Spring Rate Ratings

[nuffsaid]

Hi all

I am looking for some adjustable coilover units and many places quote spring rates like the following.

E.g. for a R34 GTT the fronts are 5k/250

but for a R34 GTR the fronts are 5k/275

What does the bit at the end mean? ie. whats the differene between 250 and 275 even though they are the same spring rate?

[Sydneykid]

Hi all

I am looking for some adjustable coilover units and many places quote spring rates like the following.

E.g. for a R34 GTT the fronts are 5k/250

but for a R34 GTR the fronts are 5k/275

What does the bit at the end mean? ie. whats the differene between 250 and 275 even though they are the same spring rate?

Could be free height of the spring, the fronts are around 250 mm and the rears are slightly taller, so 275 mm is logical.

cheers

Edited April 18, 2006 by Sydneykid

[nuffsaid]

See here:

http://translate.google.com/translate?u=ht...Flanguage_tools

if you compare the ER34 GTT and the BNR34 GTR spring rates, they have almost the same rate, but the 250mm and 275mm difference in the fronts is what puzzles me.

[Sydneykid]

See here:

http://translate.google.com/translate?u=ht...Flanguage_tools

if you compare the ER34 GTT and the BNR34 GTR spring rates, they have almost the same rate, but the 250mm and 275mm difference in the fronts is what puzzles me.

The title of the column is not "Spring Rate" it is "Basic Spring Set". That means the diameter (70 mm) rate (5 kg/mm) and height (250 mm) of the main coil springs (as distinct from the helper/tender springs).

cheers

[nuffsaid]

Thanks for the clarification.

Then in that case, does the height or the diameter of the spring have any effect on the stiffness of the spring?

Or can we simply look at the spring rate? ie. 5k.

[Sydneykid]

Thanks for the clarification.

Then in that case, does the height or the diameter of the spring have any effect on the stiffness of the spring?

Or can we simply look at the spring rate? ie. 5k.

The spring rate is the spring rate. How tall the coil is makes absolutely no difference to the spring rate. It only affects how high or low the car can go.

Cheers

[nuffsaid]

Thanks SK!

Also, can it be possible that a coilover unit, even though the spring rate may be higher, may actually provide a smoother ride more comfortable ride than a coilover unit with a lower spring rate?

I hear Aragosta is a v good brand and copes well with rough roads.

See: http://www.aragosta.co.jp/Aragosta/comfort.aspx

For a R34, its spring rate is F 8.8 R 6 (seems a bit high)

Or a set of JIC's http://page14.auctions.yahoo.co.jp/jp/auction/s23405334

Or Zeal Function XS http://www.nengun.com/catalogue/product/384

Has anybody used any of these units on the street?

[Sydneykid]

Thanks SK!

Also, can it be possible that a coilover unit, even though the spring rate may be higher, may actually provide a smoother ride more comfortable ride than a coilover unit with a lower spring rate?

I hear Aragosta is a v good brand and copes well with rough roads.

See: http://www.aragosta.co.jp/Aragosta/comfort.aspx

For a R34, its spring rate is F 8.8 R 6 (seems a bit high)

Or a set of JIC's http://page14.auctions.yahoo.co.jp/jp/auction/s23405334

Or Zeal Function XS http://www.nengun.com/catalogue/product/384

Has anybody used any of these units on the street?

Arogosta street kits used to use Japanese Ohlins. Their race kits use genuine Swedish Ohlins. I have used them both, there is no comparison the Swedish Ohlins are far superior.

The only Jic's I have seen have been leaking like crazy, so I don't have a very high opinion of their life.

Never seen Zeal in a car.

Shock rates will affect the ride comfort, particularly bump (compression) valving. The rebound valving has to be in line with the spring rates and to a lesser extent the stabiliser bar rates. So a 12 kg/mm spring is going to need substantial rebound valving to control it. Otherwise the spring will recoil many times after the initial compression (think pogo stick).

Most definitely a 12 kg /mm spring is going to feel harsher with a crap shock, than one with decent shock valving sophistication. It is very unlikely that a coil over with a 12 kg/mm spring rate is going to be as comfortable as a coil over with a 4 kg /mm spring rate, given equal shock valving sophistication.

cheers

Edited April 19, 2006 by Sydneykid

[nuffsaid]

But a 8k spring rate shock with good valving can be as comfortable (maybe even better?) than a 4k spring rate shock with average valving?

So its not just always about the spring rates, but also the level of valving sophistication right?

In that case, I have a couple of questions for you regarding the design of the Tein Super Streets:

1) is the valving there pretty ordinary?

2) Also are these monotube shocks?

3) I believe they are bump and rebound adjustable (correct me if I am wrong)

4) are these quality units? I dont want the thread and stuff rusting on me and hence they wont be height adjustable anymore

5) i believe these are not fully height adjustable, as changes in height affect the preload on the spring, is this a big deal on the street?

Thanks again

[Roy]

3) I believe they are bump and rebound adjustable (correct me if I am wrong)

However if you adjust one you adjust both as they use the same adjustment. Not like some other brands/models where you can adjust the two characteristics seperately.

Some pretty quick cars are using Tein Super Streets by Fulcrum out of QLD, so they sure make the car handle pretty well.

As for the other stuff...who knows, put them on a shock dyno owned by a third party and see for yourself. Outside of that you may always be gettign a buy line form the distributer... ?!?!?!?!

[Sydneykid]

But a 8k spring rate shock with good valving can be as comfortable (maybe even better?) than a 4k spring rate shock with average valving?

So its not just always about the spring rates, but also the level of valving sophistication right?

In that case, I have a couple of questions for you regarding the design of the Tein Super Streets:

1) is the valving there pretty ordinary?

2) Also are these monotube shocks?

3) I believe they are bump and rebound adjustable (correct me if I am wrong)

4) are these quality units? I dont want the thread and stuff rusting on me and hence they wont be height adjustable anymore

5) i believe these are not fully height adjustable, as changes in height affect the preload on the spring, is this a big deal on the street?

Thanks again

Suggestion to your questions follow;

1. Yep

2. Some are monotube, some are twin tube

3. As Roy posted, yes, but both at the same time. So if you want, say, 10% more rebound damping, you also get X% more bump damping. Even if you don't want any increase in bump (it is already stiff/harsh enough). You will have to ask Tein what the X% really is, it varies from partically nothing to ship loads.

4. The hardware is very nice and shiny, good quality. But if you don't lubricate the threads they will seize anyway. It is hot, dirty, wet and dusty under there.

5. Preload on the spring is only relevant to how much droop and compression travel there is available. It DOES NOT affect the spring rate (don't know where that stupidity came from). Usually there is plenty of travel as long as you keep it at a reasonable ride height. Some people get carried away and lower them so far there is no travel left. But by then the suspension geometry will be so far out of whack travel is the least of their worries.

cheers

[nuffsaid]

1. Is their simplistic valving adequate for Sydneys roads?

2. How do you know which Super Streets are mono and which are twin? I dont know where I got the idea that monotube is better, correct me if I am wrong.

4. Is that with pretty much all aftermarket coilover units? the threads need to be lubricated or else they will seize? The Tein Flex units have teflon coating on them, is it fair to say that they will seize also if not lubricated?

5. Thanks, good to know that preload isnt much to be concerned about on the street. I am not planning on slamming the car anyways, the super streets are set up by default to reduce ride height on a R34 by 45mm front and 35mm rear.

[MerlinTheHapyPig]

i also have a question, because "valving compexity" seems to get mentioned a bit.

How can you tell if a shock has "simplistic valving"?, why is "complex valving" better?, what aspects of shock valving are considered desirable? how do we know if i have x brand shock if it has good valving or not?

Sydney Kid, i know you always mention this when the "jap shock" and "high spring rate" arguments come in to question, however your comments on shock valving seem to be taken as gospel, however i never seem to see any elaboration on the topic.

Say, compare the bilstein valving from the group buy with Tien super street mentioned above.

can you explain the differences between the valving in the two specific models?

(sorry for the long list of questions, but this topic has always been bugging me, and i need someone to explain it for me)

Edited April 19, 2006 by MerlinTheHapyPig

[Sydneykid]

i also have a question, because "valving compexity" seems to get mentioned a bit.

How can you tell if a shock has "simplistic valving"?, why is "complex valving" better?, what aspects of shock valving are considered desirable? how do we know if i have x brand shock if it has good valving or not?

Sydney Kid, i know you always mention this when the "jap shock" and "high spring rate" arguments come in to question, however your comments on shock valving seem to be taken as gospel, however i never seem to see any elaboration on the topic.

Say, compare the bilstein valving from the group buy with Tien super street mentioned above.

can you explain the differences between the valving in the two specific models?

(sorry for the long list of questions, but this topic has always been bugging me, and i need someone to explain it for me)

I have a set of stuffed Teins that I am in processes of dissassembling, in my spare time (there ain't much of that). I will then post up some pictures of the Bilstein valving compared to the Tein valving. The only problem I see with doing this is once I have done Teins people will ask for KYB, or Jic or ............

In the interim;

The number of valves is important, there are shocks with 3 valves

One for rebound, to dampen the spring oscillation

One for bump, to dampen the compression, help the spring absorb the bump

One for gross dump (to prevent shaft damage (bending) when a large bump/hole is encountered.

These would be considered unsophistated compared to shocks with 5 valves;

One for low frequency rebound, to dampen the spring return after hitting a bump

One for high frequency rebound, to dampen the spring rebound after hitting a ripple in the road

One for low frequency bump, to help the spring absorb the bump

One for high frequency bump, to dampen the chassis motion on a ripply road

One for gross dump (to prevent shaft damage (bending) when a large bump/hole is encountered.

There are shocks with 8 valves, oneextra bump and two extra rebound.

The size of the valves is important, there are shocks with valves as small as 1.5 mm, they can't fit larger valves because of the restrictions caused by the piston diameter. Obviously for the same given OD, a twin tube shock will have a smaller piston diameter than a monotube shock.

The type and size of spring used to control the valve is important. The less sophisticated shocks use bevel washers as springs, as they are cheap compared to torsion bars or coil springs.

cheers

[Beer Baron]

i think that sums it up nicely! lol.

[dangerous_daveo]

I have a set of stuffed Teins that I am in processes of dissassembling, in my spare time (there ain't much of that). I will then post up some pictures of the Bilstein valving compared to the Tein valving. The only problem I see with doing this is once I have done Teins people will ask for KYB, or Jic or ............

In the interim;

The number of valves is important, there are shocks with 3 valves

One for rebound, to dampen the spring oscillation

One for bump, to dampen the compression, help the spring absorb the bump

One for gross dump (to prevent shaft damage (bending) when a large bump/hole is encountered.

These would be considered unsophistated compared to shocks with 5 valves;

One for low frequency rebound, to dampen the spring return after hitting a bump

One for high frequency rebound, to dampen the spring rebound after hitting a ripple in the road

One for low frequency bump, to help the spring absorb the bump

One for high frequency bump, to dampen the chassis motion on a ripply road

One for gross dump (to prevent shaft damage (bending) when a large bump/hole is encountered.

There are shocks with 8 valves, oneextra bump and two extra rebound.

The size of the valves is important, there are shocks with valves as small as 1.5 mm, they can't fit larger valves because of the restrictions caused by the piston diameter. Obviously for the same given OD, a twin tube shock will have a smaller piston diameter than a monotube shock.

The type and size of spring used to control the valve is important. The less sophisticated shocks use bevel washers as springs, as they are cheap compared to torsion bars or coil springs.

cheers

And that is the short version people! I asked the question and got a 30min description (for which I am eternaly greatful for!) If SK gets the time to put up the whole thing it would be well worth reading. But basically jap shocks are flawed because they use springs to do everything, (as springs are cheaper to make than sway bars for eg...) so then the shock valving is done to suit the spring, as they are smaller valves to start with (pie r 2 = area...) it makes a large difference. Goes on and on and on.

Anyway. Gary if you want to cut up my shocks after you swap them over go for gold. I believe they are KYBs revalved to suit my springs, non adjustable so it would be good to compair them.

[T04GTR]

AND THERE IS LIGHT.

mad. thats how i had asumed they worked. cool.

now. can my biltstens be re valved to suit the current spring rate?

or more importantly have the "dump/large bump in road" valving increased?

the rest is sweet. just sik of them going BANG over a sharp bump. ie tree root bulge in road.

cheeres

[dangerous_daveo]

AND THERE IS LIGHT.

mad. thats how i had asumed they worked. cool.

now. can my biltstens be re valved to suit the current spring rate?

or more importantly have the "dump/large bump in road" valving increased?

the rest is sweet. just sik of them going BANG over a sharp bump. ie tree root bulge in road.

cheeres

Rebound is for upwards stuff. Bump is for downwards stuff. So in otherwords there is no dump for up.

[T04GTR]

Rebound is for upwards stuff. Bump is for downwards stuff. So in otherwords there is no dump for up.

i do believe "bump" is bump ie: a bump

and rebound is for the rebound( car going back up)

well. thats how the sachs one work on the v8 super car team i work for

that is. i need the big bumps valve harder cheeres

[MerlinTheHapyPig]

thanks for the reply mate, very helpful

pity i can't find out how my shocks are made without pulling them apart!!