Soarer Central: Archive through April 20, 2009

Soarer Central Bodywork and Exterior Aerodynamics! Archive through April 20, 2009

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Joe Russell
TryHard
Marlborough
4.0 V8 GT-L(UZZ31)

Posts: 335
Reg: 10-2008

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Tuesday, April 14, 2009 - 06:53 pm, by: Joe Russell (Joe_r)

So, I've been looking into aerodynamic info and pictures for the Soarer and I've found:

0.32 Cd (Coefficient of drag)
0.31 Cd with a spoiler.

...So F all.
Does anyone have anything more? It would be great to find these things out and see what we can do to improve down force or fuel efficiency, depending on what you want.
If not, I think I'll try find out things for myself

David Vaughan
Goo Roo
NSW
V8 Ltd manual

Posts: 4281
Reg: 07-2005

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Tuesday, April 14, 2009 - 08:35 pm, by: David Vaughan (Davidv)

Tell us what you want to achieve. Down force and fuel efficiency are more or less mutually exclusive, loosely speaking.

Aaron Casey
DieHard
nsw
'94 jzz30 gttl, 2 mini's one supercharged :-)

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Tuesday, April 14, 2009 - 09:30 pm, by: Aaron Casey (Blownminiturbo)

i guess the question is do you want better downforce for cornering or high speed circuit racing or just trying to get better fuel efficiency.
im interested to hear what people say that know more about it than me..
id love to have awesome fuel efficiency with good downforce to corner... guess you could also try graft a speed adjustable rear wing. but that would give more downforce and less fuel efficiency

Joe Russell
TryHard
Marlborough
4.0 V8 GT-L(UZZ31)

Posts: 336
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Wednesday, April 15, 2009 - 04:50 am, by: Joe Russell (Joe_r)

Well I'd like to see what the Soarer is like as a base, find out the wake length and shape(for exhaust position and angle), see what goes on underneath and near the front lip(to try different types of lips and undertrays)

To be honest, I'm looking for both-not necessarily from the same car.

David Vaughan
Goo Roo
NSW
V8 Ltd manual

Posts: 4283
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Wednesday, April 15, 2009 - 07:23 am, by: David Vaughan (Davidv)

Buying downforce will not have much effect at road-legal speeds while damaging your fuel economy considerably. On the track, you are probably not finding fuel economy the most significant issue.

For fuel economy, start by closing everything, sealing every gap and minimising air intake so that the engine just manages to stay cool enough. A variable inlet might be useful there, opening it up for traffic and closing it down for the highway.

A height controller will let you drop your car a little for cruising at speed, or just screw it down to the legal minimum using the adjusters then get a new suspension alignment. Reducing effective frontal area has a big effect. Fold in your mirrors while cruising

Oh, and wash the car before driving.

Ben Lipman
Goo Roo
NSW
Soarer TT manual

Posts: 1425
Reg: 04-2006

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Wednesday, April 15, 2009 - 09:39 am, by: Ben Lipman (Ben12a)

I have been toying with the idea of making a plywood front splitter for my track car. Allegedly there is around 40kg of downforce at 100kph to be had there if you get it right.

Only thing holding me back is the balance of the car. On high speed corners the back lets go before the front, so I really need a rear spoiler before I go and add downforce to the front.

A friend of mine was telling me there was a test done on a series six Rx-7 around Tsukuba (spelling?) circuit. No wing, stock wing, and GT style wings were tested on the same car, same driver, same day. There was a small gain by using the stock wing over no wing at all, and the GT style wing gained a wopping two seconds a lap, being able to carry more speed through a corner.

Obviously the figures are second hand info, and may be inaccurate. Also the track characteristics will play a big part in any gain.

I think when I get home, I'll look at getting a proper adjustable motorsport wing for the track car.

Joe Russell
TryHard
Marlborough
4.0 V8 GT-L(UZZ31)

Posts: 337
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Wednesday, April 15, 2009 - 01:37 pm, by: Joe Russell (Joe_r)

I have a height controller and do that

I'm talking about real mods, bodywork and such, which will affect fuel economy and drivability, and change flow considerably.
If someone has done research or if Toyotas is floating around it would be great to get a hold of, and post up, to better understand our cars.
Otherwise I might end up doing some wool tuft tests, which would be fun!

Joe Russell
TryHard
Marlborough
4.0 V8 GT-L(UZZ31)

Posts: 341
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Wednesday, April 15, 2009 - 01:53 pm, by: Joe Russell (Joe_r)

How interesting Ben! Makes sence too.
Yep, our weight balance is rather front biased-I imagine in your track car it is even more so.
Now we need Soarer info...

David Vaughan
Goo Roo
NSW
V8 Ltd manual

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Wednesday, April 15, 2009 - 02:44 pm, by: David Vaughan (Davidv)

I was going to mention plastering your car with wool tufts...

. Will be interesting to see what you discover. Big wings will have a huge impact on lap speed but better still if you can mount them on the suspension rather than the body, or else you take compliance out of the suspension. It is not clear to me how radical you wish to be.

Ben Lipman
Goo Roo
NSW
Soarer TT manual

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Wednesday, April 15, 2009 - 03:12 pm, by: Ben Lipman (Ben12a)

David Vaughan wrote on Wednesday, April 15, 2009 - 02:44 pm:
if you can mount them on the suspension

A lot of different competition rules don't allow this. But, if you aren't in a competition, and dont care to open your boot, go for it. Buggered if I know how you'd do it. There is a whole lot of car in the road.

The other thing to consider- if you can mount your rear wing as far back as possible you can maximise your downforce due to the lever action, getting more downforce for the same amount of drag.

David Vaughan
Goo Roo
NSW
V8 Ltd manual

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Wednesday, April 15, 2009 - 03:24 pm, by: David Vaughan (Davidv)

There are probably rules about how far back the wing can be as well, or what height. Low and to the rear will lead to loss of lift (downforce) from turbulence over the wing anyway. I guess I'm just trying to puzzle out what are Joe's targets or constraints.

Joe Russell
TryHard
Marlborough
4.0 V8 GT-L(UZZ31)

Posts: 343
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Wednesday, April 15, 2009 - 03:44 pm, by: Joe Russell (Joe_r)

Sorry guys I'll make myself clear

I want to find information on the stock Soarer aerodynamics, including:
air flow diagrams and pictures, wake details,
stagnation areas, etc, for any use what so ever,
and to hopefully help in development of modifications(Vortex generators, undertrays, deflectors, rear wings, whatever).

David Vaughan
Goo Roo
NSW
V8 Ltd manual

Posts: 4286
Reg: 07-2005

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Wednesday, April 15, 2009 - 04:07 pm, by: David Vaughan (Davidv)

Right!

Um, well, now that you mention it I do not recall seeing anything of that nature on any forum, which is not to say I haven't missed it so, er, good luck

Joe Russell
TryHard
Marlborough
4.0 V8 GT-L(UZZ31)

Posts: 352
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Sunday, April 19, 2009 - 09:01 am, by: Joe Russell (Joe_r)

Okay, here we go!

I got out yesterday and did some wool tufting, here are the pics and descriptions(Some are rather surprising)
The testing was done at 80kmh on cruise control, with minimal wind and a flat as possible road:

This gives a good overview, showing laminar(attached) flow over the bonnet and roof, into the intake ducts and around the corner of the car.
The flow around the wing mirror is great, Highly directed and minimal turbulent(detached) flow.
However, the area after the mud guard and front wheel is terrible-we'll look at this further.
Any further back is a bit deceptive,as it differs from other photos and I believe this is because of the photo cars wake.
(Observant types will notice my lack of front lip-I'm sure the difference will be small from this point of view, but under car flow will be highly affected)

This photo was an accident, and a good one too. The photographer didn't mean to be so zoomed in, but it shows great details!
For instance, look at the wiper area-notice how the wool goes over and is pushed back down behind the wiper, how the other tufts at the end of the bonnet are pushed down-
this is a very high pressure area, and the wipers are heavily exposed to the air here, possibly resulting in wiper noise or drag at high speeds. Another area to look more closely at.

The turbulent area behind the wheel and mud guard is small, but significant. Look at the tuft going forwards instead of back-not good.
It may be reduced by removal of the mud guard.
The front and mounting area of the wing mirror is great, with flow directed well and staying fairly attached.

The side of the car is odd, and a sign of things to come; air is not so controlled, is slightly turbulent-where wool has two strands, it is flapping(I had to draw over these as they were hard to see. I was as accurate as I could be).
The area above the mud guard shows air flowing down, maybe a vacuum/low pressure is being created by the mud guards.
It gets better halfway along where the air is flowing up and over the c-pillar.

Me looking awesome.

Haha here the airflow over the roof is great, as is the small amount of turbulence around the handle. Very nice.

Here things start to go pear shaped.
First off, the good:
Good transition from the roof to rear windscreen.
Spoiler is working well, with the air flowing off it.
Good laminar flow over the side and halfway along the boot lid(length ways).

Now the bad:
Halfway along the windscreen, flow is no longer attached(vortex generators may fix this)
The mud flap is screwing with airflow again(I hope-if it's actually the wheels that's harder to fix)

The Ugly(even though that rear is very good looking

):

What the •••• is going on at the bottom of the bumper? That is nasty!
You can see the wheel well is in the way, increasing the size of the wake, and before the exhaust exits there is no flow-I want my exhaust to be sucked out, and with turbulent air that isn't going to happen(I think).
A rear under tray may fix this, possibly stainless to handle exhaust heat.
More testing required, obviously.

You can also see how the wiper and rear window have turbulent air all around, creating extra drag. Again hopefully vortex generators can fix this.

Next things to do:
Work out wake size, and derive our own Co-efficient of drag by area(CdA)
Test a car with a front lip.
Test a car with no spoiler.
Take mud guards off and test.
Test rear under trays.
Try vortex generators on the roof, and maybe on the rear under trays.

And one last thing, which is a doozy:
How to view under car airflow in a real world situation.
Any ideas?

Ben Lipman
Goo Roo
NSW
Soarer TT manual

Posts: 1443
Reg: 04-2006

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Sunday, April 19, 2009 - 09:13 am, by: Ben Lipman (Ben12a)

Can you get a small digital camera, knock up a mount and attach it under the car? Obvoiusly it will cause some disruption of its own, but if you set it to video, and accelerate up to 80kph, and then slow down, you'd get an idea. Maybe have to do it several times with the camera at different
spots.

If you know some one with one of those motorsports camera systems maybe you cold borrow it. It has a base station with a couple of tiny cameras attached via cable.

Ben Lipman
Goo Roo
NSW
Soarer TT manual

Posts: 1444
Reg: 04-2006

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Sunday, April 19, 2009 - 09:16 am, by: Ben Lipman (Ben12a)

I am considering removing the spare wheel well on the track car. I was looking for weight saving, but by the look of that their may also be an aero advantage also?

The area around the front wiper is interesting, and contradicts what many, including me, expected. I thought this area would be low pressure, hence why people remove the rear rubber strip, and cut vents in this area chasing underbonnet cooling.

Michael Fabian
TryHard
Queensland
JZZ31 2JZ

Posts: 162
Reg: 07-2008

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Sunday, April 19, 2009 - 09:19 am, by: Michael Fabian (Mf_sc300)

WOW!!! Nice wright up

Joe Russell
TryHard
Marlborough
4.0 V8 GT-L(UZZ31)

Posts: 353
Reg: 10-2008

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Sunday, April 19, 2009 - 09:34 am, by: Joe Russell (Joe_r)

Ben Lipman wrote on Sunday, April 19, 2009 - 09:16 am:
Can you get a small digital camera, knock up a mount and attach it under the car? Obvoiusly it will cause some disruption of its own, but if you set it to video, and accelerate up to 80kph, and then slow down, you'd get an idea. Maybe have to do it several times with the camera at different
spots.
I am considering removing the spare wheel well on the track car. I was looking for weight saving, but by the look of that their may also be an aero advantage also?

The area around the front wiper is interesting, and contradicts what many, including me, expected. I thought this area would be low pressure, hence why people remove the rear rubber strip, and cut vents in this area chasing underbonnet cooling.

You read my mind Ben, on all three of those.

The idea of removing the bonnet strip now seems stupid, as pressure at the rear of the bonnet is high and that would let air in... unless that's what you want.

I do have a small usb camera which may work, but it is very low resolution.