How does this work?

ste_bla

ste_bla

ste_bla

Soldato
Joined
9 Aug 2004
Posts
7,795
Location
Milton Keynes
Just wondering, going up a dual carriage way earlier following a mate in convoy. Now I was quite suprised as he was in a 1.4 (i think) fiesta and I was just managing to keep up with him.

Now fine I get that my car is heavy and big however then I was wondering as it goes at about the same rate upto 60/70, however it tops out @ ~115/120 and mine goes to ~140. How does that work?
 
What car do you have?

Unless there is a massive power/weight difference, rates of acceleration at higher speeds aren't massively different. It takes big power to 'leave cars standing' at higher speeds.
 
just got longer gearing, people in a car like that might want to cruise faster. That doesn't mean it will get there very fast.

There were some guys in my apprenticeship that raced a 1.25 fiesta and a scorpio cosworth auto down a runway at some autocross thing. Fiesta won and they got up to 100 or so i think.
 
milgo said:
just got longer gearing, people in a car like that might want to cruise faster. That doesn't mean it will get there very fast.
.
Click to expand...

It's not about gearing, you could have long gearing and yet never have your car be able to redline in top gear. However short gearing can limit your top speed.
In this case it's more to do with how the larger displacement engine with more bhp will always be able to exceed more of a top speed than a smaller engine with less power. His car simply does a similar 0-60 as although his is less powered it's also less weight and thus the power/weight is similar (or so i assume without looking at the specs)

ever wondered how 1.6 type r's are pretty fast in both a straight line and on a track and yet when it comes to 100+ speeds a competitor bmw or similar with a big v6 would walk all over it?
 
Last edited:
Well obviously it is about gearing. I assumed most people in here would know that a 2.5l engine should have more torque than a 1.6 throughout the rev range.

Because ste bla said the acceleration was roughly the same but the omega has a higher top end therefore one would assume the gearing is longer, especially given the type of car it is. Its really not that difficult, I was responding with a simple answer to a simple question, you could go on forever about all the different variables. What about drag? You didnt consider that?

"ever wondered how 1.6 type r's are pretty fast in both a straight line and on a track and yet when it comes to 100+ speeds a competitor bmw or similar with a big v6 would walk all over it?" oh wow I never knew that, cheers mr.
 
Did you have a poo before setting off?
Did he have his seats folded down?
Do you weigh more?

Also you know he could have bigger wheels, they make you go faster as you need bigger wheels if your upping power and stuff.


:D

I'll get my coat...
 
ste_bla said:
Why though?

Same sort of time 0-60 but yet higher top/max speed?
Click to expand...

Your car has a higher top speed because your car has more BHP and better aerodynamics.

The lighter weight of the Fiesta keeps acceleration similar at lower speeds due to a similar power-to-weight ratio, but top speed is determined by BHP and aerodynamics, weight has little to do with it.
 
DreXeL said:
Your car has a higher top speed because your car has more BHP and better aerodynamics.

The lighter weight of the Fiesta keeps acceleration similar at lower speeds due to a similar power-to-weight ratio, but top speed is determined by BHP and aerodynamics, weight has little to do with it.
Click to expand...

I thought, theoretically weight is out of the picture? Also what about rolling resistance, does that come into it?
 
Muffin` said:
I thought, theoretically weight is out of the picture?
Click to expand...

Yes, that's what I was refering to when I said weight has little to do with top speed. Substitute 'little' for 'almost nothing' ;)

Also what about rolling resistance, does that come into it?
Click to expand...

I suppose it does to a certain extent, but BHP is the main factor. More BHP means the car can push through rolling resistance and aerodynamic deficiencies.
 
You must log in or register to reply here.
Back
Top Bottom