improving aerodynamics with OEM parts

[coullstar]

Very intelligent modifications.

That brace will do nowt, Robin. Unless they can prove me wrong..

and me, looks pointless.  It seems to narrow to add any noticable chassis stiffness and the holes in it will nowt.

[the bruce]

Do You know these braces?

[the bruce]

There's only enough space for it when there's no center exhaust or if you have a
very small c.e. like ATP or Supersprint:




(number 3 in the picture)


1K0 825 206 A - Unterbodenverkleidung links hinten
N 909 707 02 - Schnappmutter 2 x
WHT 000 713 - Sechskantbundmutter (2 x ??)
1K0 825 221 - Winkel
N 905 483 03 - Sechskantbundschraube M8
N 901 838 02- Sechskantbundmutter selbstsichernd
N 908 338 01 - Spreizmutter

[RedRobin]

Do You know these braces?

....I don't know any of these braces. The consensus of opinion here seems to be that the Mk5 Golf chassis doesn't need stiffening braces. Obviously there wouldn't appear to be any aerodynamic improvements. I don't know enough to have formed an opinion yet.

[danishmkvgti]

2a and 2b and 4, do you have partnumbers fo these and accesories??  thx  

[the bruce]

"4" is "Verkleidung Hinterachse" = "Hinterachsverkleidung" = rear axle cover:

Easy and quick to install !!

Part numbers for 2a and 2b will come soon, these are OEM-parts from Audi TT and A3.

Attention, all these parts at the rear do fit fwd cars only !!



@ Robin:
I know that the Golf V doesn't need additional braces. But when I saw the braces
on page 1 I'd too show You these.

 

[gillm]

Very intelligent modifications.

That brace will do nowt, Robin. Unless they can prove me wrong..

me too , looks like the only thing it will do is lighten your pocket , mk5 is stiff enough for road use which 99.9% of car on here do . also "my thoughts only" if you have a mk5 really stiff on the back defeats the point of indapendant rear corners

[the bruce]

I guess we all agree to this.  


2a & 2b:

left side:  1K0 511 539 E 5,12 €
right side: 1K0 511 540 C 5,30 €
8E0 825 267 0,44 €  4 x

Pease note: little bit tricky to fit !!

[bodger00]

Really interesting stuff here. I wonder if they make any difference to fuel consumption?

[the bruce]

Really interesting stuff here. I wonder if they make any difference to fuel consumption?

a very small amount at highway speed 

Most parts are factory fitted to the eco Golf TDI blue motion, so they should make a difference.

My main motivation was reducing aerodynamic lift at the rear (~ 35 kg @ 200 km/h) for better
stability when high speed cornering. I don't like huge wings, so I went for invisible parts.

[RedRobin]

My main motivation was reducing aerodynamic lift at the rear (~ 35 kg @ 200 km/h) for better
stability when high speed cornering. I don't like huge wings, so I went for invisible parts.

....Invisible wings, huh? But will they make your baby fly?  

Btw, we don't get much opportunity to enjoy autobahn high speeds in the UK  

[the bruce]

I'd try these one underneath my car. Any tipps for fitting them at the right place? 

   As you see - wings add safety !! 

Perhabs you have more race tracks in the UK. And high speed on autobahn becomes boring in the long run.
Safety and noise emission regulations make it hard to in germany to converse former airbases to race tracks.

[cmdrfire]

Does anyone know if the 'golf ball' pattern actually makes a difference?

The dimples do make an improvement aerodynamically, primarily by inducing a lowering of the drag coefficient by improving the Reynold's number:



As a note, maybe 10-15% of an "eco" car's efficiency gains are from improved aerodynamics on the underside.

Remember though that increases in aerodynamic downforce also result in increases in drag, making the vehicle less efficient and and reducing vmax.

I saw a few years ago on one of the American forums someone had fitted an undertray and a crude diffuser which he said improved high-speed stability; something which is entirely plausible, but which lacked any form of quantiative testing.

Undertrays designed to reduce drag will not, in my opinion, improve high-speed stability.

[RedRobin]

^^^^
Still pissing excellence I see, Neo!

Now stop all that and get on progressing the LED tails project      [I got your txt -Ta]

[the bruce]

Thanks for the pic. 

Remember though that increases in aerodynamic downforce also result in increases in drag,
making the vehicle less efficient and and reducing vmax.

.....

Undertrays designed to reduce drag will not, in my opinion, improve high-speed stability.

Yes, but we talk about reducing our Golfs' lift. There's no chance for real downforce. 
These undertray parts reduce turbulences and these tubulences cause both - drag and lift.
A smoother undertray helps getting a laminar air stream. The smoother, the faster the air
will pass the car's underbottom. The faster the air, the less drag and lift.

Just advantages, no problems. Just my 2 cents.