Mythbuster: continuing project thread of my 1303 '75

[Wally]

Originally Posted by verbeekb

Hey Walter,

Somewhere I saw you mounted polybronze bushing on your spring plates. Someone mentioned the lack of the knobs that are on the VW bushings, you replied that you were going to give it a try. I feel the same way, yet, I have new Porsche springplates with the stock vulcanized-on rubber bushings, everyone replaces them with the VW parts, but since mine are new I'd just like to use them the way they are and not bother with them.. have you had problems without the knobs?

Hi Brian,

I haven't driven the car yet, but there is a significant difference with what your asking/suggesting and what I am/will be running:

The original bugs inner torsion housing has not only the holes for the knobs of the bushings, but the whole outer diameter of this torsion housing where the bushing resides, is concave in shape!
The 944 inner torsion housing is plain, so a circular bushing fits perfectly.
Now, we want a plain, straight (rubber) bushing to fit the concave housing... Thats the reason it doesn't exactly fit. The knobs are just 4 parts where the bushing doesn't mate flush, but thats minor imo.

However, the 944 bushing does mate the VW torsing housing at one point exactly and thats the most inner part of the concave part of the housing.
So, the bushing sits at just half a cm snug and not the full 5 cm or about 2 inches (width of bushing approx.).
Now, with the hard poly-urethane outer rim of the poly-bronze bushing I use, this may just work (or not). I also filled up the rest of the space with a sort of hardening glue. With an already soft original rubber bushing, this is much more of a concern I would think.
The whole idea that you are using porsche parts for suspension upgrades, but are keeping the rubber bushings and now let one of the bushings carry on only its outer rim in the housing, is counterproductive regarding thinking about suspension upgrades imho.

So, in conclusion, I think a black urethane VW IRS inner bushing would be a good upgrade from the stock rubber. The red urethane usually squeecks too much for my taste and the black may not squeeck or less. I have bought (very cheap, Topline) a set already if the inner polybronze doesn't work, but the set is too nice not to try it out at least

Hope it made sense; difficult to describe from here...