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Shockabsorber 101

Sydneykid
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Sydneykid
Sydneykid

For some time lot's of guys have been asking me to explain the differences between a good shock and a bad one, what sophisticated valving really means, why a monotube shock is better than a twin tube

Sydneykid
Sydneykid

Following are pictures of some twin tube shocks, the first is a standard GTR front shock. Below the spring seat you can see the step up in diameter, showing where the ouside chamber is located for the

Sydneykid
Sydneykid

I get asked quite often how to tell if second hand shocks are OK. While it is not 100% perfect, you can do some easy checks, if any of these show a problem then its rebuild time. 1. The first job is

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Beer Baron Grand Master

Beer Baron

Posted
Posted

hi mate, currently using the 10kg fronts and the 8kg rears. it's ok. if i drove it every day it may be a bit much, but the times I drive it I dont mind it. damper settings are another matter. that's a work in progress!

driftmeister Community Regular

driftmeister

Posted
Posted
baron how did you go with the settings on your nismos?

i have same in Ohlins, what spring rates did you use?

I am using Nismo R-Tunes for my R34 GTT, however i still do not understand how to set up the rear as they are 8 setting compare to 4 for the front. If i set the front at 2, should the rear be 4? Kinda lost till now since i bought this shocks 2nd hand with no manual or whatsoever.

Appreciate everyone's input.

Beer Baron Grand Master

Beer Baron

Posted
Posted

the GTT R-tunes are very different to the GTR versions. The GTR versions are all alloy shocks, with 4 way adjustment, totalling 600 settings per shock (20 X bump, 30 X rebound). From memory the GTT versions are a conventional steel shock with just combined bump/rebound adjustment in only a few steps. so I dont think I can help, sorry :laugh:

driftmeister Community Regular

driftmeister

Posted
Posted
the GTT R-tunes are very different to the GTR versions. The GTR versions are all alloy shocks, with 4 way adjustment, totalling 600 settings per shock (20 X bump, 30 X rebound). From memory the GTT versions are a conventional steel shock with just combined bump/rebound adjustment in only a few steps. so I dont think I can help, sorry :laugh:

Today i tried setting the front 3 and the rear 5, felt much better though the bumps are quite immediately felt. However when lifting off throttle during mid corner the car handle quite neutral while adjusting the degree of the turn. However i didn't want to open throttle worry it may drift since the rear is set quite hard. Highest i've gone is 6 (rear) but the ride quality suffers on bad quality roads though the rear bounces less on wavy roads.

I was told an uprated stabiliser bar would help when use with suspension with high spring rates. Is that true? Sorry im quite a blurr when it comes to suspension...

  • 3 months later...
ak_stylez Community Regular

ak_stylez

Posted
Posted

Hey,

This may seem a really stupid question, but I've asked everybody I know and no one seems to be able to answer me.

Exactly what is a coilover? How does a coilover suspension set up differ from a traditional springs + shocks? what are the pros and cons of each?

I've got a r33 gtst (street car) and my shockers are really worn (i think) so I'm lookin to upgrade my suspension and I don't know what I should get.

Thanks!

Beer Baron Grand Master

Beer Baron

Posted
Posted

a coil over has the coil spring wrapped around the shock with a lower spring seat on the shock body itself. simple as that. it's basically better packaging that having the damper and sping located on seperate mounts. many people mistakenly refer to coilovers as only being threaded height adjustment coil-overs.

ak_stylez Community Regular

ak_stylez

Posted
Posted (edited)
it's basically better packaging that having the damper and sping located on seperate mounts.

so dynamically, they're not a better option?

EDIT:

Also I'll add:

lets say Tein Monoflex/superstreets vs sydneykid's group buy

which would be better for mainly road use (albeit spirited), with occasional drift/track outing? If my question is too broad please tell me as I'm pretty lost when it comes to suspension.

p.s. the bilstein shockers in SK's GB, are they monotube?

Edited by ak_stylez
Sydneykid Grand Master

Sydneykid

Posted
  • Author
Posted
so dynamically, they're not a better option?

Yes they are, because the spring and shock move together, same leverage ratio, same movement ratio, no differential in contact friction. This makes it easier to tune the spring and damper rates.

Also I'll add:

lets say Tein Monoflex/superstreets vs sydneykid's group buy

which would be better for mainly road use (albeit spirited), with occasional drift/track outing? If my question is too broad please tell me as I'm pretty lost when it comes to suspension.

No contest, the Bilsteins will give superior ride and handling.

p.s. the bilstein shockers in SK's GB, are they monotube?

Yes

:) cheers :)

ak_stylez Community Regular

ak_stylez

Posted
Posted
Yes they are, because the spring and shock move together, same leverage ratio, same movement ratio, no differential in contact friction. This makes it easier to tune the spring and damper rates.

Well, do you have a coilover option (or suggested equivalent) in (for) the group buy? or would that be useless as the spring/shock set up you have outlined has already been "tuned"? Would a coilover set up have the potential for better tuning, or just easier to get where you've already brought the springs/shocks?

If springs/shocks really are the way to go, what coilover features would I be sacrificing?

I'm really sorry for all the questions, I hope I'm not frustrating you.

Sydneykid Grand Master

Sydneykid

Posted
  • Author
Posted
Well, do you have a coilover option (or suggested equivalent) in (for) the group buy? or would that be useless as the spring/shock set up you have outlined has already been "tuned"? Would a coilover set up have the potential for better tuning, or just easier to get where you've already brought the springs/shocks?

If springs/shocks really are the way to go, what coilover features would I be sacrificing?

I'm really sorry for all the questions, I hope I'm not frustrating you.

My job is to decipher prima donna race car drivers’ ramblings about handling every day, so no problems answering your questions.

The standard R32/33/34 suspension features coil overs (the spring goes around the shock) front and rear. So I am not sure what you mean.

The Group Buy Bilsteins have additional circlip grooves added so you can set the height you want before you fit them. There are 6 grooves 8 mm apart and I can tell you the height that you will get from each groove. Keep in mind that GTR's handle best around 355 mm front and 345 mm rear (centre of wheel to guard) and GTST's around 350 mm front and 340 mm rear.

If you want infinite, on car height adjustment, I can arrange that using Eibach coil springs and Bilstein conversion kits. For most people this is a an overkill (waste of money), they set it once and then forget about it.

Adjustable shocks are only worthwhile if you know what you are doing with the adjustments. Most of the time shocks have adjustment to cover up for their unsophisticated valving. This means they only work in a small range of conditions and so they have to have the adjustment. Bilsteins have very sophisticated valving and consequently have a large window that they operate well in. Simply put, they don't need adjusting. Plus I have selected the valving to suite the Group Buy kit.

This is really a technical thread, and we are way off topis, so best if we take any further correspondence to PM's.

D cheers :nyaanyaa:

  • 1 month later...
Hotwire Veteran

Hotwire

Posted
Posted

I have a question about Pedders "comfort Gas". When asking them whether they were monotube or twin tube the only answer they would give me is "it has our new VRD system, which adjusts the shock for all conditions" so I dont thin the sales guy knew. Now looking at the pics on their website, it gives NO indication of what they are.

Gary, can you shed some light on these?

  • 3 weeks later...
Sydneykid Grand Master

Sydneykid

Posted
  • Author
Posted

I get asked quite often how to tell if second hand shocks are OK. While it is not 100% perfect, you can do some easy checks, if any of these show a problem then its rebuild time.

1. The first job is to check for oil leaks around the top seals, on the shock body where the shaft goes through. Any oil (even a tiny bit) is bad news.

2. Next make sure that the shocks have equal gas pressure, take the springs off and compare the front pair with each other. Push them down equally and make sure that it takes the same amount of force to push them down. Any difference (even a tiny bit) is bad news.

3. Then make sure that they come up together at the same speed. Any difference (even a tiny bit) is bad news.

4. Do the same for the rear pair.

5. Lastly look at the shock shafts, if they are not perfectly shiny, the same all the length and all the way around, then that is real bad news. They must have no rust, no scratches and no visible wear marks. New shafts cost more than whole shocks.

That's about it, if the shocks pass those tests then chances are they are OK, for now.

:) cheers :)

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