The max speed calculation is real complicated and weight is not overy
significant with that, (check out Lawrences website
http://home.hiwaay.net/~lemay) I don't know what diff the fins would make. I
don't think that either of these things would really alter the top speed too
much, the excess weight may knock it 2 or 3 percent at a guess.
The 1/4 mile E.T is not too bad. Does the 2900 include driver?. I'll do it
for both 2900 and 3060lb:
working off Jims 220hp at the wheels gives a E.T. of 13.8 secs for 2900 lb,
and 14.0 for 3060 lb.
Here is the formula for hp at wheels calculated from a cars E.T. and weight:
hp = weight / (ET/5.825)**3 (**3 = cubed, weight is in lb)
Greg
----- Original Message -----
From: <Jay_Laifman(at)countrywide.com>
To: <alpines(at)autox.team.net>
Sent: Friday, 14 April 2000 08:53
Subject: HP Calculations
> Greg Locke writes:
> >Ok guys. I've sat down and done my arithmetic properly regards
> >these rather fast alpine/tigers. The original figures I used were
> >from graphs I had made for my 4 cylinder rootesmobiles from the formulae,
> >but the range was not high enough (250hp out of a 1725 engine...
> >I don't think so).
> >Anyway, an Alpine, with a CD of 0.45, a frontal area of 18 sq ft,
> >and weighing 2400lb would need theoretically 211 hp at the wheels
> >to do 150mph. 211 at the wheels would prob be about 280 flywheel
> >hp (about 75% makes it to the ground).
>
> I'd just like to point out that the Alpine in question is a 1955 Alpine.
> This is not a finned model, but the Cary Grant/Grace Kelly style. I know
> it weighed 2900 pounds. I do not know its CD, but assume it was worse
than
> the later Alpines. I'd be interested to know how your calculations work
> for that car.
>
> Jay
>
>
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