thats another question though... the different spring rates (as it pertains to the new design)... I think most of what I have read (in other areas) are from original design.

 

Well I was curious as to how the spring being linear or progressive would affect your decision. Would it be a deal breaker if they happen to be one way or another? If the question is confort or performance, IMHO the spring rate would be the greatest factor here. Or the dampening rates if you ramp them up that high

 

For me its an important factor for 2 reasons - #1 I am in working on handling characteristics of the car and am looking for reasonable ride with good/excellent cornering (for road racing and auto crossing) – for predictability on stout handling linear would be my preference… on the other hand: #2 I already have Eibach (which are progressive) and am contemplating coilovers or struts… if these (BC) are progressive, I might be more inclined to go the more economical route of just getting adjustable struts while keeping the Eibachs and deal with less performance and more streetabilty. I’m not concerned about coilovers simply for ride height function…

But why are you concerned about other people’s needs? The thread is about the design of the BC coilovers, not why people want to better understand the design.

 

Why not ask why? Because I like to read why people prefer linear or progressive springs?

The compromise inbetween ride/performance is always there. But you compare the progressive Eibachs to these BC coilovers if they are also progressive. I guess you compare the two because the spring rates you choose for the BC units would be similar to what your Eibachs are at now?

I wasn't aware that progressive meant automatically giving up track/auto-x performance. If a stiffer spring is chosen, the progressive nature would still hinder the performance over your Eibachs?

I just thought the spring rate choice would affect the performance/ride more than if the spring was linear/progressive?

 

that’s precisely why I said it brings up another question - and that is spring rate... the variety of spring rates available is clearly going to be different if in fact they are progressive... and no, I'm not comparing Eibach's progressive spring rates the BC I'm gathering information to decide which way I want to go...

Everything I had read prior to yesterday was about the original design. So my interest in better understanding how the new design varies is to determine (for myself, I don’t care about your interest) is whether or not the information I gained previously will be relevant to the new design.

 

I would prefer to not use progressive springs because I don't need the compromise between handling and comfort. I like a nice linear springrate that responds in a more predictable manner. Thats not to say I wouldn't buy these BC coilovers just because they are progressive, but it would depend on the change from the initial springrate to the final springrate, it seems like the difference here is small, unlike some of the springs on the market, so it is likely that they would behave similar to a linear spring once installed. I would still like to know this information before making any decisions though, and it hasn't been provided.

 

Are progressive performance springs unpredictable by nature? Even on a higher spring rate?

 

Progressive springs can be unpredictable because they have a sharper change in springrates when the coils bottom out, so usually with progressive springs, you will have more initial body roll with more sudden dropoff in body roll. This is because usually the initial springrate is softer than you would normally run because its a compromise for ride quality, and the final springrate is stiffer than you would normally run if it was a linear spring, so you can limit the travel after the lower springrate section has already fully compressed

 

thats what the testers usually say.

 

What if the intial/final rate differences weren't that dramatic? ie.. a spring for a performance coilover system? I guess we just have to wait how this issue pans out and what springs are available ultimately (and their specs)

 

This is what I would like to know as well. A progressive spring with a small change in intial to final springrates would likely be the best compromise

 

The thing that i don't understand is how difficult is it for one of the suppliers on this forum to call the actual company and find out the exact explanation to why are these springs linear like they are claiming to be.

 

What, you actually want them to do their job?

 

My thoughts as well. A slightly softer intial rate only in a small limited range might soak up minor road bumps/rattles but would stiffen up anytime the car would be driven aggressively. (ie.. spring travel past the intial rate/travel)

 

So since this is obviously a conical spring, if the spacing is different that would mean the pitch would be different (since the angle would change) and thus it would be a linear spring, correct? The spacing looks like it's slightly closer towards the narrow end of the spring to me.

I understand you don't necessarily like listening to the people that work at these companies. I just don't understand why the heck they would lie about whether or not the springs are linear vs. progressive. It's not like one is necessarily worse than the other, that's just based on what you're looking for in a spring and opinion. So there really wouldn't be a need to lie.

I think there's only one way to solve this. I can easily just release the spring from my rear spring bucket and measure the spacing between the damn coils. Would that help out?