Looks wise the strano springs dont give you enough of a drop, almost looks stock

 

You think the cars seen in this thread look stock? https://ls1tech.com/forums/suspensio...ng-setups.html

My rear springs aren't really low, on purpose because that is a primary reason for terrible manners and ride quality. Anyone could also do the isolator mod if they wanted a bit more drop....

 

Because I'm honest, I have to tell you that a huge change would not be forthcoming. The rates and heights are overall too similar to see anything massive. That said, you would end up dragging around less weight, and having a bit more supple ride from the back of the car.

If you want more performance and it came down to a spring change or a change to Koni's, it'd for sure be the Koni's I'd recommend.

Now, don't interpret that as my thinking the springs are the same. I don't think that anymore than I think an LT1 is the same as an LS1 because they are similar in being about 5.7 liter GM V-8's....

 

Says somone who's not done it.

You say that, and seem to forget the BMR springs are stiffer than mine are in the rear of the car.... So please enlighten me on how you come to the conclusion my springs can't launch as well as BMR's which are stiffer when you say that mine are too stiff for launching?

And to address the Koni side, well I have a lot of customers with springs and Koni's in the 1.6's and 1.7's with that setup. And one customer who pulled a 1.50 on Koni's vs. his previous best of 1.58 on a combination of Afco and QA1's. (both setups on stock springs).

I know you have a theory, but that's all it is. And I had forgotten about another car that many know... The GMHTP magazine Camaro called "1SC-YA" has a suspension I did on it. Not only did it go 3.4 seconds faster on a road course on street tires... but with Strano Springs, bars and Koni's also ran a 12.23. Now that might not be impressive until you realize the mph was 109. That ET came from the launch, showing that a handling car can indeed leave pretty freaking well.

Strano springs are not drag springs. Eibach drag springs are drag springs. And if drag racing is most important with decent handling, then NO lowering spring is right for that job and you'd be best served with stock spring and good shocks.

 

Sure thing, anytime.

 

Fair enough.... but let's not forget the amount of weight the car is supposed to carry is only about 700 pounds in total. Considering that most of that mass is likely to be carried in the seats (between the wheels) and not cantilevered out back, mass does has an effect on my springs more because they are not as stiff. But they are still about 25% stiffer than stock in the rear.

And from a handling standpoint, I don't know many that go driving all that hard with a lot of weight in the car.

From the shock standpoint, as Bryan said the Koni's adjust rebound. If you just turn the shocks up to "compensate" for weight, you can overdamp the springs (and you can overdamp the BMR's too, but wtih more rate is takes a little more shock to do it). The shocks do not adjust compression, and even if they did compression damping deals with unsprung weight *not* sprung weight. In short you are turning the shocks up for the wrong reasons and they are not responding in they way you think because that's not how they work.

In situations like yours there is an easy fix that allows you to keep my springs on and get the rate you like better when "empty", but give you some more spring rate when you load up. Best of both worlds. Called airbags. They fit inside the springs, and only cost about $100. Deflate them when empty and you ahve my springs. Add air when you pile in weight and you have as much extra spring rate as you want.

But other considerations. If anyone as an SS or WS6, we change rear bumpstops to the softer more progressive Z28/Formula versions so the "hit" when you contact the bumpstop (and all springs do) isn't as sudden. Now you can do that with more spring rate too, but more spring is always more spring, and we don't always need that much spring. So I prefer the softer spring and less abrupt rising rate bumpstop (which don't return energy like springs do, so they aren't the same as a progressive spring).

 

I wasnt comparing BMR springs I was comparing QA1 shocks and springs versus your koni/spring combo on the track

 

Fair enough! I appreciate the honesty, which is why I went with you in the first place! Which Konis would you suggest? I never go to the track and frequently do a lot of spirited, nice, twisty mountain road driving. Thoughts?

 

It depends on how much control you want over the rear shock damping. The 4th gen rears allow for more precise adjustment and let you do the adjusting while they are on the car. The 3rd gen rears have a more course adjustment (only 4 settings) and must be adjusted off the car. I went with the third gens because I felt I could get the setting close enough to what I wanted (and I did) and I didn't see myself adjusting the shocks very often. Also the 3rd gens were a bit cheaper.

 

4/4's are the most recommended due to the ease and range of adjustment. 4/3's are about being more cost effective (I know, not inexpensive, but $120 less is $120 less). Niether is wrong, and frankly 4/3's are better than anything else you could put on except for 4/4's, so it's a classic cost vs. potential thing, just like buying anything.

And no problem on the spring info. The truth is not every spring is decent, or even workable, but some are as long as you know what the differences are and the result of them. In this case, the thing you need are shocks, and good ones.

 

So I guess I'd need 4/4's. With the setup I have now, if I even accelerate the least little bit over any type of bump, the back end hops and causes that rather unpleasant little lurch once the wheels regain contact with the road. Is it because the dampening is too stiff? That's what I'm leaning towards.

Once again, I really appreciate your help with this!!

 

It's a lack of rebound damping added to messed up compression damping. As the stock stuff (or any other shock wears) they are less able to control what's going on. This is why the ride gets worse and worse as the miles add up. The springs don't get stiffer, the dampers get worse.

And the above reasons are why folks are well served to run quality dampers that not only have enough damping to suit their needs to start, but will down the road. Otherwise the same thing can happen again. And it's not all down to quality. This is where a Bilstein is great for a stock spring, but as the springs get stiffer and shorter start to get overworked. The quality is excellent, the damping, not as well suited.

 

So essentially the Bilsteins I have aren't necessarily suited to the BMR springs and are therefore responsible for the issues I'm having. If I switch to Koni 4/4s then I'd have more control over the ride quality and be able to essentially eliminate the problems I'm having now? I just want to be able to hit undulations in the road and not have to worry about the back end stepping out... lol

 

The shocks you have are suited to stock springs, which are around 300 lbs/in front and 115 or so rear. The springs you have are much stiffer at both ends of the car. The rears getting to 170 lbs/in or about 35% stiffer than stock.

It's a double edge sword. Both the springs and the shocks effect how well the axle works over bumps. I prefer a little softer rear rate so the axle moves more easily up and over bumps. BMR goes a little stiffer. So there is an effect there and shocks can't make the spring rate softer. However, shocks do effect how the car impacts the bump, and damp the movement of the impact on the springs and how the car reacts to it. Remember how jumpy the back of the car was with stock shocks (if you experienced them)? That was with much softer springs, but the shocks didn't match them well and the result was a jittery, jumpy car that was prone to skip and over broken pavement.

Parts have to work with each other for the best results. Your shocks are not a good match for lowering springs, and the stiffer the springs get the more you ask of the shocks and these are pretty far from stock rates.

To put it in perspective. GM and Bilstein have done setups for years together. Lots of GM vehicles come with OEM Bilstein's (valved to GM spec). But the 1LE's had for the first 3 years specially valved DeCarbon's, then in 1996 through to the end of the 1LE package came with Koni DA's. This is relevant as the spring rate on a rear 1LE spring was 130-170 (some claim 180). Sound familiar? Except you are trying to damp that rate in lesser travel, which again demands more damping.

So GM added Koni's and not Bilstein's to the 1LE with similar rear rates. But the 1LE would have been easier to damp given the taller height and greater range of travel the shock had to do it's damping.

The "problems" you are having now are not something I can assess by e-mail or PM. The rear jumping out can happen for a number of reasons, and in different ways. Binding LCA's can cause it to be worse. The car is still a solid axle too.

I think this is a classic case of a little face to face talk, so to speak is the best way to get an appropriate answer. I can't know the details I need. But yes, Koni's are better dampers for your springs. And if you find anyone who's had lowering springs and gone from Bilstein to Koni, you'll find they think it's worth the change.

 

Perfect Sam, thanks! Once I get settled in to my new house I'll be giving you a call!

 

Sam you were talking about softer bump stops than my SS factory ones, do you have a part number by chance. I would admit that would help when its loaded down and I bottom it hits hard, and worry about breaking something.

Thanks as allways for your honest answers, thats what's great about these forums

 

The stock bump stops off Z28 cars are what he recommended earlier. I think the stealership is the only place in town that we can get them. I've been looking everywhere else around here for a set with no success.

 

I recommend exactly what tpunk stated. Stock Z28 stops w/o the SS/WS6 spacers. Use the GM parts.

But the majority of the slamming hits is usually due to the shocks, not the stops. The bumpstop change is simply an additional help by replacing the harder, square stops with the more progressively stiffer triangular type Z28 stops. The shocks matter more because the SS stops aren't rock hard, just harder. And the harder and faster you hit any bumpstop the more you feel it. That's why the dampers are so key, to slow the rate at which you impact the stops regardless of which type they are.

 

BMR any word if the new design is in yet? The G/F wants to get me something for Christmas

 

I think they have switched over to the new ones at this point.