What Spring Rate Do I Need? | Suspension Setup

How to choose spring rates.

Getting your spring rates to a sensible starting point for you car and application is something we all struggle with when starting out. This lesson, taken directly from the Suspension Tuning and Optimisation course, will hopefully help make it a little bit easier for you.

Using a mechanically biased RWD road legal circuit car for the example, Tim runs though the calculations used to work out our spring rates for the front and rear of the car noting along the way some differences in doing so for a race application vs road use.

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0:00 - One Module From A Full Course
0:45 - RWD Circuit Racing Coupe Example
1:21 - Key Information
1:31 - Total Corner Weights or Weight Split From OEM
2:03 - Pro Tip: Unit Consistency
2:25 - Back To Weights
3:00 - Sprung Mass Only
3:48 - Our Example Continued
4:18 - Motion Ratio
5:52 - Purchasable Spring Value
6:10 - Rear Axle
6:50 - Rear Vs Front Frequency Race Use
8:00 - Simplified Calculation
8:45 - Suspension Tuning
9:18 - Lateral Load Video - Linked Below
9:35 - Just One of 37 Modules
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LINKS:

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#highperformanceacademy #suspensiontuning #springrates #suspension #springs #racing #datanerd #gofasterwithdata #racecraft #learndriveoptimise #motorsports

[hpa]

0:00 - One Module From A Full Course
0:45 - RWD Circuit Racing Coupe Example
1:21 - Key Information
1:31 - Total Corner Weights or Weight Split From OEM
2:03 - Pro Tip: Unit Consistency
2:25 - Back To Weights
3:00 - Sprung Mass Only
3:48 - Our Example Continued
4:18 - Motion Ratio
5:52 - Purchasable Spring Value
6:10 - Rear Axle
6:50 - Rear Vs Front Frequency Race Use
8:00 - Simplified Calculation
8:45 - Suspension Tuning
9:18 - Lateral Load Video - Linked Below
9:35 - Just One of 37 Modules

[johnterpack]

Wait, wait, wait... you can't just go putting up car videos that have actual numbers and engineering in them. You're supposed to talk about "fitment" and stuff. The way you're going, somebody might accidentally learn how cars work. Where would F&F be if the Vin Diesel fan club realized everything they grew up believing was wrong?

[InitialDIYmods]

I can't like this video enough. Great job mate. Once I'm done with the engine setup at HPA, I really need to get the suspension settled 😁👍

[therkid]

Okay! okay! Ill buy the courses! Well done.

[michaelblacktree]

Perfect timing! I need to select spring rates for my project car. 👍

[forgottenautos]

The angle of the shock can change the appropriate spring rate needed. Two cars that have the same weight ratios can have wildy different spring rates. Just something to think about in case you have a car that has a very high angle spring (0 degrees being vertical).

[zaydabbas]

Damn this course is legit, we use the same quarter car model in my control systems class

[peejay]

This is giving me nightmares from uni calculating the undamped natural frequency of a system :-)

[gordowgwg]

Excellent introduction.
With the spring rates, if one cannot find what one needs, two shorter springs can be combined to get what is required.

[SLUMOVIES]

You guys are nailing the course ☺️
Some day I'll go through them all

In the mean time 😂 I'll slap my airbags on my tein suspension with edfc 😂 and hope for the best

[Owen-wgmd]

How did you find the frequency of the system?

[nathancupp]

Bro sounds so close to the guy who usually does these. I wasn't looking at the screen and thought he just had a cold.

[__dm__]

4:41 -- omega is the angular frequency, not regular frequency, so the symbol should be "f"

[akioasakura]

From where do the base frequencies come from? Why was 1.5-2.5 chosen for the low aero circuit car? I want to get to the root of the issue if you get me. Good video, thank u for uploading

[enjoying_life]

Great Video! I did not find the link for the cheat sheet. Can you help me find it?

[s]

Great video, you really explain things very easily!

I’ve been racing for a good long while and it time to develop the suspension for the race car.

Out of curiosity, what spring rate did you finally end up with on the SR86? Was it close to the ball park the calculations got you?

[GP-fcjv]

It looks like you are using a 86/BRZ for your example am I right?

[elkabongg]

Could anybody clarify for me where do the numbers 4 and 2 come from in that equation. What do they represent or are they simply contstants.

[Malficion]

I knew the ideal was 8kgf/mm F & 6kgf/mm R 😮

12kfg/mm F & 9kfg/mm R is way too high for a street car.

[elitecol]

When are you doing the g25 660 comparison?!