E30 Aerodynamics

[Eric]

Andrew Lang is the owner of the white car.

[GillesBigCowboy]

You wanted an E30 with a rear diffuser? This isn't the greatest pic, but it has one.


Upon closer look, he has vortex generators as well as a really tall spoiler.
Will

Oh, yeah, baby!!!
That is wicked. It has side skirts as well... I would love to see more detailed photos of this one or similar. In future, we will likely be redeveloping my brother's specE30 into something more, and I am fascinated by this sort of aero. I discovered F1 in the skirted years of the late 1970s, and now lots of 18 wheelers are even using skirts... anyone who has good/detailed pics of diffusers and skirts on e30s, please post them!

[jalopi]

Wow that is ugly... but I bet it all works together quite well. Spoiler reminds me of the old Chaparral cars.

[DER E30]

Awesome :up: I like the LED light bar.

[BlackbirdM3]

You wanted an E30 with a rear diffuser? This isn't the greatest pic, but it has one.


Upon closer look, he has vortex generators as well as a really tall spoiler.
Will

[rwh11385]

I run a Brooks Pro wing with a plywood splitter. Gave me about 1.5s per lap. I run the wing with barely any AOA. It's amazing how affective it is on high speed corners.

That car is great.

[Chris916]

I run a Brooks Pro wing with a plywood splitter. Gave me about 1.5s per lap. I run the wing with barely any AOA. It's amazing how affective it is on high speed corners.

[DER E30]

I keep dreaming of a diffuser... thinking that could add some good downforce without adding much drag...
I don't think I have ever seen one on an e30.

DO IT!

I keep dreaming of building a chopped (bout 2.5inches) e30 showcar, M style trunk, modded C pillar like an M-ish, integrated cage (bars IN the pillars), my interpretation of M fenders, bags, S65...

[GillesBigCowboy]

I keep dreaming of a diffuser... thinking that could add some good downforce without adding much drag...
I don't think I have ever seen one on an e30.

[BlackbirdM3]

I've always thought it would be a neat experiment to slap on all the M3 drag reducing aero bits (Evo valences, rubber seals, rear windows, trunk, etc.) on a 318is just to see if the MPG is better. I can't decide if M3 C-pillars, rear window and trunk (sans spoiler) would look weird and cool without the box flares or just weird and ugly.

It would look different. Lets put it this way I can get about 28 mpg on the freeway with the rear spoiler extended (I tried running it in closed position and seem to get worse mileage) at an average speed of 75 mph. This is on an engine that is a little tired. I've pulled well over 300 miles out of a tank of gas. I'd be really interested to see what it could do with a fresh motor.

I have the Evo hood seals, the Evo front seal across the top of the grill, below the hood, and I also have the one for the bumper, but its still sitting in a box.

Will

[word is bond]

Best aero mods for an E30? Pretty simple, look at an M3, all done by the factory,tested, and race approved. The rear window and trunk lid made a huge difference in reducing drag. That alone lowered the CoD from 0.39 to 0.33, front splitter and airdam? Evo 2 airdam with Evo3 splitter. Seal up all the gaps around the hood and grill, (all stock evo parts that can be ordered with little trouble.)

Will

I've always thought it would be a neat experiment to slap on all the M3 drag reducing aero bits (Evo valences, rubber seals, rear windows, trunk, etc.) on a 318is just to see if the MPG is better. I can't decide if M3 C-pillars, rear window and trunk (sans spoiler) would look weird and cool without the box flares or just weird and ugly.

[SA E30]

[RoccoB517]

A pretty good explanation of gurney flaps.

http://www.youtube.com/watch?v=TK8-VuwPqq4

[TobyB]

The stock E30 is drag limited at an absurdly low speed, so keeping drag down may actually
be more beneficial than trying to add download for corners- any gain in the corners can
be more than eaten up in a straight line by drag.
That said, aero download that doesn't cost you much in drag,
especially something like a big front splitter,
will let you readjust suspension settings (in particular, reducing static front camber)
to gain in other areas, particularly braking.

Racing isn't always the best guide, though, as the M3 in DTM was aero- restricted-
sure, they did the best the factory could, but they were restrained by rules that may
not apply to you. Likewise, there is "no" aero development in Pro3 because we can't.
Not because we don't want to.

And Mythbusters proved that you want to dimple it just like the golf ball, didn't they?

t

(ps, a Gurney flap is a way to increase wing download a LOT at the cost of relatively
minimum drag, and since it's easy to change, it's very useful for tuning)

[Ether-D]

@RWH, I was there that weekend. It was hotter than the devils anus and I was changing tires the whole time I think...