LS1LUNATIC

iTrader: (3)

I recently had a shop install BMR spring all way around, however I was advised since my car only has 38k miles on the clock that my stock orange shocks were still good. Now I've noticed that when I have a little bit of speed going (45 mph and up) if I hit a bump in the road it will either bottom out, or hit the bumpstop, i'm not sure. Has anybody else run into this problem before? Will replacing my stock shocks prevent this? I love the stance, and have had very little issue with ground clearance, its just the bottom out which bugs me.

Also, when I reverse out of my drive way and go over the little bump at the end, the rear end makes the same kinda sound as like jumping on a old coil bed. Sounds like something is making noise as it compresses. Is this noise the shocks or the springs? Sorry for the long post, just looking for some good advice. Thanks in advance

JD_AMG

Probably should have searched before you did the install.
While the stock decarbon shocks might not be "worn out" at 38,000 miles, this doesn't by any means mean they will work with lowering springs.
Thats like swapping in a big cam on a low mile bone stock engine and saying you don't need a tune because the engine has low miles on it.
The stock shocks were not valved for lowering springs in the first place, and poorly valved for the stock springs (result is sloppy ride and handling). So now you are making them do more work (high spring rate) with less space (less travel) so its certainly not going to ride or handle good. and because of this you are probably feeling the car hit the bump stops harder than it did stock, the shocks cannot slow it down fast enough.
First thing I would do is make sure everything was installed properly. If so, start searching through this section for shocks, and gather your own opinion about what you want.
I'll tell you to do it right once and buy Koni 4/3's.
Unlike the other shocks out there they come with a lifetime warrenty, are rebound adjustable (and only adjust the rebound), and a high quality part.

ClemsonT/A

iTrader: (2)

I have the combo *stock shocks in the back but kyb adjusts in the front).. as well as true duals.. I do not have bottoming out problems but I do scrape often. This could be attributed to the kyb shoks ont eh front however I am told they are nto much better than the decarbons.

I am tired of how the car rides though (being a daily driver) and I just (just as in 30 minutes ago) ordered a set of 4/3 konis from Sam Strano.. I will report back in a few weeks when they get installed (football season so Saturdays are busy )

ALso konis are going up in price significantly on the 1st of September.. that was the motivating factor in me buying them now.

toadzq8

iTrader: (43)

One way to keep from bottom hitting the bump stops is to install a set of air lift bags inside the springs, only about 60-70 bucks ( BMR or Thunder) and you can adjust by adding or taking out air, I had the BMR springs and had problems with them hitting on bad bumps and if I had the rear loaded on a road trip (Power Tour) it was real bad. Installed a set of the bags and keep about 5-7 PSI in then problem solved and if I am traving and have a lot of stuff I will put in 12-15 PSI keeps the car level and don't take away from the ride because of the added weight.

jimmyblue

iTrader: (11)

In my opinion even -1" is getting to be "too low
for bad road".

Check out the bump stops, if you have the hard
"square looking" ones with aluminum spacer you
probably want to swap these out for the "regular"
ones. After doing this my car did a lot less
"bottoming" (or, more softly so I don't feel it).
The new one are white polyurethane from the
look of them and more "triangular".

I also run Gabriel air shocks out back ( style!)
which I did back when the -1" Hotchkiss were still
on there, better than bags in my book. But I leave
them depressurized except at the track.

z28bryan

iTrader: (7)

A lot of people think they got the answer, and the shop who installed the springs have no clue what they are talking about. Brand new stock shocks won't dampen aftermarket springs correctly, and don't last very long with stock springs. You need better dampers plain and simple if you want to control the BMR springs. There's a massive amount of info out there on shocks. Make sure you aren't reading old out of date threads as shock choices and valving has changed significantly over the past 2-3 years.

Sam Strano

iTrader: (41)

I need to say this right now, flatly and bluntly. Folks toss around the term "bottoming out" recklessly and have no idea what it means. They all assume it means hitting the bumpstops, and that's what's causing their sudden and jolting ride quality.

In reality it is not the fact the car hits the bumpstops that causes this. Also, it's not going to stop regardless of what springs you put on, or what shocks you use. The car has relatively little travel to the stops, and they get used even on a bone stock car.

The issues that causes the bang-bang ride are shocks and springs and how they work individually as well as together.

You are finding out right now why you don't use stock shocks with lowering springs. Hell, they ride like crap with the stock springs. This is where good shocks excel. As for your springs, you could do worse. At least the BMR's aren't too low, or super stiff. I think they are stiffer than they need to be, but in all honesty are far from the most hateful things out there. You need better shocks, period. The speed at which you hit the bumpstop needs to be controlled. The bumpstops aren't hugely stiff, unless you ram into them at 600 mph (so to speak).....

The shop (not knowing who they are) is guilty of at best delusions that the stocks shocks are any good to start with, and worst complete ignorance because anyone with any sort of basic knowledge should realize when you take shocks meant for taller and softer springs and ask they to control lower and stiffer springs--it doesn't work well. And is doubly bad when the stock shocks do a lousy job of controlling the aforementioned stock springs.

So, yet again I find myself preaching about shocks. They are, bar none, the most important suspension part under the car if you want it to work at all like a good suspension should.

LS1LUNATIC

iTrader: (3)

I would like to start of by thanking everybody who has chimed in, this is exactly the advice I was looking for. I was hoping Mr. Strano would chime in, I didnt want to bother him with such trivial questions. From what I gathered from doing my own searches is:

Bilstein would work better on non lowered cars, so thats crossed out.
QA1 would help out tremendously, however all the adjustability factors mean nothing to me when I have no idea how to set it up.
Tokico is the runner up if I was on a tight budget
Koni 4/4 again are similar to the QA1's being too advanced (I might be wrong) for my knowledge.
Koni 4/3 should be my best solution. They seem to have a good success rate with a lot of members on the board, Mr. Strano with his endless knowledge of suspension recommends them and they are within my price range.

By no means do I want to discredit the shop that installed my suspension, I take partial blame (about 80%) for not researching that the orange stockers would perform terribly with lowering springs. However I agree with you guys that the shop should have recommended otherwise.

Once again I would like to thank everybody who posted their experiences, I look forward to my new shocks and axing my old ones.

z28bryan

iTrader: (7)

QA1's probably aren't what you want. Those are drag racing shocks.

I think your choices are probably going to be konis 1 and then KYB AGX shocks for the cheaper runner up solution.

Sam Strano

iTrader: (41)

My recommendation from top to bottom:

Koni 4/4
Koni 4/3

Then kind of a two way tie with AGX, Bilstein but for different reasons. AGX's allow you to tune the ride where the others don't. Bilstein's normal valving is a little wacky but we use a different rear shock that nobody else does to compensate...but you have no adjustment.

Then Tokico. The cost is very similar to Bilstein, slighly less.... but they aren't as durable and again have no adjustment to tune anything

Then we're talking QA1's. While adjustable, a crappy one on a shock that isn't very durable isn't anything I'd want to spend money on. In fact I'd cross them right off the list.

As for adjustment. Don't let it scare you. I deal with it and customers everyday, and take a lot of time to explain how it works and effects the car. It's not hard once you understand how it works and is nothing to be scared of.

LS1LUNATIC

iTrader: (3)

Thanks for your input Sam, I think I've made my decision.

Sam Strano

iTrader: (41)

You're welcome.... my pleasure. Your posts were concise and to the point which makes things a lot less hassle.

LS1LUNATIC

iTrader: (3)

Got my Koni's 4/3 installed and within miles I noticed a difference. The car seems much more stable and body roll is virtually gone. I going to play with the front shock settings some more, but the rears are set. I went to this cursed dip in the road near my house where I used to bottom out hard, hit it at about 40 and not a hint of bumpstop. Plus my car has turned into a real corner carver. Now all I need is some better tires and I got me a ferrari hunter

Thanks Sam for taking some time out of your busy day to give me some guidelines, everything seems great so far.