BODYLIFT BIBLE DOCUMENT
Posted: Fri, 19 Jun 2009 8:35 +0000
As we all know, a bodylift is when we lift the body of the Hilux up and away from the chassis of the Hilux. On older model this hasnt been a problem due to the fact that most older Hilux's haven't had airbags fitted, but the current vehicle has and unfortunately for us up to now vehicle engineers have been hesitant to sign off on this particular modification because (A) they dont understand how the airbag system work and (B) they are reluctant to sign off on a modification that (as I have been told by 2 different engineers in the past) may contribute to the death of a vehicle occupant in an accident by affecting the deployment of the airbags, and they are not prepared to stand in front of a judge and explain why they signed off on a dangerous modification.
The truth is, the modification is not dangerous if dont properly and has been done for a while now is both Europe and South Africa.....some places in Europe are even engineering 4" bodylift's (100mm) without suspension lifts, and being TUV Certified.
I'll begin with the location of the bodymounts on the Hilux and then continue with the information you will all need to put forward to your vehicle engineer of choice to consider for a bodylift for a hilux.
Location of Hilux Bodymounts
NOTE: NOTE: The front two factory body blocks as seen on the diagram above are 50mm OD and the rest are 76mm OD, meaning you must use the same diameter replacement blocks as factory or larger otherwise the weight of the cabin is supported by a mount smaller than the factory. This could result in the floor pan cracking or worse, the mount joining you inside the cabin from constant pounding on dirt roads.
I'll now get into the document that myself and Rod put together that you will all be able to use in the future-
Components needed for Bodylift
The truth is, the modification is not dangerous if dont properly and has been done for a while now is both Europe and South Africa.....some places in Europe are even engineering 4" bodylift's (100mm) without suspension lifts, and being TUV Certified.
I'll begin with the location of the bodymounts on the Hilux and then continue with the information you will all need to put forward to your vehicle engineer of choice to consider for a bodylift for a hilux.
Location of Hilux Bodymounts
NOTE: NOTE: The front two factory body blocks as seen on the diagram above are 50mm OD and the rest are 76mm OD, meaning you must use the same diameter replacement blocks as factory or larger otherwise the weight of the cabin is supported by a mount smaller than the factory. This could result in the floor pan cracking or worse, the mount joining you inside the cabin from constant pounding on dirt roads.
I'll now get into the document that myself and Rod put together that you will all be able to use in the future-
Hilux SRS Airbag system (April 2005 on)
The vehicle is equipped with a Supplemental Restraint System (SRS), which consists of a steering pad, front passenger airbag, seat belt pretensioner, center airbag sensor and front airbag sensor.
The location of these items is shown in Figure 1 and Figure 2, Below:
The schematic for the SRS components shown above are outlined in Figure 3 below:
Operation in case of front collision
When an impact that is larger than a predetermined level occurs in the highlighted area in Figure 4. the airbag is deployed automatically.
The center airbag sensor deceleration sensor uses the front airbag sensor's deceleration sensor signal to determine whether or not to activate the airbag.
The center airbag sensor safing sensor is designed to activate at a deceleration rate that is lower than that of the center airbag sensor deceleration sensor. When the safing sensor and deceleration sensor turn on simultaneously, current flows to the squib and the airbag deploys. This is shown graphically in the diagram below.
When the vehicle is in a collision and the shock is greater than the specified value, the SRS is activated automatically. The safing sensor and deceleration sensor are built into the center airbag sensor. The safing sensor is designed to be turned on at a smaller deceleration rate than the deceleration sensor. The deceleration sensor determines whether or not SRS deployment is necessary based on signals from the front airbag sensor. Current flows to the squibs to deploy the SRS when the conditions shown in the illustration in Figure 6 below are met.
Affect of a body lift on the SRS
General Discussion
It can be seen from the technical description above that all of the SRS components and the wiring shown schematically in figure 3 are located on the passenger body shell. There are no SRS components or wiring attached to the vehicle chassis.
Therefore, there is no affect on the SRS system if the body shell is raised in relation to the chassis.
The only possible consideration could be that the point of impact of a collision being higher where a body lift of up to 50mm is considered. However, it is noted that raising the point of impact by the same amount can just as easily be achieved by a 50mm suspension lift that fully complies with the suspension travel requirements of VSR 8. The point of impact in a frontal collision can also be affected if the vehicle is airborne at the time of impact. This is quite probable where a vehicle leaves a built up roadway and collides with a stationery object within the shaded areas of Figure 4. Under these conditions, if deployment conditions are met, the SRS airbags will deploy regardless of whether a body lift is installed in the vehicle or not.
Steering
The steering wheel and column contains two SRS components. The spiral cable and the steering pad containing the driver’s side airbag.
These components are not affected where a body lift is installed as the spiral cable is designed to accommodate extension and compression of the steering shaft and the adjustable height steering column. Whilst a slight alteration in steering column angle may occur because of the body lift, this is within the limits of the adjustable height steering column. Airbag deployment is not affected by extending the steering shaft and the relationship between the steering pad and the driver remains within normal ergonomic limits that are expected for drivers of different physical characteristics.
Where the steering shaft need's extending, (eg. for body lifts 40mm and over), it is recommended that the steering shaft be extended by using a splined extension similar to the one shown in figure 6 below at the base of the steering shaft:
copyright rodw c/o newhilux.net 2008
Components needed for Bodylift
2 x 50mm diameter x 40 mm high HDPE (high density polethelyene) or aluminium blocks
4 x 75mm diameter x 40 mm high HDPE blocks
6 x 175mm M12 x 1.25mm Grade 8.8 high tensile nickel plated bolts with nyloc nuts and washers to suit
4 x 8mm (or 10mm) radiator spacers with two holes drilled 4omm apart, (one could have a tapped thread, but nyloc nut would do. Refer to Offroad Factory's photographs below.
Notes on application:
Supplementary Restraint system (SRS)- not affected - produce documentation above if queried.
Steering - not affected
Brakes - not affected.
Don't use the black 8.8 bolts as the rust from experience in this application.
When fitting the HDPE blocks, Sikaflex them to the body to get rid of squeaks.