Help with too rough of a ride from Hotchkis/lowering

[arepee]

I’m looking for some help to soften the ride of the rear suspension specifically. I have had the full TVS kit from Hothckis installed for about 8 months and love the way the front of the car handles/rides, however the rear suspension could knock your dental work out. Any tips on softening this ride up a little?

Current Rear Setup:
1. Hotchkis TVS Kit - http://www.hotchkis.net/product/201...tchkis-suspension/?mk=54&yr=2012&md=688&sm=39
2. Koni STR.T shocks (orange)
3. 20x10 Wheels
4. Hankook Ventus V12 Evo2 – 285/30/20

My first thought is the tires, which I don’t particularly like my current tires. I understand that they currently have a very short, and therefore very stiff, sidewall. Would going with a taller sidewall be of considerable help? I’m thinking my next set of rear tires will likely be Nitto NT555R 305/35/20.

My second thought would be shocks. Is it time to upgrade to a nicer and possibly adjustable shock, maybe koni yellow?
Lastly, it is time to throw some grease at this pig. Should I also consider swapping out bushings with something that has more give?

Any help would be greatly appreciated, and please let me know if more information would be helpful.
Thanks,
Ross

 

[Skrapmetal]

Are you riding on the rear bump stops all day long? That might be a cheap and simple thing to look at that might help some.

 

[noldevin]

Those springs are pretty soft, and the Koni Oranges aren't exactly stiff either. I'd bet you're hitting rear bump stops.

 

[paulyboy928]

+3 for the bump stops

 

[greenscobie86]

I cut the bumpstops on my car after lowering and the ride did improve somewhat, of course you can still bottom it out.

 

[arepee]

I did cut down the bumpstops, twice actually. The first time was the top "section" (which is what Hotchkis recommended) and the second time was the next section down. I guess it would be possible I'm still hitting them, but I hope not. I'll put a little bit of grease on top of them and see if it transfers to where they are supposed to bottom out.

 

[djclark]

I'd start with swapping out the STR.T for Bilsteins ( http://www.vorshlag.com/product_info.php?cPath=141_142_179&products_id=642 )

 

[Skrapmetal]

If you cut them that far and are still hitting them it would be pretty jarring.

If it IS that, the FRPP bumpstops are a bit more compliant and might be a good fit for you.

 

[noldevin]

It could be that your rear springs and shock combo are just too soft. If it's too soft you'll ride the bump stop all day.
They are progressive rate springs that start off wayyyy below stock rate and end at about stock rate, except they're much shorter. I'd bet they're compressing quite a lot as you go over even small bumps, so yeah, I'd probably try a different rear spring. I definitely wouldn't address this with a softer bump stop, because you shouldn't be hitting the bump stop to begin with.

Some numbers for you:
The Hotchkis spring is Progressive from 125-180lb/in
Stock Brembo/Track pack rear springs are linear 167lb/in (and 1.6" taller)
Boss stock rears are linear 186lb/in (and 1.6" taller)
Standard BMR rears are linear 160lb and 0.1" taller
Steeda Sport rears are linear 175lb and 0.6" taller

My BMR "handling" rears are "dual rate" 200lb and are still comfortable with my Koni Yellows set to about 1/3. They get pretty rough if I crank up the shocks but I can't say I've ever felt bump stops. I think any linear spring would do the trick to keep you off the stops. The BMR ones are a similar drop to the Hotchkis and pretty popular.

 

[arepee]

Thank you all for the assistance, and now I have some homework to do. Planning on greasing everything this weekend and will find out if I am in fact riding the bumpstops - if I am, I like noldevin's idea and the $110 or so that it'll cost for the new rear springs will be worth trying out. Maybe my wife will complain less about my car after this!

Thanks again,
Ross