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#1 Gsybeach

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Posted 28 September 2010 - 09:26 AM

Has anyone tried putting a rear diffuser/floor tray on a Zcars mini? If so, does it make much difference to handling at speed?

#2 Sam Walters

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Posted 28 September 2010 - 12:22 PM

Has anyone tried putting a rear diffuser/floor tray on a Zcars mini? If so, does it make much difference to handling at speed?


Pm me your email address ill send you some information related to mini aerodynamics.

Edited by Sam Walters, 28 September 2010 - 12:23 PM.


#3 brandon7

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Posted 28 September 2010 - 08:10 PM

I can tell you in three words... Brick on Wheels

Anyway
Do you think you go fast enough to need a diffuser? Are you planning on tracking your car

#4 Gsybeach

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Posted 29 September 2010 - 08:36 AM

I take it you've tried it then??

Was thinking more for one the track

#5 cptkirk

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Posted 29 September 2010 - 08:56 AM

One thing it will definitiely do is stop the back of the car acting like a sail.

I put one on mine but I havent been able to test back to back with or without it, I would has at a guess that it does help, it may be marginal but I think if you coupled it with a decent roof/ aft of roof spoiler then you would see greater gains in downforce at the rear, but thats only half the car sorted.

However - that said it is shaped like a brick and IMO if your doing speeds that'll require the extra downforce you'll really need to address the whole car with a front splitter and smooth under belly to assist the diffuser. I aim to add front splitter in the future.

Carbon Weazel diffusers are real nice looking and super F-ing expensive, I was of the thinking that something is better than nothing, its not going to creat drag so go for it.......

#6 Sam Walters

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Posted 29 September 2010 - 09:43 AM

One thing it will definitiely do is stop the back of the car acting like a sail.
Carbon Weasel diffusers are real nice looking and super F-ing expensive, I was of the thinking that something is better than nothing, its not going to create drag so go for it.......


And well useless. It would only be beneficial with a flat under tray going out to a splitter at the front, something iv`e been banging on about for years, designed, but haven't got around to creating.

Posted Image

For the effect to actually work, you would need to run skirts also. But the reality is, your probably never going to be able to get a non space frame mini that low.

Edited by Sam Walters, 29 September 2010 - 09:59 AM.


#7 cptkirk

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Posted 29 September 2010 - 11:22 AM

It would only be beneficial with a flat under tray going out to a splitter at the front, something iv`e been banging on about for years,



Hold on - isnt that what I just said >_<


you'll really need to address the whole car with a front splitter and smooth under belly to assist the diffuser.



Sam I agree with what your saying.


But the reality is, your probably never going to be able to get a non space frame mini that low


Out of interest how low is low? Are you talking a 50mm ground clearance or greater? I am led to beleive that 50mm is about the lowest you would want to go and 100mm the greatest....

Also isnt a throat of about 3degs best from the splitter to the flat bottom?

Edited by cptkirk, 29 September 2010 - 11:24 AM.


#8 benpopham

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Posted 29 September 2010 - 02:33 PM

http://www.carbonwee...ects/index.html

Jim Whites Hill climb Mini... all aero work designed and tested by us, just won his class at gurston winning 8 out of 8 events and resetting the record >_<

full flat floor, splitter, airdam, closed off grill, diffuser and boxed in sills. also runs 60mm ground clearance

The reports are that hes experiencing alot more grip, front and back.

Ben :lol:

#9 e11evns

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Posted 29 September 2010 - 03:11 PM

I can tell you in three words... Brick on Wheels

Anyway
Do you think you go fast enough to need a diffuser? Are you planning on tracking your car

ive had a diffuser fitted and i go fast enough! once ive had the front done too i will test the car and let you all know, even if it did nothing which i doubt i think they make the car look nicer and it tidys up the exposure at the rear.

#10 Gsybeach

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Posted 30 September 2010 - 05:29 AM

Thanks for the replies - vey useful.
The diffuser looks good but at that price I think I would probably gain more by spending that money on the engine. Maybe one day though!

#11 Sam Walters

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Posted 30 September 2010 - 02:13 PM

Thanks for the replies - vey useful.
The diffuser looks good but at that price I think I would probably gain more by spending that money on the engine. Maybe one day though!


Plus to add to it, over the length of the diffuser the curve seems more then 12-14 degrees. The air will separate from the diffuser.

Also. its wet lay carbon. So unless your a tart, its only as good as fiberglass.

Edited by Sam Walters, 30 September 2010 - 02:16 PM.


#12 e11evns

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Posted 01 October 2010 - 02:15 PM

Thanks for the replies - vey useful.
The diffuser looks good but at that price I think I would probably gain more by spending that money on the engine. Maybe one day though!


Plus to add to it, over the length of the diffuser the curve seems more then 12-14 degrees. The air will separate from the diffuser.

Also. its wet lay carbon. So unless your a tart, its only as good as fiberglass.

A tart? nice....do you even own a zcar?

Edited by e11evns, 01 October 2010 - 02:17 PM.


#13 WISC

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Posted 14 October 2010 - 05:15 PM

Thanks for the replies - vey useful.
The diffuser looks good but at that price I think I would probably gain more by spending that money on the engine. Maybe one day though!


Plus to add to it, over the length of the diffuser the curve seems more then 12-14 degrees. The air will separate from the diffuser.

Also. its wet lay carbon. So unless your a tart, its only as good as fiberglass.

A tart? nice....do you even own a zcar?


im guess-in he ment that its negligible weight wise and that it looks nice carbon.

#14 z cars chris

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Posted 23 November 2010 - 10:54 PM

i know ive not been on here for a while ive been busy building wind turbine monitoring masts
anyway we fitted a front splitter and rear wing and diffuser to the works mini racer late on this season i reckon its made 3 seconds a mile difference in lap times the cars planted and really confidence inspiring
its faster down the straights and through the corners seems more stable under heavy braking which i think is down to the extra downforce on the rear of the car helping the rears grip more
i cannot believe the difference in the car its crazy
ive been struggling to get anywhere near a real trick suzuki cappuchino this year and he has been running in the top five regularily in our championship overall so after id fitted the aero i suddenly out qualified him and beat him in the race
theres some footage of us at oulton in the race section
you can tell the cars planted and fast by just looking at how easy it is to attack in the corners and under braking
so in answer to your question aero works and is worth messing with even on a mini
chris

#15 Sam Walters

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Posted 24 November 2010 - 12:52 AM

Chris, is this a Monte Carlo version?

This is my understanding, however i may not be correct.

The ideal is to reduce the pressure under the car so it is less then the pressure upon the majority of the outside of the car. 

Pressure is really, force/area reduce the force i.e. the ability to flow air under the car, you reduce the pressure and your onto a winner. 

Sooooo.

Posted Image

TADAA!

So whats the advantage of a flat under tray and a rear diffuser?

Make a pea size hole with your mouth, blow as hard as you can. You'll feel a pressure. 

Open your mouth, do much the same, you notice the pressure on the inside of your cheeks? A lower pressure.

Fluids will travel from higher to lower pressure areas. Notice how the speed was lower when you had a restriction caused by your mouth. 

So thats up to the front of the diffuser. This is an area for the air to decelerate, and to blend with the air not causing the flow to separate with the low speed air at the rear of the car. As this would cause drag and flow separation. Also. the air exiting the car relives some of the low pressure at the rear of the car. Filling in the wake as such. 




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