Show us your spoilers!

[dlacey]

This is an original ~1973 Alpina Alloy Air Dam,  fitted in UK when car was new, together with these 'quarter bumpers'.

 

This type of airdam mentioned in James Taylor's BMW Alpina book, it says these alloy ones were quickly superceded by glass fibre designs

 

 

[bento]

Very nice @dlacey. I really like the bumper too. I’ve never seen either before.

[tzei]

As wide, high and far back as rules allow.

[e31fan]

[Pdxguy]

On 4/4/2021 at 7:22 PM, Teelinger said:

Koogleworks front.

 

Which style of the kooglewerks? (long, medium, short or slim), and high mount I am guessing? Great look

[Teelinger]

@Pdxguy slim and low mount. 

[visionaut]

10 hours ago, tzei said:

 

As wide, high and far back as rules allow.

 

Damn, your wing looks surprisingly close to where my BMP Design wing sits. Would you happen to know those rule dimensions offhand? (and whose regulations?)

 

Curious as to your impressions on the differences in stability at speed with each of your rear aero bits..

 

Tom

[irdave]

9 hours ago, e31fan said:

 

Dude.  Maybe some more pics of this?

[tzei]

8 hours ago, visionaut said:

Would you happen to know those rule dimensions offhand? (and whose regulations?)

Width as per FIA homologation so i use #1663. From side view it has to fit in a 200 x 200 mm square with all mounting parts. Max overhang from chassis is 50 mm. De Facto same rule as our national group F rally cars. Governing body is Historic Race Finland. Safety regs comes from AKK motorsport.

 

About aero bits in back… can’t really do a-b testing with these exept the wing. As for rear wing i can tell that all helps at speed. 1st was narrow & low, 2nd was this wider but low mount and difference could be felt. This wide & high config - i’ll find out next weekend. So far so good.

Edited June 30, 2021 by tzei

[visionaut]

16 hours ago, tzei said:

Width as per FIA homologation so i use #1663. From side view it has to fit in a 200 x 200 mm square with all mounting parts. Max overhang from chassis is 50 mm. De Facto same rule as our national group F rally cars. Governing body is Historic Race Finland. Safety regs comes from AKK motorsport.

 

About aero bits in back… can’t really do a-b testing with these exept the wing. As for rear wing i can tell that all helps at speed. 1st was narrow & low, 2nd was this wider but low mount and difference could be felt. This wide & high config - i’ll find out next weekend. So far so good.

Thanks - great info.

 

FWIW, my wing has 175mm chord length, 25mm thick profile, with cambered upper and lower surfaces. My span is much narrower at only 120cm width, as it ends above the deck lid creases on each side. My trailing edge sits only 20mm aft of the deck trim, and 145mm above (so not as tall), and has a fixed angle of attack obviously. It wouldn’t fit your 200x200 spec mainly due to the length of the risers.

 

I’m an aero geek - and dig the workings and specs. (I’ve even applied the taped yarns to see the effects… and started working on a Gurney flap add-on for it. Lol..)

 

Mine seems to help reduce buffeting and settles the rear at speed… even with the turbulent surroundings. I expect It’d be better if I could manage the airflow to it or place it farther aft in the flow to max it’s potential, but I’m okay as-is.  My brick flies well enough.

 

Good luck with your upcoming weekend!  Curious to hear your impressions/results with version #3.

 

Tom