Drag coefficient
Drag coefficient
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Discussion

TJW

Original Poster:

3,848 posts

276 months

Thursday 31st August 2006
quotequote all
Does anybody know the drag coefficient for the cerbera's? I just watched the Extremeclarkson review of the Tuscan R and he said that the tuscan R had a drag coefficient of just 0.32, what would you think a cerb would have? Or anybody knows?

UncleDave

7,155 posts

260 months

Thursday 31st August 2006
quotequote all
As soon as I saw the name of this thread I knew you had just watched that video
I've looked for that info before but have never found anything available. Just checked again on various 'car spec' sites and again.. nothing

ridds

8,372 posts

273 months

Thursday 31st August 2006
quotequote all
A quick trawl I made so time ago came back with various results from 0.32 to 0.34 and even 0.36.

whitey

2,508 posts

313 months

Thursday 31st August 2006
quotequote all
just have a guess. I doubt even TVR actually know.

simonsparrow

1,599 posts

291 months

Thursday 31st August 2006
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Depends which way the wind was blowing on the promenade in Blackpool that day.

BCA

8,651 posts

286 months

Thursday 31st August 2006
quotequote all
Bristol Avenue - TVR's own windtunnel...

The figure for the Tuscan was 0.34 and the Tuscan R/ T440/ Typhon was 0.32 according to Evo magasine. The Cda would be less favourable as the T440 variants have a much larger frontal area.

I thinkt hats the right way round, but im tired.

Independantly tested Cerbs/Tuscans at Vmax would suggest that they have similar drag co-efficients as they run similar Vmax's, which are incidentally higher than the T350's/Sags there... of course that doesnt mean to say they are particularily aerodynamically good, I have no doubt a Sag would have alot less lift than say a Cerb, but they do appear to be relatively slippery. There are several potential areas to improve them though.. if thats the kind of thing you are wanting to acheive?

*Phoenix*

3,065 posts

286 months

Thursday 31st August 2006
quotequote all
The drag-coeff on stock cerbs is terrible, turbulence takes place at 14 zones, pressure increases by 20% at 5 zones by the time you get up to 160 and from them on its steep curve, which works out at a ratio of 1:3 over time increasing to 1:5 at 170. A lot can be done to change this, but theres no point, the limiting factor of gaining more speed is the gearing, a change of rear-end-ratio would help, but can hurt low-end, in that case a change of ratio on 5th can help, or just get a 6-speed box thrown in. I've got $$$k's worth of aerodynamics studies if anyone wants to pay for them... be it more relative to the phoenix shell...

Mr Freefall

2,323 posts

287 months

Friday 1st September 2006
quotequote all
*Phoenix* said:
The drag-coeff on stock cerbs is terrible, turbulence takes place at 14 zones, pressure increases by 20% at 5 zones by the time you get up to 160 and from them on its steep curve, which works out at a ratio of 1:3 over time increasing to 1:5 at 170. A lot can be done to change this, but theres no point, the limiting factor of gaining more speed is the gearing, a change of rear-end-ratio would help, but can hurt low-end, in that case a change of ratio on 5th can help, or just get a 6-speed box thrown in. I've got $$$k's worth of aerodynamics studies if anyone wants to pay for them... be it more relative to the phoenix shell...



Ash, whats the state of play now with the Phoenix?

Mr F

GreenV8S

31,017 posts

313 months

Friday 1st September 2006
quotequote all
*Phoenix* said:
The drag-coeff on stock cerbs is terrible, turbulence takes place at 14 zones, pressure increases by 20% at 5 zones by the time you get up to 160 and from them on its steep curve, which works out at a ratio of 1:3 over time increasing to 1:5 at 170.


Terrible compared to what, though? They look like quite a sleek shape, even if the separation points may be a bit uncontrolled. The drag rising sharply with speed is normal, it should be roughly proportional to speed squared. This is unrelated to the drag coefficient, which I wouldn't expect to change significantly with speed unless you're going transonic. Mind you, that may be an issue in your case. smokin

*Phoenix*

3,065 posts

286 months

Friday 1st September 2006
quotequote all
Mr Freefall said:
Ash, whats the state of play now with the Phoenix?

Mr F


Pretty much there now! Because of the transition from previous mechs to new, a lot of groundwork had to be covered to bring things up to speed... its not far from prime time now... hopefully turn of the year should have us ready to start attempting records... if you'll be at the austec open-day I'll be more than glad to give you a tour of the phoenix shell and running engine...

Been building a watercooled pc recently too on the new conroe platform, I've overclocked to 3.7ghz on the conroe, which is the equivalent of 2 4ghz p4's in crunching performance!!!! there seems to be a pattern here, I cant get enough of speed and making things ridiculously fast.... at least I didnt have to wait 2+ years to do the pc... lol

Also I'm already working on a transplantable new bodyshape design but doubt I'll pull it off this year, thats more a bling-bling thing for next year...

BCA

8,651 posts

286 months

Friday 1st September 2006
quotequote all
*Phoenix* said:


Also I'm already working on a transplantable new bodyshape design but doubt I'll pull it off this year, thats more a bling-bling thing for next year...


Need a designer?? I have access to various small scale wind tunnels/ a small amount of Aero knowledge having been taught by Bentleys cheif aero guy/ always interested in Cerbera projects.

Must admit im with GreenV8s on this, I think the Cerbera shape has by chance turned out ok for drag, not outstanding - but no way terrible. There is alot of scope for reducing lift on them though...

Mr Freefall

2,323 posts

287 months

Friday 1st September 2006
quotequote all
*Phoenix* said:
Mr Freefall said:
Ash, whats the state of play now with the Phoenix?

Mr F


Pretty much there now! Because of the transition from previous mechs to new, a lot of groundwork had to be covered to bring things up to speed... its not far from prime time now... hopefully turn of the year should have us ready to start attempting records... if you'll be at the austec open-day I'll be more than glad to give you a tour of the phoenix shell and running engine...

Been building a watercooled pc recently too on the new conroe platform, I've overclocked to 3.7ghz on the conroe, which is the equivalent of 2 4ghz p4's in crunching performance!!!! there seems to be a pattern here, I cant get enough of speed and making things ridiculously fast.... at least I didnt have to wait 2+ years to do the pc... lol

Also I'm already working on a transplantable new bodyshape design but doubt I'll pull it off this year, thats more a bling-bling thing for next year...


I Should be there, I hopefully will be picking my car up from Paul soon. Be nice to see the work you have done

Mr F

TJW

Original Poster:

3,848 posts

276 months

Friday 1st September 2006
quotequote all
Hopefully our Cerb will be done and on the rollers