Do any F1000 cars use a third spring?
third spring
Do any F1000 cars use a third spring?
Not Needed?
I wonder if third (or heave) springs would be effective in FB.
The third spring is used primarily to maintain ride height on the car while aerodynamic pressures build. They keep the car a certain distance from the ground, while allowing the suspension elements to manage suspension movement in cornering and over uneven pavement. You get the benefit of very high wheel rates while allowing chassis compliance to keep the tires working and allowing the chassis to roll. As FB downforce does not come near enough to overpower two-element suspension systems, they are not required. Wheel rates high enough to manage downforces are still low enough to work the tires effectively.
The winning DSR from last year used third element suspension; it is also generating more than 1,500 pounds in downforce. I know of a couple of DSR's that, using two-shock setups, were essentially full on the bump stops at speed...you better have the tires warmed up for that experience!
What kind of downforce numbers does a FB generate? My guess is about 600 lbs. Wheel rates for that weight car with that amount of downforce are adequate; most of suspension compliance these days come from the tires any way. Anybody want to share their downforce numbers? What kind of wheel rates are you guys running? Pretty high I bet. My old cars (F4 weighed 650 lbs) were about 200 llbs back in the day as I remember and I used F-2000 wings on my car...pretty soft these days I am sure.
Third element with inerters is cool though!
Tom
Last edited by brownslane; 04.03.13 at 9:27 AM.
Tom Owen
Owner - Browns Lane and Racelaminates.com
The Piper FF has one, it can't be making _that_ much downforce...
Part of the Equation
True. Downforce/high wheel rates are only a part of the equation. If the designer wants to achieve low roll resistance from wheel rates, perhaps to build greater tuneability from arb's, a third spring may fit the bill. You get good pitch management and nice supple roll control. This doesn't overwork the tire and gives a wide performance envelope.
Tom Owen
Owner - Browns Lane and Racelaminates.com
The third spring is an option on all of the piper variants, I believe. Paging the Novaks!! Do you run the 3rd spring on your Piper?
Ken
Originally Posted by KenT
Yes.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
Justin Pritchard's F1000 Car
Mouse Trap,
Don Sievenpiper designed the Third Shock setup for Justin Pritchard's F1000 Piper as well as the set-up for our f1600 Piper. For further information on the design/engineering Don can be reached at jsievenpiper@aol.com
Paul
Kautz Racing
www.kautzracing.com
followup question: is anyone using an inerter?!
So am I looking at this right? Is it a torsion bar as third spring?
Last edited by mousecatcher; 04.03.13 at 4:12 PM.
No, the third spring is the actual spring connected to each rocker with struts. The torsion bar is the fron anti-roll bar with ajustable blades connected to each rocker with a second pair of struts.
Crossle 32F, Piper DF5 Honda
No, it's a coil spring. If you look at the links going forward from rockers, 2 go to the anti-roll bar (furthest forward), and two go to a pivot (right under the parts tray). The 3rd spring connects to the center of the pivot bar, which can rock forward and backward at a pivot down on the bulkhead.
Edit: BWC54 beat me to it...
Hard to tell from the pic.....is there a damper with the 3rd spring?
Ah, I see it now. Where's waldo.
3rd shock
Mouse,
The image attached might clear things up. This was our first go around, and it was taken during set-up and it wasn't complete when the shot was taken. Our current 3rd shock was redesigned to accommodate the new pedal box configuration and updates we did in the winter of 2011/2012. I've attached the image but it's minus any real detail.
Paul
Kautz Racing
www.kautzracing.com
Has anyone ever tried to replace the third spring and damper with a type of an elastomer to reduce the weight? Jay, aren't you an elastomer kind of guy? Have you ever seen this done?
Ken
Did it. It will work but requires great materials and it is not as easy to change rates as the usual materials are much too non-linear. Still very doable with the right materials & design. You might see something from us next year.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
Yes, did it as well. Replaced the spring with a shock bump rubber. The piper set up is also a droop limiter. By using the rubber it allowed the adjustability of more droop
ha...I have 4 springs.
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