Shorter rr spring

[phenom08]

It appears they took that video down

[ZERO25]

If he stopped the machine and then recorded his number, yes.

So, would that make his test accurate then?

Whats the difference in construction of the two different smashers? I was told the standard machine uses an electric trailer jack!

[MasterSbilt_Racer]

So, would that make his test accurate then?

Whats the difference in construction of the two different smashers? I was told the standard machine uses an electric trailer jack!

I have a standard manual machine with a trailer jack actuator.

Higher end machines have electric actuators that are a ball screw with brakes.

Before I left my testing job, I used a servo hydraulic fatigue testing machine that was computer controlled and cost about 70k.

[cjsracing]

video is now gone - i watched it Friday

[ZERO25]

So his test was accurate, since he had stopped the smasher at 2.5 inches?

[95shaw]

Only if the test was started at equal preload.
A 2 inch shorter spring with a 2 inch spacer may not be exactly the same.
The 2 percent that most guarantee the spring rate comes into play. Plus or minus.

If they start at the same load, travel the same 2.5 inches, and end 25 lbs different, springs are a different rate.

[crownman25]

I have ben hearing some huge rr springs at some tracks....

[Lizardracing]

Racers are full of junk science.
A few weeks ago I was arguing on FB about this spring hysteria stuff. A rep from Swift posted and how important is it was and why their springs are better than other brands because they understand it and no one else does.
I asked for the data, not to argue, but to learn something and even called the guy on the phone. I still don't have data or straight answers.
Just another example of racers making things more complicated than it needs to be and being sold a promise your too stupid to understand so buy our stuff and trust "the science". I've watched a lot of the tech videos from many of the so called chassis schools and I still haven't seen a magic trick. Not that generic info is bad thing.....I just don't like the idea of being sold a magic bean, and getting a fern.

[ZERO25]

Talked to one of the house car drivers, from one of the popular modified chassis's, and was told that theyre running a 6" rr spring. The only drawback was a lack of rubbers that work well with the tight coil spacing!

[MasterSbilt_Racer]

Talked to one of the house car drivers, from one of the popular modified chassis's, and was told that theyre running a 6" rr spring. The only drawback was a lack of rubbers that work well with the tight coil spacing!

If they running a screw jack deal, that would make a lot of sense.

But, then again, how much spring do you really need for 3" of total travel. Not much. The rest is just weight you are carrying around.