x28

I have noticed that my car has becoming increasing bouncier after changing only the springs on my RX8. Is anyone else experience this with lowering their car and only changing the springs?

winter

Typical result on any car.

Kain

elaborate please

sinkas

Hi there Kain,

The standard duty shock absorbers are not designed to cope with the increased spring rates of the new springs,
Hence they do not have the damping qualities required to damp the new springs and they also deteriorate really quickly

Cheers

Case

VeilsideRX-8

Above is correct, my friend did the same thing with his eco cavalier and its a shi%%y ride in it now. He just replaced the stock with Eibach springs and ruined it.

VeilsideRX-8

It looks nice, but doesnt last long

darkducati

What kind of springs are you using?

Gord96BRG

Yup, shock compression and rebound damping rates are matched to springs - the OEM shocks are tuned for the OEM shocks. Stiffer shocks require higher damping levels for both compression and rebound - you always need to change shocks when you change springs so that they're tuned to match each other. Changing just shocks can be OK; changing to stiffer springs without changing shocks ALWAYS causes ride and handling problems.

Regards,
Gordon

Kain

thanx everyone! so does anyone know of any companies making shocks for the rx-8 now to match with lowering springs? I am asking cause I am not sure if I really want to go all the way to the coilover method?

darkducati

What kind of springs are you using?

rev-2-9k

Is this true for the RB ones? I had heard that they were designed to work with the stock shocks.

Kain

I have TEIN that are waiting to be installed- will wait to find matching shocks now though.......any suggestions?

darkducati

Are they the H-tech or S-tech?

Kain

sorry! TEIN s-tech??? any suggestions? and in advance- thanx

Kel Rx8

yeah put them on
my car doesnt bounce
yeah ride is not the same of course
and one day (sooner)my shocks will go
but nothing drastic like a bouncing bunny civic,go for it
i dont think there are any companies other than mazdaspped shocks

darkducati

I was going to suggest the Tein H-tech or Tanabe NF210s. These are both designed to drop the car using the same as factory(roughly) spring rates, which will help in handling and should work fine with the factory shocks.

mikeb

I have eibach springs and the car still rides great after 5 months

how long until the shocks go out??

cortc

My experience in the past is that you need to change the shocks when you change springs, it is never as good as it can be if you don't... Firmer springs require more aggressive damping...

fietguy

okay, i think we all need a real mechanics opinion on this...

this somewhat pessimistic sentiment i am picking up about installling aftermarket springs just seems a little blown out of proportion....

im thinking that all caution may stem from back not too long ago when cars would just get slammed down...of course then shocks may not last too long...

but take for example, eibach's or even Teins they lower the car a little over an inch, people are making it sound like the shocks will go in 2 years....can we have a real analysis over this?

a valid argument is made the factory shocks are tuned specificially for the factory springs and vice versa...this i think is reasonable to assume, but i doubt if this is an exact science too...everything stock mind you, usually leans towards an average...who is to say Teins springs installed on stock shocks actually would be better for the car?

saying the factory springs always are tuned specifically for stock shocks is like saying the factory tires are tuned specifically for the car...and this is not always the case, its all about whats available and at what cost ----

okay sorry to be long winded but one more example on how factory specs are not an exact science, i also have a CLK 320 2004 which is running on 205/ tire in the front and 225 tire in the back 16"....the car is close to 3800 pounds....these are the factory specs, but after driving this car no one can tell me that this wheel combination is "perfectly balanced" and that a change would not do it justice", to make a long story short Mercedes cheaped out the wheels and these wheels in my opinion are way too narrow for the width and weight of the car....a quick update, news mercedes is going with a larger wheel stock for 2005's...

not all factory specs and balances are perfect for that particular car....there are idiosyncracies in the eight that are not perfect....aftermarket springs may or may not be significantly bad for the factory shocks, i think a lot have to do with the companny that produces that particular spring....

if i am wrong, and aftermarket stuff does ruin my shocks after 2/3/4/5 years then please someone let me know how they know this mechanically, and how they can quantify the extent of which it will...thanks

Gord96BRG

You're wrong. BUT - there's no such thing as "perfectly matched" to the car - the auto manufacturer's engineers have a set of design goals, for suspension and tires those include ride quality, smoothness, cost, noise, handling balance, responsiveness, grip, durability, etc. Their objectives are an average of what they think the customers of that particular model will want. Not all customers would choose the same compromises that the engineers chose (and, of course, everything is a compromise and a balance of all the factors).

SO - Mazda chose spring rates for the RX-8 standard and sport suspensions (they're not the same springs). I don't know if the shocks are the same, but I'd doubt it. After choosing the desired spring rates, they would have spec'd shocks with appropriate shock and rebound damping rates for THOSE springs, to achieve the desired handling and ride characteristics.

If you just change the springs to stiffer springs - the shock absorber's damping curves will NOT be properly matched to the springs, and you WILL have inadequate damping. The ride will be less well controlled, but to call it "bouncy" would be an exaggeration. The stock shocks with the new springs will not get ruined or blown out much earlier than with the stock springs. They will just be inadequate and poorly matched for their entire life.

How to know this? Lots of experience and lots of reading - there are quite a few good "textbooks" out there with this information. Just go to www.amazon.com and search for "car handling" and you'll see a bunch of hits to start with.

Regards,
Gordon

Sputnik

No it's not the same thing. Carmakers do spend alot more effort matching springs/shocks/geometry/etc. than with the tires.

---jps

fietguy

okay thanks for the feedback,

so the aftermarket springs installed will not blow out the shocks significantly earlier than the factory springs would...but the ride will be more unconfortable and inadaquate for the rest of the car's life?

how about the people who have installed aftermarket springs and have concluded the ride is the same? in fact, in this forum, besides the guy who said his ride was bouncy, most people have said their ride is 'feels much like stock' yet with a great reduction in bodyroll in the twisties.

do these people not feel that with their new springs, the dampening is now not adequate?

Omicron

I've had the Tein H-Tech for about 1000 miles now, and have seen no degredation in handling. If anything, it's better.

ScudRunner

I've had my RB springs for about 500 miles now...ride is less forgiving when it comes to bumps (to be expected, I would imagine), but certainly not "bouncier"...to the guy that started the thread, did you get an alignment done after you swapped the springs out?

manok_adobo

I just had my Tien s-tech springs installed wednesday. less than an inch off drop in front. less roll on corners