8kgmm front, 6 kgmm rear springs too stiff for shocks

[ONCE-NA]

Hey guys, I'm running AJPS 8kg front springs and 6kg rears with (new) KYB excel G shocks and the car is bouncy as. The dampers arnt good enough to controll the springs. So I have 2 options I guess:
Softer springs- would these shocks control 6kg fronts and 4.5kg rears?
Or better shocks, which I assume will cost a lot more than a new set of springs, and prehaps the 8kg/6kg combo is too stiff for street use anyways.

[15LIDE]

i have 6's in the back of my keto with kyb's its still bumpy it all really comes down to how bad the roads are where u drive, but alot of people do recommend 6 in the front n 4.5 in the back for daily use

[ONCE-NA]

I've only driven it up and down the driveway at this point! Lol, but over the bump into the shed it bounces and if you jounce the car by hand its like the shocks are stuffed... It keeps shaking for a bit

[Konakid]

Need AGX adjustables or softer springs.

[takai]

6 and 4.5 is much better.

and also front 8kg and the kyb are fine, the rears with 6 is pushing it, but ive got a heavy duty boge if you want to try them


Need AGX adjustables or softer springs.


Bloody hell i thought i would never see people on here admitting that 8/6kg is too heavy a spring rate for the street. Was only a little while ago that AE86 owners would scream blue murder if you ran less.

[evil86]

im running s13 setup with 10kg fronts and ksport coilovers rear 4kg and feesl too twitchy. but now i got 6kg on the front and to suit 4kg rears it feels really good, abit of body roll abit buts its ok, i like it:)

[sundee]

before jumping to conclusions - take the car for a good drive - usless this driveway you have is huggee

[4agtezza]

I run the same setup as yours, and in no way does my girl 'bounce'. Double check and tighten everything, and like sundee86 said, take it for a good drive!

[Konakid]

i had 8 and 6 with short stroke kyb excel g's and when going super hard over sizable bumps the shocks couldnt keep up. Car was quite low tho.

[s14seriesII]

i havent seen a decent set of kyb's yet.. they are all crap im sorry

i have 9/6 in my car with bilsteins and it rides like a standard evo9 on the street

[45KIDS]

Get shocks to match the spring rate. Or get softer springs.

[munki]

I have greddy coilovers which is a matched setup (8f 6r) shocks/springs/travel. As well as they work together they are on the stiff side for the street. I would personally get the softer springs and i am looking into modifying the greddy setup in the future.

[dreny...]

I recently changed over to KYB AGX's from KYB exel G's for this exact reason. At high speed the shock could not keep up with the spring and therefore became very bouncy. I currently run 8 & 6kg springs and they are now a perfect spring rate for the KYB AGX's.

Spend that little bit more money at the beginning a be rewarded in the long run. Dont skimp on suspension (especially shocks).

[redsprinter]

how do you guys tell what shock works with what spring rates? something that ive always wonder . is it just trial and error thing or is there more of a math formula for it .

[dreny...]

Is more of a case of driving, altering, driving, altering, driving, testing, driving, driving and driving. Also alot of info can be had on the forums from other members experiences.

After you have been in a few cars with properly setup suspension (tarmac rally cars, modern high performance vehicles) you can use them as a base to learn from.

I noticed that my shocks were not working effectively when driving 100+ kmph as the car was 'floating' on the road quite badly (this is on a very bumpy road). The car would also bob quite badly over bumps. Getting stiffer shocks eliminated this problem and made the car more predictable, precise, and fun. It also gave more grip as the suspension was 'tracking' the road more effectively.

[redsprinter]

dampening rate was the word i was lookng for .

is there a machine or way i could compare say KYB's dampening rate to Bilsterns or TRDs . and be able to match it with the correct spring rates for a 900 odd kg car .

[slydar]

a kyb excell g is a standard replacement shock. its maybe a touch stiffer than stock. but its really not designed to control such stiff springs.

ive driven the set up and it is workable for a drift hack but by all means, better shox will make a huge difference.

8/6 will become annoying for street driving, thats for certain. its just that a lot of people dont mind the trade off, for drifting, it works well.

[ke70dave]

dampening rate was the word i was lookng for .

is there a machine or way i could compare say KYB's dampening rate to Bilsterns or TRDs . and be able to match it with the correct spring rates for a 900 odd kg car .

yep but its not gonna be cheap. you need one of those things that you see on the advertisements for the pedders "drive on shock absorber test".

essentially you need to test the response of the system with a given input.

have a google around for damping systems with the key words:

underdamped, overdamped, critically damped.

theres some cool graphs to be had.

as to what is ultimate for car use ive no idea.

one of these days i want to take my car into pedders and see if they will let me fiddle on their machine, i dont like my chancers....

on a side not, i need some adjustable shocks for the rear of my car. my current KYB's arent stiff enough to control the springs in there. suggestions?

[Konakid]

^^ Amazing ride, cant wait to get some.

[Robo86]

i run 9/7, i know it sounds stupid. but its awesome, my car goes to the track a fair bit/ alot. slides really well (can be seen in my vids).

i run kyb AGX (celica) in the front and trd blues (ae86 8ways) in the rear.

i also drive my car to work and home everyday, its bumpy but its worth it at the track :)

also for the record i have had 3 different front shocks and the agx seem the best (trd yellow ae92, trd blue ae92, agx)

[Sam-Q]

it's good to see people are realising that the dampening rate needs to be matched to the spring rate. I see posts in regard to making the dampening softer when the ride is too harsh and I shake my head. The dampening rate is for the matching of the spring not for the comfort of the driver. If it's too bouncy and already too hard then softer springs are the only solution.

I suggest trying other peoples cars and see what they are running.

[ONCE-NA]

Okay just went for a decent test drive and its shit!. Bouncing around and skipping over bumps, particulary the front. Even if i went to a 6kgmm/4kgmm combo I don't expect these shocks would cope very well.

[ke70dave]

haha yer...8kg is to stiff for these cars, unless you just want to go sideways on smooth surfaces.

im currently in the process of changing from 8kg to 6 in mine, i have AGX in mine, and although the shocks seem to handle the springs pretty good, its just that i think that the springs are just too damn stiff....bounces over bumps and carry's on.....i swear i get airborn off some of the bumps around here.

i remember going for a drive in some dudes ke70 that had 8gb and excel g shocks, i thought it was bumpy and we didnt even go very far..

[Sam-Q]

sorry if this comes across the right way but your bump-stops are chopped right?

[s14seriesII]

haha yer...8kg is to stiff for these cars, unless you just want to go sideways on smooth surfaces.

im currently in the process of changing from 8kg to 6 in mine, i have AGX in mine, and although the shocks seem to handle the springs pretty good, its just that i think that the springs are just too damn stiff....bounces over bumps and carry's on.....i swear i get airborn off some of the bumps around here.

i remember going for a drive in some dudes ke70 that had 8gb and excel g shocks, i thought it was bumpy and we didnt even go very far..



depending on roll centres and c.o.g.. 8/6 is about right you could go stiffer front....

bilsteins correctly built to suit the weight of your car and springs rates is the only way to go.. the only way to do this is to get them rebuilt on a shock dyno by a pro... you can use almost any decent brand of shock asorber for this and get good results..

as i said i have 9/6 in my car and it drives fine and thats a circuit setup for grip..
if your not getting enough weight transfer under brakes or cornering adjust to suit.. as tyre type used can also alter what springs rates you can run effectivly

[ke70dave]

sorry if this comes across the right way but your bump-stops are chopped right?

yer ive chopped 2/3 of the rear off.

the front end is 13 stuff.

also it wasnt to clear, i only have agx in the front, and excel G in the rear. the rear is ok (maybe a tad under damped perhaps)

crap sorry samq im not sure if your quote was directed at me or the original poster.


depending on roll centres and c.o.g.. 8/6 is about right you could go stiffer front....

bilsteins correctly built to suit the weight of your car and springs rates is the only way to go.. the only way to do this is to get them rebuilt on a shock dyno by a pro... you can use almost any decent brand of shock asorber for this and get good results..

as i said i have 9/6 in my car and it drives fine and thats a circuit setup for grip..
if your not getting enough weight transfer under brakes or cornering adjust to suit.. as tyre type used can also alter what springs rates you can run effectivly

yer i understand where your coming from s14series2, im starting to think i might have to bight the bullet and go for some billsteins + setup.

im just surprised that not many people seem to complain with the setup when it appears to me that its not all that great.

how does your race car (9/6kg) go on the street though? like really crappy roads with divents and extra bits of concrete everywhere?

whenever i come to roads like this i almost have to slow down or ill rattle my car to pieces.

last night for instance, had 3 others in the car, this crappy road i hit with a bit of speed (not speeding, just 60km/h or whatever it was) tightish corner combined with these epic bumps and it just did not handle it very well at all.

[racsov]

spring rates are only half of it

my 10/8 GP sport dg5s ride more comfortably then my old 8/6 jic/teins, they are also more composed and stable when pushed. its all in the shock quality

[KE70GT]

sorry if this comes across the right way but your bump-stops are chopped right?

Also if your running a standard strut that hasn’t correctly been converted to an adjustable coilover your probably only getting 30mm of travel depending on how low you car is

[shift_rook]

a kyb excell g is a standard replacement shock. its maybe a touch stiffer than stock. but its really not designed to control such stiff springs.

ive driven the set up and it is workable for a drift hack but by all means, better shox will make a huge difference.

8/6 will become annoying for street driving, thats for certain. its just that a lot of people dont mind the trade off, for drifting, it works well.

completely correct, everyone screams that kyb are so good but so little people realise an excel is a standard replacement shock

[s14seriesII]

yer ive chopped 2/3 of the rear off.

the front end is 13 stuff.

also it wasnt to clear, i only have agx in the front, and excel G in the rear. the rear is ok (maybe a tad under damped perhaps)

crap sorry samq im not sure if your quote was directed at me or the original poster.



yer i understand where your coming from s14series2, im starting to think i might have to bight the bullet and go for some billsteins + setup.

im just surprised that not many people seem to complain with the setup when it appears to me that its not all that great.

how does your race car (9/6kg) go on the street though? like really crappy roads with divents and extra bits of concrete everywhere?

whenever i come to roads like this i almost have to slow down or ill rattle my car to pieces.

last night for instance, had 3 others in the car, this crappy road i hit with a bit of speed (not speeding, just 60km/h or whatever it was) tightish corner combined with these epic bumps and it just did not handle it very well at all.

not many other ppl would realise whats good and whats not..

i was refering to driving on the street...

obviously if the road is crap enough then there is no substitute for suspension travel and a softer spring rate, but then your turning it into a rally car..
or you need standard springs and standard height...

its all about compromise but my car pushed hard on the street is fine.. occasionly the unweighted wheels will leave the ground but ive never had to slow down because of the suspension not working properly