OK, I've tried searching but there's so little real info in most threads so I'm creating my own post.

Who here actually knows something about aerodynamics? I'll be moving back to Germany soon and want to find a way to increase my MCS's autobahn-speed stability. I've been thinking that the GP underbody panels should smooth out the flow underneath, would this help? Would it be better if I tried to source GP side skirts as well? I noticed the the front gets very light at high speed. Would a front splitter/spoiler solve this or would rear downforce (i.e. JCW/M7 wing) be a better solution. I'd prefer to keep the visual changes subdued, but appreciate any recommendations.

Thanks,

Drill

 

Hmmmm well first I'd like tobe clear, is the forntend light?, if thats thecase a rear wing is going to add rear down force making the front lighter.

I'd sawy lower it, front splitter take some aluminum sheets (like the air ducting pieces at home depot, then flatten them out) cover up and smooth out what you can under neath (but I don't expect it to make a huge differance) MPG,top speed and stability will be enhanced the clear yougetrear air flow, rear diffuser, better spoiler (and I'd love to see something like the wing on the top of the rear window of a WRX on the sides to keep the air over the boot smooth and the boot cleaner) side skirts, lower and smoother get better airflow, air dam I'd say take it as low as you can legally go.

 

Here is an excellent layman's article on automotive aerodynamics check it out.

http://www.sportcompactcarweb.com/te...t_2/index.html

 

At some tuning shop here in Japan, I saw some kind of bolt on rear-diffuser plate for MINIs. I don't have the paper with the shop's name on it, but I don't think they have a good website anyway. Sorry for no pictures, they didn't want me taking any.

Anyway, this part was a replacement for that metal plate under the battery box, and covering part of the exhaust. This diffuser was about as wide as the car and had a spoiler shape and aero fins on it. Expensive, and on the heavy side too. You might be able to make something.

I don't think diffusers would make any difference unless the car was very low to the ground.

 

Thanks for the link

 

I still have to drive it But I understand your point. I think the TSW springs will have helped. I'm also looking into vortex generators (VG) but will need to find some that aren't too "rice" I may eventually wind up with the Straßentech front lip, GP underbody panels (perhaps with a strategically placed VG or 2 underneath) and then trying to find a solution for the rear

Thanks and keep the ideas coming

 

didnt hamman make a rear diffuser for the mini at one point? Im sure i used to see a pic on some website showing it. It was basically a spoiler that mounted under the rear bumper, looked alot like their front splitter actually. Beecher

 

The problem is... Hamman = $$$$$$$

 

if you can find one... GP rear wing!!! I though m7 had a rear diffuser as well. It doesn't help that our mini are basically bricks.

Another thought is hood venting like the mitsu evo. Flow is forced through the front and channelled up and out of the hood. That would certainly change the look of the hood.

Though it doesn't help, the R56 aero kit is supposed to actually help at the speeds you were looking at. I don't know if the R53/50 JCW aero kit was wind tunnel tested.

 

I wrote, if I remember for the R56 and it was lengthy, about aero. I spoke and exchanged info at length with one of the williams/BMW F1 aero engineers over a fairly long period a year ago. The advise below is what I gleaned fomr our conversations. The only real mod that you can transfer from the R56 is the little spoiler running top to bottom along the B pillar - this cleans up the air flow as it flows along the side glass and attempts to wrap around the car's rear window. This device tailors the air a bit.

The mini's short front and rear overhang make aero aids very difficult.

This is not a cheap endavor, nor is it easy. Keeping this simple, go with the GP and or Aero kit and you'll be fine

 

Drillslinger, Hope that the link helped.

All the "Diffusers" you have mentioned so far are not real diffusers, they are front lip spoilers. A true (meaning functional) diffuser will not only stick out from the front of the car but will also wrap underneath the car back to the front wheels.

Keep in mind that if you wouldn't go out and stand on the front lip aerodynamic you are thinking of installing it won't do any good.
A real aerodynamic component will generate more down force than you weigh.

So far all of the streetable MINI aerodynamics I have seen are purely cosmetic. I'd love to see some that are truly functional, so somebody prove me wrong.

 

Here's another good site for automotive aerodynamics - www.mulsannescorner.com

 

Thanks guys. I'm not looking for Lotus downforce here, just a little something to help improve things as they stand

The R56 C Pillar lip is an excellent idea. And I wish I could afford the GP rear wing, but there's just too much involved in that one :impatient

The problem with rear diffusers is space and cost Getting around the exhaust is a PITA

I understand that most parts offered are cosmetic, but I'd like to find something that looks good and functions... at least a little bit

Thanks again

 

Is this the rear diffuser that you're thinking of? It's made my Hamman. http://www.revozport.com/mini.html

It's $750 and CF, but Erebuni makes a similar fiberglass piece for only $80 or so. Looks kinda cool too.

 

Design Unit Zone




HTH

 

Thats the one I saw at the tuning shop outside tokyo! I want it.

 

Whoa... that certainly looks the part

I wonder how effective it would actually be though, and of course, I have no idea how much 88,767 ???Yen??? is

 

About $807...maybe study its shape and make your own.

 

Yeah, I was thinking about that Or at least... designing my own and having someone who actually knows what they're doing make it for me

Thanks

 

A rear diffuser is a very complicated device to get to work correctly. The photo above looks beautiful, but the are some serious draw-backs to how it actual works, in my opinion.

A diffuser works when the air mass moving thru it is clean. Unfortunately, controlling the air flow under the car begins with the front and unless all else is tailored to work with a diffuser, its affect is diluted. Managing heat, and air flow disturbance from the rear wheels are two monumental tasks.

One of the key drawbacks found with the mini is it short front and rear overhangs. The air meets the front of the car rather abruptly and then leaves it rahter abruptly...it takes time and distance ( length) to gather up the air moving under the car. The purpose is two fold; clean up the flow, and, merge the two ariflow masses joining at the rear of the car - from above and below.

I began to study this area when I stumbled across the notion of creating a traped vortex off the mini's hatch. The idea here was to get the air to form a vortex at speed that would literally suck air off the roof, bring it down close to the hatch and have it merge GENTLY with the air mass leaving the diffuser. The length of the diffuser, and its angle is critical!!! Get it wrong and the potential is much more drag than a tock set up.

The above diffuser probably works to some degree, but its angle, and, its position - does not extend far enough out from the bumper - look a wee bit off to me.

The new mini, have some very interesting aero details, all of which work. Pay close attention to the tabs and their exact position under the front bumper, and, to other tiny details. This car's over all shape, however, is not aero, witnessed by it rather upright windshield.

Proper aero design requires a windtunnel and lots of money...an interesting tid bit, among others; a car with huge down force complicates gearing since the added down force drives the tires into the ground decreasing their working circumference. So the interaction between gearing, downforce and tire construction play a huge role as well - obviously this is related to pure race cars, but the point here is that this is a very complicated subject.

 

yeah, that hammann one was the one. That revosport site is dodgy, ever notice how there is no way to contact them on there. Weird. that DUZ one is hot, i want it. Next winter i was going to try to get my hands on some GP underbody bit, but i might just make my own, but man, with my car slammed, and this diffuser sticking out, it would look killer Beecher

 

nice! rough guess is 1k usd plus shipping and duty.

Well, Drill Slinger, ask 'em for a discount as you will do high speed testing on das autobahn for 'em!!!

 

Check out the rear diffuser on the JCW Challenge car. This is the sweet, (and I'm sure FUNCTIONAL), setup.



You want down force?

I got your down force right here!

 

I hear ya meb, and I'm not looking to affect my Cd much, if any. I just want a little more stability at speed. And the last thing I want is to do the wrong thing and induce porpoising