E89 Roof Modifications

Gwest44 · Post by **Gwest44** » Mon Feb 12, 2024 4:49 pm

Having previously owned 3 E89's (pre & post-facelift) I feel like I should know the answer to this but I don't so thought I would canvas the opinion of the great and the good.

According to Wikipedia from 2012 and ahead of the LCI changes in 2013 the roof mechanism could be operated at speeds up to 25mph compared - prior to that it would only operate at a speed of around 5mph.

So my question is did BMW modify the the roof mechanism to achieve this or did someone just decide it was good for the increased speed?

The only modification I can recall was the inclusion of the elastic netting on the facelift models which did nothing for the roof operation directly but did ensure you were less likely to snap the parcel shelf hinges when the magnetic fasteners were released.

RobbiZ4 · Post by **RobbiZ4** » Mon Feb 12, 2024 4:58 pm

Gwest44 wrote: ↑Mon Feb 12, 2024 4:49 pm So my question is did BMW modify the the roof mechanism to achieve this[...]?

No and yes:
Nothing has been changed in the roof mechanism. Neither a technical improvement nor a quality improvement.

But, to close a minor safety risk of the rear roof shell, a 4th solenoid has been attached to the hydraulic pump. In addition, a modified hydraulic loom with 2 additional wires to the pump as well as an updated CTM (to manage the 4th solenoid) were built into the E89 as of mid 2012. And, of course, the elastic net in the trunk.

Gwest44 · Post by **Gwest44** » Mon Feb 12, 2024 5:06 pm

RobbiZ4 wrote: ↑Mon Feb 12, 2024 4:58 pm
Gwest44 wrote: ↑Mon Feb 12, 2024 4:49 pm So my question is did BMW modify the the roof mechanism to achieve this[...]?
No and yes:
Nothing has been changed in the roof mechanism. Neither a technical improvement nor a qualitity improvement.

But, to close a minor safety risk of the rear roof shell, a 4th solenoid has been attached to the hydraulic pump. In addition, a modified hydraulic loom with 2 additional wires to the pump as well as an updated CTM (to manage the 4th solenoid) were built into the E89 as of mid 2012. And, of course, the elastic net in the trunk.

B21 · Post by **B21** » Mon Feb 12, 2024 5:39 pm

Gwest44 wrote: ↑Mon Feb 12, 2024 4:49 pm Having previously owned 3 E89's (pre & post-facelift) I feel like I should know the answer to this but I don't so thought I would canvas the opinion of the great and the good.

According to Wikipedia from 2012 and ahead of the LCI changes in 2013 the roof mechanism could be operated at speeds up to 25mph compared - prior to that it would only operate at a speed of around 5mph.

So my question is did BMW modify the the roof mechanism to achieve this or did someone just decide it was good for the increased speed?

The only modification I can recall was the inclusion of the elastic netting on the facelift models which did nothing for the roof operation directly but did ensure you were less likely to snap the parcel shelf hinges when the magnetic fasteners were released.

FWIW the original US technical briefing paper for dealers said you couldn’t be moving to deploy the roof…

In things like Protool you can set the max roof deployment speed within certain ranges…I’ve not tried the 125 mph version.. ..yet!

flybobbie · Post by **flybobbie** » Mon Feb 12, 2024 6:17 pm

Why risk damaging the roof, the boot is a big air brake.

flybobbie · Post by **flybobbie** » Mon Feb 12, 2024 6:19 pm

I am surprised no one has converted one to a soft top.
Obviously easy to make it a summer car with no roof.
Or the one panel above driver removable like a T bar car.

B21 · Post by **B21** » Mon Feb 12, 2024 7:18 pm

flybobbie wrote: ↑Mon Feb 12, 2024 6:17 pm Why risk damaging the roof, the boot is a big air brake.

The issue as always is the manufacturer has to protect himself and the owner from their own misjudgments…

When you look at the aerodynamic load on the boot when it’s fully up it’s quite frightening…

Unlike an aircraft the aerodynamic load will change whether it’s going into still air or a head wind..

Trying to deploy the roof with say a 20 mph headwind gusting 30 mph wind whilst doing 20 mph is quite some drag…

It’s a good job the ‘nannies’ exist..

N4LLY · Post by **N4LLY** » Mon Feb 12, 2024 7:45 pm

I have used quite a few times, but only approaching traffic lights etc.

The last time i used was in very heavy traffic at the Dartford tunnel. It was 32DC and to damn hot. Closed and aircon to max. Heaven.

mcbutler · Post by **mcbutler** » Wed Feb 14, 2024 12:48 pm

Use mine all the time at around 25mph plus (coded via carly) - never had any issues,.
Just dont try to do it when cornering or on an incline, it doesnt like that and youll get a bong

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