Suspension Database

[Peterpilot]

Toughdog data added.

[Peterpilot]

Additional information about the Bilstein front strut and their circlip adjustable spring seat after I visited the Bilstein distributor and had a look at a Bilstein BE5-A712 strut:

1: The bottom circlip position is the standard height position which equates to the same distance from spring seat to bottom suspension mount as a Toyota strut.
2: Each circlip groove is spaced 7mm apart which should equate to about 14mm lift per groove or 28mm from bottom to top position.
3: Bilstein quoted me 552mm as the open length of the strut, I measured the strut and confirmed.

[Peterpilot]

Added Lovells Gas Legend strut and shock data according to what Lovells quoted me. I'm not convinced that it's correct, 510mm extended length for a strut seems very short, but Lovells say it's good for up to a 50mm lift.

[Peterpilot]

I measured a rear TEMS shock absorber out of my car today and while the extended length is the same 575mm as a regular OE shock, it seems that the TEMS mechanism inside the shock reduces copmression by 31mm for a closed length of 387mm. I guess that's why the rear bump stops are different in the TEMS equipped Grande compared to the conventional Prados.

[Peterpilot]

If you increase the preload of a spring (eg. moving the spring seat on the Bilstein strut to a higher position) you gain more lift. The spring rate is still the same.

Yes, I am aware of this. Moving the seat of a spring up the strut will increase ride height. This is the same way that ride height is adjusted on many coil over struts, as well as Bilstein struts, Ironman Struts and Ridepro struts. In fact Ridepro struts have 5 positions for the circlip which means that they can also be used in a Hilux by changing the circlip position accordingly.

To clarify; given a constant spring seat height (like that of a standard strut), the ride height of a given vehicle is a function of spring length and spring rate.

Also, the way we measure ride height does not equate to spring compression at the front axle. There is a multiplier involved. eg. if someone achieves 50mm lift, this does not mean that the distance between the top strut mount and the strut eye has changed by 50mm. It is in fact less than this.

Correct, a ride height change of 50mm at the wheel is approximately 25mm at the front strut. Conversely, if you increased the weight on the front of the car by 50kg (eg:by adding a steel bullbar and 2nd battery), then this is multiplied at the strut so that the front springs have to carry approximately another 50kg each.

If you increase the preload of a spring (eg. moving the spring seat on the Bilstein strut to a higher position) you gain more lift. The spring rate is still the same.

Also, the way we measure ride height does not equate to spring compression at the front axle. There is a multiplier involved. eg. if someone achieves 50mm lift, this does not mean that the distance between the top strut mount and the strut eye has changed by 50mm. It is in fact less than this.

[Peterpilot]

If the free height of a spring is known and the amount of weight applied to a spring is known and the resulting compressed height of a spring is measured then the rate can be calculated. If the weight applied in pounds is divided by the spring compression in inches then the answer is lb/in.

Weight (lb) / Spring Compression (inches) = Spring rate (lb/in)

Also spring compression can be calculated if the free height and spring rate is known:

Weight (lb) / Spring Rate (lb/in) = Spring Compression (inches)

I have decided to take ARBs data with a pinch of salt. According to my calculations and based on actual lift achieved by other members, I suspect their spring rate to be considerably higher than the 590lb/in that they claim. Also, there is a clear discrepancy between what MickL measures on his OME strut and the measurements supplied by ARB.

Just have to be aware that not only the spring rate determines the ride height/amount of lift. The amount of spring preload also determines this. Just saying, and you may be right about the discrepancy.

Also, even if you have the dimensions of the coils, you still need the spring material to determine the spring rate. It would be hard to calculate the spring rate without knowing for sure what the material the spring is made from.

[Peterpilot]

Has anyone or is anyone using the SRC suspension package??

Superior have only done a few of these on Prados so far:

http://www.pradopoint.com/showthread...l=1#post290320

[Peterpilot]

Suspension Database

I have decided to take ARBs data with a pinch of salt. According to my calculations and based on actual lift achieved by other members, I suspect their spring rate to be considerably higher than the 590lb/in that they claim. Also, there is a clear discrepancy between what MickL measures on his OME strut and the measurements supplied by ARB.

[Robuck]

Has anyone or is anyone using the SRC suspension package??

[Peterpilot]

Suspension Database

Added revised data as supplied by ARB.

[Peterpilot]

Interesting how the 150 has much different rear springs to the 120. No wonder they droop so much under tow in standard trim.

Actually, the standard data needs to be revised as soon as I get more accurate spring rates. There is no way the standard 120 series springs are as high as 270lb/in at the rear, or 624lb/in in the front. Especially when some aftermarket springs are rated lower than this.

[Peterpilot]

Suspension Database

I agree with that method of measuring shocks, as depicted here:

[MickL]

Thanks Mick,
The OME data is from this thread: http://www.pradopoint.com/showthread...component-info.
What is the OME part number of the strut you measured?

N140S, the newer sport range (9000) measure the same. The actual travel is right, just not the open and closed length.
No idea how OME measure but center of eye to base on top pin seems logical (ie; the mounting points) to me and matches more closely the other brand specs.

Mick