Steeda's New Dual Rate Ultimate Handling Springs - (Track Proven Winner!!!)

Steeda Tech,

I have bought your progressive springs and adjustable shocks and struts, awaiting the spring thaw to install them here in Alaska....what's the difference between my progressive and the new dual-rate springs? I am looking for a comfortable controlled ride (daily driver no track usage).

Thanks....

Falconeddie said:

Steeda Tech,

I have bought your progressive springs and adjustable shocks and struts, awaiting the spring thaw to install them here in Alaska....what's the difference between my progressive and the new dual-rate springs? I am looking for a comfortable controlled ride (daily driver no track usage).

Thanks....

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Stay with the progressive springs for your objective.

The new dual rate spring has a much firmer ride and is geared for the on track enthusiast.

Iceman said:

Well I already have the fixed sitting in my garage, bought for a hell of a deal on black Friday. Just trying to pick a spring to go with them. Thanks for the info

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Same here. I would stick in the 200-250 and 850-950 range for springs with the fixed dampers for a quite handling-focused, but still completely acceptable ride for daily driving. Depending on the drop you're comfortable with/want, the options get pretty clear quickly.

BmacIL said:

Same here. I would stick in the 200-250 and 850-950 range for springs with the fixed dampers for a quite handling-focused, but still completely acceptable ride for daily driving. Depending on the drop you're comfortable with/want, the options get pretty clear quickly.

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Yea I think I'm going to just stick with the steeda ultra lites like I originally planned.

I'm looking at a setup for mountain roads. Around here the roads don't usually have guard rails. I ride them on my Harley, and I often think if I went off the road and down the embankment and got hurt, I would never be found. Naturally, I pay particular attention riding in the mountains. I'd like a combination of tires and suspension components that would reduce the chance of the rear end coming loose and sliding.

Jim Bronson said:

I'm looking at a setup for mountain roads. Around here the roads don't usually have guard rails. I ride them on my Harley, and I often think if I went off the road and down the embankment and got hurt, I would never be found. Naturally, I pay particular attention riding in the mountains. I'd like a combination of tires and suspension components that would reduce the chance of the rear end coming loose and sliding.

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I totally get it. There are awesome roads up here (Mount Baker, Hurricane Ridge) with great twisties, sick views and death a moment away.

In general, I would steer clear from any springs/setup that is too stiff. The increased rigidity provides more control in smooth surfaces, at the expense of a faster reaction time. Balance is key. You probably would be better served with one of Steeda's many awesome softer springs than this particular offering. Also, a progressive tire like Michelin PSS or many of the other tirerack rated picks is going to serve you better (people also rave about the new FireStone Indy 500s and the Bridges tone RE11s). A lot of racier compounds dont work until heated up and provide high grip but also sudden loss of control. Again, I'm generalizing. The entire setup and how it works together is key.

SteedaTech said:

Both linear and progressive springs can provide less roll with increased rate. What's being said,is that in roll a progressive spring on the inside wheel will contribute less to upward force because of the decreased rate. I hope this helps everyone understand a little better.
Both are great choices, it all depends on your objectives.

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A progressive spring on the inboard side may "lose" less force at any given amount of rebound movement, but since it is softer in its rebound range and the load transfer forces have to balance, the inboard side of a progressively sprung car will rebound further until the forces lost on the inside balance the forces gained on the outside. This increases the amount of roll experienced slightly, and the car's sprung mass CG rises some small amount. This is mitigated but not eliminated by the front and rear sta-bar stiffnesses.

For handling, dual-rate springs should be operating at the upper rate more than half the time, meaning that the closely spaced coils should be touching each other with the car at rest and full weight on all four tires.


Norm

Iceman said:

Yea I think I'm going to just stick with the steeda ultra lites like I originally planned.

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For your objective yes.

Norm Peterson said:

A progressive spring on the inboard side may "lose" less force at any given amount of rebound movement, but since it is softer in its rebound range and the load transfer forces have to balance, the inboard side of a progressively sprung car will rebound further until the forces lost on the inside balance the forces gained on the outside. This increases the amount of roll experienced slightly, and the car's sprung mass CG rises some small amount. This is mitigated but not eliminated by the front and rear sta-bar stiffnesses.

For handling, dual-rate springs should be operating at the upper rate more than half the time, meaning that the closely spaced coils should be touching each other with the car at rest and full weight on all four tires.


Norm

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From curb to jounce the Steeda dual rate spring is linear. It is not progressive.

I understand the nature of dual-rate springs, how they differ from true progressives, and at least one of the reasons you'd use this approach that's not related to ride quality. Linear at the soft rate as you compress them from free length until the closely spaced coils close up, linear at the firm rate with further compression from there.

It's behavior on the rebound side, curb to droop, that I'm looking at, specifically at (and beyond) the point in rebound where the rates abruptly switch from firm to soft and the spring demonstrates a step-change version of progression.

Then, if the lateral load transfer is held constant, going into the soft rate will allow greater extension from 'curb' (more roll). Further, if the extension goes into the soft rate and is held to the same value as with a linear spring as stiff as the dual's firm rate, the amount of load transferred laterally has to be less (and this will be because you aren't cornering as hard).


Norm

Okay, so I can't tell if you like this spring design or not, Norm. I'll let you know if I "don't corner as hard" when I eventually get these...

I don't have a fits-all answer for that because there may not be one. Like many things, the devil is in the details, and there is good potential here. As a way of being able to use a pretty firm rate for much of the travel actually used, without risking the springs falling loose somewhere in droop it's a good solution for the same reason that tender springs are used in coilover applications.

In a little more detail, I don't think I'd not want the rates to switch at a ride height lower than maybe an inch up into rebound. That puts the spring working at the firm-rate most of the time where only the last bits of extension get into the soft rate. That's my preference as a corner-carver where cornering performance and handling feel have priority, and where I'd also be using sta-bar and shock/strut damping to reduce suspension travel/overshoot.


Norm

Steeda's New Dual Rate Comp Springs Soon To Be Released !

Will be shipping March 1, 2017

They will will work awesome with the Steeda Pro-Action adjustable shocks!

Get ready for your spirited driving or track events!!

Norm Peterson said:

I don't have a fits-all answer for that because there may not be one. Like many things, the devil is in the details, and there is good potential here. As a way of being able to use a pretty firm rate for much of the travel actually used, without risking the springs falling loose somewhere in droop it's a good solution for the same reason that tender springs are used in coilover applications.

In a little more detail, I don't think I'd not want the rates to switch at a ride height lower than maybe an inch up into rebound. That puts the spring working at the firm-rate most of the time where only the last bits of extension get into the soft rate. That's my preference as a corner-carver where cornering performance and handling feel have priority, and where I'd also be using sta-bar and shock/strut damping to reduce suspension travel/overshoot.


Norm

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So, I'm going to find the money to run these springs starting in the spring after a couple track days with my Swifts. I'm very interested in this concept, mostly because I want to know what changes for my own development in terms of understanding how to setup a car. Probably more technical, more mathy ways to go about it, but... I don't care what a computer model tells me. I want to know if it meshes with me, the driver. I know Steeda does not rely on a computer model to determine if their springs are done right, then sell them and hope for the best. I would have no respect for them if they did. Anyway, I have numerous track events already paid for or planned this year and I will be happy to answer questions with real world experience once I get it vs. continued speculation.

That said, IMO, the S550 needs help with the inside wheel in sharp turns. You can pretty much float it over a crater in the earth going around a fast turn. I'm not sure if I am losing grip as a result, especially after a rapid hard brake, turn, apex, accelerate sequence. I want that wheel on the ground, gripping, but not rotating the body of my car.

I see this as a sort of next level track spring option that I wouldn't be surprised if track-aggressive GT350 and even 350R owners go for it, let alone your Regular Joe S550.

Everything I've posted in this thread comes from a basic understanding of how springs work and only that. No math, no computer analysis. The crux of the 'roll vs dual-rate springs' lies in whether the spring ever extends up into its soft rate region and if so, how much roll would be required to get it/them there. That this could happen does not need analysis; it's needing to know where it happens that does.

Load transfer being what it is, the inside tires are going to be lightly loaded no matter what you do outside of an impossible amount of CG lowering. The inside tires just aren't doing a whole lot of the work, and the math for this is pretty simple.

You could consider 'floating the inside tire over a crater' as twin to being able to roll it over an apex curbing and barely feeling the bump. Chances are that the chassis is less upset by momentary loss of a lightly loaded tire's grip in the first case than from being slammed into sudden bump travel in the second. Especially if the tire gets launched clear of the pavement for zero grip anyway . . . after first shaking the entire car and disturbing the other three tires' grip.


Norm