I ran Dunlops unshaved 225 front and 255 rear for the second half of last season on stock suspension... no issues whatsoever... very eaven tread wear at that, even with my Autox oriented tirewear be damned alignment.

 

[QUOTE=neurotic,Jan 14 2010, 02:39 PM] Since I have no experience with the aforementioned upper spring mounts, I have a question.

 

Wait a sec, I don't fully understand your question. The GC units are functionally identical to stock. The damper is controlled by the rubber bushings and the spring is essentially compressed against the chassis.

I would expect the bushings would do just as fine as they do when stock.

 

If you are really concerned about misalignment/coil bind/unequal load distribution, you can get a set of hydraulic spring perches. I researched this a while back when I was ordering shocks for my civic, and found that it wasn't worth the money, and additional maintenance. (you need to keep them clean and lubed, at least once a season)

You should be able to get rid of most of the issue with a set of torrington bearings on the perch. I did this for my shocks on the civic, but I have no clue if it made a difference. I didn't worry about it for the S2000 shocks.

The Science of Speed pillowball mounts arrived today for our car.

 

This was discussed a page or two back, so I'm only digging up the recent past.

I am questioning the necessity/utility of the upper spring perches with OE and GC 'top hats'. If the lower shock bushing is highly compressed, the functionality/utility of the 'top hat' may be compromised.

The load path may look weird, but it is not really exaggerated. With the upper spring perch the spring's load transfers from to the perch, to the washer, to the lower shock mount bushing, to the 'top hat', to the chassis. Without the upper perch, the spring's load transfers to the spring rubber, to the 'top hat', to the chassis. Thus, the loads through the lower shock mount bushing are dramatically different with and without the upper spring perch; the bushings now carries the car's unsprung load.

I pressures applied to the rubber components are also dramatically different. With the spring perch the load is carried through the relatively small lower 'top hat' bushing, whereas the spring rubber carries the load over the surface area of the spring (much larger).

With the lower 'top hat' bushing carrying a much larger load, it could be fully bound and ineffective at allowing the spring/shock to pivot through the 'top hat'. Consequently, the bending loads applied shock could be increased rather than decreased.

Those seem like another good, albeit expensive option: http://www.pegasusautoracing.com/productse...sp?Product=1870

Although I question the need for any mechanism to minimize unequal spring loads; the stock class guys seem to get by OK with a larger range of motion (softer springs) and greater angle changes (at least I think they do).

 

They make threaded ones that fit on Penske and Moton shocks too.

But.. the Torrington bearings should fix most of the issue for a whole lot less $.

 

I forgot to add this to my long winded multi-quote response.

With the Koni upper spring perches, both the spring and shock loads transfer to the 'top hat' through the lower shock mount bushing. At least that is how I understand they work.

Does anyone have a picture of an assembly with the OE 'top hat' and Koni spring perch?

 

Don't the torrington bearings solely allow one end of the spring to rotate around the shock? This would minimize some unequal loading, but not account for potential non-parallel surfaces between the lower and upper spring perches.

 

I worry more about the twisting more than the un-equal distribution on the perches.

Nevertheless, the Moton shocks have beefy shafts and pretty nice perches. Combined with the SoS top mounts, they should work fine.

-Brian

 

No, when I meant exaggerated, I was saying that it's too long. It doesn't go from bushing all the way to the mounting bolt of the upper mount, it goes out to the first point of metal contact with the chassis, which is where the upper mount becomes horizontal.

As for the stock guys, they don't have the choice to run upper spring perches, but we do, so why not? I'm more worried about how fast the seals will wear on my shocks, as the valving makes the internal pressures much higher than OEM. Dealing with blown shock is a PITA, esp becuase of the downtime required.

James Yom