moespeeds

I've got the whole car apart, basically replacing everything, ball joints, bushings, etc. It's got about 8k hard track miles on it (car is track only). I've got PFADT coilovers, they have valves on them that I'm assuming is for the nitrogen. When should I rebuild them? Should I check or add nitrogen?

RX-Ben

Regularly check nitrogen.
Typical rebuild time for a race type shock is on the order of 30 hours (though not sure what Pfadt specs), so it wouldn't hurt.

joenationwide

If you see any signs of leaking from the seal head (where the shaft enters the body) then its time to rebuild them.

froggy47

Just curious where that comes from, it seems pretty frequent. Is this for real racing like Nascar, ALMS, etc?

RX-Ben

Penske manual, which says 30 hours or annually (for a race car).
Pfadt feather doubles are real race shocks, should be similar across the board among brands.
They won't fall apart, but their performance will degrade.
Not sure of pfadt singles.

froggy47

Bill32

If you're serious about your shocks, you'll have them dynoed once a year. That's the only to determine their condition. And if you're buying good shocks, you should ask the seller to provide dyno sheets on the new ones.

If they are leaking, you waited way too long or you hit something (curb).

We rebuild the race shocks every season or about 21 track hours.

Shocks degrade way faster than most people think.

froggy47

Is it true that Penske shocks can be rebuilt by those of us who are reasonably handy around cars?

RX-Ben

Yes, with the right tools, which cost a few bucks. This goes for any real damper (from the relatively cheap Bilstein race units to the high dollar Penskes etc.).

Also, I would be interested in seeing a new OEM C5Z damper dyno vs a used one, to see how a quality lower end damper degrades. Race units generally use "lighter" seals that need regular attention, from my understanding (which result in better performance).

geerookie

If they are leaking it is waaaaayyyyy too late!

Shock oil is like motor oil but it has one extra purpose (control of the springs).

It still has to lubricate and cool. As a result of all the heat built up in the shock it will break down the same as motor oil.
Also the shim stacks can weaken over time/use/abuse and should be replaced during a rebuild.

Shock dyno will reveal weakening or failing components but if it indicates broken down/degraded oil, again it is way too late!

froggy47

It would also be very informative to see a dyno of an "over due" shock, one that has leaked oil for example. Before and after a rebuild.

Maybe a "shock guy" has something to post up.