D spec shock issue maybe?

[tw557]

I have an 05 gt that I'm trying to get the rear suspension just right The car came with Roush shocks. Seemed ok but just a little soft particularly on little g out dips. I bought a set of koni yellow. Seemed ok but still a little soft on compression even compared to Roush. Plenty of rebound. I then saw tokico d spec on Amazon for $33 a piece! I just got 2. I have a lever I attach on the bench to test up and down. I can't feel any difference at all turning the Allen screw. Soft comp and really strong rebound at any setting. Turning the screw is so loose with no tension at all. Any ideas? Is this normal for tokico d spec?

 

[redfirepearlgt]

MY understanding of shocks is that they respond to sudden changes in direction through dampening. Isn't the whole concept of compression and rebound with respect to dampening a sudden change in direction? Therefore simply compressing the strut would not demonstrate any change. One way you could see if this is the case though it would be very elementary, would be to tighten the strut setting to full, attach a spring gauge for measuring resistance and generate a sudden change in direction. Then loosen the setting to full loose and do the same. If then there is no change, you may have an issue.

Why not contact the maker of the device and get their professional feedback? I find this to be very useful 95% of the time. You've obviously got the manual open and that alone will gain a ton of respect from phone support techs. Trust me, most on line techs keep a running tab of what is known as RTFM fixes. These are a pet peeve. I know. I have worked in tech support in various industries. You are already past that hurtle, so give them a call.

 

[Gab]

Wow, $33 a piecei is a steal! I run the Ford Performance dynamic damper kit, which I've read are bascially Tokico D-Spec dampers. The stiffness from full soft to full hard is palpable, with about seven turns (Tokico advises to not turn the adjusters out more than this). I autocross with these dampers and am pleased with them, they perform quite well.

 

[01yellerCobra]

Would the D Specs be a step up from the Koni STR.T's?

 

[tw557]

I do have a jig I have set up at home from back when I would work on motorcycle shocks. Mount the bottom and then mount the top to a long arm. At the end of the long arm I would attach different weights and see how long it would take to bottom out. Or just simply push up and down on the long arm to get a feel. By doing this I can not feel any difference at all. I do realize there are essentially 2 different speeds of dampening also slow and high speed. The high speed does need to move very fast to sort of be activated. Also when I compress these they BARELY return up on there own. and I need to pull quite hard to get them up. but push in so much easier. It is just so weird to have absolutely no resistance on the adjusting screw at all.

I bought from amazon so I couldn't call them. I did find a number for Tokico and actually did get someone to talk too. He didn't seem too knowledgeable on these and just said they are old and that is probably just how they work and give them a try. Thats when I decided to try on here for some experience. The $33 a piece was just unreal. But I guess at this point I will send back and stick with the Koni or Roush for now. Maybe the ford racing adjustable one day or try the bilstiens.

 

[ESP41]

The rear shocks are so easy to swap out, why not change them and go for a ride?

 

[tw557]

They are pretty easy to change but I'd like to easily return if something is wrong with them. Since the compression seems a lot less then the Roush I took off and once compressed they very very slowly return to full extension. I just don't feel like they are working. The box is brittle and rubber parts all have a old dryed film on them. I wonder is the gas charge is gone.

 

[Gab]

It is just so weird to have absolutely no resistance on the adjusting screw at all.

I know what you mean, it's like it's not attached to anything. But on my dampers, they make a pretty good difference.

 

[thump_rrr]

With them dialed all the way in you should have a difficult time trying to compress them quickly.
Dialed out 7 turns from full clockwise they should be very easy to compress.
There is virtually no resistance to the dial.

 

[tw557]

The resistance to push down as quickly and as hard as I can is a lot easier to push down then The Roush and Koni I have. And from snug to 7 turns out there really is like zero difference on compression or rebound. The koni would feel pretty quick to return pulling up to the point I couldn't pull it up at all with 2 turns of adjustment. Oh well, amazon is good for returning so I guess I'll just do that. I assume I will be plenty happy with the Koni's once I try a few adjustments.

 

[07 Boss]

Shocks do not spring back unless they are gas filled. A gas filled shock will feel totally different than a normal shock with the same rebound and compression. So if they are different types of shocks the gas filled one will feel harder to compress and will rebound more quickly if you're manually testing them.

 

[Norm Peterson]

You may have to "prime" the shocks first, to get the air or gas out of the compression-side chamber (it tends to move around when the shocks are stored on their side for extended lengths of time). Do this by standing them up vertically running them through full stroke a few times.

By hand, you're only working the shocks at very low piston speed, well below what they will experience even in gentle driving. While this plot is for Koni yellows, what I'm getting at is that by hand you're operating somewhere below 1 inch/second where the bump side damping curves (the positive force numbers) aren't separated by much at all. Bump damping mainly controls the unsprung weight (wheels, tires, brakes, hubs, about half of the suspension linkage, etc.) and is less critical for handling as long as it's somewhere near right at the piston velocities encountered.

Norm

 

[Norm Peterson]

Turning the screw is so loose with no tension at all. Any ideas? Is this normal for tokico d spec?

I've had what was probably the D-specs' predecessor (Illuminas) on a couple of different cars, and I don't recall there being much force required to make adjustments. One thing I do know about the Ill's (something you couldn't help but notice unless either you or them were dead) was that they were harsh as hell over short sharp bumps on most any setting. Think railroad grade crossings. That could be from having too much bump damping, particularly at higher piston speeds (8 in/sec or higher).

I couldn't tell you if Tokico continued that damping philosophy over to the D-specs or went possibly a bit too far the other way with softer bump damping everywhere. Chances are that some of the same people were involved, for whatever that's worth.


Norm

 

[tw557]

Norm. Thanks for the chart. I always like data. I have a lever setup to cycle the shocks with pretty good force and decent speed. At the same weight on my lever the d spec traveled twice as far as the koni and Roush. But when I pull up which is then by hand on the lever if feels about twice and hard as koni on soft. I did set them upright for 3 days and cycled about 20 times per day. And after all this not one little difference I can tell full hard to full soft. On bump compression it will travel about 3in or so in one second at 100 lbs force. I decided not really worth the experiment since I'm looking for more compression damping anyway. I'm trying to match the bump firmness of my ecoboost. It would have been interesting to mount and try but I sent them back. But at 33$ a piece I just wanted to try.

 

[Norm Peterson]

There's also the matter of seal friction that takes a little time and a few miles to "break in". It's probably higher in some dampers than others.


Norm