> Does anybody know the benifits of the new internal helix design that is
> supposed to be in the new ZR580? It looks very similar to a Polaris
> design. I don't think a roller kit will be as easy and cheap to apply
> as to the old design (if the outside face has to be replaced also). My
> dealer offered to exchange the clutch for the old design at no charge.
> Unless this new design offers some significant advantage I think I'll
> opt for the old design and install the roller kit.
> Bob Alger
I know someone who qualifies as a clutching expert. He has been working
with clutching for over 20 years and designing and prototyping clutches and
components for over 10 years. He feels strongly against the new AC clutch.
He feels they had a better design with the old style (and with the
addition of a roller kit). This is his reasoning:
The Polaris design upshifts and backshifts faster than the AC (old design)
but the bearings are close together. These bearing have a tremendous
torque load on them and therefore wear out faster. The replacement cost is
expensive. The bearing are wore, he claims, at around 1000 miles.
Although the torque is near the bearings, the clutch does shift faster.
The reason the Polaris shifts this way is because the torque of the belt is
located directly over the helix and buttons. The AC clutch, on the other
hand, has the helix outside of the belt torque. The AC clutch, though,
lasts longer and is stronger because the bearings are located further
apart. The clutch shifts a little slower, but with the addition of a
roller kit, it shifts actually faster than a Polaris. This is why the
roller kits work so well.
He claims that if he was the owner of AC, and he paid engineers to come up
with a "new" design and they copied Polaris, the engineers would be looking
for another job ;-)
If this isn't enough, I talked to a racer who is AC sponsored and goes to
all the race meetings. He said that the racer group and the engineering
group don't agree on the new clutch. If it was up to the engineers, the
"new" design would be on all the AC sleds this year. It's because of the
racers (who want the old design) that it didn't happen.
I put an AC driven (old design) with a roller kit on my '91 Indy 500 more
than 3 years ago and I won't go back to a Polaris "style" driven unless I
had no choice.
The choice is up to you. I'm just giving you information and you can
Shane Zeppelin :-)