4 link, swing arm and fixed rear end.....

[37chevy]

Hey guys, ok maybe a completely noob question but I've never really understood the difference between the 3 rear ends on drag cars! Whats the difference? How does this affect the setup and the feel of cars on the strip?

[CH3NO2ADDICT]

I'm no expert but that's never stopped me opinioneering in the past so I'll have a go, based on a very basic knowledge.

I'd be interested to hear from someone who really knows, whether this is right.

• Swing arm - bit like a bike really, single pivot point in front of the axle. Axle, c/l rises and falls in a (large) arc.

• 4-Bar: If the links were all same length and had the same pivot position in z and y then in theory the axle c/l would rise and fall vertically. But a drag racing 4-bar link is smarter than that ... for example, tweaking the relative lengths of the top and bottom links and the pivot positions alters the pitch dynamics of the car on launch (% squat/anti-squat).

The 4-bar linkage geometry, the wheelie bars setting and the front and rear shocks are probably some of the key chassis tuning parameters for launching a door car?

• Solid rear end gives maximum rigidity/stability, which allows the maximum torque to be transmitted to rear tyres. The launch dynamics are then more dominated by the frame flexure and the tyre itself?

Even this is ... er... a bit wrong, it may prompt someone to correct it and give a good answer! Cheers.