PROJECT ND: Parts Development, Testing, Measurements, DYNO

[Brian]

Finally Shipping for ND and Fiat 124.

RoadsterSport ClubSport Coilovers - ND / Fiat 124
2016-2025
Longest Available Travel Equals BEST Sport Touring SPRING Rate Setup with Ride QUALITY!

[BillK336]

What are the rates for the secondary portion of the springs?
Are they fully compressed at rest?

[Brian]

Yes, helper spring section is compressed when car is standing still on level ground, and extends as needed over dips in the road, when it is the unloaded side in the turns, etc. Details from the product description on the site:

You'll often see high-end coilovers with multiple springs per shock; a main spring and a helper spring. This is particularly necessary for coilovers with higher spring rates so that as you move the lower spring perch to adjust ride height you aren't trying to compress the strong main spring further and further. The "helper" spring is a lighter secondary spring that is relatively easy to compress. The usual helper spring maintains pressure on the lower perch as you move the lower perch up or down on the shock while presenting minimal resistance to you as you make adjustments. The helper spring also helps with traction over bumps through a corner on the unloaded side of the car.

We rolled the helper and main spring into one spring by working with Progress Technology to develop a special spring that has both a main rate portion and a lower helper rate portion. Having this all incorporated in one spring eliminates the complexity of needing adapters and bearings between multiple springs. Some coilovers need up to 7 individual parts to make up one spring stack on a shock! Here you have just one spring and no potential noise sources that traditional multi-spring stacks can suffer. Reduction in complexity also helps reduce costs and this setup has a price nothing with comparable travel can touch. All this and more on the spring rate options is covered in detail in the product description.

[Brian]

We gave our Fiat 124 with this new coilover kit to our friends at Grassroots Motorsports for a day of canyon driving fun and they wrote excerpt below. Please see the FULL article (behind paywall on their site for members) at: https://grassrootsmotorsports.com/artic ... 24-spider/

[Brian]

Our new Adjuster for koni.

[Brian]

Koni tiny low profile Adjuster next to ours.

[Brian]

RoadsterSport ClubSport LONG TRAVEL Coilovers.

It might look like the car is still on the lift here, but it is NOT on the lift. With spring perch raised until the 'helper' part of the spring is juuust shy of all the way compressed, the car sits at 15.5" front 16" rear. We just wanted to see if we could get stock heights and easily we can.

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We then lowered it down to more typical coilover heights per the customer's request, which in this case was Front 13-1/2” and Rear 13-5/8”. Customer running a bit taller 215/45 tire on stock wheels.

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Ken's Miata ClubSport.jpg (1.06 MiB) Viewed 1583 times

[Ryan @ GWR]

Pics of the new ClubSport coilovers for ND

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RS ND ClubSport 1.jpg (1.2 MiB) Viewed 1565 times

[Ryan @ GWR]

For those wanting numbers, total shock stroke for the new ND ClubSport coilovers is 136mm Front / 181mm Rear.

For those wanting numbers, total shock stroke for the new ND ClubSport coilovers is 136mm Front / 181mm Rear. So we got more travel than just about any coilover out there ( for example ND XIDA are 126mm F / 180mm R, so we beat them a lot on the fronts and "1 more" on the rear.). But that doesn't tell the full story. Picture below shows the ClubSport shocks next to Koni Sport shocks. Full length Koni Sport shocks are just 125mm Front / 181mm Rear. So we were able to pack MORE stroke than an OE length front shock and same stroke in the rear into the ClubSport coilover that is actually a shorter body length than OE. That shorter body length means that more of that stroke is available as bump travel, aka compression travel.

RS ND ClubSport Comparison to Koni Sport.jpg (747.81 KiB) Viewed 1537 times

[Brian]

Got asked for sway bar rate today, a favorite pet peeve of mine. Will repeat this here, have made this explanation dozens of times in the past but time to have it near the recent posts.

Our ND Progress Sway Bars are serious bars and we do not publish naked bar rates. The sort of numbers that Hotchkis and other sway bar makers quote are a complete joke, because they are spring rates for a naked bar. The car does NOT use a naked bar, and there is NO standard for how that bar gets attached to the car. Variables include bushing hardness, bushing thickness, bushing width, bracket design and bracket material, etc. Does the bracket have gussets or not? I can make a 19mm solid bar easily outperform a 25mm solid bar with just harness of the bushings, or how stiff I make the mounting bracket.

Thus, we don't put naked bar info out because folks spreadsheet and compare brand to brand as if that info has meaning when in fact it is utterly worthless info. If you look at the Progress brackets in particular you quickly realize that all brackets are not created equal and that the Progress Bar at rear for ND in particular with the included braces for the factory mount is going to have much more effective stiffness as installed than bar of actually BIGGER size but using lesser brackets and support. See again the entire story of how the rear bar was developed (summarized in product description). In brief, we found .62 solid bar MORE effective than .75 inch solid rear bar, if the .62 bar had the bracing of the OEM mounting position. Many other brands of rear sway bar are thicker bars that are actually less effective rate as installed because those brands did not figure out the need to support the factory attachment point.

If we lived in a world where the mounting bushing design was standardized, and bushing material was standardized, and the bushing thickness was standardized, and the bushing width was standardized, and the bracket design was standardized, then bar data might have meaning. We don't live in that world.

Factory ND Rear Mount.

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Factory ND Rear Sway Mount WITH Progress Support to fully box the mount, and the Progress Rear ND Sway:

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