You can safely raise a Torsion bar Hilux about 40mm in the front without damaging the CVs. I don’t really agree with winding up the original torsion tough. Firstly the height adjusters, or torque arms are only intended as levelling devices on installation and not for additional height or load carrying. If you wind up the original torsion bars, they become overstressed and lose their spring memory which leads to failure and poor handling. A lot of companies will suggest you wind up the originals bars and just put on heavy duty shock absorbers which throws the system out of balance and compromises the comfort and handling due to incorrect compression and rebound control.
An after market Torsion bar will raise the vehicle approximately 40mm over standard, produce a little bit more bump stop clearance and have a lot more flexibility compared to the standard ones. The aftermarket bars also have higher spring ratings for different accessories and dramatically improve the comfort and handling. A lot of it really comes down to the torsion bar design and manufacturing quality. The original ones are built to a compromise and don’t provide as many benefits as an after market one. One of the most common things we see with torsion bars vehicles is people wind them up and they’re ok for around 12 months. After this the bars sag a bit so they get wound up again and so on. Eventually this just creates too much tension in the spring and they snap. (they literally go off with a bang and most go straight through the floor on 4runners and hiluxs
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Unfortunately in our industry the true benefits of well designed torsion bars are not generally recognised. Here’s a quick list of why they are a lot better and more reliable:
-Ride comfort is maximised by controlled suspension travel with minimal disturbance to the vehicles occupants
-Controlled weight transfer increase braking ability in a straight line without loss of traction or drift at rear wheels
-Safer, more comfortable cornering with a balanced vehicle delivering maximum tyre traction
-Greater load carrying
Basically a torsion bar is a spring and should be tailored to suit the vehicle and integrated as a complete kit. All suspension works in diagonals and it's crucial to get the system working together. We provide a heavy duty torsion bar for vehicles with a lot of accessories upfront and progressive torsion bar for lighter vehicles looking for more height, comfort and controlled articulation. It may not be the cheapest way to raise a vehicle but it definitely is the safest and provides the best results.