thepest
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| posted on 3/11/08 at 04:47 AM |
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locost max speed
Is there such a thing of a safe max speed on a track with a locost? I have done close to 100mph on a 1/4 mile track, however on a trackday for
instance whats the fastest speed anyone has done while still keeping a locost under control?
As for aerodynamics, other than the wings from Carbonmods are there any other issues that could be addressed?
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speedyxjs
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| posted on 3/11/08 at 07:44 AM |
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I beleive that unless you have like a million horses, the aerodynamics will only allow about 130
How long can i resist the temptation to drop a V8 in?
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procomp
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| posted on 3/11/08 at 08:10 AM |
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Hi.
The LOCOST race cars with there 85-90 bhp 1300's will do 110 mph in a slipstream whilst racing. The larger engined KIT racing cars with bhp
ranging from 160-200 will do 132 mph in a slipstream . Most know of the caterhams that have been tweeked and had a few aero mods done such as the 260
CSR's will do inexcess of 140 mph with 260 bhp. All of the above feel very stable at those speeds quoted for them.
The Aero mods for the caterham CSR range where all done by a forum member whilst he was working at MIRA. Give Rob Palin a U2U.
Cheers Matt
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smart51
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| posted on 3/11/08 at 09:28 AM |
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My MNR Vortx will do 120 at the red line in top gear. It feels beautifully stable at that speed. There’s no reason a well set up locost wouldn’t be
just as good.
My engine showed 152 BHP on the rolling road at 10,100 RPM, dropping to 102 at the red line. The car was still accelerating slowly at 120 MPH. To
add to Matt’s figures, 100 BHP should give 120 MPH (without a screen).
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BenB
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| posted on 3/11/08 at 09:57 AM |
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Aerodynamics of a brick mean you'll struggle to get above 120-130 as mentioned above....
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nick205
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| posted on 3/11/08 at 10:29 AM |
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About 110mph in my standard 2.0 Pinto engined Indy. RR figures of between 107 and 112 on 2 different RRs.
Car feels well planted and holds a straight line when you take your hands off the wheel too 
This was on my private test strip BTW 
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loggyboy
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| posted on 3/11/08 at 12:04 PM |
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quote:
Originally posted by BenB
Aerodynamics of a brick mean you'll struggle to get above 120-130 as mentioned above....
Surely a locost is more aerodynamic than a Nova??
Mistral Motorsport
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MikeR
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| posted on 3/11/08 at 12:15 PM |
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NS Dev spannered for a caterham race team. Using the data logging they had (trying to remember, but it was covered in a post recently) 140mph with i
think 230ish hp.
This assumes that the data logging is accurate, bear in mind most speedo's aren't accurate & should be reading fast.
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loggyboy
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| posted on 3/11/08 at 12:34 PM |
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Thats suprising, with 230bhp i'd expect closer to 150. The Nova manages 140 (verfied by GPS and gearing calculations)
Mistral Motorsport
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iank
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| posted on 3/11/08 at 12:49 PM |
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quote:
Originally posted by loggyboy
quote:
Originally posted by BenB
Aerodynamics of a brick mean you'll struggle to get above 120-130 as mentioned above....
Surely a locost is more aerodynamic than a Nova??
FWIW A quick browse around the web shows
Vauxhall Nova (aka Opel Corsa A) has a Cd of around 0.35
Lotus 7 has a Cd between 0.65 and 0.75 (depending on whether it has clamshell bodywork).
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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loggyboy
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| posted on 3/11/08 at 12:57 PM |
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quote:
Originally posted by iank
FWIW A quick browse around the web shows
Vauxhall Nova (aka Opel Corsa A) has a Cd of around 0.35
Lotus 7 has a Cd between 0.65 and 0.75 (depending on whether it has clamshell bodywork).
Very interesting find. I find aerodynaics most fasinating. Somthing thats the shape of a big brick is more aerodynamic than something thats the shape
of a small brick!
I guess it could be down to the cockpit, must create alot of drag.
Mistral Motorsport
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smart51
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| posted on 3/11/08 at 01:33 PM |
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quote:
Originally posted by iank
quote:
Originally posted by loggyboy
Surely a locost is more aerodynamic than a Nova??
FWIW A quick browse around the web shows
Vauxhall Nova (aka Opel Corsa A) has a Cd of around 0.35
Lotus 7 has a Cd between 0.65 and 0.75
But a Nova has more projected frontal area than a locost (aprox figures 1.77m2 for the Nova, 1.35 for a locost with screen, 1.2 without) so overall
the CdA figure is .62 for the nova and .60 for a racing locost without a screen.
as a rough guide if 100 BHP gives 120 MPH then theoretically:
MPH BHP
120 100
130 125
140 155
150 190
160 225
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Rob Palin
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| posted on 3/11/08 at 01:36 PM |
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#Edit# Awww, I was beaten to it!
The figures above are about right and the drag coefficient is a measure of how 'aerodynamic' the car is, so the Nova does win by a mile.
When it comes to top speeds though, it's the CD times frontal area that's important and the two are much closer: 0.7ish for the Nova vs
0.8ish for the Lotus 7.
With all the aero forces on cars it's important to remember as well that they increase with the square of speed (and hence power requirements
with the cube!).
At 140mph the lift and drag on a car are double what they are at 100mph. The power requirement is nearly triple (2.7x).
You can still have plenty of fun at 100mph though. The rest's just showing off! 
[Edited on 3/11/08 by Rob Palin]
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loggyboy
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| posted on 3/11/08 at 01:48 PM |
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Its quite scary (stupid and sad too) to say that i dont find 140 that fast anymore. the few times ive done it in the nova it was scary, but in the
lexus it feels almost civilised.
Mistral Motorsport
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DarrenW
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| posted on 3/11/08 at 02:32 PM |
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i know what you mean. Ive been in the back of a LS430 with the seat massagers on while it was doing 250KPH and it felt very civilised and stable
(brand new almost empty road in China). That said i hate driving fast. 100mph in the 7 is quite fast enough!
Interesting discussion regarding aerodynamics etc.
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clutch_kick
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| posted on 3/11/08 at 03:31 PM |
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hmmmm phil .... are you planning on taking sophie to Pergusa ????
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thepest
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| posted on 4/11/08 at 06:04 AM |
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yep pretty much charlie. Where else can I find a race track around here?
Thanks guys, as for the aerodynamic mods, would closingup the underside of the car completely help?
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clutch_kick
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| posted on 4/11/08 at 04:18 PM |
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Phil ... i'm on leave for a few days ... i'll come over your place. We need to close up the underside, front nosecone canards and a
diffuser , and hope we get it right first time.
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austin man
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| posted on 6/11/08 at 11:46 PM |
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I read somewhere that a VW campervan had better aerodynamics than a seven my 1.8 zetec carbbed motor has done around 125 really slow pickup after 110
was reached.
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