iridearocket

This topic was under debate with TeamRX8 and a few others in another post. I want to rehash it becuase the logic makes no sense to me.

What I gather from other comments made, is that a shock just provides 2 way resistence and the distance and location of the piston in the chamber does not increase or decrease at any point in the shocks travel. Such that lowering a car (having the piston closer to the end of it's compression stroke) does not increase any pressure on the piston seals in any way. (to reduce the shocks life)

But when you compress a damper by hand, (you have to push on it pretty hard) it returns itself to the extended position naturally, becuase of the compression pressure that is generated as you move the piston closer to the end of it's compression travel.

I propose that if the shock spends all of it's life closer to the end of it's compression travel (car is 1-2" lower, so the shock might be 1/2"-1" closer to the end of it's stroke) then the piston is always under that increased pressure that is not allowing the shock to want to return to it's fully extended position. (it never gets to it's fully extended position becuase of the weight of the car, but by lowering the car, you are increasing the shocks compression stroke) Hence the shock wears out slightly faster under this increased stress on the seals.

Can any one explain why it would be otherwise?

TeamRX8

iTrader: (25)

I'll be fair. I'm expecting a call-back from the Koni NA Motorsport /R&D Dept. I'll ask your specific question and relay back word for word what they say.

However from my own experience a shock seal in deep compression will greatly outlast a shock seal in extension. The longer the distance between the piston seal and the shaft seal the better supported the seals are against excessive side loading forces

salituro64

Maybe that's why the Mazdaspeed springs require installing shorter shocks

staticlag

You seem to have the correct answer.

Its not so much a position arugment that makes the shocks wear out, as it is a spring/shock weight distrobution arugment. Imagine you had a car with only standard springs supporting it. It would never stop its oscillations. Now imagine you had a car with only shocks, in essence you would have a pressurized "airbag" type system. Granted that both systems could be adapted to function separately, these cars of ours were designed with specific roles for both parts. The shocks were not meant to support the car, they were meant to control the spring's motions. The springs were designed to support the car. By forcing the shocks to assume a greater than normal load you shorten their life, pretty simple.

TeamRX8

iTrader: (25)

not at all, but I'll use the experts words

deam

I was at the shop today and i actually talked to them about installing tein basics, and they asked me if i had shocks too, and i said no, he said itll decrease at least 30% of the shocks life????? Which one is it??!??!?!!?!?!?

IZoomZoomI

tein basics are coilovers they do have a adjustable shock.

deam

I ment the tein specs, sorry

iridearocket

Deam,
The performance stores use this as a sales tool to sell you shocks too, so you have to keep that in mind... but there is no question your car will start bouncing after only 1 year of driving if you replace a tight spring, but don't replace the shocks with ones that have tighter dampening. Unfortunately, there is no getting around that.

What we are debating is whether the car is bouncing due to:
a) excessive shock wear caused by the different position of the shocks piston.
or b) just the fact that a tighter spring will cause you to feel a wearing shock earlier.

Either way your will notice quick deterioration of the shock.

My last car (VW Corrado) bounced within 1 year, but the shocks were already 3 years old. So I tried the same thing with a new 8. The RX-8 has started bouncing (not bad, but starting) after only 1 summer. The car was brand new only 1 year ago so it seems stock shocks don't have much resilience to tight springs.

If you don't want to replace the shocks, you should go with a spring like the Racing beat, a bit softer than some other performance shocks and they don't lower the car very much. Then you'll be safe. The more performance you demand, the more $$$ you will spend. That is my only guarantee.

Dark8

^+1. It is the higher spring rates of the lowering springs that kill the shock. In some cases, like on my eclipse, the increased travel from cutting the bump stops can also damage a shock if they bottom out.

TeamRX8

iTrader: (25)

see my comments in the original thread