420d vs 435d suspension

420d vs 435d suspension

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Speed addicted

Original Poster:

5,561 posts

226 months

Wednesday 19th February 2020
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4 months ago I sold my 645 and got an Xdrive 420d Gran coupe, I'm doing a lot more miles now and it was the sensible decision.

The 420d is, obviously, a lot slower. It's also a bit boaty in the corners, where the 645 would corner pretty much flat the 420 leans.
This is actually annoying me more than the lack of power. I noticed it a little on the test drive but it's become more noticeable in daily use.

As far as I understand getting the Xdrive means that you don't get the slightly lower/firmer M Sport suspension and get SE suspension instead.

Do the more powerful variants of the Xdrive 4 series (435d) have better suspension or would I need to go RWD for something that will allow me to corner without excessive lean? I'm not talking extremes here, things like dual carriageway roundabouts seem to be a bit much for it.


SteBrown91

2,360 posts

128 months

Wednesday 19th February 2020
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All xdrive cars have SE suspension. A lot of people fit AC schnitzer springs to sort this out

Speed addicted

Original Poster:

5,561 posts

226 months

Wednesday 19th February 2020
quotequote all
SteBrown91 said:
All xdrive cars have SE suspension. A lot of people fit AC schnitzer springs to sort this out
Cheers, if it’s just springs this could be reasonably cost effective too. I’ll have a look!

numtumfutunch

4,704 posts

137 months

Wednesday 19th February 2020
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Speed addicted said:
SteBrown91 said:
All xdrive cars have SE suspension. A lot of people fit AC schnitzer springs to sort this out
Cheers, if it’s just springs this could be reasonably cost effective too. I’ll have a look!
Exactly this - check out the Bimmerworld forums for 3 series stuff

I had a post facelift/LCI 335d Xdrive

Its handing was shocking
Apparently the pre LCI Xdrive cars were worse - this beggars belief

CHeers

RobM77

35,349 posts

233 months

Thursday 20th February 2020
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This is essentially the difference between SE and M Sport. Years ago, SE was fine and M Sport was very firm, but both have softened now to the point where I can't cope with SE at all and find it awful, whereas M Sport is really good. Better than both, in my humble opinion, is Birds, but it costs money and may invalidate your warranty (may... I don't know that).

The other thing you'll notice is the reduced weight over the nose on the 420d compared to the 435d - with the right suspension the handling should be fantastic.

Speed addicted

Original Poster:

5,561 posts

226 months

Thursday 20th February 2020
quotequote all
RobM77 said:
This is essentially the difference between SE and M Sport. Years ago, SE was fine and M Sport was very firm, but both have softened now to the point where I can't cope with SE at all and find it awful, whereas M Sport is really good. Better than both, in my humble opinion, is Birds, but it costs money and may invalidate your warranty (may... I don't know that).

The other thing you'll notice is the reduced weight over the nose on the 420d compared to the 435d - with the right suspension the handling should be fantastic.
I don't have to worry about warranty, it's 5 years old. Bought it mainly for 12K a year commuting. I don't expect it to be this floaty, it's certainly the worst I've encountered out of 9 BMWs including X5s. Annoyingly the test drive didn't really encounter the sort of high speed corner that really shows it up.

So my options are,
Live with it - free but it's annoying me already.
Upgrade the suspension to what BMW really should have fitted in the first place. Schnitzer springs are £338 plus fitting, so probably around £500 total and get's good reviews. This should solve most of my issues with the car, apart from the lack of thrust that I knew about while buying.
I'll ask the mechanic for a quote to fit springs when it goes for an oil change next week.

Or I could buy a RWD BMW again, been looking at 5 and 6 series but I'll need to add about 4-5K to the pot to get something a similar age with the most powerful diesels. Only issue with them is that I'd loose the practicality of the hatchback and 4WD.

Also my wife is likely to hurt me if I change the car again after 4 months.


RobM77

35,349 posts

233 months

Thursday 20th February 2020
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I had a day's test drive in an F30 a while ago, looking to change from my E90. I'm really glad I did, because the SE suspension was truly awful. I wrote a review for Pistonheads, but it was so scathing I didn't publish for fear of the backlash. Your post is making me wonder if the incoming vitriol would have been worth it to pass on the info to people who would benefit from knowing.

Birds on my E90 cost me £1500 plus fitting, so it's not cheap. That did include ARBs though, which imho were the best bit - the cornering was so flat, yet the car was so supple in a straight line. I bought it when in your situation with my second E90 - the first's SE suspension was fine, but the LCI was all wallowy (I think this is when the softening of all models started).

Speed addicted

Original Poster:

5,561 posts

226 months

Thursday 20th February 2020
quotequote all
RobM77 said:
I had a day's test drive in an F30 a while ago, looking to change from my E90. I'm really glad I did, because the SE suspension was truly awful. I wrote a review for Pistonheads, but it was so scathing I didn't publish for fear of the backlash. Your post is making me wonder if the incoming vitriol would have been worth it to pass on the info to people who would benefit from knowing.

Birds on my E90 cost me £1500 plus fitting, so it's not cheap. That did include ARBs though, which imho were the best bit - the cornering was so flat, yet the car was so supple in a straight line. I bought it when in your situation with my second E90 - the first's SE suspension was fine, but the LCI was all wallowy (I think this is when the softening of all models started).
It is a proper chunk of change, however if it's a car you intend to keep and do miles in it's not that horrific. I've had a look on the Birds website but they don't list much for the 4 series with smaller engines, I imagine a phone call would sort out what could be fitted to give the flat cornering I'd like. I did wonder if bigger anti roll bars would be the answer to keep things in check while being driven enthusiastically.

I don't think I'd be willing to chuck £2k upwards at a car as I do tend to change them regularly, this is my 21st car in 25 years of driving. I've stopped owning two at once though!
.
The annoying part is that the 14 year old 6 series was so good, obviously it was initially a far more expensive car (and it had active anti roll bars) but it cornered flat all the time, while being steerable on the throttle.
I miss it... I've even been kind of looking at the last of the E63 shape 6 series knowing full well that they're old cars that in my case needed a lot of expensive maintenance, but they're so nice when they work properly. And 18mpg isn't that bad really..

Alextodrive

350 posts

74 months

Thursday 20th February 2020
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I've just bought an F31 330D touring with XDrive and I've got to be honest, I can happily chuck it round corners at as fast as I think would be safe to go at and I've not had any bother with how much it leans.

Having said that, I'd be curious to see how much these springs change the ride.

I've just purchased a set of Goodyear assymetric 2 run flats (cracking deal at Cotsco right now. £505 for all 4 fitted - with their standard 5 year warranty) so I'll be curious to see how that changes the ride from the Potenza's that came with the car.

Do the springs make speed bumps and lumps in the road even more unpleasant?

RobM77

35,349 posts

233 months

Thursday 20th February 2020
quotequote all
Speed addicted said:
RobM77 said:
I had a day's test drive in an F30 a while ago, looking to change from my E90. I'm really glad I did, because the SE suspension was truly awful. I wrote a review for Pistonheads, but it was so scathing I didn't publish for fear of the backlash. Your post is making me wonder if the incoming vitriol would have been worth it to pass on the info to people who would benefit from knowing.

Birds on my E90 cost me £1500 plus fitting, so it's not cheap. That did include ARBs though, which imho were the best bit - the cornering was so flat, yet the car was so supple in a straight line. I bought it when in your situation with my second E90 - the first's SE suspension was fine, but the LCI was all wallowy (I think this is when the softening of all models started).
It is a proper chunk of change, however if it's a car you intend to keep and do miles in it's not that horrific. I've had a look on the Birds website but they don't list much for the 4 series with smaller engines, I imagine a phone call would sort out what could be fitted to give the flat cornering I'd like. I did wonder if bigger anti roll bars would be the answer to keep things in check while being driven enthusiastically.

I don't think I'd be willing to chuck £2k upwards at a car as I do tend to change them regularly, this is my 21st car in 25 years of driving. I've stopped owning two at once though!
.
The annoying part is that the 14 year old 6 series was so good, obviously it was initially a far more expensive car (and it had active anti roll bars) but it cornered flat all the time, while being steerable on the throttle.
I miss it... I've even been kind of looking at the last of the E63 shape 6 series knowing full well that they're old cars that in my case needed a lot of expensive maintenance, but they're so nice when they work properly. And 18mpg isn't that bad really..
Birds don't list the smaller engined models because they don't get much business from people like us who care about handling but are less bothered by straight line performance. My 320d was great on their Birds kit though. They did insist I had an LSD if I got the ARBs, but with the '20d's power and torque I didn't have an issue with traction.

Speed addicted

Original Poster:

5,561 posts

226 months

Thursday 20th February 2020
quotequote all
RobM77 said:
Birds don't list the smaller engined models because they don't get much business from people like us who care about handling but are less bothered by straight line performance. My 320d was great on their Birds kit though. They did insist I had an LSD if I got the ARBs, but with the '20d's power and torque I didn't have an issue with traction.
I've sent an inquiry to Birds, might as well see what they think. I'll put the reply in here when it comes back.

Pica-Pica

13,621 posts

83 months

Thursday 20th February 2020
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Alextodrive said:
I've just bought an F31 330D touring with XDrive and I've got to be honest, I can happily chuck it round corners at as fast as I think would be safe to go at and I've not had any bother with how much it leans.

Having said that, I'd be curious to see how much these springs change the ride.

I've just purchased a set of Goodyear assymetric 2 run flats (cracking deal at Cotsco right now. £505 for all 4 fitted - with their standard 5 year warranty) so I'll be curious to see how that changes the ride from the Potenza's that came with the car.

Do the springs make speed bumps and lumps in the road even more unpleasant?
I agree. I must say, I don’t the big issue with post LCI F3031s, my F30 335d seems fine. Would love to drive one back to back with mine, but I cants see how a few hundred quid would make a tremendous difference. If I was convinced, I would pay up for a swap.

Speed addicted

Original Poster:

5,561 posts

226 months

Thursday 20th February 2020
quotequote all
Birds got back quickly

“Yes, the SE spec. is a bit soft and floppy, whereas the M-Sport is
uncompromisingly harsh. Ours sits somewhere in the middle in terms of
ride quality, but is in a different league in terms of body control over
fast bumpy roads.

The kit cost is £1089.85 + VAT and shipping, but if you ever find
yourself in this area, we'd be happy to demo one of our cars to you so
you can confirm what you will be getting, and we could do the install
for £1562.35 + vat within 6 hours total.”

They also recommended ditching the run flats, which I’d been planning to do anyway.

The higher performance models may be better in the first place.






Alextodrive

350 posts

74 months

Thursday 20th February 2020
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Pica-Pica said:
I agree. I must say, I don’t the big issue with post LCI F3031s, my F30 335d seems fine. Would love to drive one back to back with mine, but I cants see how a few hundred quid would make a tremendous difference. If I was convinced, I would pay up for a swap.
Mines a 2015 pre-facelift and I still don't see what all the fuss is about. If anything a bit of lean adds to the fun wink But I would be happy to be shown otherwise, its hard to know without comparing the two side by side.

And for £1600, I'd want that birds suspension to be a damn sight better than the £400 springs.

smashy

3,030 posts

157 months

Thursday 20th February 2020
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op what year is your car?

Speed addicted

Original Poster:

5,561 posts

226 months

Friday 21st February 2020
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smashy said:
op what year is your car?
2015

BFleming

3,589 posts

142 months

Friday 21st February 2020
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SteBrown91 said:
All xdrive cars have SE suspension. A lot of people fit AC schnitzer springs to sort this out
The Schnitzer springs are made by Eibach. They're not the same as what you would buy from Eibach, but Eibach do know their stuff. For the 420d X Drive they sell these: https://www.eibachshop.co.uk/eibach-prokit-perform...
£210.08, and they lower by 25mm front, 20mm rear. I've run Eibach stuff for years, nowhere near as harsh as M Sport suspension, but lower and slightly stiffer than SE springs.
For cornering I'd recommend swapping the ARB's for fatter ones. Your front ARB is 22.5mm; the one from the 430d & 435d is 23.6mm, so slightly stiffer. Go secondhand on these.
Anyhow, all this will come in (fitted) at well under half the price Birds charge. Never quite get the fascination with their stuff, there are a lot of alternatives out there.

Speed addicted

Original Poster:

5,561 posts

226 months

Friday 21st February 2020
quotequote all
BFleming said:
SteBrown91 said:
All xdrive cars have SE suspension. A lot of people fit AC schnitzer springs to sort this out
The Schnitzer springs are made by Eibach. They're not the same as what you would buy from Eibach, but Eibach do know their stuff. For the 420d X Drive they sell these: https://www.eibachshop.co.uk/eibach-prokit-perform...
£210.08, and they lower by 25mm front, 20mm rear. I've run Eibach stuff for years, nowhere near as harsh as M Sport suspension, but lower and slightly stiffer than SE springs.
For cornering I'd recommend swapping the ARB's for fatter ones. Your front ARB is 22.5mm; the one from the 430d & 435d is 23.6mm, so slightly stiffer. Go secondhand on these.
Anyhow, all this will come in (fitted) at well under half the price Birds charge. Never quite get the fascination with their stuff, there are a lot of alternatives out there.
That's a good shout actually, I did wonder about the ARBs.

The Birds kit is springs and shocks but not ARBs. The standard suspension feels ok on bumps etc, it's more the lean and lack of accuracy I don't like.
A bit of googling suggests that a rear ARB change is a bit of a hassle due to needing to drop the subframe?


BFleming

3,589 posts

142 months

Friday 21st February 2020
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Speed addicted said:
A bit of googling suggests that a rear ARB change is a bit of a hassle due to needing to drop the subframe?
Genuinely not sure - but possibly/probably correct.
This is interesting also... https://f30.bimmerpost.com/forums/showthread.php?t...

RobM77

35,349 posts

233 months

Friday 21st February 2020
quotequote all
Speed addicted said:
BFleming said:
SteBrown91 said:
All xdrive cars have SE suspension. A lot of people fit AC schnitzer springs to sort this out
The Schnitzer springs are made by Eibach. They're not the same as what you would buy from Eibach, but Eibach do know their stuff. For the 420d X Drive they sell these: https://www.eibachshop.co.uk/eibach-prokit-perform...
£210.08, and they lower by 25mm front, 20mm rear. I've run Eibach stuff for years, nowhere near as harsh as M Sport suspension, but lower and slightly stiffer than SE springs.
For cornering I'd recommend swapping the ARB's for fatter ones. Your front ARB is 22.5mm; the one from the 430d & 435d is 23.6mm, so slightly stiffer. Go secondhand on these.
Anyhow, all this will come in (fitted) at well under half the price Birds charge. Never quite get the fascination with their stuff, there are a lot of alternatives out there.
That's a good shout actually, I did wonder about the ARBs.

The Birds kit is springs and shocks but not ARBs. The standard suspension feels ok on bumps etc, it's more the lean and lack of accuracy I don't like.
A bit of googling suggests that a rear ARB change is a bit of a hassle due to needing to drop the subframe?
yes When I had my suspension fitted I was using a very good independent BMW specialist, and he mentioned he had to drop the subframe to fit it.

The ARBs were stunning though; I've raced for 20 years and obviously have often fiddled with setup on various cars, so I'm used to feeling differences, and those fatter anti-roll bars were a really key change from the BMW setup. It followed the old Colin Chapman ethos for the Lotus Elan: softer springs, but fatter roll bars.