For a clean stockish look a diffusor would be be best,but it's hard to realize on a bug and remain subtle yet effective.

A diffuser will never be very effective on a beetle because of reasons already mentioned, but a little bit of effect from both would probably do enough.

One solution is to have a large rear wing like mine but make it removable. I can unbolt the wing and stanchions from the back of the car if I need to. It only leaves the feet of the stanchions on the car, you may have seen this on "ricer" cars. A smaller wing might fit up front or in the back seat for transport.

You could also try to make the ducktail spoler you allready have more effective.

In this autospeed article they talk about the vortex generators of the Mitsubishi Evo: Blowing the Vortex part 2
(a quote: "The longer the arrow, the faster the airspeed." :lmao: ..inside keversite joke)

They talk a lot about less drag in the article, but I think these vortex generators are also there to direct more air to the rear spoiler, making it more effective.

The new Beetle RSi also does this, but then with a rear window spoiler:

http://www.vwvortex.com/gallery/albu...e%20RSI/12.jpg

I think its primary function is to direct more airflow to the rear bonnet spoiler.

Just some food for thought.

Edit: I found the Mitsubishi research article, interesting read: Research article

Jason,sorry i missed your post up there, but to answer you, yes, i run it bare, running low is the secret, and lots of castor, i run it at 40mm as my regs dictate, a bit less actually, ive cut off or clearanced all the low points, and i also exploit the open deck technique, whereby the underflow air is used to flow into the normally turbulent air behind the car, killing drag and lift, you see it on many sports proto types etc, my deck lid and rear panel are massively vented to exhaust the airflow from over the motor, the deck lid hinge panel is gone for the same reason, the engine bay is also open to air, another huge plus for the wasser motor. does it work? well its a very stable platform,and i feel an outright win is on the cards next season. we'll see, there's no hiding place out there.

Cool! Tnx for the pic and article. We just need to be carefull not to seem as if we are 'trying' (although a watercooled engine is not trying of course..)...:rolleyes:

I think I am pretty close to a decent placement with my old wing I tried a few years ago. Could maybe just be a tiny little bit wider with a bit bigger end plates. Plenty work to do this winter :)
http://i174.photobucket.com/albums/w...03/DSC_281.jpg

And yes, good airspeed is always important ;)

Ive been following the latest comments here recently as I find the aerodynamics of a bug quite interesting.Have you got any pics of the rear or underside of your car Spannermanager.

Hi Mate, nothing with any detail, black just makes a lousy picture as all the detail is lost, this rear shot is curtesy of the apex festival,but its hard to see all the venting, the Red Maguire Imp is also exploiting open deck theories. I run various fairings underneath, all a bit crude as they get damaged often when running low to the deck, its smooth underneath all the way through to the rear torsion housing and rear ARB where there are more fairings, the ARB and mountings have to go next, Porsche style mounting is no good on a track car, its far too low, there are no jack points or lower 'a' arm shock mounts either, the a arms are flipped to improve the camber, nice and clean for the air, it will be flat bottomed right the way through over the winter, special parts are a pain in the butt when they get damaged!! you have to start all again, you also have to plan your hard points to jack the thing up quickly, and also carry ramps to meetings etc etc. I love it all tho', :)heres the Apex link,http://www.apexfestival.co.uk/event/Circuit_Racing.html

Just got back from Dyno-day (BTW 564 Nm = 418 lbs.ft) :):
http://i174.photobucket.com/albums/w...4.jpg~original

Wally is that wheel or adjusted at engine regardless very impressive and unbelievable.
Congrats
Alex

Thanks; thats corrected to flywheel-hp. A healthy totally stock 1584cc T1 with just cheap header exhaust made 55 hp and another stock 1600 with electronic ignition made 52hp, so the dyno seemed very well calibrated.
I think it turned out to be about 15% correction iirc, so its about 400 RWHP for you guys ;-)

Well done Wally.

Wow! 564NM!! It seems the new cam did make a difference.300NM at around 3600rpm! I bet it pulls like an elephant on crack....
Well done Wally!!

is the small dip at 4000rpm the cam coming on? my n/a engine has the same small dip at 4000rpm as it comes on cam. very good numbers and i hope we can match your numbers with our new engine.

Calling that a dip or even a small dip is somewhat eggagurated perhaps, but I think I understand the spot you mean.
But no, thats not the 'cam coming on' imo. Cam comes on much sooner then that, as does boost. I'am sure I can tune that out if I wanted to, but it would be for visual pleasure only. Its not like you feel that minute change in rising rate hp-climbing ;)

I think the engine is now 'perfect'. Early super high torque and very high hp when you step on it some more. It does everything you throw at it. I wouldn;t know what to change or what would make it better. It also picks up from 1200 rpm onwards in 3rd gear (mine is a long one too) crawling through town.
So, I was thinking of selling the engine and all ancillaries that make it work (for way less then the parts cost alone) to finance my new '36hp Challenge' -love and I would also love to see the Apfelbeck-project through someday.
Not sure if there is a demand though.