Vert Aerodynamics
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FC3C 90, PGT 89.
Joined: Dec 2005
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From: Maryland USA
Vert Aerodynamics
So I recently got my convertible motors working again. Now I can put the car into Targa mode =) (w00t) While driving on the highway it seemed to have more drag due to wind resistance. I am wondering if anyone knows what mode is the most aerodynamic for the FC vert. I figure the roof up in 'rainy day' mode is the most streamline.
Also is there a way I can test this? perhaps install some kind of aeronautics device?
Also is there a way I can test this? perhaps install some kind of aeronautics device?
Do a 0-100 run with the top up, then top down and time it.
Which is faster?
That's is crude, but about the only way I can think of doing it. $20 on top up being faster.
Which is faster?
That's is crude, but about the only way I can think of doing it. $20 on top up being faster.
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From: BC, Canada
Do a coasting test on a straight, level road and see how long it takes to go from, say 80-60, then repeat it going the other way. Test all configurations and you'll have your answer, the longest time to slow down = the lowest drag. It'll ineveitably with the top up, targa section in place.
Former Moderator. RIP Icemark.
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From: Rohnert Park CA
.33 Cd top up and in place
.38 Cd Top down and covered with aeropanel up
.35 with Targa section removed (which intresting enough is almost the same as the sunroof only half way back on the S4 GXL (.348 Cd))
.38 Cd Top down and covered with aeropanel up
.35 with Targa section removed (which intresting enough is almost the same as the sunroof only half way back on the S4 GXL (.348 Cd))
Originally Posted by Icemark
.33 Cd top up and in place
.38 Cd Top down and covered with aeropanel up
.35 with Targa section removed (which intresting enough is almost the same as the sunroof only half way back on the S4 GXL (.348 Cd))
.38 Cd Top down and covered with aeropanel up
.35 with Targa section removed (which intresting enough is almost the same as the sunroof only half way back on the S4 GXL (.348 Cd))
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Former Moderator. RIP Icemark.
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From: Rohnert Park CA
Originally Posted by My5ABaby
Where'd you get those numbers?
BTW: the most aerodynamic FC is the 86-87.5 Sport with its low .29 Cd. Normal GXL models are typically .31 while turbos where slightly higher .315 Cd(wider tires).
Last edited by Icemark; Nov 6, 2006 at 06:34 PM.
Originally Posted by drakeco
putting top down can act as a wind deflector..this mean that drag force would increase...So yeah..top down is the best
Originally Posted by Icemark
.33 Cd top up and in place
.38 Cd Top down and covered with aeropanel up
.35 with Targa section removed (which intresting enough is almost the same as the sunroof only half way back on the S4 GXL (.348 Cd))
.38 Cd Top down and covered with aeropanel up
.35 with Targa section removed (which intresting enough is almost the same as the sunroof only half way back on the S4 GXL (.348 Cd))
targa mode is the worst when it come to drag force b/c there is the wind is not reasomated very well in high speed. however, if the car is convertible...putting the top down at the angle of 45 degree act as a wind deflector
Former Moderator. RIP Icemark.
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From: Rohnert Park CA
Originally Posted by Juiceh
Pretty interesting on the targa\sunroof numbers there. The opening the targa section creates is a hell of a lot larger than the sunroof opening and only adds .002 Cd.
*edit< Now if you removed the sunroof and associated hardware all together, then I would think that just having the opening would be a lower CD than the Targa.
Last edited by Icemark; Nov 6, 2006 at 08:35 PM.
Originally Posted by Icemark
commonly published Mazda reported numbers found in countless sources including Mazda Brochures, and Jack Yamaguchi's books.
BTW: the most aerodynamic FC is the 86-87.5 Sport with its low .29 Cd. Normal GXL models are typically .31 while turbos where slightly higher .315 Cd(wider tires).
BTW: the most aerodynamic FC is the 86-87.5 Sport with its low .29 Cd. Normal GXL models are typically .31 while turbos where slightly higher .315 Cd(wider tires).
I've read Yamaguchi's book and found only the following numbers:
Cd = 0.31 base (0.29 aero kit)
Clf = 0.08
Clr = 0.14 (0.07 aero kit)
A = ~2800 in^2
Cd x A = 0.56 (.524 aero kit)
I'm assuming the others are in the brochures. Correct?
Former Moderator. RIP Icemark.
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From: Rohnert Park CA
Originally Posted by My5ABaby
Are these brochures available anywhere online?
I've read Yamaguchi's book and found only the following numbers:
Cd = 0.31 base (0.29 aero kit)
Clf = 0.08
Clr = 0.14 (0.07 aero kit)
A = ~2800 in^2
Cd x A = 0.56 (.524 aero kit)
I'm assuming the others are in the brochures. Correct?
I've read Yamaguchi's book and found only the following numbers:
Cd = 0.31 base (0.29 aero kit)
Clf = 0.08
Clr = 0.14 (0.07 aero kit)
A = ~2800 in^2
Cd x A = 0.56 (.524 aero kit)
I'm assuming the others are in the brochures. Correct?
Its pretty common knowledge... don't know why the concern. The info has been out for 22 years on this.
Thread Starter
FC3C 90, PGT 89.
Joined: Dec 2005
Posts: 262
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From: Maryland USA
Originally Posted by Icemark
.33 Cd top up and in place
.38 Cd Top down and covered with aeropanel up
.35 with Targa section removed (which intresting enough is almost the same as the sunroof only half way back on the S4 GXL (.348 Cd))
.38 Cd Top down and covered with aeropanel up
.35 with Targa section removed (which intresting enough is almost the same as the sunroof only half way back on the S4 GXL (.348 Cd))
Does it mention what position the windows are in for these numbers?
When I drove with in the Targa mode it seemed to have more drag then with the top down, no cover on, aeropanel (I am assuming this is the wind blocker behind the seats) down, and the windows down. I can say with out a doubt that the most aerodynamic position is with the top up, targa roof installed, and the windows up. It seems to squirt through the soup we call atmosphere like a fish!
Matt|ttaM
Thread Starter
FC3C 90, PGT 89.
Joined: Dec 2005
Posts: 262
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From: Maryland USA
Originally Posted by Turbo II
As long as you can keep moving you can leave the top down in the rain. I do it all the time.
Matt|ttaM
Originally Posted by Icemark
Jack has 3 RX books that talk about the FC (don't know why people only think there is one), but yes, in his books and in the brochures as well as countless other places.
Its pretty common knowledge... don't know why the concern. The info has been out for 22 years on this.
Its pretty common knowledge... don't know why the concern. The info has been out for 22 years on this.
Rx-7 the New Mazda Rx-7 and Mazda Rotary Engine Sports Cars
As for the brochures, any hint as to where to get a hold of them?
And... no clue what you mean by "why the concern".
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