Kamike

Im confused, in another thread going on at the moment the general jist is that you need 500bhp to hit 180mph?

So beeing a bit dim I googled the first car that came into my head, Mondy ST 220. Now the figures quoted said

Power 217bhp
Top speed 155mph

Why would you need 300 extra bhp to achive 25mph extra, is the wind resistance that much at these speeds or are are people trying to get 180+ mph in a much shorted distance meaning you need much more acceleration?

Or am I way of the mark here and should hang my head in shame for even asking?

scoooby slayer

iTrader: (4)

its not the case that it will do 180, my car will do 180 but it wouldnt do it within the confines of brunters. 1.7 miles or there abouts iirc.

doctor stavros

BHP vs gearing would give you top speed predictions. Then there will be many other factors like aerodynamics/wind resistance, the length of strip on which to test the speed etc

Chip

iTrader: (3)

Rod was talking about a specific application, ie a cossie at brunters.

Not cars in general, which will vary.

Kamike

Right so the high bhp figures are because of the limited space rather than a long stretch of mway to build up the speed?

Kamike

Or putting it another way lets say a car with 200 bhp could hit 180+ it wouldnt be able to do it a Brunters because there isnt enough room?

doctor stavros

correct

Chip

iTrader: (3)

correct

correct

Kamike

I suprise myself sometimes

JohnnyB

would 200bhp hit 180 it would have to have a very low Drag Co?

Chip

iTrader: (3)

In the right vehicle, yes no problem at all given enough distance.

Kamike

Don't know, I just picked that number as an example

JohnnyB

well thinking about it chip I can hit about 100 mph in my 1.2 clio it just takes me 10 miles to do it. lol

foreigneRS

a bike will hit 180mph with less than 200bhp even though the Cd of the bike is worse than that of an average car

JohnnyB

are you sure, a bike has a smaller indent into the air mate.

I am going to beg to differ on that

C4llyT

Much smaller frontal area compensates.
Power to weight is a tad better on the bike too.

TerryTibbs

According to Noel Edmonds the sierra minker (with 3.14 diffs would do 170mph+ with only 323 bhp but as they are like platted rocking horse p*ss we will probably never know?

JohnnyB

I can see why the minker 323 could do 170+ it had tall diffs and fuck loads of to torque.

Benni

If a bike was the same size as a car, with it's shape. It would have an awful top speed. There is how effecient,/dynamic it is, and how big it is.

Benni.

RWD_cossie_wil

iTrader: (9)

Don't forget as speed doubles, drag quadrouples, so at 50Mph your car will be suffering drag of say 100Nm (just random figures to show) ,at 100 Mph it will be suffering from drag of 400Nm, so you need a LOT more power to go a tiny bit faster.

Rich_w

I forget the exact details but a McLaren F1 requires about 300BHP to do 200mph. Veyron is somewhere round 350-400BHP to do the same IIRC

saph4be

how much to get a saff to 200mph without a distance limit then?

JohnnyB

I think about 350 to 400 bhp will do it, but you would have to change your gearing.

Steven_RW

The CD of the bike is higher than the car, but the CDa is higher for the car than the bike.

CD is just drag for any given size/shape. You need to multiply it by the frontal area to get the real "CDa" which is what impacts top speed.

RW

sbd16v

thats because you need to add the frontal area into the equation

Rod-Tarry

Here are some Speeds from Vmax gives you an idea of whats called for to do 180 at Brunters

Ferrari F430 177mph
Porsche 997 gts 176mph
Ferrari 575 175mph
E39 M5 166MPH

as a guide in a Cossie it would take.

180mph 500bhp
190mph 600+bhp
200mph 720ishbhp
206mph near800bhp
210mph 850+bhp
215mph over 900 thats for sure.

foreigneRS

you can beg to differ if you like, but facts are facts. you need to understand the meaning of the word coefficient

Rod-Tarry

This guy would struggle

Cam

Holy shit!
Now they are serious apehangers