Delrin bushes (was: Re: BTDT for front control arm bushings)

[R Mangas]

   Javad, Mark,

  Thanks for the detailed replies!  This is probably a project for next
year, so I have some time to consider...

  Thanks again,
Robert






>From: "Mark L. Chang" <mchang at ee.washington.edu>
>To: quattro at audifans.com
>Subject: Re: Delrin bushes (was: Re: BTDT for front control arm bushings)
>Date: Wed, 6 Nov 2002 22:41:37 -0800
>
>Some background - 90q20v with 16" wheels and 205-45/16 tires. Eibach and
>Bilstein shorties with Delrins up front and OEM out back. The Delrins
>are sleeved and were turned by Todd Candey. All other bits from the
>waist down were replaced at the same time - Hell, find out here:
>http://www.audi-quattro.org/mycars/90q20v/suspension/
>
>My beef is not with ride. Ride is great. Again, Seattle has nice roads
>(IMHO) and it works out well here. The car is tight as a drum, no doubt.
>The problem I have is definitely with NVH and harshness of imperfections
>in the road. For instance. Crossing a bridge such as I-90 here you get
>metal expansion joints. Those can be a real sharp and jarring feeling
>with the delrins in there. They are definitely felt more, um,
>"accurately, as Javad said.
>
>Upside is that turn in is crisp. Very crisp. My 4kq with a similar setup
>but without delrins was tight but not as crisp in turn in.
>
>The complete package lends itself very nicely to carving the roads. I
>don't know about on the track, because I've never taken the car out on a
>track, but it's definitely fun to drive. I recommend the eibach/bilstein
>setup. Very nice ride, IMHO, and the wife actually doesn't mind it as
>long as the road is smooth enough to not give us the effects of delrins.
>Now *that's* saying something.
>
>The 45-series tire and the Delrins definitely add up to more harshness
>over poor surfaces. If you live in Chicago, forget about them. Bob
>Dupree had 'em in his car, and that was my advice to him as well.
>
>Would I use them again? Maybe, maybe not. I thought I'd give them a
>shot. I would never have considered them if the roads here weren't
>amenable to them, for sure. As far as reliability, a buddy with a CQ and
>2B delrins up front had an issue with them rounding out. His were not
>sleeved, though, so the bolt was turning in solid delrin and not in a
>metal sleeve. Different design that 2B went away from in later
>revisions.
>
>On Wed, Nov 06, 2002 at 09:49:22PM -0500 or thereabouts, JShadzi at aol.com
>wrote:
> > Well, as has been pointed out, it could be an issue in areas where roads
>are
> > really bad.  Here in Sunny California, the roads are pretty good,
> > pothole-wise, but there are still plenty of cracks and bumps in some of
>the
> > roads, which can be felt more "accurately" once you have the delrins in.
> > Overall, though, bushings are not shock absorbing devices, and the end
> > resulting ride should be determined by shock and spring/tire tuning.
> >
> > Busings will result in varied NVH (Noise, Vibration, and Harshness), but
>the
> > ride is really determined by your shock/spring combo, and also the tire
> > specifications such as side wall height which will greatly affect ride.
>Mark
> > may want to expand on his experience with Delrin bushings and how they
> > affected his ride, but IME it was more harshness and not a ride issue.
> >
> > As far as reliability, Delirn bushings are as good as it gets when it
>comes
> > to Audi control arm bushings.  I have used Delrin bushings in some race
>cars
> > for 4 seasons and counting, on the street I don't think they will ever
>need
> > replacing (specifically with 2Bennett bushins IME).  I'd like to hear
> > anyone's reliability experience with Delrin bushings that wasn't
>excellent.
>
>--
>www.mchang.org | www.acmelab.org | decss.zoy.org


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