Predicting performance - speed + acceleration (0-60)

[eSteve]

Hi,

I have been wondering what sort of performance one can expect from a Haynes Roadster and to this end have collected the performance data from Caterham's web site for their various cars. I have spoken to Andy Noble of Caterham cars and he has no problem with me publishing the data here.

I have attached the tabulated data and a graph giving power along the bottom and top speed on the left and acceleration on the right in the form of a pdf file.

So if you've some idea of your engine power you can get an estimate of its performance, (emphasis on estimate and assuming your cars weight is about 550kg).

It's only an estimation but gives one some idea.

To open a pdf file you will need a pdf viewer Adobe's one is free and can be downloaded from here:

http://get.adobe.com/uk/reader/

(You'll need to wang it round 90 deg in Adobe as I created the PDF as lanscape and Adobe expects portriat)


Data obtained from:



Clicking on each car takes you to its specification.

Start dreaming of that bigger engine...http://www.haynes.co.uk/forums/images/smilies/smile.gif

eSteve

[eSteve]

Opps..

missed out Caterham link last bit of post should read:


Data obtained from:

http://www.caterham.co.uk/assets/html/showroom.html

Clicking on each car takes you to its specification.

eSteve

p.s. the curve fitted to the max speeed data is probably a tad inaccurate for bhps under 100.


eSteve

[slimtater]

I have seen something somewhere that takes in to account other factors and diff ratio - this will explain why my 125bhp manages about 4.5secs.

[Davey]

In my humble opinion torque is what gives you acceleration not BHP. BHP is simply a mathematical figure arrived at by multiplying the torque by the RPM then dividing by a constant. It is therefore pretty meaningless in terms of acceleration. High BHP figures are often achieved by using high revs, great for a circuit car but not much use on the public highways.

My aim is a fat torque curve with a smooth, progressive delivery across the rev range which is why I'm chucking a V6 24 valve Cossie lump in mine. I recently saw a BHP/Torque graph for a similar engine that gave over 180 ft/lbs of torque at just 2000 rpm and just climbed in a near straight line from there to the 5800 rpm rev limit, max BHP at 5800 was a healthy 233BHP.

Could be fun .

D.

[spud69]

Try this one Steve:

http://www.letstorquebhp.com/calculator.asp

I have found it pretty good, tis based on historical data. My car is 170 bhp and 540kg, program says 0 to 60 in 3.9s and my car did it in 4.1s with crappy road tyres on. Will be putting Toyos on soon and will certainly get down to 3.9s or better..... Standard tyres seriously let the time down as having to control all power of the engine balanced through the clutch and throttle to get optimum traction. Happy with the sierra standard dif though, once you put loads of power through it you get equal drive to both wheels leaving parallel black lines all the way down the road (private of course).

AndyH

[Enoch]

Interesting. i guess there comes a point where traction is at least as important as outright power. I will only have 125 brake to start with but I do like what Davey's doing with that Cossie lump. That has to be one of the cheapest ways to big power ever. If mine does the 0-60 dash in 6 I will be a very happy bunny.
Enoch

[Bonzo]

If I get a sub 6 second 0-60 .... I might very well soil myself

100bhp is more than enough in a 7 anymore is just pub talk....

[spud69]

Originally Posted by fabbyglass

100bhp is more than enough in a 7 anymore is just pub talk....

Oh no no no, you do need more. But yes i would say that 180bhp is the limit. Anything else is wasted and takes the playful fun out of the drive unless you are out and out track.......

[AshG]

my little 1600 has got 90bhp and it easily does a standing start 0-60 in 6 seconds. i am fortunate that i have an all singing and dancing dash that can calculate it for me, so no stop watch errors. put it in the correct mode and floor it then review later on. i can also do quarter mile and any speed to any speed tests accelerating and decelerating.

90 bhp is more than enough to be fun and plenty in the tight twisty bits but i think i will find my self looking for a little bit more straight line power not too far down the line.