Shock Tuning Input

Erik Irvine

Well-Known Member
Need your guys input/opinions. The video is from Lucerne Valley this weekend off Bessimer Mine Rd. The first video is coming down toward Start/Finish from the Rock Pile on the MDR course, Small whoops seems to be handleing decent. The second section is coming down the course the opposite towards the dry lake bed where the whoops are big, and I don't see many beam cars soaking up the whoops 100%. They are more spread out, and deeper but I know somethings not right because I can't even maintain normal speed through there. The front end is new, and I haven't really tuned the back since I changed out the rear suspension.

I think;

Front rebound is too fast
Front Compression is too soft
Rear rebound is too slow

What do you think?

[ame="http://www.youtube.com/watch?v=KN72gDwXHl8"]YouTube - Shock Tuning -- Smaller Whoops[/ame]
[ame="http://www.youtube.com/watch?v=GHmgoOUN4U8"]YouTube - Shock Tuning - Bigger Whoops[/ame]
 

Random Thoughts Racing

Well-Known Member
The front compression is too soft or your spring is too light.

The rear rebound is too heavy and the rear is packing. Also looks like ride height is a bit low but hard to tell with the packing.

Rear compression also looks soft and will definately be soft when you stack more compression up front.

Worry about front rebound last after you adjust everything else.

More compression F/R less rebound R.
 

Erik Irvine

Well-Known Member
Thanks for the advice. Sounds like a good description of whats going on. I adjusted the rear ride height down from last trip, I was thinking I may have gone too far, so I will crank it up just a bit.

I'll adjust the compression in the front (I may need to revalve, the two comp adjusters are turned in more than half now), and the rebound in the rear to start.

I have not been bottoming out the last 3 in. in the rear, so I may tighten up the rear comp tubes since the final 100% valving stage is probably stiff enough.
 

Erik Irvine

Well-Known Member
The front compression is too soft or your spring is too light.

How can I determine if I should be changing the springs, or the shock valving?

The front springs are 200 / 250, and to get my ride height I am preloading them about 2.5 in. I have the bottom-spring-only kicking in about half way through the travel
 

Perfect Race

Well-Known Member
Your front springs are definitely close. On my 2200lb car I have the same springs with a 2 1/2" arm I pre load it 3 1/8". I measure the top of the shock can where the threads start to the top of the coil adjuster ring. If you have a 4" front arm you might have a little more leverage. I can check on the secondary measurement for you.
 

Erik Irvine

Well-Known Member
Lee, I am measuring my preload the same way, and my car weighs about 2400 lbs with two people and a full tank. I guess I need to re-weigh it with the hardtop though. Don't worry about the secondary measurement, that is probably too different between cars, drivng styles etc.

I guess I'll work on tuning the front with shock only, and if I can't get it dialed, I'll adjust springs too.
 
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