Rear trailing arm function?

[jabinya]

So I've been replacing all my bushings with the polyurethane Energy Suspension bushings and started to take the rear suspension apart. This is the first time I've ever worked on my rear suspension and was trying to understand the function of each arm.

The rear trailing arm has me somewhat confused. It is much different than, say a Integra which the trailing arm is humoungous and connects to the chassis in a different configuration.

What does the trailing arm do and how do the differences in design affect handling?

 

[jtmcinder]

The trailing arm is there to keep the keep the wheel from swinging forward under acceleration (assuming the wheel is powered) and/or backwards under braking. The difference in design is mostly due to the rear wheels not being powered on your Honduh, plus a difference in philosophy with regard to anti-squat/anti-dive and dynamic toe.

Many poeple leave the squishy bushings on the trailing arms, because the dynamic toe-in under braking is useful. (As the wheel is pulled back, the wheels toe-in, because the toe-arm is behind the lower lateral arm.) Same goes for the compression arm up front.

- Jtoby

 

[jabinya]

Helpful info!

Looking at the OEM bushings, they are cracked, dry and brittle. Would you still reccomend that I don't replace them with the ES bushings?

 

[jtmcinder]

Yes. Especially is you are a drag-racer. The last thing you need is lots of toe-out under hard acceleration.

- Jtoby

 

[WatchItExplode]

I assume that yes means "yes, installing the ES bushings is good for drag racing."

For autocross, is there any benefit to installing poly-u bushings on the trailing arm that could outweigh the benefits of better braking with rubber bushings?

 

[jabinya]

So I decided to install the ES bushings. I managed to get both trailing arm (chassis side) bushings installed. I haven't noticed any difference in braking. What has changed is handiling during acceleration; going in a straight line the car seems to stay more stable than before. Giving throttle during cornering, I notice the rear follows better and turn in is quicker.

 

[jtmcinder]

What has changed is handiling during acceleration; going in a straight line the car seems to stay more stable than before.

Because you have reduced the dynamic toe-out.

- Jtoby

 

[bjones18]

does anyone have data on throttle & braking f/r toe response before &/or after bushing modifications? Suspension kinematics play just as big, if not more of a role in toe response to for-aft loading.

As for the original question, there are many independant suspension configurations. The best way to think about a 2g rear suspention is an upper contol arm (UCA) and a lower control arm (LCA), and toe link, all controlling the motion of the knuckle (wheel plane) through suspension travel. In the 2g, the LCA is split into two different links, (1) the trailing link supports for-aft loads (along with the UCA) and the lateral link (2) supports lateral loads (along with the UCA & toe link).

I am a fan of either:

1. natural rubber bushings (including OEM).
2. ball joints (including heim joints).
3. slippery bushings.