e-Golf rear belly pan advice

[freebeard]

Thanks, I get that. Put another way, would a cambered panel begin, average or end at the prescribed angle?

Or am I just over-thinking things?

[JulianEdgar]

Originally Posted by freebeard

Thanks, I get that. Put another way, would a cambered panel begin, average or end at the prescribed angle?

Or am I just over-thinking things?

Probably 'average'. But in my opinion, this degree of precision is simply un-needed on normal cars. (It harks back too much to a prescribed template - and all that guff.)

In my book I say 8-10 degrees for rear diffuser angle. But if someone did some testing and said, say, 6 degrees worked best on their car, I wouldn't have an issue.

[IRONICK]

Originally Posted by JulianEdgar

In my book I say 8-10 degrees for rear diffuser angle. But if someone did some testing and said, say, 6 degrees worked best on their car, I wouldn't have an issue.

You realize that we don't care what you wrote in that book.
---
Ontopic, some diffusers even have rear flaps, automatically positioned as needed, maximum downforce or reducing drag.

[JulianEdgar]

Originally Posted by IRONICK

You realize that we don't care what you wrote in that book.

"In my book" = shorthand for "having read several hundred SAE aero papers, and read every major book ever published on car aerodynamics, having done on-road test and development, and having had the draft text reviewed by four top professional aerodynamicists, my summary is that...."

Since you apparently consider the number of doors a car has is an important aerodynamic criterion, I wouldn't expect you to be seeking out good information.

[freebeard]

Real [race]cars don't have doors.

[IRONICK]

Originally Posted by JulianEdgar

"In my book" = shorthand for "having read several hundred SAE aero papers, and read every major book ever published on car aerodynamics, having done on-road test and development, and having had the draft text reviewed by four top professional aerodynamicists, my summary is that....".

And so? Appreciation is earned, and not with the praise on the forums.

Originally Posted by JulianEdgar

Since you apparently consider the number of doors a car has is an important aerodynamic criterion, I wouldn't expect you to be seeking out good information.

I was too subtle in that expression it seems.

[marketroid]

Originally Posted by IRONICK

No Airtabs!

Here you have a items list with the Golf 8 new deflectors arms mounted on the Golf 7 (eGolf):

5Q0501733 - 1pcs
5Q0501734 - 1pcs
8E0825267 - 4pcs
91133501 - 4pcs
90920301 - 4pcs

Yes, thanks. I've got those sitting in my basement waiting for me to install them as well.

[marketroid]

Originally Posted by Vman455

Here's the Leaf's diffuser:



It has a pronounced upward curve. I measured the diffuser panel on my Prius at 10 degrees from horizontal.

My question about the holes comes from looking at the Leaf's diffuser -- the just barely visible one midway up the picture on the right and the three readily visible ones more toward the front (behind the axle?).

I've also been looking around to try to find a picture of the underside of a Golf TGI. The CNG tanks for CNG-powered VWs are apparently covered with shields like 5Q0825197F which also seem like they could work to fill that void, if I can figure out to attach it to a non-CNG car...

[marketroid]

Originally Posted by JulianEdgar

With the pictured undertray, it might also be a good idea to:

- add flat plates to the suspension arms so that when they are in their normal position the undertray is more continuous

- put a rolled radius on the leading edge of the undertray behind the suspension arm openings so that flow re-attachment can more readily occur

Thanks for the input! The deflectors IRONNICK posted are already on my agenda to play the role of the "flat plates" on the suspension arms.

[IRONICK]

As you can see in the pictures, you have a lot of places to support the diffuser.
Ideally, you should stiffen the diffuser an aluminum metal frame.