Lessons from Porsche owners

RSR engine mount bar – Page 2 – Pelican Parts Technical BBS.

I had the idea of reducing more weight.  A lot of my friends just dumped something like RM 2,000.00 for a factory Carbon Fiber unit and the claimed savings was about 7kg.  I doubt it very much.  I have carried it myself.  Its bulky and the strength to hold it was more spent on trying to get it balanced onto the mountings.

I have found this picture from a Porsche owner forum.  It started off a plans to change engine mounting of a rear wheel drive car.  This was impressive.  The model itself is pretty light and powerful.  What drew my attention was the work done on the bonnet (or hood for you Americans) of the engineless front of a car.  A car which is honestly light in the first place yet was known to be slap happy around the bends.  So a lighter front end seemed to be the last thing you would want?

Cheezing a Hood

I think its important to leave untouched the material close to hinges as the weight will transfer on it before reaching the hinge.  This hood above may be light but its also shaky.  I especially hate moving bonnets at high speed.

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Lightening of Hinges

RS Motorsport :: Classic Speed Restored • View topic – Simon’s Mk1 Escort Project.

Ford Escort front bonnet hinge mechanism

Some lightening works done on a Ford Escort.  The pictures with the holes seem to come from the front bonnet hinge, back bonnet hinge and wipers.  Interesting.  Some of this could not be implemented in our car as the current design does not use so much material.  Especially the hinge for the hatch.  Nevertheless, it gives some ideas of what people go through to make their cars lighter.  Suddenly I feel vindicated

Rear boot hinge lightened and quite possibly sand blasted by the look of it. Off a Ford Escort

Hinges seemed obvious targets as the are typically thick.  In design, they need to provide rigidity when the bonnet/hood/hatch is moved.  The two hinges provide a movable point and bears the load.  Thefore, rigidity and stiffness is a requirement.  If we look at door hinges, they are the more thicker and bulkier of the rest.  The load is entirely on them until the door is closed.  When a door is closed, the load is shared around the door sill and not on the hinge alone.

What I have done on my car much earlier was removal of the hinges and made more holes.

Hinges Before After

The lightening work was not as extensive as the top two.  The M6 bolts on the top hinge were replaced with Pro Bolts Aluminium ones while the bottom was a Titanium one.  I chose Ti rather than another Aluminium as I was worried that the torque was insufficient against the aerodynamic force on the top bonnet.  So the Ti bolt gives me the ability to tighten it up, whereas if it was Aluminium,  I could easily damaged the thread of the bolt.