Spring Rates

[Dan_AE86]

Im getting front coilovers and rear springs, other gear etc. from AJPS real soon, BUT.

i need to decide on spring rates, the car is my everyday driver/weekend hell raiser which i drive 70kms return for work each day on the ballina/byron road (which is shit). Use will be good street car, 3-5 meetings a year hill climb, some track drift and heaps of Street Drift/hill runs (on a track of course!) .

So my question is what spring rates does everyone run and why!and what they recommend, etc.

NOTE: THIS CAR STILL HAS FULL INTERIOR AND WILL NOT SEE A CAGE (UNLESS SHIT CHANGES.). CAR WILL HAVE A FRONT STRUT BRACE, REAR ONE LATER MAYBE..

Please HELP!

Dan.

[dori_86]

i'd say if ur planning on 5+ hill climbs plus extra curricular weekend action then 8/6 combo is decent, ive had the same spring rate AJPS coilovers and im yet to get to the track,

but its all personal opinion i know of some1 running i think 11 or 12kg in the front of an 86 and was daily driven and they liked it, so just get the norm spring rates and because there coilovers if u decide too stiff/soft u can change the springs

[rthy]

if you drive 70km on a crap road every day then theres no way you would want really stiff springs. Unfortunetly what people think is good in terms of spring rates is very subjective. I made the mistake of listening to the drifters on my fourth spring combination and I bought some 6kg springs which was a big mistake. Not only was my car slower around corner because of the reduced traction but it was horrible to live with. I then just took a gamble and went with a hunch that ws 275 pound/inch which is 4.9kg. I use custom springs for the back that are round 3.3kg/mm.

Perhaps you should just have 2 sets of springs? one for daily use and the other for the more serious work. What you need to do is drive someone elses car down that road for atlest 10 min. I drove a car with 8kg springs and it seemded good from a short distance but i know if I kept driving it would of irrited me.

Whatever you do I recomend running 2/3 of the front rates for the back, any different and it may not be neutral.

[Oly AE86]

Agree with Sam and Chris

I drive 50+ Km to/from work daily, and local roads can be very dodgy. Car has full interior and F + R Braces

I am running 350lbs front ( roughly 6kg) and 4.5kg Rears, daily driving + some track work.

I am also using the KYB AGX adjustable damper shock, so I can get the shock just right for the springs. Front feels great on setting 2/4, rear on 1/8 :o

I wouldn't go any stiffer for the street around here, especially the rear as it has very little weight and bounces a fair bit on the rough stuff.

Having said that, its got some wicked traction and a little squat giving me heaps of grip.

If you want comfort for driving, I would go 2 sets of springs, maybe 4 - 3 for the street, and 8 - 6 for drifting/track stuff.

[ke70dave]

agreed with oly

i have 11kg in my car atm at the front (waaayy to stiff), i have 8kg to go in though..

ive driven alot in bahnuggets car, with 8kg in the front and approximately 6kg or so in the rear.

its pretty good to drive in, if you remember that its a "race car". its by no means comfortable, but its good.

if i was gonna drive my car every day to work (i just walk to train station atm) i would definitely look at getting another set of springs, say 5kg and 3kg or so. with some decent shocks good handling can be achieved with comfort.

just a quick question on this topic

if one was going to go for maximum grip (disregarding comfort), what spring rates do you think you recommend????

[Konakid]

If its drift and hills, 8 and 6

If its hills, 6 and 4.5

also, Swaybars win, get them.

[Dan_AE86]

just a quick point to clear up a few little things...i really want the car's setup to be drift orientated because fuck its fun, as for grip racing id probly leave it setup for drift because im not serious about times im just in it for the fun and experience..and as for the two sets of springs idea i dont wana go down that road because i dont wana change them all the time/spend the extra money..ill see just how bad it is, if i cant stand it then yeah ill go two sets.

is there a need for adjustable shock?does it make THAT much difference?just the front or rear too?

BTW im leaning towards 7kg Front and 5Kg Rear...what do people think?

also i dont want to have to seam or spot weld anything or go a roll cage so is this too much KG?

Dan.

[rthy]

oly ae86: the fact that you find that dampner setting is right seems to sujest to me that your rear spring rates are too stiff. But I could be wrong.

ke70 dave: maximum speed specifiactions change from corner to corner. Everyone seems to say 6kg but that would make my car slower because of the loss of traction. Basicly good surface = high spring rates and dampening and poor surface = soft spring rates and dampening.

kona kid: I tottaly disagree with you on this one, I know for sure that 7kg spring would make my car slower where I love, you see the hills where I take my car arnt that well mainaned so I would have to go slower to have the same amount of traction. Also that combination of 8 and 6 I think from my personal experience in my car would cause big oversteer. As for anti roll bars, I havent tried changing them personally because quite a few people who race sprinters seem to agree stock is the best size.

dan_ae86: I think that spring combination may cause you a fair bit of oversteer but it depends on many factors. Also whats KG stand for?


I want to ask you guys something, how many of you have tried multiple different springs in an effort to get their car cornering the quickest? (that means neutral)

[Konakid]

Going by the two thirds rule the rears should be two thirds of the fronts ie 8 and 6, although many japs alter this slightly ive found.

While this setup is too stiff for genuine hills runs in Australia, it doesnt make that much difference over 6 and 4.5, realistically.

I mean, 6 and 4.5 might chop 2 seconds off your local 1 minute hills run, if your pushing that hard your taking it waay too seriously, seriously! So in theory 8 and 6 is a 'sacrifice' i guess for hills, but in the real world it really doesnt matter when your going for a punt along your fave road.

Swaybars make the biggest difference, they make the car stick so hard, but with the flick of the wheel, it will snap straight out into smooth oversteer. With the whiteline rear bar ive got atm anyway. Im currently in the market for a front one, 24mm.

go 7 and 5 if you have to but realistically id just go 8 and 6 and put up with it, its fine for hills. One thing though, is make sure you dont dump the car, limiting suspension travel otherwise it will feel and ride much stiffer than it should be as the shocks will be at the bottom of their stroke at standstill. The KYB's form AJPS are stiff enough for 8 and 6 so they match up quite well. Just keep sensible ride heights and it'll be fine (not stock obviously!)

There was a big thread on this but i cant find it anywhere, i thought it was in the motorsport section but couldnt find it...

[roadsailing]

while on the topic of travel, make absolutely certain you have enough rebound travel, as this is crucial to comfort and handling.

i'd reccomend 6 front 4 rear or therabouts, my car has 5.8 front and 4.3 rears, its fine on the road and reasonable on the track.

i calculated the natural frequency this gives, and according to some oldish book on suspension it is on the high side what you would want for a circuit car with no aero.