Once again I have been revisiting certain parts of my car and I have never really been happy with my rear view 
I have come up with an idea that is more cosmetic than anything else, although it does give a nod towards being a diffuser. I will say at this point
that my car is primarily a road car, my daily driver in fact, so I am not concerned with ground effect efficiency.
Anyway, here is my rear view as it is now.
Rescued attachment Aeon diffuser idea.jpg
.... and this is what I am thinking of doing...
Rescued attachment Aeon diffuser idea1.jpg
So what do you think guys? I will leave it up to you to decide if it gets made or not. I am open to suggestions too 
quote:Yes and it's georgous!
Does my bum look big in this?
i like it! i would say though, make it a bit deeper, ie lower to the ground. what i don't like about the back of your car is how short it is
(i'm not sure that makes sense...) a deeper diffuser will make the back look less squashed up
i don;t tthink i explained that very well....
Oh yes 
that works very well go for it
i aslo say go for it it will look great
NICE ARSE in the second picture. GO FOR IT
Would have to say GO FOR IT! it will look the dogs dangalies.(not that it doesn't already but will definately suit it).
john
really finish's it off, go for it
Mitch
DO IT! DO IT! DO IT! 
in a way i like the metal work, but from a design point of view the second picture would make it look a lot better alrite, go for it i say to
instead of making unnecessary bit for your car, you should be cleaning the block paving of moss !! 
looks v.good; but could be better if you cean do soemthing about the sides to make it blend in a bit more with the skirt above; no idea what though.
Good idea, but I would make the vertical bits curved - they're a bit angular as they are.
Do it, but perhaps in black? Carbon would be nice (but not fake stuff)
If you are going to make a diffuser, why not make it (more) functional?
I have just read a book on downforce (by err err.. I'll let you know) and I think I understand a little bit about it, and with a couple of subtle
changes to your design you could make it a lot more functional (NO disrespect to your design intended at all!)?
atb
Steve
quote:
Originally posted by RazMan
.... and this is what I am thinking of doing...
I think the diffuser looks cool but why double up the tail pipes?
Caber
Wow, quite a response already!
Thanks for all the suggestions - I will try to answer them...
quote:
Originally posted by blakep82
i like it! i would say though, make it a bit deeper, ie lower to the ground. what i don't like about the back of your car is how short it is (i'm not sure that makes sense...) a deeper diffuser will make the back look less squashed up
quote:
Originally posted by David Jenkins
Good idea, but I would make the vertical bits curved - they're a bit angular as they are.
quote:
Originally posted by 02GF74
instead of making unnecessary bit for your car, you should be cleaning the block paving of moss !!
looks v.good; but could be better if you cean do soemthing about the sides to make it blend in a bit more with the skirt above; no idea what though.
quote:
Originally posted by balidey
Do it, but perhaps in black? Carbon would be nice (but not fake stuff)
quote:
Originally posted by worX
If you are going to make a diffuser, why not make it (more) functional?
I have just read a book on downforce (by err err.. I'll let you know) and I think I understand a little bit about it, and with a couple of subtle changes to your design you could make it a lot more functional (NO disrespect to your design intended at all!)?
quote:
Originally posted by caber
I think the diffuser looks cool but why double up the tail pipes?
Do it
i think just a flat black carbon look-a-like sheet would do the business.
My concerns would be it becoming a water and stone trap. Perhaps leave a 1" gap between it and the lowest chassis rail it meets. Should allow the
rubbish to drop out.
Yes, Yes, Yes, Do it, Do it, Do it
go for it i think it looks great
How about bring the grp lower on the wheel ? or is that too much work ?. I'm going to put some lower 'fins' on my rear as well
Rescued attachment Picture 034.jpg
like it a lot-but why not paint all the visible metal black so your eye is not drawn to it so much?
quote:
--------------------------------------------------------------------------------
Originally posted by MikeR
i think just a flat black carbon look-a-like sheet would do the business.
My concerns would be it becoming a water and stone trap. Perhaps leave a 1" gap between it and the lowest chassis rail it meets. Should allow the
rubbish to drop out.
--------------------------------------------------------------------------------
A very good point - you should see how much gravel I've collected in the front section I'll put in a couple of exit slots to let everything
drain out.
quote:
--------------------------------------------------------------------------------
Originally posted by jonno
How about bring the grp lower on the wheel ? or is that too much work ?. I'm going to put some lower 'fins' on my rear as well
--------------------------------------------------------------------------------
I am actually thinking on similar lines - I have noticed a lot of spray when driving on wet roads, so a kind of spat (as in your pic) built in would
be nice. See pic below
quote:
--------------------------------------------------------------------------------
Originally posted by ruskino80
like it a lot-but why not paint all the visible metal black so your eye is not drawn to it so much?
--------------------------------------------------------------------------------
Now that's just cheating I chose powder coated silver for the chassis so painting over it would not be much fun.
Here's my latest offering which has slightly lower fins , is wider and with more 'spat'. I've also removed part of the centre
spar
Jeeez how am I going to make this?
[Edited on 18-5-07 by RazMan]
Rescued attachment Aeon diffuser idea2.jpg
That makes the back look so much more 'finished', you should definitely do this.
Raz,
this is the book that was been lent by a racer friend of mine, as I intend to build a diffuser for mine (when I recover some money from actually
building it!)
If you are interested in some of the changes that it would suggest you make from both of your after pictures, then please U2U me and I will describe
in as much detail as I remember those changes !
cheers,
Steve
I have now done a scale drawing of my diffuser - quite a simple thing really.
Have I made any howlers?
The smaller end ribs are more for strength tyhan anything else.
[Edited on 21-5-07 by RazMan]
Rescued attachment diffuser drawing.jpg
the end view and the bottom view don't correlate - from the end view the fins (outermost) look like they run perpendicular (?) to the car ie down
the length of the car (this is how I would have it). but the bottom view would suggest that they are running at an angle (fine-ish) but in a straight
line rather than curving outward (preferred) to maximise disruption in airflow After the car...
don't mean to offend - I am trying to recall the info I gleamed from the books I've read recently as accurately as I can!!
Steve
Oops! You spotted my deliberate mistake
I have also added the mesh panel for clarity - it is going to be fixed to avoid hinging problems.
Rescued attachment diffuser drawing.jpg
Hi again Raz!
In spite of your "delberate mistake" - I still maintain that the Much More efficient layout of the fins would be to probably have 6
in total.
inner two: would be doing the channelling of the airflow, which starts at the front of the car, through to the slope of the diffuser, and therefore
creating the most efficient tunnelling effect.
next two: would be curved outward to make the most of whats sometimes called dirty air - a forced creation of vortices making inefficient air AFTER
the wake of the car therefore increasing the downforce by increasing the speed of the air underneath the car AND the upward rush of the air at the
back.
outer two: would be specifically acting as "Skirts" like a Formula 1 car. This prevents the ingress of dirty air from the side of the car
entering and disrupting all the good/efficient work that your flat bottomed floor and diffuser are actually doing.
The creation and efficient working of the outer two would require a change in shape of your design. Compare the shape of yours - a fan shape (sort
of) and the shape of that Westfield "plywood " special that you emailed me earlier - a rectangle shape.
hope this makes sense!!!
Steve
hmmm I think you are on the right lines but it is drawing my eye to the grill below the number plate, and it sort of looks like the new Audi front ie
that its got a beard.
definatelly on the right lines though, have you tried the colour change to black to see the impact?
Now that you mention it, I can see what you mean about the beard I have made a couple of mods to the grille which allows me to simplify the exhaust
(for when I fit the turbo) I first tried it with a single large bore exhaust but swmbo said it looked like a cat's bum so I went with the twin
tailpipe!
I can't really change the grille colour at this stage as it would contradict the rest of the (very expensive) stainless mesh elswhere on the car
quote:
Originally posted by gttman
hmmm I think you are on the right lines but it is drawing my eye to the grill below the number plate, and it sort of looks like the new Audi front ie that its got a beard.
definatelly on the right lines though, have you tried the colour change to black to see the impact?
quote:
Originally posted by worX
In spite of your "delberate mistake"
inner two: would be doing the channelling of the airflow, which starts at the front of the car, through to the slope of the diffuser, and therefore creating the most efficient tunnelling effect.
next two: would be curved outward to make the most of whats sometimes called dirty air - a forced creation of vortices making inefficient air AFTER the wake of the car therefore increasing the downforce by increasing the speed of the air underneath the car AND the upward rush of the air at the back.
outer two: would be specifically acting as "Skirts" like a Formula 1 car. This prevents the ingress of dirty air from the side of the car entering and disrupting all the good/efficient work that your flat bottomed floor and diffuser are actually doing.
The creation and efficient working of the outer two would require a change in shape of your design. Compare the shape of yours - a fan shape (sort of) and the shape of that Westfield "plywood
hope this makes sense!!!
Steve
Yes yes yes.... go for it. All o fthe ideas look great. Love the mesh and the twin tail pipes. Certainly finishes of an already superb car very well indeed.
How about painting the mesh body colour? That way it won't clash with the stainless mesh and removes the beard? I photoshopped the wrong image,
but you get the idea:
Looks miles better with silver mesh IMO.
Car design by committee, don't you love it?
quote:
Originally posted by flak monkey
Looks miles better with silver mesh IMO.
quote:
Originally posted by Tralfaz
quote:
Originally posted by flak monkey
Looks miles better with silver mesh IMO.
Agreed.
quote:
Originally posted by Tralfaz
quote:
Originally posted by flak monkey
Looks miles better with silver mesh IMO.
Agreed.
quote:
Originally posted by gttman
... but I would still like to see what the difuser looks like black.
I like that, I'd make it and paint it black.... if it doesn't look right you can always colour code it later...
Ok then, I have now made a very rough prototype from plywood (a la Westfield )
Rescued attachment Diffuser Prototype 1.jpg
And another view...
I have already decided that the radius on the rear edge of the fins needs to be increased as it looks too square.
What do you think guys?
[Edited on 30-5-07 by RazMan]
Rescued attachment Diffuser Prototype 4.jpg
That looks great... slap a bit of Hammerite on it and it'll be just fine!
Seriously though, it's a good shape.
Can you make the change in angle between the sections any less? I think this would make it more effective aerodynamically from what I remember.
I know your main reasons are aesthetic but if you can make it work at the same time then why not?
quote:
Originally posted by chriscook
Can you make the change in angle between the sections any less? I think this would make it more effective aerodynamically from what I remember.
I know your main reasons are aesthetic but if you can make it work at the same time then why not?
The angle the 'horizontal' bits make to the floor - ie make it smoother and less staircase like
does that make sense?
Maybe it needs to be a bit more aggressive, like this - From the GD website
Cheers
Fred WB
[crocodile dundee mode] Now THAT is a diffuser Maybe a tad too agressive for my car but thanks Fred
Chris, I see what you mean now but unfortunately I'm not very good at bending plywood The alloy version might be a bit bendier but it all
depends on getting things close to the mounting frame.
[Edited on 31-5-07 by RazMan]
That will look superb, go on you know your going to
I've now made an alloy version  (600 x 450).jpg)
I got tiggy with it (well actually a good friend did as I can't weld for toffee ) 2mm alloy for the main part and 3mm for the fins (which are
just tacked in for now)
[Edited on 2-6-07 by RazMan].jpg)
The view so far...
My main criticism is that the fins need to be thicker as they seem to dissapear when viewing from a distance. I might apply some rubber edging and see
if that improves things a bit.
[Edited on 2-6-07 by RazMan] (600 x 450).jpg)
Looks good that.
Are you still going to redo your exhausts?
quote:
Originally posted by DIY Si
Looks good that.
Are you still going to redo your exhausts?
OOppps. Should realy look at the before and the after pics before commenting! Single oval should look good, Boxster style job?
<Jealous>
I HATE you Raz (and TrevD)... you both make it look Soooo Easy! and Soooooo Goooood!.
</Jealous>
Cant wait to see the finished article, if its like the rest of the car, it will be brill.
thumbs up from me.
Ok then, here's the finished diffuser
Rescued attachment Painted & Fitted.jpg
And another shot - lots of shadows today.
I decided to add some silver coloured rubber edging to the fins, making them a little more visible.
[Edited on 7-6-07 by RazMan]
Rescued attachment Finished.jpg
Looks good Raz.
What ground clearance are you running your car at?
Cheers
Fred W B
quote:
Originally posted by Fred W B
Looks good Raz.
What ground clearance are you running your car at?
So my planned 80/90 mm is a bit ambitious then?
Cheers
Fred W B
Depends how many speed bumps you have! And wether you need the lower level for aero effects. You can also add 4-5mm black rubber sheet around the edge to give the lower apperance and help contain air flow under the car.
quote:
Originally posted by Fred W B
So my planned 80/90 mm is a bit ambitious then?
Cheers
Fred W B