Performance mounts for 4Kq
martin at quattro.ca
Fri Apr 18 09:30:53 EDT 2003
This is a multi-part message in MIME format.
[ Picked text/plain from multipart/alternative ]
For this kind of damage to occur the car would have to be in rally type
conditions, I don't buy it for a second that this is caused just by solid
subframe mounts. Those only get a work out in cornering, and with stock
rubber control arms you still have some sort of vibration and shock
With the solid snub nose, you basically move the pivot point for engine
movement up front (natuarally it is about the driveshaft or motor mounts).
This increases the movement in the engine and tranny mounts (especially
those due to the distance from the pivot point) probably causing them to
fail prematurely. For the whole set up to work properly you have to make
every mount solid or at least two more. The solution to this would be a
solid tranny mounts (or at least way stiffer than they are).
As for the bearing support, I have seen someone struggle for weeks to get it
to work without vibration, it's almost impossible.
Again, making one thing solid while having the tranny and rear diff on soft
bushings means that the driveshaft will never be aligned and perfectly
straight due to engine and rear diff movement, it works on race cars because
everything is solid and the propshaft is always straight...
Anyhoo... I think these are great parts however there are certiain designs
that have to be accompanied by other mods to work properly.
Just consider the impact of the design. The good and the bad and the
Just my $0.02
From: JShadzi at aol.com [mailto:JShadzi at aol.com]
Sent: April 18, 2003 01:21
To: Martin at quattro.ca
Cc: quattro at audifans.com
Subject: Re: Performance mounts for 4Kq
Hey Martin, I've seen subframe bolts pull out of the frame rails, frame
rails begin breaking spotwelds as well as the same for the subframe itself.
I've seen this in two instances. The snub mount actually does not create
any stress on the chassis, it simply stabilizes the front of the motor, when
the motor is static there is no weight on the snub mount, same pretty much
goes for the Delrin driveshaft bearing.
Not saying that solid subframe bushings _cause_ the problems I've stated
above, but definitely correlation existes since i've never seen these
problems with the stock rubber bushings. I have a set of Delrin Subframe
bushings I'd like to put in soon, so I'll let everyone know how they do. I
believe in a true race car seam welding the unibody and subframes will
prevent the problems I've described above.
In a message dated 4/17/2003 11:34:20 AM Pacific Daylight Time,
Martin at quattro.ca writes:
O.K. I have to ask here, WRT solid subframe bushings, what kind of
punishment have you seen??
And this from someone who designed a solid engine snub nose and solid
propshaft bearing mount? ;)
I have been using aluminium subframe mounts for years now (daily driver
and ocasional track use) and have not had any issues. With stock control
arm bushings the ride is so smooth you wouldn't even know they are in there.
I've had good luck modifying stock mounts by filling the voids with
utty, stiffens things up very nicely but not too much so. I don't
d solid subframe bushings, I've seen the unibody and subframe take some
ishment due to overly stiff subframe mounts.
More information about the quattro