Hoosier vs American Racer; spring rate.

[avt007]

So, finding spring rates is tough. AR responded to me and said they have no data. Hoosier has some data out there, but not for the exact tires we used to run.
Our series switched from Hoosier to AR and my car isn't happy. So with a lack of data, I'm asking for opinions instead.
Do you think ARs are softer (lower spring rate) than Hoosiers? Any data you may have is appreciated.
Thanks!

Rob
91 Citation

[TATaylor]

I asked Hoosier for spring rates a while back and they sent me data for 18-20 psi pressures. I used Excel to generate the curve for those points and extrapolated down to 16-17 psi since I heard many were running them at lower pressures. Graph is attached (I hope). Hope it helps.

[Roland V. Johnson]

Do not confuse spring rates with wheel rates.

[avt007]

Thanks, any info helps. My car definitely isn't the same on ARs, so I may have to change springs.

I asked Hoosier for spring rates a while back and they sent me data for 18-20 psi pressures. I used Excel to generate the curve for those points and extrapolated down to 16-17 psi since I heard many were running them at lower pressures. Graph is attached (I hope). Hope it helps.

[TATaylor]

I should have used better wording. What Hoosier gave me was the spring rate of the tire at the specified hot pressure and loading.

[Garey Guzman]

Another thing that might help is Carroll Smith's "Engineer in your Pocket", which is a handy-dandy little flip book he made. It even has a drawing I made for him!

Anyway, it has a basic car "problems" with several possible causes, which may help you work through improving your car. It's basically Cause-Effect

Not sure who now maintains his site, maybe his son?
https://www.carrollsmith.com/books/pocketbook.html
(nevermind, just goes to Amazon)

[problemchild]

Calculations are for establishing a baseline.
You already have a baseline established by racing the car previously with a setup that you seemed happy with.
It is time to go to the track with some springs and drive the car!
10% softer and 10% stiffer will establish the desired direction. Based on your commentary, I would try softer first and perhaps you won't even try stiffer. If your AR bars have enough range, they may be able to steer you in the direction you need to go.