Shock stiffness

Hey everyone! While replacing the shocks on my 2011 Lexus ISF I decided to do an unscientific test of compressing the new shock vs the original shock.

My new shocks are Bilstein B6 monotube and the original OEM shocks are made by Tokico and are twin tube.

The Bilsteins I'm able to compress fairly easy and could do it with 1 hand and some body weight. The OEM shocks I struggle to compress them with both hands and my body weight on it I really have to push hard and it takes awhile to compress.

I tried to compress both at the same time to see which one rebounds faster but I couldn't hold down the OEM shock with 1 hand. Doing them seperately they seem to take about the same time to extend back out.

I know this isn't a proper test but I think it's safe to say the Bilstein B6 is softer than the OEM shocks at slow speed compression?

I currently have the car apart installing new shocks and superpro bushings and should have it finished by the end of the month. Then I'll turn on insurance and motorsports start next month. I use this car for weekends, autocross, hpde, and time attack so I'm a little concerned that I may be making my suspension perform worse. What do you guys think?

That's very, very slow speed, compressing by hand. It doesn't really tell you much at all. Rebound speed is as much a test of internal pressure as anything else - I've had some shocks that didn't self-extend at all because they didn't require pressurization.

Lube the bejeebus out of those bushings.

Right, that's basically just a test of gas force. That said, I'm a little bit surprised because monotubes generally run higher gas pressure than twin tubes.

I'd have to say you're not actually testing damping force at all. What you're dealing with is gas pressure.

Thanks guys!

Pics of the IS-F?  Love those things

In reply to Placemotorsports :

Oh yeah for sure here are some action shots!

We have some talk on shock absorber valving from the archives that might help.

And another article on shock valving.