Just fitted MAC1 screen to the Indy at the weekend, and will be fitting a heater soon.
No Just kidding
Seriously, I fitted the screen because I was getting severe helmet lift at high speed
The screen has stopped the lift but I seem to be getting quite a high frequency buffetting now.
Is this normal?
Or any suggestions to stop it?
I was wondering about trimming the height down a bit further, or removing some of the side return?
Regards
Rescued attachment sml190_9100.jpg
i would say hight is the problem, i've had mine on a "private road" at speed with no probs
graememkoct15
We chopped our aeroscreen down by about 50mm IIRC. No buffetting at all until you get to about 90mph.
Phil
Indy Web Picture
[Edited on 23-1-07 by Hellfire]
i had one of these on my last car and did'nt experience any buffeting even at silly speeds.
maybe it is the hieght your sat at that puts your head in the turbulant air,i had grp seats which sit quite a lot lower than your cobras
it could also be the air swirling around the return edges and into the cockpit area
Some sports cars have a fine mesh over the roll bar area, maybe this would help if you have no luck, i assume thats why they do it?
[Edited on 23/1/07 by andrew-theasby]
I've got the Mac#1 screen and I find that the airflow hits my forehead (though it is constant and doesn't buffet as such)... I guess it
depends on your height, the thickness of the seat and how far back the seat is (and maybe the angle of the screen). Whatever works for you. If you are
thinking of cutting down the screen it might be worth making a plywood template first and gradually take more off until you get something that does
the trick.
Good luck
[Edited on 24.01.2007 by Humbug]
Cheers guys, I'll give it another try at tha weekend if it's not snowing and see if I can measure how high this screen kicks the wind and
look to trimming it down a bit 
I would agree that Cobras on runners probably sit me about 40mm higher than shell seats, mind you if they did'nt I might struggle to see over the
screen
Anyone got a wind tunnel?
[Edited on 25/1/07 by ReMan]
My screen just kicks the air to my chin, so it's not a lot of use. It is however more an extension of the scuttle than an actual aero screen. I'm quite tempted to add something extra to help with this, although I'd still have to wear a helmet, as I wear glasses.
quote:
Originally posted by DIY Si
My screen just kicks the air to my chin, so it's not a lot of use. It is however more an extension of the scuttle than an actual aero screen..
No buffeting on mine with same screen. Wind doesnt hit forward head but im not the most vertical of people.
Colin :-
.....and you're so tall! 