Datsun Rear Suspension Stiffening Experiment

g2_view=core.DownloadItem&g2_itemId=353&g2_GALLERYSID=TMP_SESSION_ID_DI_NOISSES_PMT” alt=”BackClamp” width=”495″ height=”371″ />After my brother and I crawled around the Datsun last week looking for some interesting and cheap ways of stiffening the old ladies arse, we realized that these little bakkies leaf springs are quite interesting.
They have

4 blades, 3 is quite thin and are used for normal non loaded driving, the fourth one is what I know it as a helper leaf. It is only used when the vehicle is heavily loaded and is more that double the thickness of one of the other 3 leafs.
After some more investigation we came up with a plan to clamp the top 3 to the helper leaf,

thus the vehicle will be lower to the ground and suspension travel will be limited a lot while stiffness greatly improved.
Yesterday evening Johan and I installed these 10 x 50mm Flat bar pieces to the bakkie. We found a reference point to measure ride height and suspension travel. We were astonished with the results, this old lady is as tight as an 18 year old.

Here are the results:
Clamped Loaded – 85kg Measurement Remarks
Not Not 283mm
Not Yes 248mm 35mm travel
Yes Not 250mm 33mm drop
Yes Yes 238mm 12mm travel
Adjustable Pending Pending Pending
Adjustable Pending Pending Pending

We took it for a drive and found it losing traction very easily around sharp corners. Obviously this was to much. We raised the bakkie on one corner and realized that it starts lifting the wheel. We basically replaced body roll with wheel lift, travel will have to be increased. Ruan joined, after some more experiments we loosened one of the clamps on each side on the front of the leafs and the travel increased, now we are able to adjust travel and stiffness as needed.

Next step will be to weld the top bracket to the leaf, this will ease installation and adjustment and also keep the clamp in place. Last night this was done, it works beautiful, just a shame there will be no time for some practicing before this weekends race. Won’t mind to get time to test and adjust these pieces. – Do not do this, we learned the hard way that welding on leaf springs will cause them to brake and waste your Sunday afternoon resting time.

Have a look at more detailed pictures of the Datsun Rear Suspension Stiffening Experiment

Note: this is not recommended for normal day to day driving