled with 45 profile tyres if on 18's, Not taking into account if you are running the correct tyre pressures. I still think running 19's is a vast improvement over 18's. The suspension on the 3 series is probably ok for a high percentage of its UK buyers anyway, it's only a selected few that buy a large car like the 3 series and want it to handle like it is on rails. That is why they have the M3 in their range. (i am not claiming that the M3 handles like it is on rails though.) But handles better than the car in question from the op.

Sorry but you're just talking nonsense with this banging-on about 19" wheels making the car handle a lot better; they don't, they're primarily about looks and bling when the car's parked-up and have little or nothing to do with improving performance on the road.

My F31 335d has adaptive suspension and yes, I do use it in Sport mode regularly and often; most of the time it's ok but on a twisty, undulating, road, it's still a bit soft and roly-poly IMO. Obviously an F31 isn't going to handle like a Lotus Elise or an M3 (and I never expected that from my car) but, as has been pointed out, the S-Drive versions with M-Sport suspension are much better and hence the shortcomings with the 335d aren't all attributable to size and weight; suspension set-up is a major factor and by all accounts the ACS springs make a significant difference. BMW could and should have made a better job of this at the factory in my view but I'm sure after-market suppliers like ACS and Birds are happy they didn't.......

[Ady555]

JNW1 said:

I think you'll find the general consensus is that the car will drive better on 18's but look better on 19's;

Yes i agree with that. You are always going to get a softer comfier ride on 18's than on 19's. But BMW have designed their car with the suspension and wheel option to probably suit the mass market, and not just a number of enthusiasts in the Uk that like to enjoy a spirited drive out on a Sunday every now and again. With the exception of Teaston.

[Ady555]

JNW1 said:

the S-Drive versions with M-Sport suspension are much better and hence the shortcomings with the 335d aren't all attributable to size and weight; suspension set-up is a major factor

Yes, suspension set up is a major factor, i am not deneighing that. Are you saying that the S drive handles better in the twisties than the Xdrive?