Racecar Engineering

[ThatPhilBrettGuy]

http://www.racecar-engineering.com/

It might be worth tracking down this months and the next couple too. There's a good insight into Noble aerodynamics, and the other articles are always interesting.

[Lakelord]

Or just read it here..

http://www.nobleforums.com/showthread.php?t=3722

[Jenx]

That article sounds a bit negative, but I think we'll see the other side of the coin in the next couple. It would be interesting to see a set of lap times with and without all the mods.

M.

[DanH]

Ouch 0.47 cd!

Great to see people going to these lengths looking at the cars aero. Well done chaps.

[Adrian W]

DanH said:

Ouch 0.47 cd!

Great to see people going to these lengths looking at the cars aero. Well done chaps.

997 GT3 is .31 but 0 downforce, what was interesting is in the end we doubled the weight of the car with aero but with very little drag penalty.

[DanH]

Adrian W said:

DanH said:

Ouch 0.47 cd!

Great to see people going to these lengths looking at the cars aero. Well done chaps.

997 GT3 is .31 but 0 downforce, what was interesting is in the end we doubled the weight of the car with aero but with very little drag penalty.

Did you manage to get a better front rear balance too?

(Porsche quote 0.29 for the 7 and 0.30 for the 6 GT3, with maybe 0.01 more for the RS flavours)

[ThatPhilBrettGuy]

DanH said:

Did you manage to get a better front rear balance too?

More in part 2 or 3

DanH said:

(Porsche quote 0.29 for the 7 and 0.30 for the 6 GT3, with maybe 0.01 more for the RS flavours)

You can bet the 0.31 is the real one if Mira say so (for a production car off the normal production line, not one off the special line that only does press cars).

[DanH]

ThatPhilBrettGuy said:

DanH said:

Did you manage to get a better front rear balance too?

More in part 2 or 3

DanH said:

(Porsche quote 0.29 for the 7 and 0.30 for the 6 GT3, with maybe 0.01 more for the RS flavours)

You can bet the 0.31 is the real one if Mira say so (for a production car off the normal production line, not one off the special line that only does press cars).

Are you talking about Jon Oakleys car?

[m12_nathan]

[ThatPhilBrettGuy]

DanH said:

ThatPhilBrettGuy said:

DanH said:

Did you manage to get a better front rear balance too?

More in part 2 or 3

DanH said:

(Porsche quote 0.29 for the 7 and 0.30 for the 6 GT3, with maybe 0.01 more for the RS flavours)

You can bet the 0.31 is the real one if Mira say so (for a production car off the normal production line, not one off the special line that only does press cars).

Are you talking about Jon Oakleys car?

They just said production car. They never give names out, understandable when you see some of the things that get tested there.

Truly an amazing place MIRA. The operators of the tunnel could say which corner of the car you'd put a 50p piece on, the balance is that sensitive. Only bad thing about the place is the hourly rate! Although to be honest it's not so high that any small car manufacturer could afford a day in it. Why most don't is beyond me.

[Adrian W]

DanH said:

ThatPhilBrettGuy said:

DanH said:

Did you manage to get a better front rear balance too?

More in part 2 or 3

DanH said:

(Porsche quote 0.29 for the 7 and 0.30 for the 6 GT3, with maybe 0.01 more for the RS flavours)

You can bet the 0.31 is the real one if Mira say so (for a production car off the normal production line, not one off the special line that only does press cars).

Are you talking about Jon Oakleys car?

I was, Ive seen the numbers from that session, they explane why Porsches achieve such high top speeds.

[egomeister]

ThatPhilBrettGuy said:

DanH said:

ThatPhilBrettGuy said:

DanH said:

Did you manage to get a better front rear balance too?

More in part 2 or 3

DanH said:

(Porsche quote 0.29 for the 7 and 0.30 for the 6 GT3, with maybe 0.01 more for the RS flavours)

You can bet the 0.31 is the real one if Mira say so (for a production car off the normal production line, not one off the special line that only does press cars).

Are you talking about Jon Oakleys car?

They just said production car. They never give names out, understandable when you see some of the things that get tested there.

Truly an amazing place MIRA. The operators of the tunnel could say which corner of the car you'd put a 50p piece on, the balance is that sensitive. Only bad thing about the place is the hourly rate! Although to be honest it's not so high that any small car manufacturer could afford a day in it. Why most don't is beyond me.

What is the rate for the MIRA tunnel, and what support do you get for that cost?

[ThatPhilBrettGuy]

egomeister said:

What is the rate for the MIRA tunnel, and what support do you get for that cost?

Rates probably vary a lot depending on the task. Something that ends up in a publication is probably going to be cheaper with the prospect of aero geniuses dropping in a big bonus. Not my place to state rates, but you could probably get a good amount of data tweaks in for less than 5 figures.

[m12_nathan]

The Oakley car isn't standard though is it? or did you see the before and after figures? interesting stuff though, look forward to reading the reast of the articles.

[DanH]

Have to say I can't see Porsche publishing incorrect figures! Of course if it was with his new aero parts for more downforce I could see drag increasing a bit, or if he had the wing set at an angle. Most cars these days are in the 0.30 type range though.

[ThatPhilBrettGuy]

DanH said:

Have to say I can't see Porsche publishing incorrect figures! Of course if it was with his new aero parts for more downforce I could see drag increasing a bit, or if he had the wing set at an angle. Most cars these days are in the 0.30 type range though.

Front and read ride heights can change the figures that amount I suspect. I'd be surprised if the exact same car produces the full set of performance figures they publish.

Not just pointing the finger at Porsche as they all do it I'm sure.

It's interesting stuff though and teaches you that aerodynamics isn't always intuitive.

There was an interesting test with a couple of Nascars. They put them in the tunnel with the same small gap that they have when they bash around the ovals. As you'd expect the aero drag on the rear car went down by nearly 50%. But the surprising thing to me was the front car had 30% less drag.

Ever time a new car comes out that looks aerodynamic I always ask if it's been in a tunnel and tested. It's the only way to know what's really going on.

[chillidog]

ThatPhilBrettGuy said:

There was an interesting test with a couple of Nascars. They put them in the tunnel with the same small gap that they have when they bash around the ovals. As you'd expect the aero drag on the rear car went down by nearly 50%. But the surprising thing to me was the front car had 30% less drag.

Yup, apparantly some drivers cooperate when drafting in order to get a gap on the rest the field, at least until the last lap or so.
--
Richard

Edited by chillidog on Wednesday 16th July 14:55

[DanH]

ThatPhilBrettGuy said:

DanH said:

Have to say I can't see Porsche publishing incorrect figures! Of course if it was with his new aero parts for more downforce I could see drag increasing a bit, or if he had the wing set at an angle. Most cars these days are in the 0.30 type range though.

Front and read ride heights can change the figures that amount I suspect. I'd be surprised if the exact same car produces the full set of performance figures they publish.

Not just pointing the finger at Porsche as they all do it I'm sure.

It's interesting stuff though and teaches you that aerodynamics isn't always intuitive.

There was an interesting test with a couple of Nascars. They put them in the tunnel with the same small gap that they have when they bash around the ovals. As you'd expect the aero drag on the rear car went down by nearly 50%. But the surprising thing to me was the front car had 30% less drag.

Ever time a new car comes out that looks aerodynamic I always ask if it's been in a tunnel and tested. It's the only way to know what's really going on.

Yeah the car in front loses drag but it also loses downforce particularly at the rear!

[JLSELAN]

ThatPhilBrettGuy said:

DanH said:

Have to say I can't see Porsche publishing incorrect figures! Of course if it was with his new aero parts for more downforce I could see drag increasing a bit, or if he had the wing set at an angle. Most cars these days are in the 0.30 type range though.

Front and read ride heights can change the figures that amount I suspect. I'd be surprised if the exact same car produces the full set of performance figures they publish.

Not just pointing the finger at Porsche as they all do it I'm sure.

It's interesting stuff though and teaches you that aerodynamics isn't always intuitive.

There was an interesting test with a couple of Nascars. They put them in the tunnel with the same small gap that they have when they bash around the ovals. As you'd expect the aero drag on the rear car went down by nearly 50%. But the surprising thing to me was the front car had 30% less drag.

The same principle is at play when you ride a bicycle in a group of other riders--and it's pretty exciting when you actually feel the change in drag on your body as you slip in behind another rider .

Edited by JLSELAN on Wednesday 16th July 16:36

[ThatPhilBrettGuy]

JLSELAN said:

ThatPhilBrettGuy said:

DanH said:

Have to say I can't see Porsche publishing incorrect figures! Of course if it was with his new aero parts for more downforce I could see drag increasing a bit, or if he had the wing set at an angle. Most cars these days are in the 0.30 type range though.

Front and read ride heights can change the figures that amount I suspect. I'd be surprised if the exact same car produces the full set of performance figures they publish.

Not just pointing the finger at Porsche as they all do it I'm sure.

It's interesting stuff though and teaches you that aerodynamics isn't always intuitive.

There was an interesting test with a couple of Nascars. They put them in the tunnel with the same small gap that they have when they bash around the ovals. As you'd expect the aero drag on the rear car went down by nearly 50%. But the surprising thing to me was the front car had 30% less drag.

The same principle is at play when you ride a bicycle in a group of other riders--and it's pretty exciting when you actually feel the change in drag on your body as you slip in behind another rider .

Edited by JLSELAN on Wednesday 16th July 16:36

We all know the being behind a rider makes life easier but would you have thought that being in front and having a tail would help?