Monthly Archives June 2014

Suspension Design: Double Wishbone

In part II we briefly analyze the first type of suspension: trailing arm. Now let’s take a look at the second major type: double wishbone suspension.

This type of suspension uses two “A” shape arms, one place on the top and the other in the bottom. Because each A arm can limit 2 degrees of freedom, so the two A arms together limits 4 out of the total 6 degrees of freedom. Therefore we still need one more restriction to make the whole system to be 1 degree of freedom.

For front wheels, the extra restriction is the steering arm; for rear wheels, car designers usually use a toe angle control arm.

In the below chart, the one labeled...

There is a rumor saying the redesigned 2015 Mustang will gain around 200 – 300 lb of weights, now it seems this is not true. Below is the official curb weight of all models of the 2015 Mustang:

2015 Ecoboost Manual: 3517 (Convertible: 3642)
2015 Ecoboost Automatic: 3512 (Convertible: 3661)

2015 V6 Manual: 3526 (Convertible: 3644)
2015 V6 Automatic: 3529 (Convertible: 3654)

2015 GT Manual: 3704 (Convertible: 3825)
2015 GT Automatic: 3727(Convertible: 3852)

For your reference, below is the current 2014 model curb weights:

2014 V6 Manual: 3501 (Convertible: 3630)
2014 V6 Automatic: 3523 (Convertible: 3652)

2014 GT Manual: 3618 (Convertible: 3735)
2014 GT Automatic: 3675(Conv...

Today Mercedes-Benz officially announced the detailed specification of the upcoming AMG GT’s engine, codenamed M178.

Highlights as below:

The M178 engine is rated at 510 PS (375 kW, or 503 hp) at 6,250 rpm, with a maximum torque of 650 Nm (479 lb-ft) within 1,750 rpm and 4,750 rpm. The same engine will goes into the W205 C63 AMG, but tune to a lower output (probably around 470 – 480hp). The AMG GT will be announced this fall and go on sale next March as a 2016 model.

Insider news indicates BMW Group’s high-end brand Rolls-Royce, is currently busy with the design of the first SUV model in the brand’s history. The project’s internal name is called “Cullinan”.

The SUV will be positioned above the Ghost sedan, and below the Phantom flagship. The company is expecting to sell 2,000 unit annually, and the production version will be debut in 2018, around the same time that BMW rolls out its X7 SUV.

As you may know that the Rolls-Royce Ghost sedan is sharing the platform with the BMW 7-Series, there is no doubt that the Rolls-Royce SUV will have something in common with the BMW X7.

Meanwhile there is further information available, but please e...

Automobile Suspension Design 101 (Part II)

In Part I of this article, I provide a general review and some background knowledge of the automobile suspension system. There are four types of suspension geometry. In this article we will briefly analyze the first type: trailing arm.

A trailing arm system is using a solid arm, which connect one end to two locations of the car chassis (so it can only “swing” in a 2-dimensional plane); and the other end is connected to the wheel hub, with the wheel hub fully fixed to the arm.

Because the arm connected to 2...