Been wanting to do this for a wile and unfamillias question about seat weights got me thinking...

So time to blow out a fue cobwebs and put some of my schooling to real life.

What I wanted to do was to try and relate weight loss to h/p gain atw.......ie fit fi glass bonet=xxx amount of h/p gain.

As we all know weight loss wont incress h/p atw, but I wont to try and relate weight loss to an incress in h/p somehow.

For example, you could add extractors a webber carb and get a gain of 5 hp atw, or for the same gain you could remove seats and heater and get the same relation in gain, hope this make sence.


So here goes,

Datsun 1200 700kg
a15 engine 90h/p (55 h/p atw)

1000/700=1.428x90= 128.57 h/p per ton.


Aply weight loss

remove back seat -20kg
remove carpet -10kg
remove passenger seat -12kg
fit race seat -6kg
remove heater -3.5kg
fit fi glass bonett -6kg
fit fi glass bumpers -8kg

Total weight loss -65.5kg

Datsun 1200 700-65.5= 634.5kg

1000/634.5=1.576x90= 141.84 h/p per ton

141.84 - 128.57 = a h/p gain of 13.27 per ton.


This is where I got stuck, but here goes, pull me up if i,m wrong.

If I have an extra 13.27 fly wheel h/p per ton after weight loss,

then
13.27/ 1.576= 8.42h/p per 634.5kg,

or the same as adding 8.42 flywheel h/p to a 700kg datsun 1200....

Anyone following this, i,m lost.

So from this you could say that a loss of 65.5kg = 8.42 gain in flywheel h/p or about 6 or so h/p atw wheels.


Thats it from me as I think I have smoke coming out my ears now.

I like your thinking!

The other thing is, adding HP only makes the car accelerate faster.
If you remove weight, the car will accelerate faster, stop quicker, corner better and get better fuel milage!

Good point sikyne.

So a 634.5kg, 55 rw h/p 1200 compaired to 700kg, 61 rw h/p 1200 is going to be better performing car in lots of ways.

Probably all exept top speed.

At speed, aero drag takes over. With lightening the car the car shape hasn`t changed so the car with less Hp and less weight would have a slower top speed. But might do a faster 1/4 mile.

This is something that is often overlooked - or moreso something that is acknowledged but not paid attention to.

Power to weight, torque to weight, brake to weight, and tyre to weight are some of the most important performance factors.

I'm currently building a Hilux, alongside my 120Y, but once I sell one or the other I'll be going a 'less is more' project.

Removing 10% weight improves acceleration more than adding 10% power. Also, remnoving 10% weight also improves everything else like economy, braking, handling, tyre wear, etc.

This dudes sig over at BMSC always made me laugh

"To increase speed add lightness"

that is the lotus' fundamental. too add speed, add lightness.

The best thing about "adding lightness" is it can be zero dollar. Hell you'll always take out your jack and spare tyre at the drags. I am now kicking myself really hard for getting rid of my fibreglass boot, bonet, and guards that I once owned. The bonnet and guards weighed less than just the steel bonnet alone.........
One of the first rules (If not the 1st rule) of Force, motion, and mass is, F=MxA. (Force equals mass times acceleration) So to increase Acceleration, increase the force, or decrease the mass. (Or do both!)

and yes, you get a better mileage. who doesnt love good mileage fast car?

Ya gettin gready now!!

Na, I weighed heaps of the bits that went on my circuit car. And thought, can this be made lighter... Did you know that H4 headlights are 80grams lighter each than sealed beams!!
There are new Lithium starter batteries that weigh only 1.7kg. Bit out of my price range tho!