Which exhaust?

[Ben C34]

On 12/10/2021 at 7:12 PM, hardsteppa said:

interestingly (or not) the biggest change in exhaust note that I have found, apart from changing from the stock exhaust obviously, was changing to Supertech valve springs and titanium retainers (on an RB25det-onation). Immediately picked up a sharper more RB26-like sound once they were fitted.

I find that extremely hard to believe . Any other changes at the same time?

[hardsteppa]

None. Take it or leave it.

[Ben C34]

On 12/10/2021 at 8:23 PM, hardsteppa said:

None. Take it or leave it.

But how? You know how an engine works right? How is it even remotely possible that changing springs and retainers affects the sound at all?

[hardsteppa]

 Resonance frequency. https://eibach.com.au/motor-sport/evs/

[hardsteppa]

some more light reading for a couple of you

https://www.chevyhardcore.com/tech-stories/engine/valve-spring-tech-overview-of-valve-spring-design-dynamics/

[Ben C34]

On 12/10/2021 at 9:37 PM, hardsteppa said:

some more light reading for a couple of you

https://www.chevyhardcore.com/tech-stories/engine/valve-spring-tech-overview-of-valve-spring-design-dynamics/

Still a hard no on me believing springs and retainers change an engines sound.

 

Valve follows cam. Unless springs can't control valve, which is bad.

Yep springs have harmonics and all kinds of design considerations, but they don't change the sound unless your previous springs were somehow allowing the valve to bounce around all the time which would be quite bad.

 

Why did you just change springs and retainers?

[hardsteppa]

On 11/12/2021 at 7:52 AM, Ben C34 said:

Still a hard no on me believing springs and retainers change an engines sound.

Good to know. Far be it from me to tell you what to think.