Hello all, I am newly registered to the site, I have search the site and haven't been able to find any posts where someone has decided to go with a newer Porsche wheel design utilizing the modern Porsche wheel off-sets. I have considered ordering custom made wheels but have decided if I ever wanted to change I would find myself in the same predicament. I am not willing to install spacers due to the inherent dangers. I am looking into having new hubs machined out of chro-moly. I will of course have to draw them in Auto Cad and send them out for quotes. If anyone here has tried this or knows of an easier way please let me know.
Thanks for your help
Dean Fink
Full Version: 914 Wheel hubs
Dean,
Spacers are used by the factory and are safe. Just have longer studs pressed into your hubs for more thread and run spacers.
Spacers are used by the factory and are safe. Just have longer studs pressed into your hubs for more thread and run spacers.
"Chro-moly"? Just what you need, a ton of additional unsprung weight.
The Cap'n
The Cap'n
QUOTE(Cap'n Krusty @ Aug 21 2014, 11:55 AM) 
"Chro-moly"? Just what you need, a ton of additional unsprung weight.
The Cap'n
If you have compared aluminum to chromoly you would see there is a weight difference, but minimal and acceptable when you consider the added safety due to increased lateral force on the piece.
You typically don't see people machining many new splined components because they are rather expensive to make (usually).
If you are going for it make sure you calculate bending stiffness of the new design. The factory design is about as stiff as you can make it due to the close coupling of the splined shaft to the flange. Poor bending stiffness will mess up the as-designed suspension kinematics due to compliance, possibly risk fatigue failure, and kill bearings faster.
Installing spacers is most likely better from a stiffness perspective since the moment of inertia of a spacer (assuming correctly seated and tightened) should be much higher than that of the small shaft. I haven't calculated this so I have no idea, but I would think the bending stiffness of the wheel studs is probably higher than that of the shaft. Note that this only comes into play is the wheel bolts are not tight and the wheel is flopping around.
Technically you should machine them out of 4340 or 300M which has been heat treated; typical 4130 is not really the right material for a shaft.
If you are going for it make sure you calculate bending stiffness of the new design. The factory design is about as stiff as you can make it due to the close coupling of the splined shaft to the flange. Poor bending stiffness will mess up the as-designed suspension kinematics due to compliance, possibly risk fatigue failure, and kill bearings faster.
Installing spacers is most likely better from a stiffness perspective since the moment of inertia of a spacer (assuming correctly seated and tightened) should be much higher than that of the small shaft. I haven't calculated this so I have no idea, but I would think the bending stiffness of the wheel studs is probably higher than that of the shaft. Note that this only comes into play is the wheel bolts are not tight and the wheel is flopping around.
Technically you should machine them out of 4340 or 300M which has been heat treated; typical 4130 is not really the right material for a shaft.
QUOTE(jd74914 @ Aug 21 2014, 12:38 PM)
You typically don't see people machining many new splined components because they are rather expensive to make (usually).
If you are going for it make sure you calculate bending stiffness of the new design. The factory design is about as stiff as you can make it due to the close coupling of the splined shaft to the flange. Poor bending stiffness will mess up the as-designed suspension kinematics due to compliance, possibly risk fatigue failure, and kill bearings faster.
Installing spacers is most likely better from a stiffness perspective since the moment of inertia of a spacer (assuming correctly seated and tightened) should be much higher than that of the small shaft. I haven't calculated this so I have no idea, but I would think the bending stiffness of the wheel studs is probably higher than that of the shaft. Note that this only comes into play is the wheel bolts are not tight and the wheel is flopping around.
Technically you should machine them out of 4340 or 300M which has been heat treated; typical 4130 is not really the right material for a shaft.
Point taken, just nervous about spacers. I have been looking at some of the concentric spacers that bolt to the hub and have 5 other bolts for the wheel. Thanks for the input. Very much appreciate everyone's help
QUOTE
... I have considered ordering custom made wheels but have decided if I ever wanted to change I would find myself in the same predicament. ...
Other solution depending on your view of 'custom', is there are several places
that will make Fuchs-style 3-piece wheels. These would then be re-configurable
with different readily-available BBS halves.
I think the safest way to change the 914 offset would be to fabricate new trailing arms.
Considering Porsche has spent millions on R&D and many, many Porsche's have spacers, I think you are over worried about nothing.
I would not run spacers with built in lug bolts but the factory ones with longer studs are fine. I have never seen a factory spacer fail.
Considering Porsche has spent millions on R&D and many, many Porsche's have spacers, I think you are over worried about nothing.
I would not run spacers with built in lug bolts but the factory ones with longer studs are fine. I have never seen a factory spacer fail.
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