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aerodynamics v's mini https://www.ausmini.com/forums/viewtopic.php?f=2&t=58639	Page 1 of 3

Author:	Phat Kat [ Mon Nov 09, 2009 11:40 pm ]
Post subject:	aerodynamics v's mini
Yeah yeah I know,,, its a brick why the hell are you asking .. No seriously,, just wondering if anyone know of any successful attempts to do something about the aerodynamics of these cars? What I have heard is a little conflicting.... I have read one very well know engineer saying that 123mph is THE top speed for a mini.... I have read another hillbilly say that one of his speedway minis got up to 122mph on a speedway circuit.... And I vaguely remember one of Paul Gulsons clubmans could do a stable 140mph and would start getting shaky at 150mph,, and that he could hit 140 at Amaroo!!.... And another credible source has also stated that 150mph is where they take flight..... So whats the go? Anyone know? Does anyone know of *the* fastest speed ever reached in a mini? Does anyone know of any bodies attempts to de-brick-ify minis for the sake of making the go faster that have worked? There has been alot of questions lately about 0-100 times and gives us your engine spec blah blah blah,,,, this is just one of those ones that has always nagged at me... its my turn to ask one of those questions that every body's ""inner ten year old"" always wants to ask but never does Any ideas?

Author:	BALLISTIC [ Tue Nov 10, 2009 12:04 am ]
Post subject:	Re: aerodynamics v's mini
Phat Kat wrote: Does anyone know of any bodies attempts to de-brick-ify minis for the sake of making the go faster? its my turn to ask one of those questions that every body's ""inner ten year old"" always wants to ask but never does Any ideas? Yes

Author:	Asphalt [ Tue Nov 10, 2009 12:13 am ]
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http://www.carbonweezel.co.uk/testing.html I hit a genuine 108MPH with a MG-ish engine. And I know that the Honda guys (over 140BHP) can hit the 130-135MPH barrier. What do we learn? Air resistance climbs exponentialy, not linear. "With a doubling of speed the drag (force) quadruples. Exerting four times the force over a fixed distance produces four times as much work. At twice the speed the work (resulting in displacement over a fixed distance) is done twice as fast. Since power is the rate of doing work, four times the work done in half the time requires eight times the power" (wiki). So to go past the 140MPH barrier he must've had... A hell of a lot of BHP

Author:	mickmini [ Tue Nov 10, 2009 6:18 am ]
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Dunno about what the absolute top speed ever measured in a Mini is, but I can answer some of the other questions. First a little maths - boring I know, but it explains everything. The ultimate top speed is determined by the force that you can apply to overcome the air resistance. In other words you will keep getting faster until the thrust you can apply is equal to the drag force - i.e. you reach equilibrium. Thrust (P) = Drag (Fd) Fd = Cd x 0.5 x rho x A x V^2 P = Fd x V So rearranging to V = (P/[Cd x 0.5 X rho x A])^-3 So the power to speed is basically a cubic relationship. You can see that you can increase the speed by increasing power, decreasing frontal area or reducing drag. We all know how to increase power, so you can reduce frontal area by removing the windscreens as in the speedway cars or like this OR you can reduce the Cd like this Will be very interested in the results of the MIRA testing in the link that Asphalt put up ..... cheers michael

Author:	Blokeinamoke [ Tue Nov 10, 2009 6:21 am ]
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or you can reduce frontal area like this

Author:	GT mowog [ Tue Nov 10, 2009 6:42 am ]
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blokeinamoke wrote: or you can reduce frontal area like this That's a fairly in-expensive route to doing the job, but the passange might end up with a crick in the neck..... Might also have a bit of trouble passing MOT (or is it RCW?) as the wipers are a bit dubious and the washer jet might not hit the windscreen. Must be a quick car though, judging by the crowd that it has drawn.......

Author:	'77 clubby van [ Tue Nov 10, 2009 8:19 am ]
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I think it might pull a little to the right too, which might be a little distracting at 140mph!

Author:	peterw [ Tue Nov 10, 2009 10:03 am ]
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Might run alright at the speedway.

Author:	'77 clubby van [ Tue Nov 10, 2009 11:09 am ]
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peterw wrote: Might run alright at the speedway. Nah, wrong direction for the speedway.

Author:	Blokeinamoke [ Tue Nov 10, 2009 11:11 am ]
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'77 clubby van wrote: peterw wrote: Might run alright at the speedway. Nah, wrong direction for the speedway. not in reverse

Author:	'77 clubby van [ Tue Nov 10, 2009 11:32 am ]
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blokeinamoke wrote: '77 clubby van wrote: peterw wrote: Might run alright at the speedway. Nah, wrong direction for the speedway. not in reverse Come on. Be serious. It would be dangerous to drive in reverse around a speedway track. Bad for your neck!

Author:	Curly [ Tue Nov 10, 2009 1:23 pm ]
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I once built and raced a very quick, light-weight, Cooper S engined Moke that was log-booked with CAMS as an 'Open Sports Car' (that's why it has doors and extended rear guards ). It had a raked front end and was at least 120kg lighter than my Group Nb car; it was faster too - up to about 80 mph, but after that it was hopeless. The aerodynamics of a 'Brick', although nothing flash by today's standards, are still streets ahead of the Moke

Author:	feralsprint [ Tue Nov 10, 2009 2:48 pm ]
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Tried sports sedans with big front air dams but that only helps a little but this is how you fix a bricks aero I think Steve Evans had the fastest evre speed in a mini at Sandown in the old KG 1600 crossflow something like about 145ish MPH, as for Amaroo the straight was uphill and had a right hand turn in it so no 140 there

Author:	Kennomini [ Tue Nov 10, 2009 5:35 pm ]
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I would like to know what can be done/added to a std shell to increase the aero and down forces. Like a body kit that actually increases performance, a rear spoiler or "whale tail" to increase down force or reduce drag, is it worth while adding alloy/plastic plates under the sub frames to smooth out the underside to reduce drag, is it worth while removing the badges, gutters and seams?

Author:	Morris 1100 [ Tue Nov 10, 2009 5:47 pm ]
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feralsprint wrote: ...as for Amaroo the straight was uphill and had a right hand turn in it so no 140 there Yes but it was Paul Gulson. That alone would have to be worth 15mph. It would be possible to do 140 or more on the track. You just need a more aerodynamic car in front of you. I got over 100 on the F4 in my 1275LS with a Toyota in front of me! The fun ended when he changed lanes and I lost 10mph. The fastest bit at Amaroo in my Holden was around the back through Mazda corner. I am glad they moved the dirt bank in the late 80s. I tried to move the dirt bank in 81 with my first Morris.

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