Coilover Spring Rate

[mr_crust]

im looking at getting a set of coilovers from Just Jap:

http://www.skylinesaustralia.com/forums/in...howtopic=108386

These are the g4 ones going for $1399, now the spring rate is : 13 (F) 8.7 ® Kg/mm, now i have read that its quite hard that rate.

can anyone tell me what a decent spring rate would be for a street r33 gtst-t as just jap make can get them at custom spring rates for both front and back

[ISC-Performance]

my coilovers usually have 12 fronts and 10 rears for r33 gtst, and most customers seem to be happy with that for street/track use, as above though we can also change the spring rates at your request

thanks,ryan

[neil_se]

Those rates are very stiff for a street car, you'd want something closer to 7/5 or 6/4.

Edited April 18, 2006 by neil_se

[Sydneykid]

13 & 8.7 kg/mm is beyond belief. We run 6 & 4.5 kg/mm on the 2WD race cars and 4 & 3.5 kg/mm on the 2WD road cars.

cheers

[MerlinTheHapyPig]

standard rate for jap coilovers is 8kgmm/6kgmm for front and rear

usually this is considered too stiff for australian streets, so maybe something a bit softer is in order. Fulcrum distribute Tien Super street coilovers tuned for australian conditions, might be worth a look.

[turbohectics]

I'm gettin my teins for $1800 tomorrow if any one wants some and got the cash in sydney i'll pick em up for em ,mine is for 32 gtst prob same price for 33

Prefer to pay $400 extra and get much superior than just jap bodgys from thailand ,vietnam wherever there made

PM

[BADR33]

i have BC coilovers in my r33. the spring rate for mine is 8kg front and 6kg rear and it rides fine on the bumpy NZ roads.

if you wana harden it up you just dial up the dampning.

jap coilovers are often insanly hard with there spring rates.

[Chris Wilson]

Here in the UK most of the very quickest Group N touring car R32 GTR's, in their heyday, ran 1000 plus pound inch front springs and around 700 lbs inch rears. They were fully caged, so the shells were a LOT stiffer than stock, but it seems to differ greatly from SK's findings, even given the big weight differences between RWD and 4WD cars.

[Sydneykid]

Here in the UK most of the very quickest Group N touring car R32 GTR's, in their heyday, ran 1000 plus pound inch front springs and around 700 lbs inch rears. They were fully caged, so the shells were a LOT stiffer than stock, but it seems to differ greatly from SK's findings, even given the big weight differences between RWD and 4WD cars.

Since we race a Production R32GTR N1 spec and an Improved Production R32GTR I guess I can comment on the differences;

Group N cars aren't allowed to change their stabiliser bars, so they have to run high spring rates front and rear to compensate.

Group N cars aren't allowed to change their anti dive, so they have to run high front spring rates to compensate.

Group N cars aren't allowed to change their anti squat, so they have to run high rear spring rates to compensate.

Group N cars aren't allowed to change their caster, so they have to run high front spring rates to control the roll enough for the camber to compensate.

Group N cars are allowed to run full slick racing tyres, which will tolerate a much higher spring rate than a road radial or even an "R" tyre.

Lastly, shock absorber technology has moved a long way since 1989 and we simply don't have to run the high spring rates now that we did then.

Hope that answered the question.

cheers

PS; The tracks in the UK are a lot smoother than what we have locally.

Edited April 23, 2006 by Sydneykid

[Chris Wilson]

Since we race a Production R32GTR N1 spec and an Improved Production R32GTR I guess I can comment on the differences;

Snip

As always, an admirable reply, thanks for your time

[Optimus Prime]

Hi

I have a question about the spring rates on my car.

l own a r33 gtst and it feels like l'm in the flintstones car, it is that stiff l dont like driving it,

l called whiteline and they said they could make some springs up for me, however l'm not too sure on the spring rate to give them. l was advised at 6kg for front and 4 kg for the rear. Can anyone give me a comparison as to what 6/kg 4/kg would feel like? (not so smoothe roads still feel heaps bumpy??)

After driving my car for the past few months l am really sick of it.

what is the best rate for me?

I am just driving it to and from work, l dont race it ( i'll still have these coils to changeover if l ever want to), rarley thrash it. l just want more comfort over potholes and dips in roads. (right now reflector's on the road feel like potholes, and potholes feel like l'm driving on a cattle grid.)

l am about to measure the springs now to give to Whiteline. They want to know the inside diameter of the spring and the spring height.

and my last question is ( if l can explain myself properly)

When l give these dimensions to them will factor in the softer rate that l want and give me a longer spring to compensate the "squish" ( l'm sure thats not the correct terminology) or compression its going to be under?

l have JIC coilovers, and there yellow( l dont know if they colour code their shocks just a bit of FYI)

Sorry for the longass post and for any one that has read this far and those that reply, thanks in advance.

[r33_racer]

13 & 8.7 kg/mm is beyond belief. We run 6 & 4.5 kg/mm on the 2WD race cars and 4 & 3.5 kg/mm on the 2WD road cars. (SK)

- As stated by SK, the 4 and 3.5kg/mm im sure would be fine for your road car which sees no track work. About the springs, i think they will make them to the same as what you have on now, they will just be a weaker spring.