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i wanted something more than a Locost, i did that 14 years ago

when i tested the car, there was a lot of wind buffeting, so i am making side wind deflectors to try and limit this to a tolerable level.

so i sent the wife to get some acylic sheet when she was in town as my local true value doesn't have any,

i told her 3' X 2' will do 1/4"thick.

expecting her to return without it, but low and behold, thats what she came back with.

so i need to make some wind deflectors for either side of the windshield.

cut it with a jigsaw with a metal blade, lubricated the cut with wd40, left the film on.

it gets too hot, used water and it was o.k. if i paid attention to stopping the cut healing up.

now i want to put a bend in it, just a few degrees, i mark where the bend needs to be with a fine sharpy.

take off the plastic, cover the vice jaws and insert it, being careful not to mark it.

take a propane torch and warm the pen line, whats that you say, "the ink will catch fire and burn the pen line into the acrylic," yup just found that out.

now when i learnt to paint cars, i was told "if you can piss, you can paint", the hard part is how to correct a problem if one occurs.

i sanded the scratch line that was quite deep, after all it was burnt into the stuff, with 80 grit and ended up with a sanded band about an inch wide.

next, i scraped it with a new razor blade to smooth out the sanding marks, this left a band of foggy about 1-1/2" wide.

and here is the amasing part, i ran the propane torch over the surface and all the scratches disappeared like magic.

now this was fantastic, so i sanded the edges that i had cut, used the razor technique and ran the torch up and down the edges, marvelouse, the edges are now clear!

what can i say, i was expecting to have to polish them but no, i don't think polishing is as nice a finish, i mean you can't see where the scratches were, and these were 80 grit scratches.

has anyone tried this?

...torches work like a charm...(being careful of course)....we did that to 1/4" plexi we had cut on a bandsaw and it went clear and smooth....

(well done)

o.k. team, i need info on air flow around the windshield,

i am making some deflectors to reduce the wind buffeting,

does the wind come round the wind shield and the dash panel or just round the windshield?

does anyone know how big a deflector i will need?

do i, in fact need doors?

would a Gurney lip on the edge of the windshield pillar do the same job or make it worse?

i know that some of you are budding aerodynamisists so lets define the problem so a minimal solution can be found to a big problem.

all help is useful so jump in please!

I'm not sure you'll be able to get rid of the buffeting completely by adding deflectors. Buffeting is caused by turbulent airflow due to the abrupt opening behind the windshield and scuttle. You can either try to get yourself out of the airflow completely, which I imagine would require substantial pieces sticking out the top and sides, or try to smooth it out. One thing you could try is smoothing the transition around the windshield by having the deflectors go straight back from the frame, with a little lip curve out on the end.

i have considered having the deflectors stick out infront of the pillars to force the air over the top as well as extending rear wards and out slightly.

the thinking is a bit like nascar roof runners which stop the air spilling over the sides.

i think it's a thing about balancing all the air comming into the cockpit to try and create a sort of dead area where my head is.

perhaps i should look behind the head position with a shield of some kind to trap air in the cockpit.

From an earlier post:
viewtopic.php?f=23&t=13379&p=137457&hilit=buffeting#p137457

Most of the Brits resort to 1/2 or full doors to stop the buffeting. That is what I am planning.

the air appears to scoot round the lower windshield, would some little deflectors pointing forward from the windshield posts help?

Judging from the streamlines on Chuck's simulation, I'd say side curtains would do a lot since most of the air seems to enter just behind the windshield. I wonder if you could get some cheap, clear plastic and cut it to fit, taping it on with painter's tape (or duct tape) to the windshield frame and side bodywork to simulate side curtains? That would give you a cheap way to evaluate their potential anyway. Maybe you could put some PVC pipe up in the shape of a roll bar behind the seats to have a rear attachment point?

It's a thought, anyway.

Cheers,

The air hits those big fenders and then deflects inwards towards your head is what I remember. If these cars didn't have the fenders near your head it would be less of a problem. So I vote for some type of plexiglass side curtain.

I think things on the sides of the windshield still leave the air to hit the rear fenders and come in. DOes anyone have the pointers to the pictures Andrew posted?

You'll get some good advice from some of our folks that are putting miles on their cars...

experiment time, long deflector for driver's side, short deflector for passinger side.

when my diff parts arrive, i can test it out to see if one is better than the other.

i will make some forward facing deflectors to see if they have any significant effect by preventing the spill over around the base of the windshield.

if all of this fails, i guess it's got to be doors and a roof.

the longer i looked at it the more obvious it became,

i need doors,

i've started making a plug for the passinger door from foam, this will be a lost plug layup 'cos i cant afford the cost of a mould.

looks straight forward to do, i will mount the hinges where the lift out roll cage fits, and if i need the roll cage, i can take the doors off.

note to myself, make a trailer big enough to fit the roll cage in.

I was looking at something else and one of Jack McCornack's videos came up. Here is a video of a test of cockpit turbulence. It's interesting and shows screens to make the windshield wider may not help much. Looking at this, I'm not sure I'll start with a traditional Seven body style after all.

http://www.youtube.com/watch?v=RU0R_r1yC-g