Life expectancy of a shock

[ramoncito89]

I currently have AGX shocks in a nissan b13 chassis and I am switching to coilovers KSPORTS and I was told by an AGX distributor that their shocks will last 30k to 50 k in a normal car but in mi case that I put on my car 1000 track miles a year what would be reasonable seen as a change of shock intervals for racing if there is any?

[Racerlinn]

I'm currently on the "till-they-break-in-half" plan with my old KYB's.
The pistons didn't fall out of the tube when I had them off the car in the spring, so that mean't they were still good (to me!).
Sorry, not a very good data point.....

[JLawton]

A lot of it depends on how hard you drive your car, how rough you drive it, how many off's you have, how many curbs you hit......It's not how long they will last, but how often will you blow one out or break it.

Racing isn't an HPDE.......You can't pin a number on how long they will last and I would be leery of anyone who did.

I only have experience with Koni's and Bilstein's. Those are the only ones I will use........

[benspeed]

I am pretty rough on my equipment. When I was in ITS I ran JRZ shocks and they needed a rebuild about every 8 race weekends to the tune of $800 for four. I am happily running much cheaper Bilsteins and unless they are spitting oil, I will just keep running them.

When I spoke to Koni about the Koni Reds in the Fiero they said that the shock should perform until they spit - no need to replace. Mine have about 20K miles and seem fine, but they haven't seen race conditions yet.

[924Guy]

I only got maybe a year out of the old street (yellow) Konis I ran, was underwhelmed, but then I think I did unintentionally abuse them more than even normal for racing (rookie, what can I say!)

Now I'm on Bilsteins, and I can't believe the durability... now on their 6th year, and I finally opened the rears up to tweak them a little. On discussion with a fast local Volvo driver, seems that at very least to replace the oil and recharge the N2 charge every year is not a bad thing. I checked the charge on mine before disassembly, they were both down to anywhere from 70-100psi; they're supposed to be more like 200psi, apparently.

Gonna have to send my fronts in to be serviced this winter, I guess. Seems like a general rule of every other year, if you're using them hard (I usually have 6 race weekends per year), might not be bad timing for a rebuild... if you're only managing 2 weekends a year, stretching them out to 5 years might not be the end of the world!

[CU Zcar]

* no actual experience here

From what I understand, shock oil is a "wear item" kind of like oil in an engine/transmission, the primary problem is contamination (water or dissolved gases, I suppose) in the oil causing less ideal performance than pure oil provides, i.e. increased chance of aeration or viscosity changes outside the range considered in the shock design. I couldn't guess at the lifespan of shock oil, but it probably varies as noted above with shock/suspension design and care & feeding.

In a non-rebuildable shock like an AGX, I guess you keep going as long as there's a gas charge left and the seals hold fluid! Not to say they're performing ideally any more, but there's nothing to do but replace them.

Would checking a cheap sealed shock on a shock dyno be cost prohibitive (i.e. more than a new set)?

[x-ring]

Would checking a cheap sealed shock on a shock dyno be cost prohibitive (i.e. more than a new set)?
[/b]

I have no idea what it costs to have a shock run on the dyno, but when we were checking SM shocks on a dyno at the runoffs last year they took about 10 minutes each, so that shouldn't cost more than what, $100? :D

[RSTPerformance]

Koni's strut incert (front) lasted on our cars (Audi's) about 10 - 15 miles (yes that is correct) the Bilstiens have lasted 1 season worth of racing and no issues have even started to be a concern, at this point they look like they will last forever!!!

Raymond

[924Guy]

Koni's strut incert (front) lasted on our cars (Audi's) about 10 - 15 miles (yes that is correct) the Bilstiens have lasted 1 season worth of racing and no issues have even started to be a concern, at this point they look like they will last forever!!!

Raymond
[/b]

Sounds pretty similar to my experiences Koni vs Bilstein... I ran my Bilsteins for maybe 5-6 years before even touching 'em, and that only to revalve. Probably shoulda had 'em rebuilt after 3-4 years, though...

PS - note that after that 6 years, I ran within tenths of the lap record...