Shocks are shot, Bilsteins time?

Mittens · Post by **Mittens** » Fri Dec 23, 2016 7:29 pm

Hi,

My front two struts are likely to fail the MoT at the end of January so I'm going to replace them in the new year.
Since the stock ride on the Z4 is often criticised and Bilsteins (on a Z4) often praised, it seems like a no brainer.
I've done my reading so I'm sorry this is retreading a lot of ground, but need a few pointers:

1) I believe I have the sports pack (5 spoke wheels, [sport] button) and so my suspension is lower than standard? dose this mean I need the Bilstein B8s on my springs?

2) I was going to stick with the factory springs since navigating the local manatee-esk speed bumps is already fun enough of a morning commute. Is this sensible, or would I really be better off going to eibach route?

Cheers.

Steve84N · Post by **Steve84N** » Fri Dec 23, 2016 10:38 pm

B8 is for lowered springs, I believe you want B4.

hopz121 · Post by **hopz121** » Sat Dec 24, 2016 12:43 am

Either go B4's and standard springs OP or a B12 kit which is B8 shocks and eibach springs

Ed Doe · Post by **Ed Doe** » Sat Dec 24, 2016 12:59 am

B4s = OE replacement
B6s = uprated dampers for standard ride height
B8s = uprated dampers for lowered ride height

I have b8s, they are sufficiently low that with an m front bumper I have to be pretty careful with speed bumps. If you're concerned I'd opt for B6s if you want an upgrade but to maintain standard ride height....

Mittens · Post by **Mittens** » Sat Dec 24, 2016 10:47 am

Thanks all.

Ed Doe wrote: I have b8s, they are sufficiently low that with an m front bumper I have to be pretty careful with speed bumps. If you're concerned I'd opt for B6s if you want an upgrade but to maintain standard ride height....

Looking further into it B8s would drop my car by an additional 10-15mm (assuming I'm on -15mm sports package springs). Every so often I scrape my nose coming down off the speed bumps, so I best avoid that. (Though the scraping could be, in part, due to the knackered shocks)
So it looks like B6s are the way forward for an upgrade that doesn't leave me stranded on my street.

I'm looking at the demon tweeks website and they have two B6 shock absorbers:
http://www.demon-tweeks.co.uk/performan ... front-left - BLS22-104885

http://www.demon-tweeks.co.uk/performan ... ont-left-2 - BLS35-124092

I can't see any mention of the difference apart from the price and code though.

maxman · Post by **maxman** » Sat Dec 24, 2016 12:01 pm

Strange one ,they have 3 listed ,price range £103 -£175.
I would give them a call to see why the difference .

Sandy · Post by **Sandy** » Sat Dec 24, 2016 8:41 pm

I've just fitted the Bilstein/Eibach kit with Meyle HD wishbones and revised alignment, a massive improvement all round. It's lost the initial smoothness of the ride, but doesn't suddenly jerk on the second rate, like it does on the originals, which I prefer.

Ed Doe · Post by **Ed Doe** » Sat Dec 24, 2016 8:42 pm

Have a gander at Bilsteins catalogue - should confirm the correct part numbers. I bought my kit through a German ebay company - when the euro was weak mid-2015, think it was about £450 back then.... Worth shopping around though

Rassi · Post by **Rassi** » Sun Dec 25, 2016 10:02 pm

The B12 kit is really not too low or too harsh - mine was an SE so obviously the lowered ride is more noticeable but no problems with speed bumps or steep parking entrances. May be different with an M front bumper, though?

Mittens · Post by **Mittens** » Mon Dec 26, 2016 1:03 pm

Looks like that website (demon tweeks) is wrong, and thier codes are internal rather than the bilstein ones.

Bilstein do front Mono-tube and Twin-tube and rear twin-tube designs in the B6 range. The B12s are twin tube, which seems to be the newer and superior technology, though firmer.

I'm slightly concerned that you have to have twin tubes on the rear with B6s, I'd have through you'd want to keep everything the same.

For those with B12s, how is the "long" distance driving? I occasionally have to do 150 mile trip (300 mile round trip over a few of days) - For reference I'm on 18" wheels with proper tyres (non run flats)

MDUBZ · Post by **MDUBZ** » Tue Dec 27, 2016 12:27 am

I guess that will depend on the type of roads you're likely to be using on the long trips and the type of drive you want: what is the concern?

B12, 108s, non run flats & poly bushed: I drove to Le mans and it was no probs; in fact i was a hoot. It can be a bit crashy on a poorly surfaced road but tbh you're in a sports car, you didn't buy it to waft about in did you

Ed Doe · Post by **Ed Doe** » Tue Dec 27, 2016 1:25 am

I've driven to cornwall and back with the wife last summer (300+miles each way). No issues at all. As above, on more broken road surfaces it is a bit crashy, but it's a riot when you're driving for pleasure - mum much better body control. I daily mine - I've probably done 15k with the Bilsteins and polybushes and will continue to do so

Mittens · Post by **Mittens** » Tue Dec 27, 2016 11:37 am

Ed Doe wrote:I've driven to cornwall and back with the wife last summer (300+miles each way). No issues at all. As above, on more broken road surfaces it is a bit crashy, but it's a riot when you're driving for pleasure - mum much better body control. I daily mine - I've probably done 15k with the Bilsteins and polybushes and will continue to do so

MDUBZ wrote:I guess that will depend on the type of roads you're likely to be using on the long trips and the type of drive you want: what is the concern?
B12, 108s, non run flats & poly bushed: I drove to Le mans and it was no probs; in fact i was a hoot. It can be a bit crashy on a poorly surfaced road but tbh you're in a sports car, you didn't buy it to waft about in did you

The worse is the length of the A34. You've put my mind at rest, my concern was I'd loose too much of the cars GT credentials.
I once saw a couple of people in old TVRs trundling along in the left hand lane not looking very comfortable, I just don't want to be those guys.

Found the B12s at Lark Speed for £671 (plus a tenner for P&P), seems decent?
http://www.larkspeed.com/shopper/i/9146 ... ension-Kit

Scooba_Steve · Post by **Scooba_Steve** » Tue Dec 27, 2016 4:06 pm

The B12 kit is no worse than stock IMHO. I actually found it less crashy, it absorbs initially a bit better than stock though of course it is firmer overall.

Steve84N · Post by **Steve84N** » Wed Dec 28, 2016 8:04 am

http://www.regalautosport.com/shop/Bils ... 20bmw%20z4

My cut is just half your saving.

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