Spring Rates

[Konakid]

<div class='quotetop'>QUOTE (driftspec @ Nov 7 2007, 10:00 PM) </div>QFT


That is the general rule of thumb, not sure if I really made that point in my previous post. Same deal with putting strut braces on: you stiffen that part of the car, you lose overall grip there.

I might not have qualified myself as much I though when explaining the drift-style setup, the softness at the rear is more to allow the throwing of the weight around from one side to another. Of course, at speed the forces generated exceed the lateral force the tyres, thus the weight and lack of lateral grip force the tail to go around in that direction.

There are plenty of factors involved in getting the overall suspension setup right for how you like it. Plenty of people (especially Sam) have been working on it, I hope to get the time to get the kind of practical knowledge you have
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Hi josh, i see you thar....

Anyway, Driftspec, stiffening the chassis does not reduce grip as such, but help retain the geometry of the car through keeping the chassis aligned under load. For example, putting a front strut brace on your car doesn't decrease the grip available but keeps the strut towers from flexing allowing the struts to work as they should with out dealing with loads that come from a force on the opposite side of the car. Basically braces help retain standard geometry, allowing the suspension to do its job more precisely.

Stiffer springs = less grip, this is a given. As there is less compression when the the weight transfers onto a corner, the tyres take the brunt of the weight, not the sagging of the stock soft springs. In turn, the tyres break traction more easily.

Drift cars use stiffer rear springs than circuit cars (generally) to make this happen with a flick of the steering wheel. The stiff springs also help to control the weight transfer easily during maneuvers that involve flicking the car. The driver is not left wondering when the tyres are going to break traction because you have to wait for the body to stop rolling before they slip, instead is is instant, the body moves only a tiny bit before the tyres break loose making the rear end predictable when sliding.

Stiffening the chassis is a good thing and does not decrease the cars grip, this is different to stiffening the suspension.

Ill just add that the softer/grippier tyre that you are running, the stiffer suspension settings you can get away with due to the tyres having a lot of grip, i.e semi slicks.

[rthy]

i tottaly agree with you on this one Konakid,

the shitty thing about springs is that what someone loves someone else hates. You really need to get into someones sprinter and take it for a drive and a decent drive, idealy in your area.

If I try to remember I think I have tried 7 different spring combinations on the front and possibly 8 on the rear to get what I want, it was a painfull and expensive process. All because I couldnt test someone elses car with simular specs in my area. So if you have the oppertunity take it, when you drive it check these things:

- is it too firm for my roads?
- is the turn in good?
- does it oversteer on corner exits?
- is it too soft/leans too much?

[Driftspec]

We could be on this one for days

I agree with you KonaKid, I think I was a little too general and vague in what I was saying. It does strengthen the chassis/car at that area, but I will say it can also have the affect of 'stiffening' (not an exact term, best I can think of) that area as well. By preventing the flex of the chassis and geometry at that point, there is a side affect of it keeping the weight at that point, which can in turn reduce grip (depending on setup). This is one thing I have experienced first hand with handling setups: In this case, front strut brace = car more prone to understeer. That was matched with (I believe) 8kg front and TRD short-stroke shocks. Of course, that can just come down to having spring/shock combos that are a little too stiff at that point for the rest of the car's setup.

Still important to stiffen the chassis, again handling gains can be made by doing that, to allow the suspension to more accurately do its job. Its all about balance, matching it with the setup of the car, its purpose, and how you feel while driving it.

[riojin]

well all i know is that my ride is too rolly for me at 8kg and 6kg and a 18mm rear swaybar, especially at the back.

ill buy this setup and see what happens. i have a feeling itll be understeery as all hell, but ill try and compensate this by playing with the camber settings to get it just right

[Konakid]

To much roll with 6kg rears? Serious! What speeds are you cornering at? Track car only? damn! 8 and 6 is plenty stiff for street thrashing.

Can i ask what shocks you have? these can make a big difference to the feeling of the cars stiffness and rolling.

[riojin]

i always corner hard....

its my daily driver. but i have monroe gas shocks in the rear. thats whats prolly making it roll too much (well for my liking anyway). i didnt have them put it, its still the previous owners suspension setup.

[rthy]

just remember that roll isnt necessarily a bad thing, it is needed to get the right arc of the suspension and not load the tyres up too much from sideways force or something like that

[anastasios]

i rekon upgrade your shocks 1st

[RobertoX]

TRD blue in the rear FTW

i have stock too

and 6 is hard in the rear


what tyres are you using?

[riojin]

i think im gonna give you a call soon dave and get some stuff from you.

im gonna get some custom springs lowered and with real compression rates of 8 and 6. theyre supposed to be that now but i have a feeling theyre not.

im gonna do the whole suspension in one hit so ill buy more than that

tyres are some nankang garbage atm but im looking into toyos atm