# two cars acceleration?

why is it? that if you have a lotus elis 1.8l with 120bhp (o-60 in about 5 secs) and lets say a rx7 with a 2.6l with about 270bhp (o-60 in about 5 secs) their different weights cause them to reach 60mph in the same time.. then my question is why then does the rx7 start to pull away form the lotus say from 70mph to 100mph and leave the lotus behind. why is their accelaration not constant "as it was form o - 60 miles per hr" has it something to do with the lotus not producing enough torque?

Relevance

Gear ratios in the gear box for starters. But also the RX-7 has turbos, once you get past the turbo lag and they spool up, then the RX-7 has a major power boost later in the race.

• vdubz
Lv 4

The Rx7 has more horsepower. Horsepower is more important for top speed and higher end speeds. A smaller lighter car maybe be good at accelerating from a stop, and many other factors play into that such as tire traction, whether you have computerised traction controls, whether you have automatic or standard transmission, etc. But higher horse power is it's reason for higher speed, and also the gearing of it is why acceleration is not constant. Some cars are geared for higher speeds, some are geared for acceleration. For example, i have a 200cc motorcycle with the gears VERY close together. It can accelerate well untill you pass 45, then it sucks

Wind resistance gets higher as speed increases. The higher horsepower/torque RX-7 is able to push through the resistance and accelerate faster than the Lotus as resistance increases.

The gearing can also be a big factor.

• Anonymous

It's power-to-weight. Take the power (192hp) and divide that by the weight (2006lbs). This gives us a ratio, usually rounded to the nearest thousandths position. In the Lotus's case, this is .095.

The mazda has a curb weight of 2830 lbs, so the power to weight is 270 / 2830 = .095.

Using this ratio of power to weight we see both the cars are equally fast.

Source(s): Wikipedia for each car's specifications.

because once you reach higher speeds, horsepower comes into play. horsepower helps you reacher higher speeds, and the later in the race you are, the more horsepower comes into play.

the mazda probably has more horsepower than the lotus, and that's probably why. torque is only for acceleration, horsepower is for topspeed.

and turbo lag has nothing to do with this. turbo lag is gone once your in the high rpm ranges.

I don't think it would pull away. It's all about weight and lotus's are soo light.

1 different weight

2 different front ends=different air drag

3 different engines make HP at different rpm...some low end some top end

4 different rear gears and transmissions..