bouncy ride

[will 2 0]

hi, i have just had to change the coil springs ( h&r 40mm lower ) all around on my car as 1 on the front had snapped, the new ones are lesjfords 40mm lower,

 

the problem i have now is the ride quality has gone all bouncy and bottoms out at the front, i have koni ta's all around and have tried adjusting them up but they just dont give me the same ride.

 

any ideas what could be my problem, ( not sure on the condition of the bumpstops as i was not there when the springs were taken off )

 

thanks gareth

[Macdaddy 10]

Stock dampers?

 

Could be that they've been pushed too far now.

[Supercharged 2]

Usually a sign of knackered shocks

[will 2 0]

shocks are fine, koni ta's, not stock . (just went through mot after changing the springs) its just the ride is crap !!

[boost monkey 0]

sounds like you have mismatched springs and dampers. This will make your car handle really badly as they won't be tuned to work with each other.

 

Basically, it's all about chassis dynamics. The wheel hub will resonate at a certain frequency called the "hub mode". This is where the wheel will basically bounce off and slap back down on the road. The body will also resonate at a certain frequency called the "body mode". This is where the main shell of the car starts to oscillate up and down on the suspension. I've seen it on a 4-post rig and it's very obvious when occurring!

 

So basically your springs and dampers may not be isolating these frequencies and damping them properly. This will result in very poor handling, and will also explain why the shocks are behaving like they're broken when they're not.

[fla 9]

my dampers were a bit like that when i got them. Had them rebuilt with new seals and fluid and they were transformed. Did you test the shocks before refitting to confirm they were damping correctly? I know you said they're ok, but it does point to them failing. Unless its just a question of adjusting the damping rate, or as Boost has suggested, mismatched springs with the dampers.

[will 2 0]

sounds like you have mismatched springs and dampers. This will make your car handle really badly as they won't be tuned to work with each other.

 

Basically, it's all about chassis dynamics. The wheel hub will resonate at a certain frequency called the "hub mode". This is where the wheel will basically bounce off and slap back down on the road. The body will also resonate at a certain frequency called the "body mode". This is where the main shell of the car starts to oscillate up and down on the suspension. I've seen it on a 4-post rig and it's very obvious when occurring!

 

So basically your springs and dampers may not be isolating these frequencies and damping them properly. This will result in very poor handling, and will also explain why the shocks are behaving like they're broken when they're not.

 

didnt realise this could be a problem, just thought changing the springs with the same lowering drop on all 4 corners would have been ok, appart from the stiffness or poundage of the springs could be different then just adjust the dampers to suite

 

---------- Post added at 02:02 PM ---------- Previous post was at 01:58 PM ----------

 

my dampers were a bit like that when i got them. Had them rebuilt with new seals and fluid and they were transformed. Did you test the shocks before refitting to confirm they were damping correctly? I know you said they're ok, but it does point to them failing. Unless its just a question of adjusting the damping rate, or as Boost has suggested, mismatched springs with the dampers.

 

didnt check them before refitting, i just took it that they seemed fine before i found out that the spring was broke

[Kevin Bacon 5]

Your Konis are shot. Very common. Koni are not what they used to be I'm afraid. I went through quite a lot of Koni TAs in my MK2 days and also on my Corrado. Then I gave up giving them the benefit of the doubt and went coilovers.

 

Same symptoms as yours, just soggy with no rebound damping, even with them turned up to the max. They need a rebuild. Also look for damper oil seaping out of the top adjuster.