Eric in Chicago

I am doing a little off season suspension work and remember a post with info about the hyd. shock body perch. I think SundayDriver had some exp. with these. Not cheap 1,320.00 to do it on top and bottom, heck even 660.00 is a little high but if it is worth .5 to 1 sec I am sold!!! Just wondering if anyone had any real world experience with these.

Thanks in advance for any insight.

From HRPworld website

Hyperco/IPC Hydraulic (Load-Centering) Slide-On Shock Body Spring Perch substantially improves performance by allowing the spring forces to remain centered on the shock. The result, a reduction of bending load on the shock absorber of up to 96% along with an enhancement in mechanical grip at the tire.

Hydraulic Spring Perch Advantages:
Enhanced Mechanical Grip

Reduced Side Force & Friction

Reduced Wear & Load on Shock Absorber Seals

Available for Popular Applications
NOTE: Hyperco/ICP Hydraulic Spring Perches should be installed at both ends of the spring when running free lengths of 10" or less. For free lengths above 10" it is advisable to run them on only one end.
Hydraulic Perches are in constant motion when the vehicle is on the track and will require rebuilding / maintenance. Hyperco recommends a maximum time between rebuilds of 10-12 hours.

Larry Herman

Is this a joke? What exactly are they supposed to do again?

Eric in Chicago

No joke Larry. I recall reading about these. Maby the are best for a lightweight super cars like Mark's.
The point that caught my eye was "Enhanced Mechanical Grip "

Larry Herman

Maybe, but I can't see what they could be doing for a normal car. And a rebuild time of 10-12 hours? That's 3 weekends.

chris walrod

Our teams use them on the open wheel cars -- actually did in the past when they were legal to use

7% reduction in damper friction. <---- Edit: should have said with typical rising rate velocities, not sure what gains are for linear or close to linear applications such as road cars.

Bryan Watts

Definite improvement...I have a hard time believing it would be measurable in .5-1 seconds though. They are especially an improvement on the MacPherson strut, as the strut itself is dealing with a substantial amount of side load. Before spending big money on hydraulic perches, are you running needle bearings? If not, you definitely should consider those as well to free up the spring to rotate as it compresses. You'll get much more consistent spring rates (as evidenced by lots of testing on a spring/damper tester by the guys who build/prepare our car). They are a very "cheap" mod in comparison.

SundayDriver

These help on all coil over designs. As a spring compresses, there is a bending force in the spring. If the end can either pivot or unwind, this force is reduced and there is less stiction on the shock. From the people who have used these, they require rebuild at a very short interval.

I use a torrington ( needle) bearing on one end of each spring. Near zero maintenance and cost is $20-$50 for a set. They don't work quite as well as the expensive devices, but pretty close.

I seriously doubt .5-1 second gain from any of these. Maybe a tenth or a half a tenth at best but the real benefit is more likely consistent shocks, making tuning far more effective.

Geoffrey

I agree with Mark, the torrington bearings are inexpensive and work very well for the cost incurred.

Larry Herman

Thanks for the explanation guys.

Eric in Chicago

Thanks for the tip on the torrington bearings, that is what I recall reading about. and the .5-1 second gain was my wishful thinking!
Mark, Brian, Geffrey-anyone have a good source? 50.00 a side make a lot more sense for a hack like me!

Bryan Watts

I'm sure my guys can get you the bearings in the size you need if you can't track some down through your usual sources. Ultimately, you'd use hydraulic spring seats and needle bearings, but the needle bearings are really useful for their cost. If you want to try RRT, give them a call, as they won't appear in their on-line catalog:

http://www.rrtsuspension.com/index.php

Geoffrey

I think I got mine from McMaster Carr

Cory M

Here's another source, like $12/set:

http://www.resuspension.com/RE-Suspension-p-1-c-15.html

JoeMag

Hmm, that's interesting. Wasn't going to put on new car due to power steering, but didn't even think about spring twist.