Wind deflector.

[Chris_D]

You could always buy an e89 David and not have to faff around heaving the hard top on/off with the passing seasons. It's built into the e89 as standard, very practical roadsters imho
Rob

...and much heavier Rob... :wink:

1400kg instead of 1300kg isn't much difference, it's noticeable compared with an 800kg sports car like an Elise but 100kg isn't really noticeable imho
Rob

Your c of g will be a bit higher when compared with the ragtop and magnesium frame of the e85 but probably not that noticeable in comparison.
I was sure I noticed a difference in mine when I put the hard top on as I was driving quite spiritedly at the time. Maybe just placebo effect though...

 

[Grumpyowl]

I must admit my wind deflector is attached permanently, wouldn't drive without it top down.
Or without the top down side covers ( original black of course)

 

[Marlon]

...and much heavier Rob... :wink:

1400kg instead of 1300kg isn't much difference, it's noticeable compared with an 800kg sports car like an Elise but 100kg isn't really noticeable imho
Rob

Your c of g will be a bit higher when compared with the ragtop and magnesium frame of the e85 but probably not that noticeable in comparison.
I was sure I noticed a difference in mine when I put the hard top on as I was driving quite spiritedly at the time. Maybe just placebo effect though...

I can notice a difference with and without the hardtop definitely - and not just on spirited runs. Hell - I even noticed a difference going from MV2s to Style32. The difference in unsprung weight between the two set of alloys is roughly the weight of the hardtop, which means my car weighs the same with the hardtop on and the style32s as it did when I was running the MV2s without a hardtop.

 

[Petervaikimo]

My first foray into open top motoring was in the form of two Triumph Spitfire MK IV's which I enjoyed on a consecutive basis, meaning not both at once. Back then, in the early seventies, I certainly couldn't afford the cars that may have had the deflectors as standard. On lengthy trips, such as Bristol to Kendal, I learnt very fast how to obtain a stiff neck from the relentless buffing of wind. Ok I could have put the top up, but as long as a peek of blue sky was visible, I just had to drive topless.
Since the Ford Mustang drop top I drove in California, which you wouldn't dream about having a deflector on, I have learnt the hard way to always make sure that the deflector is in place. On the MX5's I had to pay extra, which was no problem and now this E85. A scarf is for having on when you walk the dog, not while zipping down the road at 80+ miles an hour!

 

[firebobby]

I did drive up to the Ace once, with D4dawg and BMWaddict, we met up at the services on the M40 and the Dawg took his deflector off, so I did the same thing. The noise from the passenger seat was unbearable 'slow down' and 'my hairs a mess' so never again :roll: :wink:

 

[enzed4]

... it does an admirable job of curtailing the in-cabin turbulence.

^^ This ^^

Without the deflector, it's not just wind in the hair (or bald pate) it's wind around your legs, arms, torso etc. You said yourself you've never tried one, yet you'll rule it out just because you perceive it looks un-cool / old-man-ish. Funny thing is, I would have thought most people would have said the same about grown men wearing a scarf, but maybe it's a cultural thing (the last person over here I saw wearing a scarf and driving was over 60, in an MGB...)
Each to their own

 

[FastInCurves]

Go for the windblox wind deflector version, it's the winner.

 

[Smartbear]

Go for the windblox wind deflector version, it's the winner.

The oe mesh deflector gives less turbulence than the solid versions, it's why bmw chose the material
Rob

 

[firebobby]

Go for the windblox wind deflector version, it's the winner.

The oe mesh deflector gives less turbulence than the solid versions, it's why bmw chose the material
Rob

Could always try a mesh scarf I suppose :wink:

 

[FastInCurves]

Go for the windblox wind deflector version, it's the winner.

The oe mesh deflector gives less turbulence than the solid versions, it's why bmw chose the material
Rob

I wouldn't think so. The mesh windscreens let wind leak through, whereas the sold body windscreens completely block the turbulence.

 

[Smartbear]

Go for the windblox wind deflector version, it's the winner.

The oe mesh deflector gives less turbulence than the solid versions, it's why bmw chose the material
Rob

I wouldn't think so. The mesh windscreens let wind leak through, whereas the sold body windscreens completely block the turbulence.

Then you don't understand how it works, the oe mesh deflector reduces cabin turbulence because it allows a small amount of air through! That's why bmw chose that material.
Rob

 

[firebobby]

The oe mesh deflector gives less turbulence than the solid versions, it's why bmw chose the material
Rob

I wouldn't think so. The mesh windscreens let wind leak through, whereas the sold body windscreens completely block the turbulence.

Then you don't understand how it works, the oe mesh deflector reduces cabin turbulence because it allows a small amount of air through! That's why bmw chose that material.
Rob

+1

 

[Chris_D]

I wouldn't think so. The mesh windscreens let wind leak through, whereas the sold body windscreens completely block the turbulence.

Then you don't understand how it works, the oe mesh deflector reduces cabin turbulence because it allows a small amount of air through! That's why bmw chose that material.
Rob

+1

+1
And that youtube vid on the windblox site for the e85 is just laughable. Has a solid deflector in place but the side windows open. Bonkers. No wonder that old git doesnt look very impressed / not so talkable. Excrutiating to watch as he's obv coerced into saying things he doesnt really believe. But they still used that vid to promote it. Hhahaha
:lol:
http://www.windblox.com/bmw-z4-2002-2008-windscreen.htm#responseTab4

 

[enzed4]

Go for the windblox wind deflector version, it's the winner.

The oe mesh deflector gives less turbulence than the solid versions, it's why bmw chose the material
Rob

I wouldn't think so. The mesh windscreens let wind leak through, whereas the sold body windscreens completely block the turbulence.

I agree with Smartbear. BMW has gone with a mesh design for a reason. Here's a quote from a company that makes (or made) wind deflectors that sums it up better than I can:
"When driving with the roof down low pressure forms inside the car, pressure builds up outside the car as the speed increases. As the high and low pressures try to equalise, turbulence forms. A well designed wind deflector reduces and controls the turbulence by disrupting this process.

The design and materials used to disrupt the turbulent air must be carefully considered. Any attempt to 'stop' rather than disrupt the equalisation process can create turbulence elsewhere.

Deflectors made from solid materials (as opposed to mesh) in an attempt to 'seal' the cabin to prevent drafts from the rear can work well at low speed (30mph or less). As speed increases the equalisation process kicks in, often causing the air to 'eddy' over the driver/ passengers' heads. As speed increases so too does the pressure on the wind deflector structure."
So, the view appears to be that at low speed, a solid deflector is perfectly fine, but at higher speeds it directs the airflow back into the cabin around the arms/feet. The mesh deflectors are designed to allow some airflow back into the cabin (around the neck/shoulders) without the noise/turbulence experienced with the solid deflectors.
As always, it comes down to personal preference, both do a similar job with slightly different results.