R31 IRS Squat

[R31Nismoid]

I've had a read of the 'What to do with hard springs' thread but it's more applied to an R33's.

R33's have a much nicer IRS setup than the primitive R31 so im finding the info hard to apply to my R31.

I know there are differnt spring rates/shocks and i have a number of different ones in my posession at the moment.

The car is getting pulled apart in a few weeks so i'm tossing up what i should put back in it to get the most out of it.

I honestly dont understand suspension much at all and i've been told

Springs are just there to take the load more than anything else and dont have as much effect as the shocker is what determines how hard the ride/squat is.

Is this correct? or is there more to do with this.

I say this as i have terrible rear 'squat' problems due to the R31 IRS.

The car will but doing circuit work and some drag, but i want it predominately setup for circuit.

As soon as the car is loaded up the rear 'squats', camber gets bad and i only have 1/2 - 1/3 of my tyre on the ground which obviously causes major traction problems.

Is this caused by the spring or shocker? And how should i fix it.

I have a bilistein coil over setup, cusco Adj tops etc etc.

Any help would be appreciated.

[slip]

Try stiffer springs and shocks. Springs are compressed by the weight of the car, loads. it takes a certain amount of kg to compress a spring 1cm. stiffer spring, takes more kg to compress it 1cm. Shocks are there to control the compression and expansion of the spring. Softer shocks will allow the spring to be compressed faster, and spring back faster. stiffer shocks slow this down.

[discopotato03]

I have a series 1 Bluebird (1982) with DR30 IRS grafted into it and came across the same problem , I was already using Bilstein rear dampers B46 0057 and custom wound 235 inch pound springs . My problem was trying to get the correct ride height and enough tension on the springs so that they would not dislodge at full droop . Purely by fluke I raised the ride hight one inch (Bilsteins usually have several circlip grooves for spring seat mounts and more can be added with a parting off tool in a lathe) and also INCREASED the springs PRE LOAD . My car now has very little squat and is MUCH more predictable . Production cars ALWAYS work better at standard ride height . Increased spring and damper rates reduce the body roll and help keep the suspension geometry as the manufacturer intended . While I'm on my hobby horse thick anti roll bars are useless . On my car I used the smallest factory front bar I could find and used custom wound 185 inch pound springs . My front struts are DR30 with the spring seats ground off and the tubes extruded to take Bilstein P36 0303 inserts (short length Commodore HDT V8 inserts)to give a good ride and acceptable roll . Screw adjustable platforms were welded on the strut tubes and adapters to take the Bilstein top nuts . I have had this car for twelve years and have bought a clean DR30RS Skyline to replace it . So far it has new bilstein rear dampers and whatever the last set of custom rear springs that the Bluebird had . The car had come with Jap aftermarket springs and dampers and drove absymally . The rear is now at std height and works well . The front now has std DR30 springs and some sort of short Tokiko damper that traps the springs and sits way too low . The Razo camber adjustable tops also got the flick for std MR30 tops and bearings . When the front is at a sane height (can't get a trolly jack under the front cross member yet) I will re assess the front wheel camber situation . The Bluebird bits go in soon .

Hope some of this helps and E-Mail me if you need to source some bits , my sources are in Sydney and loath dreamers and time wasters . One thing that comes to mind regarding R31 IRS , I think they use some sort of crude rear steer that allows the cross member to deflect and steer the trailing arms . If you have it junk it . No competition Nissan ever used it and it proved to be unsatisfactory on the road . If it fitted I'd use the DR30 IRS as it has larger piston cable type calipers and works . Have fun A .

[fatz]

just pick up a rear set of s13 coil overs

make shure you get the hight adjustable one (ohlins, tein, jic)

modifications that need to be made are basically just a new hat with studs or you can modify your rear towers to accpt two stud (bit more dodge

so you should pic up a set of rear teins ect for say 400(used)

if your going drifting leave the springs as they come with the teins

if your going circuit get some new coils made up that are far more softer

pete (cheap and easy) s13 coil overs are readily available

pete

[R31Nismoid]

It's got coil overs in there now.

Hrm....