I fitted a saturn one and although I can't comment on the aerodynamic qualities I will say it stops the back end acting like a parachute and the car feels more stable at high speed. I would highly reccomend making one.

Speaking of aerodynamics, I have seen a few 7 replicas going around with little wings attached to the front nose cone, apparently it helps with front downforce. But I haven't got a clue about aerodynamics either. Lol:D

Ok I made a rear undercover panel which I hope will stop this "parachuting" effect people are talking about. It's not going to be to everybody's taste but I might make some alterations if it doesn't look right when it's fitted.
I cut some holes in the middle outlet to release some of the air coming through the transmission tunnel. I'm thinking of adding a mesh grill to this outlet also to give it a bit of character.









Hoping it will look better when it's black and fitted to car.

I like it! I think you could sell them to others!

I'll second that. Very nice indeed :)

Very nice. I am trying to get my rear panel lined up. Is it possible you could take a picture of how you have lined it up in relation to the back and the bit of the chassis that goes along the back of the tank.


Hope that makes sense.

David

Well I've slept on it and I'm going to make a few changes:eek:
Not happy with the back, should have thought about it a bit more before ploughing in.....:o :o sorry but that's the way I am..lol
I might have time to change it later after watching my son play football at Grimsby, depends on what time I get back.

Thanks for your comments guys anyway.

Hi David, not quite sure what you mean? Do you want me to take photos from above and below the rear tub with or without the fuel tank in.

Just out of curiosity how do you multi quote people as I haven't a clue.:o

The parts you did looks very nice, the finishing is always amazing when it comes to your build, stunning :cool:

However, as Phil said on a previous threads about rear diffusers (quite a long time ago), it might help to reduce the "parachute effect", but certainly not stop it, as air will always comes from the wheels openings, where the wishbones are. Unless you close this area (and it would be quite difficult to do, considering the wishbone arms and drive shafts has to go through), air will always find its way and the rear tube act like a parachute. The only good way to suppress this parachute effect would be to cut holes in the rear tube so the air can escape. Just my humble opinion ;)

But the rear diffuser you designed and built can't be harmful anyway, very nice job :)

For multi-quote, I just open different instances of the forum on my browser, ans copy-paste.

Yes please above an below. Tank in is fine. I just seem to have a really large gap at the back

David

Ok I had another go at my under tray tonight. Not quite finished yet, got to make some pressed covers to go under the wishbone cut outs and cut more holes into the rear outlet panel and a few other tweak's.
I've created a slot at the rear above the strakes to allow some of the air to be released from the rear tub area, I guessed it might help.

I took Phil's advice and was hoping he was going to post his revised drawing (why did his original post disappear) so I took a stab at it on my own.
The angle at the rear is about 12 degrees and the whole assembly is made from 2mm aluminium.












Well that's it for tonight...cya.