I installed Impala SS springs, 'stiff' Bilstein shocks, BMR lower control arm and HO swaybars today.

I was pleasantly surprised out how comfortable the ride is. I would describe the ride as 'European' touring (the Euro's might differ and call it an softer American version.). Certainly comfortable enough for any grey haired old fart living in Florida to be envious of.

All I lost was the Cadillac 'float'. Which may make the passenger feel comforatable while he's sleeping, but as the driver of the car, it scared the heck out of me. The suspension floating around while I'm trying to drive the darn thing doesn't make me comfortable. Only proper car control makes me feel comfortable.

Next is 18" wheels and tires. This may make it slightly more jarring. But since this upgrade didn't increase the jar effect one iota, I'm much less worried about the wheel size now.

Anyone who says this set-up is rough or stiff, either lives in Iraq where the roads have some new large potholes, or they desire their road handling characteristics to mimic that of the Queen Mary. For everyone else seeking handling and comfort from an easy to assemble parts list, this is the set-up.

Oh, I forgot to say how the SS springs filled in the wheel well just right amount. Can't wait to see what the 18x8 wheels do to complement the look.

Where did you get the springs? Are they OEM or aftermarket?
BTW, there will be a BIG difference in ride quality if you do 18's

Originally posted by Katshot
Where did you get the springs? Are they OEM or aftermarket?
BTW, there will be a BIG difference in ride quality if you do 18's

They are OEM Impala SS springs I purchased off of E-bay. They were off a '95 and only had 1500 miles on them. They were just broken in.

Sure, there will be a difference in the ride quality (and an increase in the handling performance). But going from a 70 series tire to a 55 series tire, certainly won't be a poor quality ride. It will just tighten it up a bit more.

I've done the lowered car (and truck) thing for the last 20 years. The 'harsh' ride that I was told to expect, was anything but harsh after my varyious experiences with lowered (and stock) vehicles. It feels like the stock '78 Volvo 245 I once owned, except it corners better and doesn't loose the rear end when you let off in a corner.

I'll let you know how BIG the difference is going to an 18". I already bought the tires, just saving for the rim's.

If you're planning on 18's with 55 aspect ratio rubber, I think you may have a clearance problem. My 55's rub with my 17" wheels. That's why I was suggesting that the ride would certainly deteriorate with the 18's, I was figuring you'd be doing 45's or so on the tires.

You know it's funny, I've done many lowered cars over the years and people will ask me questions about the ride and talk about how rough it will be.....I usually tell the that if they do it right they shouldn't have any real ride issues. We just finished lowering a 2003 Chevy crew cab dually ( 4"/6" ) that regularly tows a 30' trailer with 8 Harleys in it and there is no noticeable difference in the ride. The reason that so many people seem to think that ride is adversly effected by lowering is because so many people that lower vehicles have no idea what they're doing!

See HRS... I told you the ride would be perfect... And that you'd regret the "floaty" Bilsyeins. :)

Glad you like it!

How about some pics? :D

Originally posted by Katshot
If you're planning on 18's with 55 aspect ratio rubber, I think you may have a clearance problem. My 55's rub with my 17" wheels.

I've been back and forth on the wheel size. I'm certainly no tire engineer. I've decided on 18"x8", I just haven't made the final decision on the backspacing.

From all that I've been able to assemble, the stock SS wheel is 8.5" wide with a 5 backspacing. Which put's 1" more wheel to the inside and .5" more on the outside over the stock FW wheel. I think it's the outside that is prone to rub.

I'm thinking about using an 8" with a 4.75 backspacing. It's .5" narrower than the SS wheel. The backspacing I'm using will put's .75 on the inside and .25 on the outside.

Or I could use a 5 backspacing which would put the extra 1" on the inside.

The tire I decided on is a 245/55 18 which I chose to keep the same overall diameter. Plus it was on sale for 85.00, which saved me enough money to make the custom ordered 18" wheel set-up become a break even proposition.

I really don't think this either set-up will be prone to rubbing anymore than an SS wheel. I like the idea of 4.75 if only for the additional .25 wheel lip, but I like the 5 for the additional peace of mind.

So the only question that remains for me is 5 or 4.75 for the backspacing?

Originally posted by toomanytoyz
See HRS... I told you the ride would be perfect... And that you'd regret the "floaty" Bilsyeins. :)

Glad you like it!

How about some pics? :D

I'm glad I went stiff too. Thanks for the input.

I was really lucky in that one week after ordering the soft ones, I called and they where back ordered so I was able to change my mind.

Pic's will follow when it gets sunny. It's raining today.

Plus, the tire shop that intalled my set-up manage to do something to my Traction control and ABS. The dash lights are on and the Traction control is off, although it sems to still have ABS.

It's not a fuse, so I'm going back to have them recheck the connections.

Originally posted by kcnewell
You know it's funny, I've done many lowered cars over the years and people will ask me questions about the ride and talk about how rough it will be.....I usually tell the that if they do it right they shouldn't have any real ride issues. We just finished lowering a 2003 Chevy crew cab dually ( 4"/6" ) that regularly tows a 30' trailer with 8 Harleys in it and there is no noticeable difference in the ride. The reason that so many people seem to think that ride is adversly effected by lowering is because so many people that lower vehicles have no idea what they're doing!
True, to a degree. On this particular case, as long as you didn't change the tires or shocks, the ride will totally depend on the spring rate you chose for the springs installed. Of course, if you changed the tires, shocks, AND springs, the final ride quality will depend totally on the experience of the person choosing the components. Tire size, aspect ratio, speed rating, and load rating will all weigh heavily on the ride quality as will the shock type and finally the spring load and rate.
When I mentioned about the ride quality deteriorating it was based on him going to a much lower aspect ratio along with SS springs. The Bilstien shocks have a lot to do with it for sure but I must admit, I've heard good and bad from people who have tried them.
As for The "new" tires rubbing, since you are sticking with a much narrower tire albeit lower profile, you probably will NOT have a clearance problem. Mine tend to rub on the inside AND outside from time to time depending on what I'm doing. Again, since your 245/55-18 is smaller in all dimensions than my 255/55-17's, you'll have no problems.

I must also add at this point that I don't think that a slightly stiffer ride is a problem either. That's the thing I liked about putting the passive KYB struts on the Seville. No more boatlike ride!

I will add, that I don't think using the 'soft' Bilsteins would have effected the handling negatively (it's the swaybars that are doing most of the work in keeping it flat around corners).

If someone is as concerned as I was initially about keeping the so-called Cadillac comfort, I still think the 'soft' Bilsteins would be an acceptable alternative. The float that's built into those should mimic the stock Cadillac suspension set-up just enough, while still providing firmer handling characteristics.

This is the only change I would suggest, if I were seeking a more stock Cadillac type suspension reaction while still improving looks and performance.

You mentioned a couple points that generally ellude people when doing suspension mods;
1. Firmer doesn't mean better handling
2. Body roll is controlled via sway bars, not shocks.

I can't tell you how many times I see guys stiffening their cars suspension in an effort to attain better handling, only to end up with a harsh-riding, (sometimes even worse handling) car.

There are MANY points that must be considered when addressing a vehicle's handling characteristics. MUCH more than just the shocks and spring height, which tend to be all many people focus on.

Originally posted by Katshot
...if you changed the tires, shocks, AND springs, the final ride quality will depend totally on the experience of the person choosing the components. Tire size, aspect ratio, speed rating, and load rating will all weigh heavily on the ride quality as will the shock type and finally the spring load and rate.


That's why I was trying to stay 'GM stock' as much as possible.

I've done the professionally engineered strut and spring route before in the past with low profile tires. It was great for the back roads and freeway on ramps, but when it was time to relax while cruising the highway the ride was jarring.

Since I'm not a suspension engineer, I figured I would be wise to choose parts that GM designed to tighten up the stock ride since they must take into consideration that the car will be sold nationally with varying road qualities to deal with.

That's why I chose stock SS springs. They are stiffer than the Cadillac but certainly not too stiff (look how many SS owners ditch them in favor of stiffer springs). They also lower it just enough to give it a better look without being inconvienent to drive daily in varying conditions.

The 'cop car' Bilsteins where designed for street use as well. All the 'stiff' vs 'soft' debate I read, was making me think 'stiff' meant road coarse stiff. That's far from the case. They are 'autobahn lite'.

Now, any ideas on a steering box? Stock SS? F-body? Grand National?

That's one BIG problem with doing these kinds of mods, they deal with a very "subjective" point of the car. What's "tight" to one person, is "brutal" to another. Or maybe still too soft for some. There's no book on this stuff so it's definately a good idea to do as you did and utilize the OEM parts as much as possible. Benefit from THEIR engineering staff ;)
As for the steering gear,
I understand the F-body gear is good but I have no personal experience with it.

I've got an SS box waiting to go in mine. :)

Bill,
It sounds like you have a lot of stuff "waiting to go on" your car.
I hope all those pieces net you some "improvements" rather than just extra work;)

I'm certain that the T56 will be an improvement worth the extra work. So will the SS steering box.

What else you got to install Bill?

You know.....I was planning on installing some aftermarket Impala SS springs so it would be lower but just the OEM Impala SS springs would lower my car. I am changing all the bushings on the front and installing a SS sway bar for both ends. What do you guys suggest on the springs? I was planning on some KYB soft shocks, but after hearing what you guys been saying maybe I should go to a stiffer shock.

I'v heard the same thing about the springs. I had the same thing happen to me also. I tried afetrmarket SS springs and it actually RAISED the car. Go figure! I ended up using some springs that I hand-picked and they are GREAT. Soft ride and just the right ride height.

I have the SS springs and bars on mine with the stiff bilsteins. I love the way it rides and handles. :)

More from the "have waiting to install list": BMR LCA's also. :)